CRUISE REPORT: TransArc-II
(Updated SEP 2019)








Highlights




                        Cruise Summary Information

               Section Designation  TransArc-II (PS94)
Expedition designation (ExpoCodes)  06AQ20150817
                  Chief Scientists  Ursula Schauer / AWI
                             Dates  2015 08 17 — 2015 10 15 
                              Ship  r/v Polarstern
                     Ports of call  Tromsø - Bermerhaven

                                             89° 55.81" N
             Geographic Boundaries  180° W                  180° W
                                             70° 59.96" N

                          Stations  173
      Floats and drifters deployed  1 Argo float deployed
    Moorings deployed or recovered  2 moorings deployed

                           Contact Information:

                              Ursula Schauer
                        Alfred Wegener Institute
                     27570 Bremerhaven • Room G-3.12
            Phone: +49(471)4831-1817 • Fax: +49(471)4831-1149  
                       Email: Ursula.Schauer@awi.de






              Final Report Assembly by Jerry Kappa SIO/UCSD








Contents

 1. Zusammenfassung und Fahrtverlauf 
    Summary and Itinerary 

 2. Weather Conditions  

 3. Physical Oceanography 

 4. Sea Ice Physics  
    4.1  Airborne sea ice surveys  
    4.2  Sea Ice thickness and porosity 
    4.3  Optical properties of sea ice 
    4.4  Routine sea ice observations 
    4.5  Sea Ice remote sensing data products 

 5. Installation of Autonomous, Ice-Tethered Platforms 

 6. GEOTRACES 
    6.1  Nutrients 
    6.2  CO2 System and dissolved oxygen 
    6.3  Clean sampling of trace metals using an all titanium ultraclean   
         ctd and sampler system 
    6.4  Dissolved Fe, Mn, Zn, Ni, Cu, Cd, Pb 
    6.5  Organic speciation of Fe 
    6.6  Organic speciation of copper 
    6.7  Mercury 
    6.8  Fe Isotopic composition 
    6.9  Cd, Cr, and Pb isotopes 
    6.10  Particulate trace metals 
    6.11  Ice-rafted sediments 
    6.12  Neodymium isotopes, rare earth element concentrations and long-
          lived natural radionuclides 
    6.13  Natural radionuclides Рshort lived 
    6.14  Radium isotopes 
    6.15  Artificial radionuclides as tracers of water masses 

 7. Plankton Ecology and Biogeochemistry in a Changing Arctic Ocean 
    (PEBCAO) 

 8. Arctic in Rapid Transition (Tracers, Organic Chemistry, Sea Ice 
    Biology and Suspended Matter) 
    8.1  Water mass signatures (δ18O, δ13CDIC) 
    8.2  Dissolved organic matter 
    8.3  Suspended particulate matter (SPM) 
    8.4  Sea ice biology 

 9. Benthic Biogeochemistry 

10. Methane and DMS in Sea Ice and Sea Water 

11. Sea Ice Field Work for Geochemistry and Biology 

12. Overview of Parameters analysed from Rosette Samples  

13. Seminars  


Appendix

A.1  Teilnehmende Institute / Participating Institutions 
A.2  Fahrtteilnehmer / Cruise Participants 
A.3  Schiffsbesatzung / Ship's Crew 
A.4  PS94 Stationsliste / Station List 



1.  ZUSAMMENFASSUNG UND FAHRTVERLAUF
    Ursula Schauer (AWI)


Die Expedition PS94 diente der Erfassung der physikalischen, biologischen 
und chemischen Veränderungen im Arktischen Ozean und war damit ein "Trans-
Arctic survey of the Arctic Ocean in transition" (TransArc II). Der seit 
Jahrzehnten andauernde Rückgang des mehrjährigen Meereises ist verknüpft 
mit Änderungen in der Ozeanzirkulation und damit mit Änderungen im Wärme- 
und Süßwasserhaushalt, mit Folgen für den Gasaustausch zwischen Ozean und 
Atmosphäre, für die biogeochemischen Stoffumsätze und für das Leben von 
Organismen im Eis, in der Wassersäule und am Meeresboden. 

Um Prozesse mit mehrjähriger Variabilität von langfristigen Trends 
unterscheiden zu können, erfassen wir im Abstand von mehreren Jahren die 
regionale Verteilung der wichtigsten Komponenten des Systems Arktischer 
Ozean. Acht Jahre nach dem Internationalen Polarjahr IPY 2007/2008 und 
vier Jahre nach TransArc (I) wurde mit TransArc II die dritte großskalige 
Zustandsaufnahme des eurasischen Sektors der Arktis durchgeführt.

Konkretes Ziel unseres Messprogramms war es festzustellen, ob die 
Advektion von immer wärmerem Wasser aus dem Atlantik und dem Pazifik 
weiter anhält und inwieweit dies im Zusammenhang mit dem Eisrückgang 
steht; ob die Akkumulation von Süßwasser in der Arktis, die über 
Jahrzehnte andauerte, und die damit verbundene Strukturänderung der 
Deckschicht jetzt einen Wendepunkt erreicht haben; ob neben der 
Ausdehnung auch die Dicke des Meereises weiter zurückgeht. Parallel 
wurden die Veränderungen in der Zusammensetzung des Phytoplanktons in Eis 
und Wasser untersucht und eine Bestandsaufnahme des Zooplanktons 
vorgenommen. PS94 stellte auch einen zentralen Beitrag zum 
internationalen Programm GEOTRACES dar, das zum Ziel hat, weltweit die 
Verteilung von Spurenstoffen und von ihren Isotopen im Ozean zu bestimmen 
um ihren Kreislauf zu verstehen. Die Arbeiten von GEOTRACES waren eng 
verknüpft mit Untersuchungen zu Prozessen, die biogeochemische 
Stoffkreisläufe in Eis und Wasser bestimmen. In situ-Messungen der 
Beschaffenheit und der Dicke des Meereises dienten auch der Validierung 
von Fernerkundungsdaten, u.a. der CryoSat2-Mission. 

Wir haben dazu Messstationen entlang von mehreren langen Transekten im 
eurasischen Teil der Arktis durchgeführt, die von der Barentssee, bzw. 
dem Gakkelrücken bis ins Makarowbecken reichten (Abbildung 1.1). Auf 
Schiffs-, Helikopter- und Eisstationen haben wir in-situ-Messungen 
durchgeführt und Eis-, Wasser- und Bodenproben gewonnen. Um die rumliche 
und die zeitliche Abdeckung über die reine Forschungsfahrt hinaus zu 
erweitern brachten wir zahlreiche autonome Messsysteme aus. Auf 
Eisschollen installiert, driften diese mit dem Eis und nehmen dabei über 
die kommenden Monate bis Jahre eine Vielzahl von Eis-, Wasser- und zum 
Teil auch atmosphärischen Parametern auf und übertragen die Informationen 
per Satellit an Land. Zwei am Boden verankerte Messsysteme werden die 
saisonale Entwicklung von Zirkulation, Hydrographie und Partikelfluss 
registrieren und zum ersten Mal in der zentralen Arktis oberflächennah 
Wasserproben in wöchentlicher Abfolge gewinnen, die nach der Aufnahme der 
Verankerung im Sommer 2016 im Labor auf die saisonale 
Nährstoffentwicklung untersucht werden.

Während der gesamten Fahrt außerhalb nationaler ausschließlicher 
Wirtschaftszonen wurde mit dem Fächerlot der Meeresboden vermessen, um 
die bathymetrische Datenlage in der Arktis zu verbessern.

Neben GEOTRACES (www.geotraces.org/), war TransArc II ein Beitrag zu den 
internationalen Programmen IABP 
(http://iabp.apl.washington.edu/index.html), ASOF (http://asof.awi.de/), 
Arctic ROOS (http://arctic-roos.org/), Transdrift (www.transdrift.info) 
und ART (http://oceanrep.geomar.de/10151/), sowie zum nationalen Programm 
RACE (http://race.zmaw.de/). Darüber hinaus trug TransArc II zur 
Implementierung des Infrastrukturprogramms FRAM (Frontiers in Arctic 
Monitoring) der Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) 
bei.

Während der gesamten Fahrt in der zentralen Arktis behinderten schwierige 
Eisbedingungen durch bis zu 100%ige Eiskonzentration und Neueisbildung, 
kombiniert mit einer zunehmend dicken Schneedecke, das Fortkommen; 
zusätzlich schränkten der häufige Schneefall und schlechte Sicht die 
helikoptergestützten Arbeiten stark ein. 

Ein Höhepunkt der Fahrt war das Treffen mit dem US-amerikanischen 
Küstenwachschiff Healy am Nordpol am 7. 9. 2015. Auch die Healy war für 
das GEOTRACES-Programm unterwegs und durch das Treffen konnten wir eine 
Interkalibrationsstation genau am Nordpol durchführen.

Die Reise war gegenber der ursprnglichen Planung durch zwei weitere 
Faktoren beeinflusst:

1. Die Transekte waren eigentlich bis in die Kara- und Laptewsee 
   geplant, um den Austausch zwischen Schelfmeeren und tiefen Becken zu 
   erfassen. Da uns die russischen Behörden keine Genehmigung zur 
   Forschung in der russischen ausschließlichen Wirtschaftszone 
   erteilten, konnten wir unser Forschungsprogramm in der Kara- und 
   Laptewsee gar nicht und im Nansenbecken nur eingeschränkt durchführen.

2. Durch einen medizinischen Notfall musste das Programm vor Ostsibirien 
   am 24.9. 2015 abgebrochen und durch ein Alternativprogramm ersetzt 
   werden. 

TransArc II begann am 17. August 2015 in Tromsø. In der zentralen 
Barentssee begann die Benthosgruppe mit zwei Multicorerstationen einen 
Schnitt entlang 30°E, der nach Norden mit einer Folge von 
CTD/Rosettenstationen fortgesetzt wurde. Zwischen den Stationen wurde vom 
fahrenden Schiff aus kontinuierlich eine Underway-CTD eingesetzt, mit der 
auch ein kurzer zonaler Schnitt über den Viktoria-Trog gefahren wurde. 
Auf dem Kontinentalhang bei 81N versuchten wir, eine Verankerung für das 
Norwegian Polar Institute aufzunehmen. Da wir kein akustisches Signal 
empfingen, lösten wir die Verankerung nicht von ihrem Grundgewicht und 
brachen die Aufnahme ab. 

Bei 81°N erreichten wir die Eiskante, aber erst bei 83°43'N war das Eis 
stabil genug für eine Eisstation. Ein anhaltendes Hoch am Nordpol und 
niedrige Temperaturen mit Neueisbildung sorgten schnell für erste 
Eispressungen. So entschlossen wir uns bei 84°24'N, den Schnitt auf 30°E 
abzubrechen und nach Osten zu dampfen um bei 60°E unseren Kurs nach 
Norden wieder aufzunehmen. Allerdings wurden die Eisbedingungen nicht 
viel besser und in der Folge mussten auch weitere Schnitte verkürzt 
werden.

Am 29.8. setzten wir im Amundsenbecken bei 85°18'N die erste von zwei 
Verankerungen aus. Am 2.9. folgte die zweite Aussetzung in der Spalte des 
Gakkelrückens bei 87°1'N, 59°15'E in unmittelbarer Nähe einer 
hydrothermalen Quelle. Den Ausstrom aus dieser Quelle beprobten wir für 
alle Parameter des GEOTRACES-Programms. Auf den folgenden Eisstationen 
setzten wir nun auch verschiedene Messsysteme aus, die mit dem Eis 
driftend ber das ganze Jahr Daten aus Atmosphäre, Eis und Ozean liefern. 

Dem Nordkurs entlang 60°E folgend, erreichten wir am 7.9. 2015 den 
Nordpol. Einige Tage zuvor hatte sich herausgestellt, dass gleichzeitig 
auch die US-amerikanische Healy im Rahmen ihres wissenschaftlichen 
Programms am Nordpol arbeiten würde, so dass wir das große Glück hatten, 
uns dort zu begegnen. Polarstern machte an der gleichen Eisscholle wie 
die Healy fest, Wissenschaftler und Mannschaft besuchten mit großem 
Interesse das jeweils andere Schiff und wir nutzten diese einmalige 
Chance, um am Nordpol synchron eine Interkalibrationsstation für 
GEOTRACES durchzuführen. 

Nach dem Treffen folgten wir dem Kurs auf 120°W ein Stück weit ins 
Makarowbecken hinein, um hier das untere Ende der sogenannten 
Transpolaren Drift zu beproben, die Eis und Flusswasser aus den 
sibirischen Schelfmeeren quer durch die Arktis in Richtung Nordatlantik 
transportiert. Aber wegen zu starken Eisdrucks änderten wir am 11.9. den 
Kurs nach Westen in Richtung Sibirien. Der nächste Wegpunkt, 87°30'N 
180°E, war eine weitere, diesmal weit im Voraus geplante 
Interkalibrationsstation für GEOTRACES im Makarowbecken; danach ging es 
zurück zum Gakkelrücken, um von dort die Aufnahme des eurasischen Teils 
der Arktis auf einem Schnitt im sibirischen Teil des Amundsenbeckens und 
am Lomonossowrücken abzurunden. 

Ein Schnitt über den Kontinentalhang der Ostsibirischen See und 
anschließend auf dem Schelf westwärts in die Laptewsee sollte das 
Programm im Quellgebiet der Transpolaren Drift abschließen. Diesen Plan 
mussten wir wegen eines medizinischen Notfalls an Bord aufgeben und 
unmittelbar nach Tromsø aufbrechen. 

Nachdem der Patient in Tromsø abgeliefert worden war, starteten wir in 
Richtung Grönlandsee um zwei Gleiter zu bergen. Die Gleiter sollten 
ursprünglich von dem Forschungsschiff Heincke aufgenommen werden, was 
aber aufgrund eines Sturmtiefs und der durch Abwettern bedingten 
Zeitknappheit für die Heincke mit großem Risiko behaftet war. Ohne die 
Bergung durch Polarstern wären die Gleiter möglicherweise verloren 
gewesen. Anschließend konnten wir zwischen Norwegen und Spitzbergen einen 
Schnitt durchführen, der ein essentieller Beitrag zum internationalen 
GEOTRACES-Programm ist, aber eigentlich für PS100 im Sommer 2016 geplant 
war. PS100 steht aber unter hohem zeitlichem Druck, sodass das Vorziehen 
des Schnittes diese Komponente des GEOTRACES-Programms sicherstellen 
konnte.

Am 14. Oktober 2015 machte Polarstern in Bremerhaven fest.



SUMMARY AND ITINERARY

The expedition PS94 Trans-Arctic survey of the Arctic Ocean in transition 
("TransArc II") aimed at capturing the physical, biological, and chemical 
changes of the Arctic Ocean. The retreat of the multi-year sea ice over 
the last decades, and the changes in ice and ocean circulation are 
tightly linked to changes in the heat and fresh water distribution with 
consequences for the gas exchange between ocean and atmosphere, for 
biogeochemical cycling and for organisms and ecosystems in the sea ice, 
in the water column and on the sea floor. 

To distinguish processes of multiyear variability from long-term, maybe 
anthropogenic, trends we capture in a distance of several years the 
regional distribution of the key components of the Arctic Ocean. Eight 
years after the International Polar Year (IPY 2007/08) and four years 
after TransArc (I), TransArc II constituted the third large-scale survey 
of the Eurasian sector of the Arctic Ocean.

Specific goals of our programme were to determine if the water that is 
advected from the Atlantic and Pacific oceans continues to become warmer 
and whether this development has an impact on the sea ice decrease; 
whether the accumulation of fresh water in the Arctic that lasted over 
the past decades, as well as the related change of the upper ocean 
stratification has reached a turning point; whether besides the extent 
also the thickness of the sea ice continues to decrease. We also studied 
changes in the composition of phytoplankton in ice and water, and 
investigated the state of zooplankton. In the same time, PS94 was a 
central contribution to the international programme GEOTRACES which aims 
at determining the distribution and cycling of trace substances and their 
isotopes in the global ocean. In-situ measurements of the structure and 
the thickness of the sea ice served also as validation for remote sensing 
products, among them from the CryoSat2 mission.

To follow these goals, we conducted a number of long transects through 
the Eurasian part of the Arctic which extended from the Barents Sea and 
the Gakkel Ridge, respectively, into the Makarov Basin (Fig. 1.1). From 
the ship, the helicopter and on ice stations we conducted in-situ 
measurements and sampled sea ice, water and sediment. We deployed a suite 
of autonomous platforms: observation systems installed on ice floes will 
record atmospheric, sea ice and water properties over the next months and  
- hopefully - years and send the data ashore while drifting with the host 
floes through the Arctic; two moorings were mounted at the sea floor to 
measure the seasonal cycle of hydrography, currents and vertical particle 
flux, and for the first time we will get once per week near-surface water 
samples from the central Arctic which will be analyzed for their nutrient 
content after successful recovery in summer 2016.

When operating in international or Norwegian waters, we recorded the sea 
floor topography with the multibeam echosounder to extend the still poor 
Arctic Ocean data coverage.

Besides GEOTRACES (www.geotraces.org/), TransArc II contributed to the 
international programmes IABP (iabp.apl.washington.edu/index.html), 
Arctic ROOS (arctic-roos.org/), ASOF (asof.awi.de/), Transdrift 
(www.transdrift.info), and ART (oceanrep.geomar.de/10151/), as well as to 
the national programme RACE (race.zmaw.de/). Furthermore, TransArc II 
participated in implementing the infrastructure initiative FRAM 
(Frontiers in Arctic Monitoring) of the Helmholtz Society of German 
Research centers (HGF).

During the entire cruise, difficult ice conditions with concentration up 
to 100 % and new ice formation, as well as a continuously thickening snow 
layer on the ice hampered the sailing. In addition, the frequent snow 
fall and bad visibility limited the use of the helicopters.
A highlight of the cruise was the meeting with the US coastguard ice 
breaker Healy at the North Pole on September 7, 2015. Also the Healy 
conducted a GEOTRACES programme and during the meeting an inter-
calibration station right at the North Pole was conducted.

The cruise was further affected by two incidents:

1. The original planning contained the extension of the transects to the 
   Kara and Laptev Sea for capturing the exchange between shelf seas and 
   deep basins. Since no clearance for research in the Russian Exclusive 
   Economic Zone was granted, the Kara Sea and Laptev Sea and part of the 
   Nansen Basin were excluded from the survey.

2. Due to a medical emergency we had to cancel our work on September 24 
   north of the East Siberian Sea. 

TransArc II started on August 17, 2015 in Tromsø. With two multi-corer 
stations in the central Barents Sea, the benthos group started a section 
along 30E which then continued northwards with a suite of CTD/Rosette 
casts. Between the station stops an Underway CTD was run continuously 
with which also a short section across the Viktoria Trough was conducted. 
On the continental slope at 81°N, we tried to recover a mooring for the 
Norwegian Polar Institute. However, after not being able to get in touch 
acoustically we stopped the procedure without releasing the mooring.

At 81°N we reached the ice edge, but only at 83°43'N the ice was stable 
enough for a first ice station. Continuous high pressure around the North 
Pole and low temperatures with new ice formation brought us the first ice 
press. Hence we decided to brake off the 30°E section at 84°24'N and try 
to get northward along 60°E. However, the ice conditions did not improve 
and we had to shorten sections throughout the cruise.

On August 29, we deployed our first mooring in the central Amundsen Basin 
at 85°18'N. On September 2, the second mooring was deployed in the trench 
of the Gakkel Ridge at 87°1'N, 59°15'E, in the immediate vicinity of a 
hydrothermal vent. We succeeded in conducting a rosette cast in the plume 
of this vent and took samples for all GEOTRACES parameters. We also 
started finally deploying a variety of observation systems on ice floes 
that will capture air, ice and water properties year-round.

Sailing along 60°E, we reached the North Pole at September 7, 2015. Only 
a couple of days before, it had turned out that the US American 
Coastguard ship Healy which was also conducting research in the framework 
of GEOTRACES happened to work at the North Pole in the very same time. 
Hence Polarstern went alongside on the same floe as Healy, and there was 
enthusiastic mutual visiting by crew members and scientists. Both parties 
took the unique chance to conduct a GEOTRACES intercalibration station at 
the North Pole synchronously.

After this event we continued the direction, now along 120°W, into the 
Makarov Basin in order to study the downstream end of the so-called 
Transpolar Drift which carries ice and freshwater from river inflow 
through the Arctic towards the Atlantic Ocean. Once more, heavy ice 
forced us to change our plans and to turn westwards to our next 
milestone, a planned GEOTRACES intercalibration station in the deep 
Makarov Basin at 87°30'N 180°E. From there we headed back to the Gakkel 
Ridge in order to comprehend the survey of the Eurasian Arctic by 
sampling the eastern Amundsen Basin and Lomonosov Ridge.

The survey should have been completed by a section across the East 
Siberian continental slope and along the shelf edge to capture the 
upstream part of the Transpolar Drift. However, we had to cancel this 
plan due to a medical emergency onboard and head towards Tromsø.

After the patient had been evacuated in Tromsø a compensating programme 
was conducted: Two gliders were recovered in the Greenland Sea and a 
section was conducted between Norway and Svalbard. The gliders had been 
planned to be recovered through RV Heincke, but due to bad weather and 
the thereby shortage of time for the Heincke, the recovery was at risk. 
Without the recovery through Polarstern the gliders might have been lost. 
The section between Norway and Svalbard is an essential contribution to 
the international GEOTRACES programme which was originally scheduled for 
PS100 in summer 2016. PS100 has however, large temporal and berths 
constraints, and by anticipating the section during PS94 this important 
component of the GEOTRACES programme was secured.

Polarstern arrived in Bremerhaven on October 14, 2015.




Abb. 1.1: Kursplot der Polarstern-Expedition PS94 (17.8. - 15.10.2015)
Fig. 1.1: Course plot of Polarstern expedition PS94 (17.8. - 15.10.2015)




2.  WEATHER CONDITIONS 

    Max Miller, Juliane Hempelt                  DWD
 

On August 17, 2015, 4:45 pm when Polarstern left Tromsø , sunshine, 20°C 
and light winds were observed. On our way north we steamed between a high 
over the White Sea and a low over north-eastern Greenland. Already during 
the night to Tuesday (Aug. 18) we reached its frontal zone with rain and 
freshening westerly winds which peaked at Bft 6 on Wednesday. The low 
moved to Franz-Josef-Land and Polarstern got at its west side. Winds 
abated temporarily but veered north on Thursday evening (Aug. 20) and 
increased up to Bft 5 to 6 again.

From Saturday (Aug. 22) on a high north of the New Siberian Islands built 
a ridge towards Franz-Josef-Land and moved itself to North Pole. First we 
observed only light and variable winds, but from Monday (Aug. 24) on 
north-easterly winds at force 4 to 5. Only sometimes the subsidence 
temperature inversion could dissipate the moist ground layer. Often low 
stratus, mist or fog were prevailing.

On Thursday (Aug. 27) a low trough extended between Norway and northern 
Fram Strait where a secondary low formed and moved towards Franz-Josef-
Land. Easterly winds at Bft 4 to 5 veered north on Sunday (Aug. 30) after 
the low had departed eastwards. A small low north of Bering Strait moved 
across the Pole and merged with another low near Novaya Zemlya. 
Occasionally winds peaked at force 5.

From Sunday (Sep. 06) on a low over Jan Mayen moved north and southerly 
winds increased Bft 5 to 6. Crossing North Pole on Monday evening (Sep. 
07) wind direction switched from south to north. The low also reached the 
Pole and from Thursday (Sep. 10) on we operated in its centre. Therefore 
light winds often changed their direction. 

A high north of Bering Strait extended a ridge across North Pole towards 
a high over Eastern Europe. Until Tuesday (Sep. 15) only light and 
variable winds were prevailing and skies cleared, but on the other hand 
shallow fog patches formed.

A new low near Svalbard rounded-up North Pole eastwards and stopped north 
of the Queen-Elizabeth-Islands on Sep. 16. After weakening a bit it 
intensified again and moved back and we got wind force 5. But at the 
Taymyr Peninsula a small high formed temporarily and strengthened the 
pressure gradient. During the night to Sunday (Sep. 20) northerly winds 
peaked at Bft 8 for short times and abated rapidly afterwards.

On Monday (Sep. 21) another low over Fram Strait moved towards the New 
Siberian Islands via Laptev Sea. It passed south of Polarstern and only 
on Thursday (Sep. 24) winds from north increased up to force 5. Out of a 
trough near Severnaya Zemlya a strong low formed and moved east, too. 
Meanwhile we had left the ice. On Sunday (Sep. 27) and Monday northerly 
winds freshened up to Bft 7 and caused a sea of 2 to 3 m.

On Monday (Sep. 28) a low formed west of Ireland, deepened rapidly to a 
storm and arrived at Svalbard on Wednesday (Sep. 30) with a centre 
pressure of only 960 hPa. Over Kara Sea it caused southerly winds around 
Bft 8 and waves up to 4 m, but observation stations around Barents Sea 
often reported higher wind forces (up to 11). After passing Kara Strait 
during the night to Thursday winds abated clearly and veered west to 
northwest around Bft 5 until we arrived off Tromsø on Saturday morning 
(Oct. 03). A swell of 4 m decreased soon, too.

While we were steaming towards the Greenland Sea easterly winds increased 
during the night to Oct. 4 and peaked at Bft 7. A small low had formed 
southeast of Svalbard and moved towards the Kola Peninsula. On Sunday 
noon, while we were entering a large area of weak pressure gradient winds 
abated. On Oct. 5, a small high had arrived over northern Norway. During 
the following days this high developed to a strong anticyclone over 
Scandinavia. Together with several lows near Iceland southerly winds were 
forced. From Oct. 8 until Oct. 12 winds along the Norwegian coast changed 
between Bft 4 to 5 and Bft 7 to 8 depending on the intensity of the lows. 
Wave heights did not exceed 3 m.

Meanwhile the high had moved to Russia but build a ridge towards Great 
Britain. At its southern side over North Sea, north-easterly winds were 
prevailing and peaked for short times at Bft 7 during the night to 
Wednesday (Oct. 14). Polarstern reached Bremerhaven at fresh winds from 
northeast to east.

Statistics of the weather during the cruise are shown in Fig. 2.1.


Fig. 2.1:  Statistics of weather parameters





3.  PHYSICAL OCEANOGRAPHY

    Benjamin Rabe(1), Rainer Graupner(1),       1 AWI
    Hendrik Hampe(1), Mario Hoppmann(1),        2 FMI
    Myriel Horn(1), Meri Korhonen(2),           3 SIO
    Sven Ober(6), Sergey Pisarev(3),            4 LEGOS
    Jean-Philippe Savy (4), Ursula Schauer(1),  5 LOCEAN
    Daniel Scholz(1), Nicolas Villacieros-      6 NIOZ
    Robineau(5)

Grant No. AWI_PS94_00


Background and objectives

Next to the dramatic retreat of sea ice, the strongest climatic signal of 
the Arctic Ocean and the Nordic Seas in the past decade are changes in 
temperature and salinity. A strong accumulation of fresh water has been 
observed in the past decades in the Arctic Ocean; the waters advected 
from the Atlantic became much warmer and saltier, and there is high 
multi-year variability in temperature and salinity of the Pacific Water 
inflow. Concurrently, there is a multi-decadal positive trend in 
continental runoff into the Arctic and decadal changes in the atmospheric 
circulation. The aim of the physical oceanography part of this cruise is 
to document and quantify the present state of the water mass distribution 
and circulation in the Eurasian and Makarov basins. The observations will 
be fundamental to understand the time-mean state of the Arctic Ocean from 
basin-scales to individual ice floes. They will allow us, in the context 
of appropriate modelling, to identify variability on seasonal to decadal 
timescales and long-term trends. Waters imported to the Arctic Ocean are 
subject to cooling, freezing and melting, altering the properties of 
these water masses. The warm inflow of waters of Atlantic origin occurs 
via two pathways: the eastern Fram Strait and the Barents Sea. These two 
branches are subject to transformation by surface processes and lateral 
mixing before and after entering the Nansen Basin. Continental runoff 
enters the Eurasian and Makarov basins via the extensive shelf regions 
north of Eurasia, before being advected within the Transpolar Drift and, 
at times, the Beaufort Gyre. At slightly lower salinity than Atlantic 
Water, Pacific Water enters the Amerasian Basin via the Bering Strait and 
even reaches into the Eurasian Basin in certain years. This water mass is 
sandwiched between the warmer waters of Atlantic origin and the fresher, 
colder waters near the surface. In the central Arctic, stratification due 
to fresh water in the mixed layer and the halocline inhibits the release 
of heat from underlying waters to the atmosphere and affects vertical 
fluxes of dissolved chemical components, such as nutrients. The strong 
stratification is maintained by continental runoff, and ice or meltwater. 
However, the variable distribution of fresh water may facilitate the 
release of some of this heat in certain areas; for example, the recent 
convergence of fresh water in the central Arctic may, for dynamical 
reasons, lead to a weakening of the stratification along the warm 
boundary current at the rim of the basins. Changes may also occur from 
the different wind mixing with and without ice cover, and the transition 
from perennial to seasonal ice cover in much of the Arctic.

To address these questions we conducted physical measurements in the 
Eurasian and Makarov basins. Several hydrographic sections were intended 
to give a quasi-synoptic view of the Eurasian and central Arctic during 
late summer and early autumn 2015. Furthermore, the observations lie in 
regions covered by earlier cruises conducted since the early 1990s with 
the icebreakers Polarstern and Oden, and within the NABOS (Nansen-
Amundsen Basin Observation System) project. These observations were 
augmented by upper-water-column hydrography perpendicular to the sections 
to capture horizontal gradients in all directions. To aid the 
interpretation of the hydrographic data and estimate transports we 
conducted continuous and on-station measurements of current velocity. We 
deployed autonomous, ice-based buoys, and bottom-moored observatories to 
extend the observational range of the ship survey in space and time. We 
used a turbulence profiler from sea-ice to obtain estimates of fine 
structure and turbulent energy dissipation in the upper water column. 
This will improve our understanding of vertical mixing processes in the 
context of large scale hydrography. Our work is part of the Helmholtz 
strategic investment Frontiers in Arctic Marine Monitoring (FRAM) and 
contributes to several projects on a national (Bundesministerium für 
Bildung und Forschung, RACE and TRANSDRIFT; AWI strategy fund, ISO-ARC) 
and international (International Arctic Buoy Program, IABP; Forum for 
Arctic Modelling and Observational Synthesis, FAMOS; French equipex 
IAOOS, http://www.iaoos-equipex.upmc.fr and http://iaoos.ipev.fr; EU FP7 
Ice Arc project, http://www.ice-arc.eu). 


Work at sea

The work of the Physical Oceanography group on-board entailed measuring 
vertical profiles of temperature, salinity and ocean current velocity. To 
study variability and distribution of temperature and salinity in regions 
and time not covered by our expedition, we deployed instrumentation 
moored at the seafloor, and deployed drifting buoys in sea ice for 
autonomous measurements. Details of buoy deployments are described in 
chapter 5.

To obtain temperature and salinity profiles we used several different 
Conductivity Temperature Depth (CTD) systems operated from the ship and 
from ice floes reachable by helicopter. For on-station work CTD sondes 
were mounted on two different rosettes with 24 bottles each for water 
sampling. The regular rosette (AWI rosette) bottles each could hold 12 l 
whereas the large rosette (NIOZ-large rosette) had Niskin-type 
watersamplers manufactured by Ocean Test Equipment, USA, each with a 
volume of 25 l. The stainless steel frame of the NIOZ-large rosette was 
manufactured by Royal NIOZ. The main part of the electronics in each 
rosette was manufactured by Seabird Electronics (USA), a central unit, 
model SBE911+. All sensors on the rosettes, except the lowered Acoustic 
Doppler Current Profiler (LADCP) system, were connected to the SBE911+. 
This unit communicated via a winch cable with a conducting core (coaxial) 
with a SBE11plus (S\N 11P16392-0457) deck-unit in the winch control room 
of Polarstern. The deck-unit was connected via an RS-232 serial 
connection to a standard PC, which was also connected to an NMEA data 
stream giving time and geographic position in real-time. The logging 
software "Seasave" was running on this PC under Windows 7 (64 bit).

The CTD on both rosettes contained double sensors for temperature and 
conductivity, one sensor for pressure and one for oxygen. A fluorometer 
for chl a fluorescence, a beam transmissometer and a downward looking 
altimeter were also attached to the frame and connected to the SBE911+. A 
fluorometer for yellow substance was mounted on both rosettes for part of 
the expedition, to derive concentrations of Coloured Dissolved Organic 
Matter (CDOM). The altimeter was mostly working well throughout the 
cruise except for one station which lead to the rosette hitting the 
bottom requiring the cable to be cut and newly terminated. Hence, a 
bottom detector with a rope and 8 kg weight was installed on the NIOZ-
large rosette, to give a signal 10 m from the bottom. Further details of 
the sensors on both rosettes can be found in tables 3.1 and 3.2. The 
primary conductivity sensor on the NIOZ-large rosette was changed once 
during the cruise due to a broken cell. The cables of the oxygen, and the 
secondary conductivity and temperature sensors on the NIOZ-large rosette 
were changed several times during the cruise due to erratic data at high 
pressure. The oxygen sensor was eventually replaced as it most likely 
suffered from a broken membrane. We determined the salinity of 61 water 
samples, taken at selected stations, using the Optimare Precision 
Salinometer on-board Polarstern and standard seawater from Ocean 
Scientific International. These measurements will be used after the 
expedition to calibrate the conductivity sensors. Likewise, the GEOTRACES 
group determined oxygen in water samples from 89 stations (see chapter 7) 
to calibrate the oxygen sensors after the expedition.  A third "ultra-
clean" CTD-rosette (UCCTD) was operated by a group from NIOZ and is 
described in chapter 7.

During a few casts a SBE35 reference-thermometer (S\N 0019) was used on 
the NIOZ-large rosette.  It appeared that the difference between this 
thermometer and the 2 profiling thermometers (SBE3, S\N 03P5115 and S\N 
03P2929) depends more or less linearly on pressure.  Assumed is that the 
more robust SBE35 is not or at least less pressure dependent than the 
fragile needle of the SBE3's.  An example of this is shown in Fig. 3.2.

An Underway CTD (UWCTD) system (UCTD 10-400) from Oceanscience 
(Oceanside, USA) was used from the stern of Polarstern, mounted on the 
reiling at the stern portside, to obtain temperature, salinity and 
pressure profiles while underway. The system contains a Seabird CTD 
measuring at 16 Hz. The profile depth is limited by the speed of the ship 
and the length of the cable. The nominal profile depth at a ship speed of 
10 kn is 400 m. However, the deepest profile only reached to about 250 m 
depth in water more than 400 m deep. The tailspool rewinder system, 
capable of extending the profile depth to about 1,000 m, was found to be 
broken at the beginning of the expedition due to moisture inside the 
system.

An XCTD-1, by Tsurumi-Seiki Co. Ltd. (Yokohama, Japan) was used to obtain 
CTD profiles up to 1,100 m water depth, some while underway from the ship 
and some from ice floes reachable by helicopter. The system consisted of 
a launcher for expendable CTD probes and a mobile deck-unit (MK-150) for 
data acquisition. The probe sinks down with constant velocity measuring 
temperature and conductivity.

All three rosette systems were used to obtain stations from the ship 
along different sections throughout the Eurasian and central Arctic (Fig. 
3.1). A total of 125 CTD profiles were taken, 56 of which with the NIOZ-
large rosette, 41 with the AWI-rosette and 28 with the UCCTD on the 
ultra-clean rosette (see A.4, station list PS94). We used the UWCTD to 
obtain 139 profiles in the Barents Sea along 30E (Table 3.3). We 
continued to increase the resolution of the CTD stations by using the 
XCTD to obtain 94 profiles once Polarstern reached the ice until the end 
of the scientific work in the Barents Sea. Furthermore, we obtained 17 
XCTD profiles from ice floes reached by helicopter (Table 3.4).
Two moorings were deployed in the Eurasian Basin: one is located in the 
Nansen Basin, south of the Karasik Seamount, the other further north in 
the deep trench of the Gakkel Ridge (Table 3.5). Both moorings are meant 
to observe the near-surface physical, biological and biogeochemical 
environment, as well as sedimentation to deeper parts of the water 
column. The mooring in the trench was co-located with a CTD profile 
showing hydrothermal vent signal in the deep part of the water column. 
Several recording CTDs, current profilers and meters, sediment traps and 
a water sampler were mounted on the mooring line. An additional acoustic 
recorder is meant to monitor marine environmental sound. A list of 
deployed moorings with devices is given in. We attempted to recover one 
mooring for the Norwegian Polar Institute, (Tromsø, Norway), northeast of 
Svalbard. However, we were not able to establish acoustic communication 
with the releases and abandoned the recovery due to dense ice cover. 

We used a turbulence profiler (MSS90L, Sea & Sun Technology) to obtain 
profiles of fine-scale motion by measuring temperature, salinity, 
pressure, current shear and light transmission. The profiler is free-
falling with a 400 m long data cable attached to an electrical winch. We 
operated the system through a hole in the sea-ice for several hours 
during ice stations. In total, sets of between 11 and 49 profiles were 
obtained at seven ice stations.


Fig. 3.1: Map of stations (blue) with station number in black and section 
          numbers in red
 

We measured profiles of ocean current velocity in the upper 300 m while 
underway with a vessel-mounted Acoustic Doppler Current Profiler 
(VMADCP). The RDI Ocean Surveyor instrument (150 kHz) was mounted at an 
angle of 45 to the forward along-ship direction in the "Kastenkiel" of FS 
Polarstern. The instrument was configured in narrowband mode and set up 
to use 4 m bin size covering a range from 15m to 500 m. The actual range 
in Arctic waters is about 200 - 300 m depending on sea state, ice 
conditions, ship's speed and backscatter signals. The ADCP was set to 
ping as fast as possible (parameter TP000000). The software VmDas 
(Teledyne RD Instruments) was used to set the ADCP's operating parameters 
and to record the data. Finally the Ocean Surveyor data conversion was 
done using Matlab (Mathworks) routines last changed by Tim Fischer 
(Geomar, Kiel, Germany) in February 2015 (osheader.m, osdatasip.m, 
osrefine.m). Our setup allows standard calibrations for misalignment 
angle and scaling constants (Joyce, 1989) as well as an evaluation of the 
instrument's performance after calibration coefficients are derived. 
Preliminary analysis using this method gave a misalignment angle of 
1.3362 and a velocity scaling factor of 1.0178. Problems to resolve 
velocities occurred due to low backscatter and shallow water depths. 
Post-cruise analysis will focus on analysing any interference of other 
acoustic devices with the velocity measurements. Interfering signals may 
originate in the vessel's Doppler log (79 kHz), the multibeam echosounder 
HYDROSWEEP (15.5 kHz) and acoustic signals to release.

The ship's pumped seawater system measured temperature and salinity 
underway at depths of 6 m (in open water only) and 11 m (ice and open 
water). The electronic engineer responsible for scientific laboratories 
on Polarstern took regular samples to calibrate the conductivity sensor 
near the intake of the underway pumped system. 

To support the oceanographic programmes and increase the amount of 
topographic data in the central Arctic, which are rare, we conducted 
multibeam surveys with the Hydrosweep DS-3 system (Atlas Hydrographic). 
The system is permanently installed on Polarstern and ensured spatially 
highly resolved depth information throughout the expedition. We used the 
ATLAS Hydromap Control (AHC) software version 2.6.6.0 with the following 
relevant parameter settings: beam spacing "Equal Footprint" desired 
number of beams "920" C-Keel source "System C-Keel" and transmission 
sequence 'equidistant transmission'. We adjusted the swath width 
portside/starboard side permanently during the expedition in order to get 
the optimum data quality. In shallow regions with water depth less than 
1,000 m the swath width was mainly set to 150 to 200 %, at water depths 
of 1,000 to 3,000 m to 100 to 150 %, and at deeper depths than 3,000 m to 
50 to 100 %. For online visualization of the raw data, the HYPACK 
software package versions 12.0.8.12, 13.0.9.17, and 15.0.9.71 were used. 
Raw data was stored in *.asd-format and *.hsx-format in 30 minute blocks. 
No water column data was collected. The multibeam survey was started on 
August 19, 2015 at 9:37 am in the Barents Sea and was continued until 
September 26 at 7:56 pm, before we entered the Russian EEZ. When leaving 
the Russian EEZ on October 2 at 10:04 pm the data acquisition was 
continued until October 9 at 04:52 am, when starting the transit to 
Bremerhaven. During station work, the data recording was stopped except 
during ice stations, where we drifted with the ice floe. Eight CTD 
profiles were used to derive the sound velocity for different parts of 
the survey. The data processing will be done after the cruise by the 
Bathymetry group of the AWI. Although continuous data recording was 
possible throughout most of the cruise, some system errors appeared 
during the cruise, causing gaps in the data acquisition. These could only 
be resolved by a total system shut down and restart. Unfortunately the 
HYPACK software broke down several times and could not be restarted 
easily. Hence, we had to change between different versions of the 
software during the surveys.

During CTD casts, we tested a new LADCP system to obtain full-depth 
profiles of ocean current velocity in an environment of low horizontal 
magnetic field intensity in the vicinity of the North Pole. The new 
system by SubCtech (Kiel, Germany) contains a Subsea MicroDI datalogger 
in a titanium housing (rated to 6,000 m water depth). The logger is 
connected to a gyro (XSENS MTi-300 AHRS), a pressure sensor (Keller PA-
35X), also contained in the same housing. The system is connected to 
external upward and downward looking LADCP heads (RDI-Teledyne 300 KHz 
Workhorse) and an external battery pack. The gyro allows for detection of 
the change in orientation of the rosette independent of the magnetic 
field. To obtain the geographic heading a GPS is temporarily mounted on 
the rosette connected to the logger system before the rosette is deployed 
in water. All measurements except those by the ADCP are saved to a micro-
SD memory card within the titanium housing. The whole system was mounted 
on the AWI rosette with specially designed fittings and cables to allow 
all 24 bottles being mounted at the same time as the LADCP system. The 
two LADCP heads were set to ping every second. We encountered problems 
during system startup of the logger due to the quality of the GPS 
acquisition. The GPS signal quality was generally only "1" but the system 
expects a minimum of "2" The LED signal on the titanium housing of the 
logger was blinking green, indicating a problem with one of the devices 
in the system. However, we were informed by SubCTech during the 
expedition that the system is supposed to work and acquire data even if 
the GPS quality criterion is not met. The initial profiles around the 
southern margin of the Nansen Basin were complemented by running the 
system during the final transect in the Barents Sea. Further problems 
were encountered when downloading the logger data (which currently 
excludes the ADCP data, downloaded directly from the RDI workhorse 
systems) using a terminal and the RS-232 connection on the titanium 
housing. However, it was possible to open the housing and reading the 
data directly from the micro-SD card. Further analysis of this prototype 
system will be done after the cruise.

We recovered two autonomous gliders, deployed during PS93.1, that had 
been operating in the Greenland Sea from July to October 2015 and one 
autonomous profiling drifter ("ARGO float") was deployed (Table 3.6). The 
measurements contribute to the hydrographic monitoring of the Nordic Seas 
with Argo floats that started in 2001.

A Picarro water vapour isotopic analyser was used during PS94 as a 
contribution to the ISO-ARC Project. This analyser performed continuous 
measurements of water vapour isotopic composition in the surrounding air, 
focusing on the isotopic fingerprint of the eastern Arctic Water Cycle. 
The instrument was running properly during the entire expedition. The 
calibration device underwent one minor liquid standard water delivery 
issue, which was easily solved by the scientists responsible for the 
instrument on-board, following the standard procedure. The instrument 
showed a strong robustness during the entire Arctic season in 2015 and 
restarted easily after being switched off in the Russian EEZ.

The automatic programme sending a daily diagnostic report to AWI PIs 
suffered a breakdown, which had no effect on the recording itself. Bug-
fixes and adaptations will be provided during the maintenance of the 
instrument before the Antarctic field season. To fill the information gap 
caused by this loss, a new simple automatic programme was established and 
installed to transfer part of the metadata by email, and allow this daily 
diagnostic. Data were acquired between 17 August and 12 September 2015, 
with the exception of the period 27 September to 03 October 2015, when we 
crossed the Russian EEZ. Preliminary results suggest that isotopic 
parameters δ18O and δD evolved similarly, and are correlated with 
humidity. An important latitudinal gradient was identified as the main 
source of variability for humidity level and isotopic composition (δ18O 
and δD), decreasing towards the pole, and for the second order parameter 
deuterium excess (d-excess = δD Р8 * δ18O), increasing towards the 
pole. On top of this latitudinal gradient, a significant synoptic 
variability was observed linked with large scale meteorological 
variations. In addition, we took daily samples from the Polarstern 
underway pumped system. The isotopic composition of those samples will be 
determined after the cruise, and compared with the measurements obtained 
by Picarro. It has to be noted however that the water throughflow next to 
the ships high-precision salinometer (intake at 6 m depth) was switched 
off in moderate ice conditions. The sampling procedure was therefore 
adapted during PS94, using a valve on the working deck, connected to the 
11 m intake.


Preliminary results

Preliminary temperature and salinity profiles show the transition between 
the warm and saline Atlantic Water inflow into the Barents Sea and the 
colder, less saline waters in the section along approximately 30°E 
(section 1, Figs 3.3ff). In the southern Nansen Basin we see the 
signature of the inflow from the Fram Strait as a subsurface warm core 
hugging the continental slope underneath fresher surface waters. Further 
north the ocean is covered by sea-ice and surface waters are colder. At 
the transect 2, along 60°E / 120°W (Figs 3.1), we gradually encountered 
fresher and slightly warmer waters (Figs 3.3 and 3.4), in particular in 
the northern Amundsen Basin and the Makarov Basin close to the Lomonosov 
Ridge. Freezing occurred until the end of transect 5 (Figs 3.5 and 3.6) 
at air temperatures below -10°C.


Data management

Data from the rosette-mounted CTDs, XCTD, UWCTD, MSS as well as LADCP and 
VMADCP data collected during PS94 will be delivered after post-cruise 
calibration to the PANGAEA database and to the appropriate national data 
centres. The gliders are piloted from AWI in real time. The uncalibrated 
data will be provided in near-real time to the Coriolis data centre for 
use in operational applications. The calibration and final processing 
will take place after completion of the mission, and the data will be 
delivered to the PANGAEA database. The ARGO float data will be provided 
in near-real time to the Coriolis data centre and replaced by delayed 
mode quality controlled data afterwards.


Tab. 3.1: Sensors used on the small AWI rosette with serial numbers 
          (right column). The AWI rosette was used during stations 
          001-01 to 036-02, 046-04 to 50-08 and 147-01 to 173-01.

CTD-sonde                   SBE 911+                7396 
——————————————————————————|———————————————————————|——————————————————————
CTD-sensors Temperature   | SBE3                  | pri. 5101 / sec. 5112 
            Conductivity  | SBE4                  | pri. 3570 / sec. 3597 
            Pressure      | Digiquartz 410K-134   | 0937 
——————————————————————————|———————————————————————|——————————————————————
altimeter                 | Benthos PSA-916       |
                          |   (until stn. 031-01) | 1229
                          |   (from stn. 032-02)  | 51533 
——————————————————————————|———————————————————————|——————————————————————
oxygen                    | SBE43                 | 0467 
——————————————————————————|———————————————————————|——————————————————————
transmissiometer          | WET Labs C-Star       | 1220 
——————————————————————————|———————————————————————|——————————————————————
fluorometer chlorophyll a | WET Labs ECO-AFL/FL   | 1853 
——————————————————————————|———————————————————————|——————————————————————
fluorometer CDOM          | Dr. Haardt (stations  | 03 
                          |  004-1 to 050-8)      |
——————————————————————————|———————————————————————|——————————————————————
rosette sampler           | SBE 32                | 0718 

 
Tab. 3.2: Sensors used on the NIOZ large rosette with serial numbers 
          (right column). The NIOZ large rosette was used during stations 
          038-01 to 046-03 and 054-02 to 134-01

CTD-sonde                 | SBE 911+                   | 09P865-0321 
——————————————————————————|————————————————————————————|——————————————————————
CTD-sensors Temperature   | SBE3                       | pri. 5115 / sec. 2929 
            Conductivity  | SBE4 (until stn. 068-01)   | pri. 3290 / sec. 3585 
                          |      (from stn. 069-04)    | pri. 1199 / sec. 3585 
            Pump          | SBE5                       | pri. 4316 / sec. 5258 
            Pressure      | Digiquartz 410K-134        | 0321 
——————————————————————————|————————————————————————————|——————————————————————
Altimeter                 | Benthos PSA-916            | 47766 
——————————————————————————|————————————————————————————|——————————————————————
oxygen                    | SBE43 (until stn. 059-01)  | 1605
                          |       (from stn. 061-01)   | 0743 
——————————————————————————|————————————————————————————|——————————————————————
transmissiometer          | WET Labs C-Star            | 1198DR 
——————————————————————————|————————————————————————————|——————————————————————
fluorometer chlorophyll a | WET Labs FLRTD             | 1670 
——————————————————————————|————————————————————————————|——————————————————————
fluorometer CDOM          | Dr. Haardt                 | 03 
——————————————————————————|————————————————————————————|——————————————————————
rosette sampler           | SBE 32 (until stn. 046-03) | 32176773-0202
                          |        (from stn. 054-02)  | 3249818-0657



Tab. 3.3: Details of UWCTD profiles

Station   Date      Time      Latitude   Longitude   UWCTD  Water 
                    [UTC]                            depth  depth 
                                                      [m]    [m]
———————  ————————  ————————  ——————————  ——————————  —————  —————
003-01   19/08/15  06:34:00  76 45.45 N  30 02.79 E   178    262
003-02   19/08/15  07:25:00  76 53.51 N  30 07.79 E   220    266
003-03   19/08/15  07:35:00  76 55.10 N  30 08.72 E   203    259
003-04   19/08/15  07:44:00  76 56.53 N  30 09.58 E   194    256
003-05   19/08/15  07:53:00  76 57.97 N  30 10.54 E   202    250
003-06   19/08/15  08:03:00  76 59.57 N  30 11.51 E   195    246
003-07   19/08/15  08:12:00  77 01.00 N  30 12.31 E   212    247
003-08   19/08/15  08:22:00  77 02.58 N  30 13.35 E   200    240
003-09   19/08/15  08:31:00  77 04.00 N  30 14.20 E   204    238
003-10   19/08/15  08:40:00  77 05.43 N  30 15.11 E   182    225
003-11   19/08/15  08:47:00  77 06.54 N  30 15.74 E   187    213
003-12   19/08/15  08:56:00  77 07.96 N  30 16.68 E   153    209
003-13   19/08/15  09:02:00  77 08.91 N  30 17.26 E   139    206
003-14   19/08/15  09:08:00  77 09.86 N  30 17.80 E   140    205
003-15   19/08/15  09:14:00  77 10.80 N  30 18.40 E   168    210
003-16   19/08/15  09:22:00  77 12.06 N  30 19.17 E   165    202
003-17   19/08/15  09:28:00  77 13.00 N  30 19.74 E   168    206
003-18   19/08/15  09:35:00  77 14.10 N  30 20.39 E   165    192
003-19   19/08/15  09:41:00  77 15.04 N  30 21.08 E   163    199
003-20   19/08/15  09:47:00  77 15.99 N  30 21.67 E   161    191
003-21   19/08/15  09:54:00  77 17.10 N  30 22.32 E   165    191
003-22   19/08/15  09:59:00  77 17.89 N  30 22.84 E   170    198
003-23   19/08/15  10:06:00  77 19.01 N  30 23.55 E   174    201
003-24   19/08/15  10:13:00  77 20.16 N  30 24.22 E   171    198
003-25   19/08/15  10:19:00  77 21.13 N  30 24.78 E   161    202
003-26   19/08/15  10:26:00  77 22.28 N  30 25.54 E   162    201
003-27   19/08/15  10:32:00  77 23.25 N  30 26.21 E   157    197
003-28   19/08/15  10:38:00  77 24.21 N  30 26.75 E   164    211
003-29   19/08/15  10:45:00  77 25.31 N  30 27.52 E   166    192
003-30   19/08/15  10:51:00  77 26.25 N  30 28.07 E   163    206
003-31   19/08/15  10:59:00  77 27.48 N  30 28.84 E   173    210
003-32   19/08/15  11:06:00  77 28.55 N  30 29.56 E   173    210
003-33   19/08/15  11:13:00  77 29.61 N  30 30.25 E   174    218
003-34   19/08/15  11:22:00  77 30.97 N  30 31.11 E   168    218
003-35   19/08/15  11:29:00  77 32.03 N  30 31.72 E   179    226
003-36   19/08/15  11:37:00  77 33.24 N  30 32.47 E   188    223
003-37   19/08/15  11:45:00  77 34.45 N  30 33.25 E   210    227
003-38   19/08/15  13:09:00  77 47.26 N  30 41.53 E   223    234
003-39   19/08/15  13:21:00  77 49.12 N  30 42.72 E   190    248
003-40   19/08/15  13:29:00  77 50.37 N  30 43.61 E   195    242
003-41   19/08/15  13:38:00  77 51.77 N  30 44.55 E   195    241
003-42   19/08/15  13:46:00  77 53.04 N  30 45.29 E   199    234
003-43   19/08/15  13:54:00  77 54.29 N  30 46.10 E   196    263
003-44   19/08/15  14:04:00  77 55.88 N  30 47.16 E   208    268
003-45   19/08/15  14:14:00  77 57.47 N  30 48.28 E   209    243
003-46   19/08/15  14:22:00  77 58.74 N  30 49.04 E   211    256
003-47   19/08/15  14:32:00  78 00.32 N  30 50.11 E   214    261
003-48   19/08/15  14:41:00  78 01.76 N  30 51.07 E   212    248


Station   Date      Time      Latitude   Longitude   UWCTD  Water 
                    [UTC]                            depth  depth 
                                                      [m]    [m]
———————  ————————  ————————  ——————————  ——————————  —————  —————
003-49   19/08/15  14:50:00  78 03.18 N  30 51.99 E   208    219
003-50   19/08/15  14:59:00  78 04.61 N  30 52.94 E   186    235
003-51   19/08/15  15:07:00  78 05.87 N  30 53.77 E   193    234
003-52   19/08/15  15:14:00  78 06.96 N  30 54.57 E   194    242
003-53   19/08/15  15:23:00  78 08.36 N  30 55.49 E   192    243
003-54   19/08/15  15:31:00  78 09.62 N  30 56.38 E   190    232
003-55   19/08/15  15:39:00  78 10.88 N  30 57.13 E   193    240
003-56   19/08/15  15:47:00  78 12.12 N  30 58.06 E   200    242
003-57   19/08/15  15:55:00  78 13.36 N  30 58.84 E   195    272
003-58   19/08/15  16:04:00  78 14.76 N  30 59.77 E   191    256
003-59   19/08/15  16:12:00  78 16.02 N  31 00.58 E   195    249
003-60   19/08/15  16:21:00  78 17.44 N  31 01.57 E   199    260
003-61   19/08/15  16:30:00  78 18.86 N  31 02.62 E   205    258
003-62   19/08/15  16:39:00  78 20.28 N  31 03.60 E   200    251
003-63   19/08/15  16:48:00  78 21.73 N  31 04.50 E   202    259
003-64   19/08/15  16:57:00  78 23.15 N  31 05.54 E   203    257
003-65   19/08/15  17:06:00  78 24.57 N  31 06.54 E   205    271
003-66   19/08/15  17:16:00  78 26.17 N  31 07.57 E   206    281
003-67   19/08/15  17:26:00  78 27.73 N  31 08.70 E   201    300
003-68   19/08/15  17:35:00  78 29.16 N  31 09.66 E   206    299
003-69   19/08/15  17:45:00  78 30.73 N  31 10.74 E   216    306
003-70   19/08/15  17:56:00  78 32.46 N  31 11.96 E   220    312
003-71   19/08/15  18:07:00  78 34.18 N  31 13.06 E   221    315
003-72   19/08/15  18:19:00  78 36.05 N  31 14.34 E   222    312
003-73   19/08/15  18:29:00  78 37.59 N  31 15.49 E   215    305
003-74   19/08/15  18:39:00  78 39.12 N  31 16.60 E   212    311
003-75   19/08/15  18:50:00  78 40.83 N  31 17.75 E   219    287
003-76   19/08/15  19:00:00  78 42.37 N  31 18.86 E   208    270
003-77   19/08/15  19:10:00  78 43.92 N  31 19.88 E   183    257
003-78   19/08/15  19:19:00  78 45.30 N  31 20.90 E   109*   242
003-79   19/08/15  19:29:00  78 46.84 N  31 21.93 E   100*   238
003-80   19/08/15  19:38:00  78 48.23 N  31 22.92 E   107*   148
003-81   19/08/15  19:47:00  78 49.60 N  31 23.97 E   93*    134
003-82   19/08/15  19:56:00  78 50.97 N  31 24.86 E   60*    124
003-83   19/08/15  20:03:00  78 52.02 N  31 25.64 E   105*   108
003-84   19/08/15  20:13:00  78 53.53 N  31 26.69 E   102*   151
003-85   19/08/15  20:21:00  78 54.73 N  31 27.60 E   65*    177
003-86   19/08/15  20:28:00  78 55.79 N  31 28.33 E   114*   202
003-87   19/08/15  20:35:00  78 56.83 N  31 29.08 E   48*    202
003-88   19/08/15  20:41:00  78 57.74 N  31 29.72 E   91*    229
003-89   19/08/15  20:48:00  78 58.78 N  31 30.52 E   137*   251
003-90   19/08/15  21:00:00  79 00.53 N  31 31.73 E   185    181
003-91   19/08/15  21:07:00  79 01.55 N  31 32.51 E   116    160
003-92   19/08/15  21:12:00  79 02.28 N  31 33.00 E   130    138
003-93   19/08/15  21:17:00  79 03.01 N  31 33.60 E   131    136
003-94   19/08/15  21:22:00  79 03.74 N  31 34.07 E   110    120
003-95   19/08/15  21:26:00  79 04.34 N  31 34.47 E   110    119
005-01   20/08/15  10:23:00  79 16.42 N  30 02.51 E   97*    253
007-01   20/08/15  12:58:00  79 34.11 N  30 00.01 E   224    263
007-02   20/08/15  13:08:00  79 35.80 N  29 59.95 E   195    257


Station   Date      Time      Latitude   Longitude   UWCTD  Water 
                    [UTC]                            depth  depth 
                                                      [m]    [m]
———————  ————————  ————————  ——————————  ——————————  —————  —————
007-03   20/08/15  13:20:00  79 37.82 N  29 59.97 E   206    263
007-04   20/08/15  13:32:00  79 39.86 N  30  0.05 E   195    256
007-05   20/08/15  13:42:00  79 41.57 N  29 59.95 E   195    270
009-01   20/08/15  15:14:00  79 47.45 N  29 59.97 E   145    152
009-02   20/08/15  15:23:00  79 48.85 N  29 59.95 E   135    142
009-03   20/08/15  15:29:00  79 49.80 N  30 00.06 E   171    210
009-04   20/08/15  15:36:00  79 50.90 N  30 00.05 E   199    264
009-05   20/08/15  15:46:00  79 52.44 N  30 00.08 E   195    243
009-06   20/08/15  15:55:00  79 53.81 N  29 59.94 E   194    245
009-07   20/08/15  16:04:00  79 55.19 N  29 59.98 E   194    252
009-08   20/08/15  16:13:00  79 56.55 N  29 59.96 E   201    245
009-09   20/08/15  16:22:00  79 57.92 N  29 59.94 E   214    273
011-01   20/08/15  19:32:00  80 09.01 N  30 00.03 E   103    298
011-02   20/08/15  19:37:00  80 09.82 N  29 59.98 E   222    284
011-03   20/08/15  19:50:00  80 11.93 N  29 60.00 E   257    299
013-01   20/08/15  20:40:00  80 16.03 N  30 00.05 E   202    234
013-02   20/08/15  20:51:00  80 17.86 N  30 00.06 E   170    205
013-03   20/08/15  21:00:00  80 19.34 N  30 00.05 E   145    150
013-04   20/08/15  21:06:00  80 20.31 N  29 59.96 E   199    194
013-05   20/08/15  21:18:00  80 22.30 N  29 60.00 E   183    198
013-06   20/08/15  21:27:00  80 23.81 N  29 59.92 E   200    236
013-07   20/08/15  21:37:00  80 25.47 N  30 00.02 E   172    175
013-08   20/08/15  21:45:00  80 26.81 N  30 00.07 E   158    338
015-01   20/08/15  22:52:00  80 31.57 N  29 46.99 E   216    501
015-02   20/08/15  23:06:00  80 32.94 N  29 35.46 E   207    314
015-03   20/08/15  23:18:00  80 34.07 N  29 25.94 E   140    174
015-04   20/08/15  23:26:00  80 34.82 N  29 19.66 E   187    258
015-05   20/08/15  23:36:00  80 35.75 N  29 11.76 E   169    191
015-06   20/08/15  23:44:00  80 36.48 N  29 05.48 E   192    326
015-07   20/08/15  23:54:00  80 37.39 N  28 57.69 E   195    261
015-08   21/08/15  00:03:00  80 38.24 N  28 50.79 E   191    305
015-09   21/08/15  00:13:00  80 39.14 N  28 42.95 E   219    485
015-10   21/08/15  00:27:00  80 40.45 N  28 32.13 E   218    444
016-01   21/08/15  01:26:00  80 45.02 N  28 28.47 E    75     80
016-02   21/08/15  01:31:00  80 45.00 N  28 31.78 E   106    121
016-03   21/08/15  01:35:00  80 44.99 N  28 34.62 E   186    191
016-04   21/08/15  01:50:00  80 45.00 N  28 49.89 E   216    492
016-05   21/08/15  01:58:00  80 44.99 N  28 58.32 E   218    501
019-01   21/08/15  08:01:00  80 47.35 N  29 33.84 E   250    423
019-02   21/08/15  08:17:00  80 49.86 N  29 26.69 E   256    399
019-03   21/08/15  08:35:00  80 52.68 N  29 20.02 E   236    431
 


Tab. 3.4: Details of XCTD profiles. Those profiles taken from the ship 
          are listed by station number from the station list PS94 (A.4), 
          those taken from sea-ice are listed as 'Heli' with incrementing 
          cast number for each profile.


 No  Station     Date Time     Latitude    Longitude   Water  XCTD s/n  XCTD       Filename
                   [UTC]                               depth            depth 
                                                        [m]              [m]
———  ———————  ——————————————  ——————————  ———————————  —————  ————————  —————  —————————————————
  1  017-01   21/08/15 02:22  80 45.01 N  029 23.58 E   480   14078062   480   XCTD-000308212015
  2  017-02   21/08/15 02:43  80 45.01 N  029 47 E      286   14078065   280   XCTD-000408212015
  3  017-03   21/08/15 02:52  80 45.01 N  029 55.44 E   247   14078069   240   XCTD-000508212015
  4  017-04   21/08/15 03:00  80 45.01 N  029 03.91 E   256   14078068   250   XCTD-000608212015
  5  017-05   21/08/15 03:07  80 44.99 N  029 12.31 E   224   14078063   210   XCTD-000708212015
  6  017-06   21/08/15 05:28  80 45.66 N  030 06.69 E   252   14078060   240   XCTD-000808212015
  7  017-07   21/08/15 03:52  80 45.41 N  029 44.27 E   304   14078066   290   XCTD-000908212015
  8  020-01   21/08/15 08:58  80 56.24 N  029 09.75 E   411   14078059   506   XCTD-001008212015
  9  022-01   21/08/15 10:51  80 04.45 N  029 03.49 E   373   14078036   471   XCTD-008108212015
 10  023-01   21/08/15 11:36  81 10.02 N  029 07.01 E   355   14078035   496   XCTD-008208212015
 11  024-01   21/08/15 12:14  81 14.65 N  029 10.02 E   333   14078034   403   XCTD-008308212015
 12  026-01   21/08/15 14:44  81 22.02 N  029 41.90 E   299   14078038   559   XCTD-001108212015
 13  027-01   21/08/15 15:29  81 25.75 N  030 04.02 E   201   14078039   297   XCTD-001208212015
 14  028-01   21/08/15 16:11  81 29.05 N  030 24.33 E   646   14078037   400   XCTD-001308212015
 15  033-01   23/08/15 07:26  81 57.81 N  030 53.65 E  3193   14078042  1085   XCTD-001408232015
 16  035-01   23/08/15 11:39  82 07.65 N  030 46.81 E  3304   14078040   116   XCTD-001508232015
 17  035-01   23/08/15 11:55  82 08.08 N  030 50.74 E  3300   14078044   793   XCTD-001608232015
 18  037-01   23/08/15 18:23  82 17.98 N  030 54.23 E  3400   14078045  1085   XCTD-001708232015
 19  039-01   23/08/15 23:28  82 32.95 N  030 54.79 E  3597   14062658   369   XCTD-001808242015
 20  041-01   24/08/15 15:19  82 53.63 N  030 54.19 E  3802   15062662   790   XCTD-001908242015
 21  Heli-01  24/08/15 15:52  82 55.47 N  032 09.17 E         15062663  1085   XCTD-002008242015
 22  Heli-02  24/08/15 16:23  82 54.64 N  029 43.77 E         15062659  1085   XCTD-002108242015
 23  043-01   24/08/15 22:10  83 12.79 N  030 57.31 E  3956   15062660   391   XCTD-002208252015
 24  045-01   25/08/15 05:45  83 32.71 N  030 58.11 E  4030   15062661   533   XCTD-002308252015
 25  Heli-03  25/08/15 12:16  83 42.10 N  034 06.91 E         15062635  1085   XCTD-002408252015
 26  Heli-04  25/08/15 12:38  83 42.27 N  033 13.20 E         15062638  1085   XCTD-002508252015
 27  Heli-05  25/08/15 13:00  83 42.62 N  032 18.58 E         15062634  1085   XCTD-002608252015
 28  Heli-06  25/08/15 13:20  83 42.60 N  031 21.69 E         15062641  1085   XCTD-002708252015
 29  Heli-07  25/08/15 13:51  83 42.03 N  027 14.26 E         15062644  1085   XCTD-002808252015
 30  Heli-08  25/08/15 14:15  83 42.26 N  028 17.83 E         15062642  1085   XCTD-003008252015
 31  Heli-09  25/08/15 15:10  83 40.57 N  029 20.36 E         15062640  1085   XCTD-003108252015
 32  047-01   25/08/15 21:15  83 53.01 N  031 00.37 E  4051   15062639   109   XCTD-003208252015
 33  049-01   26/08/15 04:37  84 12.91 N  030 54.40 E  4056   15062637   287   XCTD-003408262015
 34  Heli-10  26/08/15 08:21  84 34.02 N  031 03.74 E         15062633  1085   XCTD-003508262015
 35  051-01   27/08/15 15:30  84 37.22 N  033 30.81 E  4048   15062468   246   XCTD-003608262015
 36  052-01   27/08/15 21:48  84 46.80 N  037 29.44 E  4230   15062657   235   XCTD-003708262015
 37  053-01   28/08/15 12:37  84 58.81 N  041 14.35 E  4224   15062664   113   XCTD-003808262015
 38  055-01   29/08/15 21:12  85 05.06 N  046 57.72 E  4004   15062665  1085   XCTD-000008282015
 39  056-01   29/08/15 01:30  85 12.32 N  050 20.34 E  3986   15062668  1085   XCTD-003908262015
 40  057-01   29/08/15 07:14  85 14.34 N  054 49.07 E  3964   15062435   366   XCTD-004008262015
 41  Heli-11  30/08/15 13:11  85 13.66 N  059 06.54 E         15062438  1085   XCTD-004108262015
 42  Heli-12  30/08/15 08:23  85 31.62 N  060 17.53 E         15062442  1085   XCTD-004208262015
 43  060-01   30/08/15 20:16  85 39.05 N  060 01.77 E  3936   15062667   490   XCTD-004308262015
 44  Heli-13  31/08/15 02:22  85 59.93 N  060 00.15 E         15062443  1085   XCTD-004408262015
 45  063-01   01/09/15 02:53  86 17.65 N  059 25.58 E  2583   15062444    44   XCTD-004508262015
 46  063-01   01/09/15 03:03  86 17.80 N  059 30.18 E  2512   15062441   125   XCTD-004608262015
 47  065-01   01/09/15 12:10  86 33.29 N  061 21.78 E  2554   15062433   317   XCTD-004708262015
 48  067-01   02/09/15 00:05  86 51.04 N  061 01.77 E  3279   15062440   163   XCTD-004808262015
 49  071-01   03/09/15 20:32  87 10.85 N  057 56.08 E  3627   15062437  1085   XCTD-004908262015
 50  073-01   03/09/15 03:46  87 31.41 N  060 00.55 E  4180   15062436  1085   XCTD-005008262015
 51  075-01   04/09/15 10:37  87 51.64 N  060 16.01 E  4449   15062463   656   XCTD-005108262015
 52  077-01   04/09/15 21:43  88 10.15 N  060 44.99 E  4422   15062466   861   XCTD-005208262015
 53  079-01   05/09/15 06:23  88 30.23 N  060 47.09 E  4420   15062439  1085   XCTD-005308262015
 54  Heli-14  05/09/15 11:47  88 51.90 N  060 01.41 E         15062467  1085   XCTD-005408262015
 55  082-01   06/09/15 22:07  89 09.83 N  060 28.92 E  4391   15062464   411   XCTD-005508262015
 56  084-01   07/09/15 05:52  89 30.12 N  060 04.52 E  4351   15062465  1085   XCTD-005608262015
 57  086-01   07/09/15 16:25  89 50.10 N  046 55.03 E  4306   15062434   211   XCTD-005708262015
 58  088-01   08/09/15 12:06  89 48.47 N  113 15.86 W  4251   15062460   131   XCTD-005808262015
 59  090-01   09/09/15 05:21  89 24.17 N  119 17.57 W  2313   15062457  1085   XCTD-005908262015
 60  092-01   09/09/15 18:12  88 57.21 N  112 42.91 W  1375   15062461  1085   XCTD-000109092015
 61  095-01   10/09/15 17:08  88 32.29 N  121 02.01 W  3994   15062462  1085   XCTD-006009102015
 62  097-01   12/09/15 11:41  88 19.32 N  143 33.31 W  3798   15062458  1085   XCTD-006109102015
 63  Heli-15  13/09/15 08:26  87 56.87 N  158 56.48 W  3979   15062459  1016   XCTD-006209102015
 64  Heli-16  13/09/15 09:10  88 05.37 N  167 08.14 W         14078047  1085   XCTD-006409102015
 65  100-01   13/09/15 11:09  87 54.40 N  170 00.11 W  3979   14078048  1085   XCTD-006509102015
 66  103-01   15/09/15 09:34  87 12.33 N  162 09.81 E  4006   14078057  1085   XCTD-006609102015
 67  104-01   15/09/15 15:53  87 02.64 N  153 57.16 E  1796   14078056   247   XCTD-006709102015
 68  106-01   16/09/15 05:57  86 50.50 N  140 14.10 E  2160   14078055  1085   XCTD-006809102015
 69  107-01   16/09/15 11:14  86 39.90 N  134 46.53 E  3413   14078054  1085   XCTD-006909102015
 70  108-01   16/09/15 17:22  86 24.69 N  131 07.29 E  4282   14078053  1085   XCTD-007009102015
 71  109-01   16/09/15 22:39  86 03.23 N  126 47.56 E  4379   14078051  1085   XCTD-007109102015
 72  110-01   17/09/15 04:05  85 44.09 N  123 37.85 E  4399   14078052  1085   XCTD-007209102015
 73  111-01   17/09/15 09:24  85 24.73 N  120 53.61 E  4406   14078049   746   XCTD-007309102015
 74  112-01   17/09/15 13:16  85 12.90 N  118 23.61 E  4410   14078050  1085   XCTD-007409102015
 75  113-01   17/09/15 19:24  84 54.42 N  115 30.32 E  4425   15062656  1085   XCTD-007509102015
 76  114-01   17/09/15 23:36  84 38.24 N  113 24.68 E  4222   15062655  1004   XCTD-007609102015
 77  116-01   18/09/15 11:36  84 24.90 N  112 43.19 E  3135   15062654  1085   XCTD-007709102015
 78  120-01   20/09/15 17:56  84 55.56 N  128 22.50 E  4358   15062653   385   XCTD-007809102015
 79  Heli-17  21/09/15 06:36  84 29.73 N  115 41.58 E         15062649  1085   XCTD-007909102015
 80  122-01   21/09/15 12:30  85 06.81 N  135 13.63 E  4282   15062652  1085   XCTD-008009102015
 81  124-01   22/09/15 02:52  85 04.84 N  140 00.14 E  3911   15062650   471   XCTD-008109102015
 82  126-01   23/09/15 06:16  85 03.86 N  142 56.05 E  3402   15062646  1085   XCTD-008209102015
 83  127-01   23/09/15 07:57  85 04.49 N  144 37.98 E  2715   15062647   402   XCTD-008309102015
 84  129-01   23/09/15 16:45  85 00.88 N  149 13.02 E  1725   15062651  1085   XCTD-008409102015
 85  131-01   24/09/15 04:40  84 58.17 N  153 48.90 E  1667   15062645  1085   XCTD-008509102015
 86  133-01   24/09/15 12:29  84 58.82 N  157 11.32 E  2511   15062648  1085   XCTD-008609102015
 87  135-02   25/09/15 06:39  83 30.02 N  154 56.01 E  2779   15062422  1085   XCTD-008709102015
 88  136-01   25/09/15 07:54  83 20.46 N  154 48.68 E  2786   15062432  1085   XCTD-008809102015
 89  137-01   25/09/15 10:00  83 02.62 N  154 14.02 E  2800   15062431  1085   XCTD-008909102015
 90  138-01   25/09/15 13:39  82 42.11 N  151 57.09 E  2793   15062430  1085   XCTD-009009102015
 91  139-01   25/09/15 15:41  82 23.35 N  150 33.08 E  2798   15062425  1085   XCTD-009109102015
 92  140-01   25/09/15 18:51  82 01.55 N  148 25.69 E  2665   15062423  1085   XCTD-009209102015
 93  141-01   25/09/15 21:18  81 43.23 N  147 00.30 E  2556   15062429  1085   XCTD-009309102015
 94  142-01   25/09/15 23:17  81 22.41 N  145 53.29 E  2313   15062428  1085   XCTD-009409102015
 95  143-01   26/09/15 01:22  80 59.60 N  144 35.64 E  1871   15062426  1085   XCTD-009509102015
 96  148-01   06/10/15 22:17  74 36.35 N  023 57.92 E   211   15062424   200   XCTD-000210062015
 97  150-01   07/10/15 05:12  74 10.26 N  023 43.81 E   414   15062427   396   XCTD-009610072015
 98  151-01   07/10/15 06:16  74 00.89 N  023 36.49 E   455   15062669   433   XCTD-009710072015
 99  152-01   07/10/15 07:17  73 51.97 N  023 28.98 E   469   15062670   453   XCTD-009810072015
100  154-01   07/10/15 18:04  73 35.63 N  023 18.42 E   450   15062671   434   XCTD-000310072015
101  155-01   07/10/15 18:45  73 29.57 N  023 14.02 E   443   15062676   428   XCTD-000410072015
102  156-01   07/10/15 19:31  73 22.86 N  023 08.97 E   431   15062673   415   XCTD-000510072015
103  158-01   07/10/15 23:25  73 08.58 N  023 01.44 E   410   15062677   395   XCTD-000610072015
104  159-01   08/10/15 00:13  73 01.15 N  022 57.93 E   413   15062674   400   XCTD-000710072015
105  160-01   08/10/15 01:11  72 52.46 N  022 53.74 E   402   15062680   391   XCTD-000810072015
106  162-01   08/10/15 11:27  72 37.34 N  022 46.49 E   382   15062679   372   XCTD-000910072015
107  163-01   08/10/15 12:38  72 27.84 N  022 41.49 E   337   15062672   325   XCTD-001010072015
108  164-01   08/10/15 13:43  72 19.13 N  022 36.29 E   320   15062675   310   XCTD-001110072015
109  166-01   08/10/15 17:00  71 59.58 N  022 24.44 E   369   15062690   357   XCTD-001210072015
110  167-01   08/10/15 18:07  71 50.35 N  022 18.80 E   373   15062678   360   XCTD-001310072015
111  168-01   08/10/15 19:11  71 41.48 N  022 13.65 E   371   15062691   361   XCTD-001410072015
112  170-01   09/10/15 01:02  71 21.62 N  021 52.01 E   319   15062692   309   XCTD-001510072015
113  171-01   09/10/15 01:51  71 15.03 N  021 39.29 E   297   15062686   290   XCTD-001610072015
114  172-01   09/10/15 02:44  71 07.69 N  021 26.42 E   228   15062688   219   XCTD-001710072015   



Tab. 3.5: Details of mooring deployments


Mooring  Latitude      Water  Instrument     Serial    Instrument 
         Longitude     Depth  Type           Number    Depth
                        [m]
———————  ———————————  ——————  —————————————  ————————  ——————————
Nansen   85°17.51 N   3870 m  ASL IPS5       51182     30
         60° 0.87 W           RAS-500        13380-02  47
                              SBE 37 ODO     13037     47
                              ET861G         896       176
                              ADCP           22388     176
                              SBE 37 ODO     13012     178
                              Sono Vault     1060      187
                              Sediment trap  2004371   209
                              ADCP           22389     216
                              Seaguard       563       722
                              SBE 37         12481     2168
                              SBE 37         12479     3168
                              Sediment trap  2004372   3723
                              SBE 37         12477     3725
                              Seaguard       522       3730
 
Karasik   87°0.97 N   4711 m  ASL IPS5       51184     65
          59°15.52 E          SBE 37 ODO     13491     72
                              ET861G         835       126
                              ADCP           23456     228
                              SBE 37 ODO     13490     230
                              Sediment tap   2009404   259
                              ADCP           23549     266
                              RCM7           8050      773
                              SBE 37 ODO     13489     3259
                              SBE 37 ODO     13488     3609
                              Sediment trap  2012411   4564
                              SBE 37 ODO     13487     4569
                              RSM8           9391      4571
 



Tab. 3.6: Details of glider and Argo float deployments and recoveries

WMO-Nr.      Ser.No       Date     Time         Position         Depth   Comments
                                   [UTC]                          [m]
————————  ———————————  ——————————  —————  —————————————————————  ——————  —————————
ARGO 
profiler                               
4901426   OIN14DARL20  2015/10/04  17:40  74°0.163'N  6°20.500'E  2225,7  deployment   

Gliders                               
68459         558      2015/10/05   7:00  75°33.43'N  2°39.72'E   3716    recovery
6800955       127      2015/10/05  10:28  75°23.43'N  1°08.59'E   3749    recovery
 


References

Joyce TM (1989) On the in situ calibration of shipboard ADCP. J. Atm. 
    Oceanic Technol., 6, 169-17



Fig. 3.2: Pressure dependence of a CTD temperature sensor SBE35 
          identified by comparison with SBE3 thermometers at 
          station 117-2.
            Upper panel: T(sbe35, S\N 19) - T(sbe3, S\N 5115) vs. pressure 
            Lower panel: T(sbe35, S\N 19) - T(sbe3, S\N 2929) vs. pressure

Fig. 3.3: Potential temperature, referenced to 0 dbar, from CTD, XCTD, 
          UWCTD and UCCTD casts along 30°E (section 1, see Fig. 3.1). 
          Locations of CTD casts are denoted by thin black lines. Both 
          the full section and an enlarged near-surface part are shown. 
          Contours denote temperature in C.

Fig. 3.4: Salinity along the section 1. Contours denote practical 
          salinity on the PSS78 scale

Fig. 3.5: Potential temperature, referenced to 0 dbar, from CTD, XCTD and 
          UCCTD casts along 60E/120W (section 2, see Fig. 3.1). Locations 
          of CTD casts are denoted by thin black lines. Both the full 
          section and an enlarged near-surface part are shown. Contours 
          denote temperature in C.

Fig. 3.6: Salinity along the section 2. Contours denote practical 
          salinity on the PSS78 scale

Fig. 3.7: Potential temperature, referenced to 0 dbar, from CTD, XCTD and 
          UCCTD casts along section 5 (see Fig. 3.1). Locations of CTD 
          casts are denoted by thin black lines. Both the full section 
          and an enlarged near-surface part are shown. Contours denote 
          temperature in C.

Fig. 3.8: Salinity along the section 5. Contours denote practical 
          salinity on the PSS78 scale





4.  SEA ICE PHYSICS 

    Stefan Hendricks(1), Robert Ricker(1),      1 AWI
    Larysa Istomina(2), Justin Beckers(3),      2 IUP
    Hazel Hartman Jenkins(1)                    3 UAlb
 
Grant No. AWI_PS94_00


Introduction 	

Recent evaluations of trends in Arctic sea ice extent observed by passive 
microwave satellite missions shows a downward trend of -3.8% per decade 
of total yearly averaged sea ice cover, whereat multi-year ice coverage 
is effected the most (-11.5 % per decade). While these are yearly 
averaged values, the spread in the seasonal cycle is most pronounced 
during the summer minimum, where the three lowest observed ice extents 
occurred between 2007 and 2012. The reduction of summer sea ice cover and 
its shift to a dominant seasonal ice type has implications on the energy 
balance of the Arctic Ocean through the ice-albedo feedback, increased 
absorption of solar radiation and the ice function as a habitat.

Except passive microwave estimations of sea-ice concentration and a 
satellite retrieval algorithms of melt pond concentrations, most 
observations of the mass balance during summer and the following freeze-
up period rely on airborne, ship-borne and in-situ observations. The main 
objective of the sea ice physics group was therefore to extend the time 
series of essential climates variables (ECV), such as sea ice thickness, 
which was taken from Polarstern during the summer and the early freeze-up 
season of 2015. Besides the continuation of the sea-ice thickness time 
series, one objective was to use technical advances of ice thickness 
sensors to measure the spatial variability of sea-ice porosity and its 
influence of sea-ice volume estimation. This is motivated by the earlier 
anecdotal findings of significant ice porosity, which might lead to a 
bias in ice volume estimation by means of sea-ice thickness measurements 
alone.


4.1  Airborne sea ice surveys 


Objectives

The summer minimum extent of sea ice is mainly controlled by its 
thickness distribution at the start of the melting season. The increasing 
loss of ice volume in the recent decade is manifested in a series of 
record lows of summer ice extent, but its magnitude is poorly quantified 
due to a lack of ice thickness information derived from remote sensing 
data. Satellite data on ice thickness exists mostly from the spring or 
late autumn period, when the ice surface is cold and altimeters can be 
used to estimate its height above the water surface. The ice thickness 
distribution during the melting season can only be measured during ship 
cruises, preferably with airborne surveys to minimize ship route 
selection bias. Sea ice thickness data derived from electromagnetic 
induction (EMI) data measured during Polarstern cruises in the Transpolar 
Drift exist from 1991 on, with additional airborne electromagnetic (AEM) 
data since 2001. The objective of airborne survey during TransArc-2 is to 
continue this time series, with additional documentation of the ice 
surface parameters. 


Fig. 4.1: Location of all EM-Bird helicopter surveys  


Tab. 4.1: List of airborne EM (AEM) sea ice thickness and aerial imagery 
          survey flights

Station       Gear   Longi-  Lati-   Comment                  Start Date  Start  End Date    End 
                     tude    tude                                         Time               Time
————————————  —————  ——————  ——————  ———————————————————————  ——————————  —————  ——————————  —————
PS94/HANT-1   AEM    30.931  81.868  ID: maisie_20150822_01   22.08.2015  11:52  22.08.2015  12:44
                                     Instrument Verification 
                                     Flight

PS94/HANT-3   AEM    30.610  84.486  ID: 20150827_01          27.08.2015  11:57  27.08.2015  12:22
                                     Instrument Verification
                                     Flight

PS94/HANT-16  AEM    58.844  87.019  ID: 20150902_01          02.09.2015  07:08  02.09.2015  09:12

PS94/HANT-21  AEM  -171.793  87.885  ID: 20150913_01          13.09.2015  12:13  13.09.2015  14:19

PS94/HANT-23  AEM   135.618  86.648  ID: 20150916_01          16.09.2015  10:45  16.09.2015  11:49       


Work at sea

We used an airborne electromagnetic (AEM) induction sensor (MAiSIE: Multi 
Sensor Airborne Sea Ice Explorer, Norwegian Geotechnical Institute) to 
measure sea ice thickness by helicopter surveys. The AEM sensor was towed 
on a 20m-long cable at an altitude between 10 and 15 m above the ice 
surface. The method utilizes the difference of electrical conductivity 
between sea ice and sea water to estimate the thickness of sea ice, 
including the snow layer if present. MAiSIE was equipped with a nadir-
looking Canon EOS 5D MkII digital camera. The nadir images are used as a 
documentation of sea ice surface conditions and for the assessment of 
melt pond fractions. The internal timestamp of the camera was 
synchronized with the GPS timestamp of the AEM sensor, so that sensor 
attitude and altitude information can be used to geo-reference each 
image. 


Preliminary results

Throughout the entire cruise, flight operations were significantly 
hampered by unfavorable weather conditions with persistent low clouds, 
fog and snow showers. Therefore, only 5 flights with the EM-Bird were 
accomplished (Fig. 4.1 and Table 4.1). The first two flights did not 
result in scientific data, but were necessary to assess sensor noise at 
altitudes higher than 300 feet and to verify the instrument readiness 
after a failure of an EM transmitter amplifier in-flight after the first 
take-off. Of the three other flights, two had to be aborted due to 
deteriorating weather conditions. 

A preliminary quality control was done on-board, but the post-processing 
and data product generation will be done after the cruise. 

Due to the sparseness of the AEM data collection, additional mummy chair 
stations with ground-based EM sensors were implemented to partially fill 
the gap of ice thickness information (see following section).


Data management

The sea ice thickness data will be released following final processing in 
the PANGAEA database and other international databases like the Sea Ice 
Thickness Climate Data Record (Sea Ice CDR). Aerial images will be 
archived at the AWI long-term data storage system. 



4.2  Sea Ice thickness and porosity


Objectives

Similar to the AEM measurements, on-ice sea ice thickness surveys using 
electromagnetic inductions sensors are a continuation of measurements 
from former cruises ranging back to the early 1990s. At each ice station 
the ice floe is surveyed with one or more EM sensors to receive thickness 
characteristics and distribution of individual floes. In addition, 
coincident snow depth measurements are necessary to assess the snow depth 
distribution and obtain sea ice thickness, since the ground-based EM 
sensors only measure the sum of snow and ice thickness. 

Under summer conditions sea ice is both highly porous and permeable; 
however, measurements of sea ice porosity and their influence on EM 
sensors and on the total ice volume are spatially and temporally limited. 
In addition to collecting data on ice porosity with sea ice cores, we aim 
to retrieve ice porosity by geophysical inversion of the same ground-
based electromagnetic induction (EM) sensors that are used for the ice 
thickness surveys. Furthermore, over the past decade several new ground-
based (EM) sensors have been developed and utilized over sea ice in the 
Arctic and Antarctic. Therefore we also test and compare four different 
sensors (Geophex GEM2-484, Geophex GEM2-512, GSSI EMP-400, GeoSensors 
SIS, Table 4.2) with respect to sea ice thickness measurements.

The primary objectives are therefore to extent existing long-term time 
series of the essential climate variable (ECV) sea ice thickness and to 
use technological advances to better assess the uncertainty of the time 
series and to obtain new parameters. The tasks for this objective can be 
broken down as following:

1. Obtain high resolution ice thickness and snow depth data of individual 
   floes (Sea Ice Thickness Surveys)

2. Compare electromagnetic induction (EM) measurements of sea ice from 
   three different sensors with varying frequencies and 
   transmitter/receiver coil spacing's (EM Inter-comparison)

3. Assess retrieval of sea ice porosity by geophysical inversion of the 
   EM sensor data using sea ice porosity measurements from ice core as 
   validation (Sea Ice Porosity)

4. Collect measurements of conductivity and temperature of the water 
   below the ice and in melt ponds as they influence the EM sensor 
   response (Under-Ice CTD)


Table 4.2: List of used ground EM devices during PS94 and sensor setups.

EM device                        Frequencies Setup [Hz]           Coil spacing [m]
———————————————————————————————  ———————————————————————————————  ————————————————
Geophex GEM2-484                 1530, 5310, 18330, 63030, 93090  1.67

Geophex GEM2-512                 5010, 9030, 15990                1.67

GSSI EMP400                      5000, 9000, 16000                1.219

GeoSensor Sea Ice Sounder (SIS)  9000                             1.0/2.0/4.0
 


Work at sea 

The on-ice work at sea was performed at:
	
• 7 full-length ice stations of more than 8 hours duration

• 1 short-duration helicopter-based ice station with two landings

• 6 short-duration stations accessed by mummy-chair. 


The scientific programme at each of the full-length stations varied 
somewhat due to fog and darkness but generally began with a floe-survey 
of total thickness using one or more of the EM sensors along with a Snow 
Hydro MagnaProbe measurements of snow depth. The floe-survey was followed 
by the calibration of the EM sensors, drilling of EM sensor calibration 
site and the acquisition of two sea ice cores for temperature and 
porosity at the calibration site. One or two shallow CTD casts were made 
at the EM calibration site using the Ruskin RBR Concerto CTD from York 
University. The depth of each cast varied with the water currents but 
always extended deeper than 40 m. 

A 50 m EM sensor inter-comparison and validation line was established so 
as to include level and deformed ice. Measurements of the EM response 
were made at each meter of the line with all of the available EM sensors. 
Then at each meter, holes were drilled and measurements of snow depth, 
ice thickness and freeboard were taken. Furthermore, the thickness of the 
refrozen melt pond ice and the depth of melt ponds were also measured. 
Additional CTD casts and porosity cores were occasionally acquired along 
the validation line along with occasional measurements of melt pond water 
conductivity.

At mummy-chair stations a reduced programme of EM measurements of sea ice 
+ snow thickness (total thickness) using the GEM2-484 sensor and 
MagnaProbe measurements of snow depth was conducted. In addition, one to 
five drill-hole measurements of ice thickness were made for 
calibration/validation of the GEM2-484. Additionally, at several mummy-
chair based stations, buoys were deployed (for a full description see 
chapter 5). At the helicopter-based stations the measurements were 
reduced to EM measurements of sea ice + snow thickness (total thickness) 
using the GEM2-484 sensor and several calibration drill-hole measurements 
of ice thickness.


Fig. 4.2: Location of all sea ice work on ice, mummy chair and helicopter 
          stations


Sea Ice Thickness Surveys

We used the ground-based electromagnetic devices to measure sea ice plus 
snow thickness. The method is based on the contrast of electrical 
conductivity between ocean water and sea ice (including snow). GEM-2-484 
surveys were made during all stations, other sensors depending on 
availability of station time. The device was pulled over the snow cover, 
mounted in a plastic sled. The sampling rate was 10 Hz. Surveys with the 
other EM devices have been carried out occasionally. For calibration 
purpose a wooden ladder was used to allow a stepwise increase of the 
distance to the conductive layer. 

The snow depth during GEM-2 surveys was measured with a MagnaProbe and 
approximately 2 m point spacing. The device measures the snow depth and 
records it on a data logger for later down-loading to a computer. The 
method is based on a disk, which slides on a pole. The height of the disk 
above the pole end indicates the snow depth and is electronically 
recorded. We started magna probe measurements after substantial snow 
accumulation where an average snow layer of >10 cm has been observed 
(station ICE-3). During the GEM-2 surveys the person who operated the 
MagnaProbe usually walked about 3-4 m in front or behind the GEM-2 sled. 

Table 4.3 gives an overview the types of measurements (survey, cal, 
drilling, drift) at each station. The MagnaProbe snow depth profiles are 
summarized in Table 4.3. 


EM Inter-comparison

EM sensor inter-comparison consisted of:
	
• EM measurements at each meter of a 50 m long profile established so as 
  to include representative ice types: level ice, melt ponds and a ridge. 
  The physical properties of the EM sensors are described under the 
  Thickness and Snow Depth Survey's section above. 

• Additional sea ice thickness surveys of the floes. In addition to the 
  Geophex GEM2-484 sensor used for sea ice thickness surveys, additional 
  EM sensors, such as the GeoSensors SIS and the GSSI EMP-400 were 
  occasionally towed along the same profile or just over the same floe in 
  order to compare the measurements point-to-point or by their 
  statistical distributions.

• EM sensor thermal drift measurements after being initialized from 
  ambient air temperature and after initialization at near room 
  temperature. Each sensor was placed in a fixed location, separate from 
  the other sensors by > 15m and set to collect data while other tasks 
  were completed.


Sea Ice Porosity

Ice core work-at-sea involved the acquisition of cores at the calibration 
site of the EM sensor. A 9 cm diameter core was acquired using a Kovacs 
Ice Drilling Equipment Inc. Mark II ice corer. At each site the 
temperature core was acquired first and temperature was measured with a 
Thermo 110 at 0.1 m intervals from top to bottom. Care was taken to 
ensure the core was not in full sun and that measurements of temperature 
were captured quickly. The porosity core was acquired next and was placed 
immediately into sealed bags. One temperature core was sectioned and 
processed as an example porosity core to develop the processing 
methodology. The method requires accurate estimates of ice volume and ice 
mass and the latter measurement cannot be performed on a ship. Ice 
porosity measurements will be completed in AWI in Bremerhaven.


Under-Ice CTD 

CTD under-ice work included:
	
• One or more CTD casts at the EM calibration/sea ice porosity core 
  acquisition site with the Ruskin RBR Concerto CTD. Each first cast was 
  triggered by a conductivity threshold of 0.1mS/cm and recorded at 6Hz 
  for both directions of travel through the column.

• Additional CTD casts at features of interest/as time allowed.


Preliminary results 

Sea Ice Thickness Surveys

A quicklook product of the sea ice thickness and snow depth surveys has 
been created of the individual floes. Corresponding maps have been made 
available for site selection of other measurements directly after the 
surveys. The final revision of the EM data will require an extensive 
quality control and postprocessing using results from the calibration 
procedures on the ice stations. Fig. 4.3 shows an example map of a survey 
using the GEM-2-484 during station ICE-6 on November 09, 2015. We used 
the imaginary part (Quadrature) of the 5,310 Hz signal for the conversion 
into thickness. A projection algorithm using DSHIP information of the 
position of the Trimble 1 GPS antenna and the heading was applied to 
create a local reference frame using a cartesian coordinate system and 
eliminate the effect of the drift and rotation of the ice floe. 


Fig. 4.3: Example ice plus snow thickness map (left panel) from gem2-484 
          on 09.11.2015 after drift correction (lower right panel). 
          Measurement locations are given in a reference frame relative 
          to the ship position (grey box). The upper right panel shows 
          the corresponding histogram. 
 
Fig. 4.4: Mean MagnaProbe-measured snow depth for each station. The 
          background shows the climatologic snow depth for September, 
          derived from the climatology by Warren et al. (1999). 
 


In the example of Fig. 4.3, the histogram reveals a primary modal 
thickness of 1.8 m. Heavily deformed, thick ice has been found at (200 m, 
350 m).

The MagnaProbe snow depth data do not need further processing and are 
ready for archiving.  Fig. 4.4 shows averaged snow depth of each ice 
station along the cruise track. All measurements were carried out in 
September. Therefore, the gridded average September snow depth derived 
from the Warren climatology is shown in the background. While the first 4 
stations coincide with the climatology, the latter stations show 
consistently higher snow depth. A composite of all total thickness 
observations from all surveys is in Fig. 4.5. The most frequent ice+snow 
thickness is 1.4 m, which is marginally thicker than in previous years 
considering the large modal snow depth of 0.15 m. 


EM Inter-comparison: Thermal Drift: Hot-Cold Drift & Cold-Drift

Two thermal drift experiments were conducted to examine the thermal 
response of the four EM sensors. Fig. 4,6 and Fig. 4.7 below present the 
EM response of the various EM sensors during the cold drift experiment. 
The EM signal amplitude was computed from the in-phase and quadrature 
response and then normalized. In Fig. 4.6 the 5 kHz response of the EMP, 
GEM2-484 and GEM2-512 are shown along with a histogram. During the cold 
drift, EM sensors were well equilibrated with the outdoor air temperature 
and set to record in a fixed location apart from each other and other 
sources of interference. The GEM2-484 and GEM2-512 were low-pass filtered 
as they record data at 10Hz while the EMP records at 1Hz. The histogram 
for each sensor has been aligned using the modal value to provide an 
indication of the distribution of the thermal noise. Interestingly, the 
GEM2-484 shows decreasing amplitude over time while the amplitude 
measured by the GEM2-512 increases over time and the EMP-400 measured a 
non-linear change in amplitude. Equivalent data exists from the same 
cold-drift experiment but for the 9 kHz response of the GEM2-512, the 
EMP-400 and the SIS sensor. For the SIS sensor, the horizontal-co-planar 
(HCP, or horizontal receiver and transmitter) and horizontal cross-planar 
(HXP, or Horizontal Transmitter, Vertical Receiver) response of all coils 
(1 m, 2 m, and 4 m) have been measured.

During the hot drift experiment the EM sensors were taken from heated 
(~20°C) storage and setup on the ice in fixed locations separated from 
each other and other possible sources of interference and set to record 
as the sensors cooled to ambient air temperature. While standard 
operating procedure is to allow the sensors to cool to ambient air 
temperature, this experiment provides an indication of the thermal drift 
rates of the different sensors and their sensitivity to such changes.


Fig. 4.6: Cold drift experiment of several EM-sensors: Any signal change 
          is due to changing sensor characteristics, not due to changes 
          of the physical environment. Exemplary data channels from three 
          sensors: (top left) GSSI EMP-400, (top right) Geophex GEM-2, 
          (bottom) GeoSensors SIS.

Fig. 4.7: Inter-comparison of different EM ice thickness sensors along a 
          profile with known thickness. (top panel) Ice thickness 
          (turquoise) and snow depth (dark blue) at drillhole locations. 
          and GeoSensor SIS Quicklook ice thickness (bottom panel) 
          normalized EM channels of other EM sensors (GEM2-512, GEM2-484, 
          EMP-400; right axis) with total ice thickness from drill hole 
          measurements (black line with diamond markers; left axis).


EM Inter-comparison: Drill-Line Inter-comparison

Fig. 4.7 provides an example of the drill-line inter-comparison but also 
shows the normalized EM amplitude response along with the total (snow + 
ice) thickness measured along the line. In addition to the thickness 
comparisons, the EM sensors will data will be utilized for geophysical 
inversions of parameters such as ice porosity, ice conductivity and water 
conductivity. 


Sea Ice Porosity

A total of 7 temperature and 14 porosity cores were acquired. Porosity 
was also measured on the temperature cores (see Table 4.3 for a list of 
all cores). Differences between temperature-core porosity and porosity-
core porosity may be due to the increased time for drainage of the 
temperature cores during the temperature measurements. Fig. 4.8 provides 
an example of the ice core salinity and the corresponding density (a 
proxy for porosity) profile for the temperature core acquired on 
September 11, 2015 (20150911A1/A2). Ice core density was measured both by 
mass and volume of solid ice and by the liquid and solid volumes. Mass 
measurements are highly inaccurate on-board a moving ship; however, 
measurements of liquid volume remain accurate.


Fig. 4.8: Example of sea-ice density profile (measured mass-wise and 
          volume-wise) and bulk salinity of melted core sections
 


Under-Ice CTD

A total of 14 CTD casts were made at 6 of the full-length ice stations 
(Table 4.3) with one additional cast performed with the RBR CTD attached 
to the main CTD-Large rosette of the physical oceanography team for 
calibration. The raw data provided has not been corrected or adjusted in 
any way. The CTD recorded at 6Hz and the raw data files include data 
collected during the downfall and upwards retrieval (Fig. 4.9). Multiple 
casts at a site were split into separate files afterwards by examining 
the depth profile. 


Fig. 4.9: CTD casts taken at stations PS94/046-1, PS95/069-1, and 
          PS94/096-1
 


Data management 

Finalized ice thickness data from the EM sensors and snow depth data will 
be made available in PANGAEA within 3 years. All data will be provided in 
both delimited ASCII files and in a self-describing compact format such 
as HDF5 or NETCDF. Ice core porosity will be processed at AWI. EM data 
will be processed at York University, the University of Alberta, and at 
AWI.



4.3  Optical properties of sea ice


Objectives 

The characteristic feature of the sea ice in summer is the presence of 
melt ponds, which affect albedo, mass balance and heat balance of the 
ice. 96% of total annual heat input through sea ice occurs from May to 
September when the melt ponds are present. The increased amount of energy 
passing through the sea ice affects also eco-systems and geochemical 
processes in and beneath the sea ice. Due to large role the melt ponds 
play in the amount of energy both transmitted through and reflected from 
the sea ice, it is important to study the optical properties of the ponds 
in detail, which is the objective of the optical work during this cruise. 
This work complements studies from the expeditions PS78 (ARK-XXVI/3; 
TransArc, 2011) and PS80 (ARK-XXVII/3; IceArc, 2012).

For the satellite retrievals of sea ice properties, an atmospheric 
correction is necessary, which includes the well-known Rayleigh 
scattering correction and a correction for atmospheric aerosols. Their 
distribution is non-uniform both horizontally and vertically in the 
atmospheric column, and their amount and distribution in the Arctic are 
not well known. Therefore in-situ aerosol optical depth (AOD) 
measurements are of extreme importance and they have also been performed 
during the cruise. 


Work at sea 

The optical measurements consisted of 
	
• Manual under-ice measurements of irradiance and radiance under selected 
  melt ponds during 8 ice stations (Fig. 4.2). These measurements were 
  performed with two Ramses spectral radiometers (320-950 nm, Trios GmbH, 
  Rastede, Germany), the first with a cosine receiver and the second with 
  a narrow angle (field of view 7) receiver fixed on a foldable arm (L-
  arm).

• Surface measurements of solar irradiance with Ramses spectral 
  radiometers above the sea ice for each measurement in (1).

• Surface albedo (incident and reflected irradiance) measurements using a 
  FieldspecPro II (350-2500 nm, Analytic Spectral Devices, Boulder, USA) 
  on L-arm cites, selected representative melt pond and sea ice surfaces 
  during the ice stations.

• A radiation station was deployed during the last ice station.


Furthermore, a total of 5 ice cores were retrieved from selected L-arm 
sites for texture analysis (Table 4.3). As a contribution to the 
extremely sparse dataset of AOD in the high Arctic, a series of underway 
AOD measurements have been performed with a hand-held sunphotometer 
Microtops II (Table 4.4). 


Tab. 4.4: List of all underway aerosol optical depth measurements taken 
          by a mobile sun photometer (Mikrotops) 

  Label           DateTime             DateTime       Latitude  Longitude
——————————  ———————————————————  ———————————————————  ————————  —————————
PS94/AOT1   08/17/2015 13:10:12  08/17/2015 13:11:24  69.698      19.074
PS94/AOT2   08/19/2015 07:32:32  08/19/2015 07:34:19  76.911      30.142
PS94/AOT3   08/19/2015 10:13:22  08/19/2015 10:14:55  77.337      30.404
PS94/AOT4   08/21/2015 11:41:38  08/21/2015 11:42:52  81.129      29.093
PS94/AOT5   08/21/2015 13:00:31  08/21/2015 13:01:12  81.285      29.174
PS94/AOT6   08/21/2015 15:46:19  08/21/2015 15:46:59  81.449      30.201
PS94/AOT7   08/22/2015 10:39:01  08/22/2015 10:40:32  81.860      30.821
PS94/AOT8   08/22/2015 13:01:05  08/22/2015 13:03:38  81.858      30.866
PS94/AOT9   08/24/2015 15:31:05  08/24/2015 15:31:59  82.912      30.933
PS94/AOT10  08/29/2015 14:11:49  08/29/2015 14:12:37  85.277      60.040
PS94/AOT11  09/13/2015 07:46:56  09/13/2015 07:48:01  88.034    -162.511
 


Data management

All optical data will be published, including related sea-ice properties 
in PANGAEA in the format of Nicolaus and Katlein (2012) and Istomina et 
al. (2013).



4.4  	Routine sea ice observations


Objectives

The longest ranging datasets of physical parameters of sea ice originate 
from visual observations during ship cruises, however standards for ice 
observations vary between different research vessels. As a recommendation 
by the Climate in the Cryosphere (CliC) Committee, a standardized ice 
observation protocol for Arctic sea ice was established. 


Work at sea

Hourly sea ice observations were carried out by observers on the bridge 
of the Polarstern. Observers were trained to follow the ASSIST protocol 
(Arctic Shipborne Sea Ice Standardization Tool) at the beginning of the 
cruise, and the observations were checked during the cruise, so that 
consistent errors could be corrected. Observations were not taken 
repeatedly while one station, as the ship drifted alongside the same area 
of ice. Some observations were taken during the ship's night by 
researchers on the night watches, but daytime coverage was more 
extensive. Photos were taken manually at the same time as the 
observations, looking portwards, forewards, and starboardwards.

During the cruise more than 280 visual observations were made. Each entry 
consists of ice concentration, ice types and thickness and surface 
properties for each ice type. Position, heading, and basic meteorological 
parameters were noted, and the ice conditions such as total ice 
concentration were additionally documented with three photos. The images 
captured cover a wide range of ice conditions and types, from freshly-
forming sheet ice to thick multiyear ice. These images have already been 
used to train observers onboard, and may be used for teaching and as a 
check against other data collected on the cruise. 


Data management

ASSIST ice observations are archived and distributed by the International 
Arctic Research Center (IARC) of the University of Alaska, Fairbanks. A 
summary table including all observations will be archived in PANGAEA 
after quality control


 
4.5  Sea Ice remote sensing data products


Objective

Sea ice remote sensing data can be used to support decision making for 
cruise track planning, ice navigation and assessing ice conditions (e.g. 
for selection of larger ice floes in the marginal ice zone) ahead of the 
time of arrival While optical and infrared maps with medium resolution, 
as well as sea ice concentration data are available at the weather office 
of Polarstern, medium to high resolution radar imagery of sea ice are not 
yet routinely available for research in the high latitudes. One obstacle 
are the rather large data sizes in areas where bandwidth for data 
transmission is limited, another is the need to minimize the delay 
between data acquisition to delivery to the ship to mere hours. 

Continuing the first trial at the Polarstern cruise PS92, radar imagery 
of the European Earth Observation Mission Sentinel-1A was sent to the sea 
ice physics group onboard. 


Work at sea

Sentinel 1A radar backscatter data provided by Drift & Noise Polar 
Services was send to an ftp server at two area sizes and resolutions (100 
km @ 40 meter ground resolution) and (500 km @ 150 km ground resolution). 
A scene was automatically generated, if one or several following radar 
images provided data within the area that was centered on the real-time 
position of Polarstern. The data files were available as ftp download and 
highly compressed quicklooks at a coarse resolution (2 km) were emailed 
for evaluation of the usefulness of each scene by an onboard operator 
before manually downloading the larger files via ftp. The larger scenes 
were received as geotiffs with a 16bit grayscale depth with a file size 
between 2 and 6 Mb. The raw geotiffs as well as postprocessed maps with 
location of stations were copied to a public server location and made 
available to the bridge with a live overlay of the current ships 
position. The order of Sentinel 1A radar data was stopped as soon as 
Polarstern left the sea ice. 

In total, 155 quickview scenes with a cumulated file size of 2.93 Mb were 
sent to Polarstern. Especially near the North Pole many of the quickview 
scenes showed insufficient coverage of Sentinel 1A data and the higher 
resolution counterpart were not downloaded by the operator. Instead, only 
15 wide area (500 km @ 150 m resolution) with a total file size of 112 Mb 
and 18 close up areas (100 km @ 40 m resolution) with a total file size 
of 89 Mb were downloaded via ftp between August 22 and September 24 2015. 

The location of the quickview, wide and close-up scenes are visualized in 
Fig. 4.10. Further post processing of selected scenes included merging 
with sea ice concentration data from the AMSR2 sensor of the Japanese 
Space Agency (JAXA). An example is given in Fig. 4.11. 


Data management

Sentinel 1A data is available at the Sentinel Data Portal of the European 
Copernicus Earth Observation Program at full resolution. 


References 

Istomina L, Nicolaus M, Perovich D (2013) Spectral albedo of sea ice and 
    melt ponds measured during POLARSTERN cruise ARK XXII/3 (IceArc) in 
    2012, doi:10.1594/ PANGAEA.815111, Pangaea.

Nicolaus M, Katlein C (2012) Solar radiation over and under sea ice 
    during the Polarstern cruise ARK-XXVI/3 (TransArc) in summer 2011, 
    doi:10.1594/PANGAEA.786717, Pangaea.

Warren S, Rigor I, Untersteiner N, Radionov VF, Bryazgin NN, Aleksandrov 
    YI, Colony R (1999) Snow depth on Arctic sea ice, J. CliM, 12, 
    1814-1829.
 

Fig. 4.11: Composite of Sentinel 1A radar image (ESA) and AMSR2 sea ice 
           concentration data (JAXA) overlaid with planned stations in 
           the Laptev Sea
 


Station      Name     date        longitude  latitude   Gear   type    file label  comment
———————————  —————    ——————————  —————————  ————————   —————  ——————  ——————————  ————————————
PS94/0046-1  ICE-1    25.08.2015  30.33931   83.71406   GEM2-  survey  gem2-484_   survey gps 
                                                        484            20150825_   file damaged
                                                                       Survey
                                                               cal     gem2-484_
                                                                       20150825_
                                                                       Calib
                                                        GEM2-  cal     gem2-512_
                                                        512            20150825_
                                                                       Calib
                                                        SIS    survey  SISSRV_
                                                                       20150825
                                                               cal     SISCAL_
                                                                       20150825

PS94/0054-1  ICE-2    28.08.2015  42.55930   85.08853   GEM2-  survey  gem2-484_
                                                        484            20150828_
                                                                       Survey
                                                               cal     gem2-484_
                                                                       20150828_
                                                                       Calib
                                                               dril-   gem2-484_    
                                                               line    20150828_
                                                                       Drill_001
                                                                       gem2-484_
                                                                       20150828_
                                                                       Drill_002
                                                        GEM2-  survey  gem2-512_
                                                        512            20150828_
                                                                       Survey
                                                               cal     gem2-512_
                                                                       20150828_
                                                                       Calib
                                                               dril-   gem2-512_
                                                               line    20150828_
                                                                       Drill_001
                                                                       gem2-512_
                                                                       20150828_
                                                                       Drill_002
                                                        SIS    cal     SISCAL_
                                                                       HEIGHTADJ_
                                                                       20150825
                                                        EMP-   survey  EMPSRV_
                                                        400            20150828
                                                               cal     EMPCAL_
                                                                       20150828
                                                               dril-   EMPDRL_
                                                               line    20150828


Station      Name     date         longitude  latitude  Gear   type    file label  comment
———————————  ——————   ——————————   —————————  ————————  —————  ——————  ——————————  ————————————
PS94/0059-1  HELI-1   30.08.2015   60.36009   85.51776  GEM2-  survey  125-xg-     two floes sampled
                                                        484            03ja-013
                                                                       126-xg-
                                                                       03ja-02e
                                                                       127-xg-
                                                                       03ja-00a
                                                                       128-xg-
                                                                       01ja-008

PS94/0069-1  ICE-3    02.09.2015   58.70657   86.99722  GEM2-  survey  129-xg-
                                                        484            01ja-010
                                                               cal     130-xg-
                                                                       01ja-128
                                                               dril-   131-xg-   
                                                               line    01ja-008 
                                                                       132-xg-
                                                                       01ja-098
                                                        GEM2-  cal     134-xr-     gps file broken
                                                        512            01ja-087
                                                               dril-   133-xr-     gps file broken
                                                               line    01ja-198
                                                        SIS    dril-   SISDRL_
                                                               line    20150902
                                                        EMP-   dril-   EMPDRL_
                                                        400    line    20150902

PS94/0081-1  ICE-4    05.09.2015   61.09556   88.99035  GEM2-  survey  gem2-484_    
                                                        484            20150905_
                                                                       Survey_001
                                                                       gem2-484_
                                                                       20150905_
                                                                       Survey_002
                                                               cal     139-xg-
                                                                       04ja-320
                                                               dril-   140-xg-
                                                               line    05ja-0d4
                                                        GEM2-  dril-   141-xg-
                                                        512    line    05ja-05f
                                                        SIS    survey  SISSRV_
                                                                       20150905
                                                               dril-   SISDRL_
                                                               line    20150905
                                                        EMP-   survey  EMPSRV_
                                                        400            20150905
                                                               cal     EMPCAL_
                                                                       20150905
                                                               dril-   EMPDRL_
                                                               line    20150905


Station      Name     date         longitude  latitude  Gear   type    file label  comment
———————————  ——————   ——————————   —————————  ————————  —————  ——————  ——————————  ————————————
PS94/0087-1  ICE-N    07.09.2015  -90.00661   89.95442  GEM2-  survey  142-xr-     North Pole ice station, 
                                                        484            01ja-1e0    gps file broken

PS94/0093-1  MUMMY-1  09.09.2015  -112.71165  88.91040  GEM2-  survey  143-xg-
                                                        484            01ja-010

PS94/0096-1  ICE-5    11.09.2015  -125.01961  88.35697  GEM2-  survey  145-xg-    
                                                        484            01ja-008
                                                                       146-xg-
                                                                       01ja-008
                                                               cal     147-xg-
                                                                       01ja-099
                                                               dril-   148-xg-    
                                                               line    01ja-2fd
                                                                       149-xg-
                                                                       01ja-0a2
                                                        SIS    survey  SISSRV_
                                                                       20150911
                                                               cal     SISCAL_
                                                                       20150911
                                                               dril-   SISDRL_
                                                               line    20150911

PS94/0098-1  MUMMY-2  12.09.2015  -144.25290  88.33872  GEM2-  survey  150-xg-
                                                        484            01ja-010

PS94/0101-1  ICE-6    13.09.2015   179.89545  87.49598  GEM2-  survey  151-xg-
                                                        484            02ja-055
                                                               cal     152-xg-      
                                                                       02ja-29a
                                                               dril-   153-xg-     no drilling, conductivity 
                                                               line    03ja-07b    measurements of underlying slush
                                                        GEM2-  cal     155-xg-
                                                        512            03ja-024
                                                               dril-   154-xg-     no drilling, conductivity 
                                                               line    03ja-024    measurements of underlying slush
                                                        SIS    survey  SISSRV_
                                                                       20150913
                                                               cal     SISCAL_
                                                                       20150913
                                                               dril-   SISDRL_     no drilling, conductivity 
                                                               line    20150913    measurements of underlying slush
                                                        EMP-   cal     EMPCAL_
                                                        400            20150914
                                                               dril-   EMPDRL_     no drilling, conductivity 
                                                               line    20150914    measurements of underlying slush


Station      Name     date         longitude  latitude  Gear   type    file label  comment
———————————  ——————   ——————————   —————————  ————————  —————  ——————  ——————————  ————————————
PS94/0107-2  MUMMY-3  16.09.2015   133.88808  86.62752  GEM2-  survey  157-xg-
                                                        484            05ja-0f8

PS94/0112-1  MUMMY-4  17.09.2015   118.41286  85.21521  GEM2-  survey  158-xg-
                                                        484            01ja-010
                                                               cal     159-xg-
                                                                       01ja-158

PS94/0117-1  ICE-7    18.09.2015   115.98337  84.56133  GEM2-  survey  160-xg-    
                                                        484            02ja-138
                                                                       161-xg-
                                                                       02ja-1fb
                                                               cal     162-xg-
                                                                       02ja-32c
                                                               dril-   165-xg-
                                                               line    01ja-020
                                                               drift   43-xg-
                                                                       31mr-038
                                                        GEM2-  cal     163-xg-
                                                        512            01ja-008
                                                               dril-   166-xg-
                                                               line    01ja-010
                                                               drift   164-xg-
                                                                       01ja-0b8
                                                        SIS    cal     SISCAL_
                                                                       20150918
                                                               dril-   SISDRL_
                                                               line    20150918
                                                               drift   SISDFT_
                                                                       20150918
                                                        EMP-   survey  EMPSRV_
                                                        400            20150918
                                                               cal     EMPCAL_CAL1_
                                                                       20150918    
                                                                       EMPCAL_CAL2_
                                                                       20150918    
                                                                       EMPCAL1_CAL1_
                                                                       20150918
                                                               dril-   EMPDRL_DRL1_
                                                               line    20150918    
                                                                       EMPDRL_DRL2_
                                                                       20150918
                                                               drift   EMPDFT_
                                                                       20150918

PS94/0125-1  ICE-8    22.09.2015   139.97401  85.08702  GEM2-  survey  168-xg-
                                                        484            01ja-028
                                                               drift   44-xg-04ap-02b
                                                        GEM2-  drift   169-xg-02ja-006
                                                        512
                                                        SIS    drift   SISDFT_20150922
                                                        EMP-   drift   EMPDFT_20150922     
                                                        400



Fig. 4.10: Location of Sentinel-1A radar image subsets available to ice 
           navigation and scientific site selection: (left) coarse 
           resolution email subsets, (middle) medium resolution wide area 
           scenes manually downloaded via ftp, (right) high resolution 
           close-ups manually downloaded via ftp.


Tab. 4.3: List of electromagnetic induction sea ice thickness profiles 
          during stations: ICE - regular ice station, HELI - Helicopter 
          station, MUMMY - mummy-chair station at starboard side of 
          Polarstern. Measurements are separated into: survey - floe 
          survey, cal - calibration with the wooden ladder, drilline - 
          measurements along 50m drilline, drift - drift evaluation at a 
          fixed position on the floe.




5.  INSTALLATION OF AUTONOMOUS, ICE-TETHERED PLATFORMS
 
    Mario Hoppmann(1), Benjamin Rabe(1),        1 AWI
    Sergey Pisarev(2), Nicolas Villacieros(3),  2 SIO
    Jean-Philippe Savy(3), Marcel Nicolaus(1)   3 LOCEAN
    (not on board), Christine Provost(3) 
    (not on board)

Grant No. AWI_PS94_00


Objectives

An important tool to increase observational data in the still sparsely 
sampled Arctic Ocean has become more and more feasible during the last 
decade: autonomous, ice-tethered measurement platforms, which are able to 
capture data year-round, and, by their drift, extend the area of manned 
expeditions. 

During PS94, a suite of autonomous instruments have been installed on ice 
floes to provide measurements of physical, biological and biogeochemical 
parameters in the upper ocean and sea ice, as well as of near-surface 
atmospheric conditions. 

Sea-ice based buoys and profilers are deployed during ice stations and by 
helicopter several kilometers off the Polarstern cruise track. Types of 
sea ice buoys include GPS drifters for the study of ice dynamics, snow-
depth and ice-mass-balance buoys for monitoring ice growth and snow 
accumulation throughout the following winter, radiation stations for 
energy budget estimations, and ice-tethered profilers to monitor upper 
ocean properties. 

The main focus of buoy deployments lies on regions as far into the 
eastern marginal seas of the Arctic Ocean as possible, which are areas 
where observations by autonomous systems are typically sparse and the 
expected lifetime of the instruments is highest. 

The buoy deployments support long-term monitoring programmes such as the 
International Arctic Buoy Programme, and are further coordinated within 
the FRAM infrastructure programme and the French Ice Atmosphere Ocean 
Observing System (IAOOS) project. 

The network of ice-tethered platforms is expected to play a crucial role 
in understanding the linkages between the atmosphere, sea ice and upper 
ocean in the high Arctic. It will further allow us to improve our process 
understanding and to derive reliable models of the physical and 
biogeochemical states of the future Arctic Ocean. 


Work at sea

Platforms were deployed during ice stations or during helicopter landings 
(Fig. 5.1). 

Nine types of platforms were deployed, investigating the properties of 
the upper ocean, the sea ice and its snow cover, and the atmosphere.

1.  Surface Velocity Profilers (SVPs), manufactured by Metocean Data 
    Systems Limited, Canada, report GPS position, air temperature and 
    barometric pressure at hourly intervals. 

2.  Sea-ice mass balance buoys (IMB), manufactured by SAMS Research 
    Services Ltd, report GPS position as well as temperature (rise) 
    values from a thermistor chain through air, snow, sea ice and ocean. 
    The chain is equipped with 240  thermistors at a spacing of 0.02 m. 
    Resistor elements mounted near the thermistors may be heated, and by 
    a determination of the temperature rise after a certain interval, 
    different media may be distinguished by their different thermal 
    conductivity.  The different parameters are transmitted via iridium 
    at varying intervals.

3.  Snow height beacons (SB), manufactured by Metocean Canada, report GPS 
    position, air and surface temperatures, barometric pressure, as well 
    as 4 snow depths at a spacing of ~1 m, at hourly intervals.

4.  A polar area weather station (PAWS) manufactured by Metocean Canada, 
    reports GPS position, air and surface temperature, barometric 
    pressure, relative humidity as well as wind velocity and direction in 
    3-hour intervals.

5.  A spectral radiation station (SRS), consisting of three RAMSES 
    spectral irradiance sensors manufactured by TriOS Optical Sensors, 
    records incoming, reflected and transmitted irradiance at 2-hour 
    intervals and transmitsthe data daily. 

6.  The Bio-ITP system (Fig. 5.2), manufactured by Woods Hole 
    Oceanographic Institution (WHOI, USA) measures temperature/salinity/ 
    depth/oxygen/fluorescence/ PAR profiles with 1 Hz (nominally 0.25 m) 
    vertical resolution between 5 and 760 m, at 36-hour intervals. The 
    McLane profiler is equipped with a CTD unit (Seabird Electronics, 
    Inc. model 41CP), a Wetlabs Eco-Triplet fluorometer and a 
    photosynthetically active radiation sensor (QCP2300, Biospherical 
    Instruments) on a wire tether, using an inductive modem to 
    communicate the data to a surface unit. 

7.  IAOOS platforms, developed by France-based LOCEAN and LATMOS, are 
    mainly composed of a profiling CTD unit which is additionally 
    equipped to measure dissolved oxygen. The profilers are comparable to 
    the ARGO float system, except that they are tethered to a cable along 
    which they can repeatedly profile vertically from the surface down to 
    800 m depth. The data is transmitted to the surface unit using an 
    inductive modem technique. The atmospheric observations are provided 
    by a microlidar and an optical depth radiometer.  Finally, air, snow, 
    sea-ice and seawater temperatures are monitored by a SAMS IMB mounted 
    on the surface unit. 

8.  The BAS IMB is another variation of a thermistor-string based sea-ice 
    mass balance buoy, provided by the British Antarctic Survey (BAS). 
    The units report GPS position as well as temperature (rise) values 
    from a thermistor chain through air, snow, sea ice and ocean. The 
    units are also equipped with a sideways-looking camera. 

9.  The SATICE is equipped with a high-rate, high-precision GPS receiver 
    reporting in sub-hourly, sub-decimeter precision in three dimensions. 
    It further features standard meteorological sensors, an ultrasonic 
    snow pinger for snow depth retrieval, a digital camera, a sea level 
    sensor and a conductivity cell. The unit deployed during PS94 is part 
    of a network of five units deployed over a time span of 5 years.

All observing systems report their data through the iridium satellite 
network at regular intervals. The buoy deployments are summarized in 
Table 1. In total, 8 SVPs, 6 SAMS IMBs, 8 SBs, 1 PAWS, 1 SRS, 2 BAS IMBs, 
1 SATICE, 1 Bio-ITP and 4 IAOOS were deployed.


Preliminary results

Fig. 5.3 shows the drift track of all SVPs, SAMS IMBs and SBs as of 11 
October 2015. 


Fig. 5.1: buoy deployments during ice stations (green), by mummychair 
          (pink) and by helicopter (orange) along the cruise track (solid 
          line). The shaded area indicates the September 2015 mean sea
          ice extent.

Fig. 5.2: Deployment of BIO-ITP

Fig. 5.3: Drift track of SVPs (purple), SAMS IMBs (red), SBs (green) and 
          ITP (blue). Image courtesy of www.meereisportal.de (11.10.2015).


Data management

SVP, SAMS IMB, SB and PAWS data are available in near real time on 
www.meereisportal.de. The positions and meteorological data of the SVPs 
and snow height beacons are automatically uploaded to the database of the 
International Arctic Buoy Program (IABP), which is publicly accessible. 
These buoys also contribute to the Global Telecommunication System (GTS). 
Data of all buoys will be archived in the online databases PANGAEA and 
Coriolis within one year after a buoy ceases transmitting. The ITP data 
can be downloaded from the WHOI ITP web site (www.whoi.edu/itp). All buoy 
data will be available through the FRAM data portal at a later time.


Tab. 5.1: List of deployed platforms with deployment data. Abbreviations: 
          SVP: Surface velocity profiler; IMB: Ice mass balance buoy; SB: 
          snow height beacon; SRS: spectral radiation station; PAWS: 
          polar area weather station; ITP: ice-tethered profiler; IAOOS: 
          Ice Atmosphere Ocean Observing System.

Buoy      IMEI             Name      Date        Time      Longitude    Latitude      Station
Type                                             [UTC]
————————  ———————————————  ————————  ——————————  ————————  ———————————  ————————————  ———————
SVP       300234062888920  2015P12   02.09.2015  16:15:00  88°54.58'N   112°45.34'W    093-01
SVP       300234062887930  2015P14   16.09.2015  13:30:00  86°37.78'N   133°52.57'E    107-02
SVP       300234062888930  2015P13   17.09.2015  13:30:00  85°12.89'N   118°23.70'E    112-02
SVP       300234062884920  2015P11   13.09.2015  11:00:00  88°05.37'N   167°08.14'W    Heli
SVP       300234061188690  2015P9    19.09.2015  05:16:00  84°45.79'N   115°45.12'E    Heli
SVP       300234061186310  2015P10   19.09.2015  05:33:00  84°30.52'N   118°21.14'E    Heli
SVP       300234061774560  2015P8    19.09.2015  05:50:00  84°15.94'N   115°45.12'E    Heli
SVP       300234061776560  2015P7    24.09.2015  04:00:00  84°58.414'N  153°10.287'E   Heli
SAMS      300234061266810  AWI7_1/   02.09.2015  16:15:00  87°00.41'N    58°39.77'E    069-01
IMB                        2015T22
SAMS      300234061264830  AWI6_1/   08.09.2015  00:00:00  88°21.79'N   125°10.06'W    Northpole
IMB                        2015T19°
SAMS      300234062427080  AWI7_2/   11.09.2015  23:30:00  88°21.79'N   125°10.06'W    096-01
IMB                        2015T23°
SAMS      300234061263820  AWI7_4/   12.09.2015  12:00:00  88°20.31'N   144°18.90'W    098-01
IMB                        2015T25
SAMS      300234062429080  AWI7_3/   22.09.2015  06:00:00  85°5.00'N    139°57.56'E    125-01
IMB                        2015T24
SAMS      300234061261790  AWI6_2/   25.09.2015  07:00:00  83°30.07'N   154°56.58'E    135-01
IMB                        2015T20
BAS       300025010842220  IMB005    11.09.2015  18:00:00  88°20,85'N   124°40'W       096-01
IMB                        
BAS       300025010848700  IMB006    14.09.2015  04:00:00  87°30'N      179°50'E       101-01
IMB
SB        300234062785480  2015S35   02.09.2015  16:15:00  87°00.41'N    58°39.77'E    069-01
SB        300234062784540  2015S33   06.09.2015  16:30:00  88°59.14'N    60°57.98'E    081-01
SB        300234062782480  2015S32   08.09.2015  00:00:00  90°N           0°E          Northpole
SB        300234062789420  2015S30   11.09.2015  23:30:00  88°21.79'N   125°10.06'W    096-01
SB        300234062328760  2015S20   14.09.2015  12:00:00  87°29.73'N   179°53.72'E    101-01
SB        300234062428050  2015S16   19.09.2015  08:00:00  84°33.78'N   115°59.81'E    117-01
SB        300234062788470  2015S29   22.09.2015  06:00:00  85° 5.00'N   139°57.56'E    125-01
SB        300234062423070  2015S21   25.09.2015  06:00:00  83°30.07'N   154°56.58'E    135-01
SRS                                  23.09.2015  01:00:00  85° 5.00'N   139°57.56'E    125-01
PAWS      300234062784500  2015A1    23.09.2015  01:00:00  85° 5.00'N   139°57.56'E    125-01
SATICE                     SATICE07  06.09.2015  16:00:00  88°59.55'N    61°10.09'E    081-01
ITP                        ITP93     23.09.2015  01:00:00  85° 5.00'N   139°57.56'E    125-01
IAOOS     300025010340400  IAOOS10   05.09.2015  22:30:00  88°59.55'N    61°10.09'E    081-01
IAOOS     300025010340050  IAOOS11   11.09.2015  15:50:00  88°20,85'N   124°40'W       096-01
IAOOS     300025010347770  IAOOS14   14.09.2015  02:44:00  87°30'N      179°50'E       101-01
IAOOS     300025010342860  IAOOS15   18.09.2015  23:57:00  84°32.55'N   115°57.65'E    117-01       




6.  GEOTRACES

    Michiel Rutgers van der Loeff(1),           1 AWI
    Micha Rijkenberg(2),                        2 NIOZ
    and the GEOTRACES scientific party 
    (the corresponding names of the 
    participating party are listed under 
    the respective articles)
 
Grant No. AWI_PS94_00


Objectives

GEOTRACES (www.geotraces.org) is an international programmeme that aims 
to determine global ocean distributions of selected trace elements and 
isotopes, including their concentration, chemical speciation and physical 
form, and to evaluate the sources, sinks and internal cycling of these 
species. This knowledge is needed to characterize more completely the 
physical, chemical and biological processes regulating their 
distributions so that the response of these cycles to global climate 
change can be predicted, and their impact on the carbon cycle and climate 
understood (Henderson et al., 2007).

Warming of Arctic terrestrial areas caused increased river discharge, 
which, combined with net loss of the Greenland ice-cap and melting of sea 
ice, resulted in a freshening of surface waters and increased 
stratification. These climate-induced changes are expected to change the 
biogeochemical cycling and therefore the distribution of many Trace 
Elements and Isotopes (TEI's).


Work at sea 

As part of a pan-Arctic GEOTRACES effort in coordination with Canadian 
and US initiated research cruises in 2015, we have carried out a sampling 
programme of TEIs (Table 6.1) including all tracers considered as key 
TEIs by Henderson et al. (2007). 

In total we have carried out 30 GEOTRACES stations (Table 6.2). At 28 
stations we sampled with the Ultra Clean CTD where we collected ancillary 
parameters with the normal Rosette (Table 6.2). At two stations we used 
only the normal Rosette. At 21 Large Stations (included in the GEOTRACES 
stations), large volume samples were collected for natural and artificial 
radionuclides and for rare earth elements and Nd isotope composition. At 
10 Super Stations (a subset of the Large Stations) we additionally 
deployed in situ pumps to sample TEI in the particulate phase and to 
sample Radium isotopes. Three Basin Stations (Sta 50 in the Nansen Basin, 
81 in the Amundsen Basin and 101 in the Makarov Basin) were sampled 
additionally for Cd and Pb and triple oxygen isotopes.

Intercalibration and intercomparison are an essential part of the 
GEOTRACES programme. For this purpose a cross over station had been 
agreed between the expeditions of RV Polarstern and USCG Healy at 87.5N, 
180E in the Makarov Basin. This station was sampled by our cruise (Sta 
101) just about 10 days after it had been sampled by USCG Healy (their 
station 20). This joint sampling with short delay will serve as 
intercomparison between the two teams for all parameters analysed. 
Additional samples were collected for intercalibration programmes to be 
distributed among GEOTRACES partners, especially with colleagues on the 
US and Canadian ships (details below). Our tracks crossed once more at 
the North Pole. This station (PS94-87, Healy Sta 19) was not scheduled as 
a cross over station and was not sampled for all GEOTRACES parameters on 
Polarstern, but the cast with the Ultra Clean CTD (PS94-87/1) will 
provide an additional opportunity for intercomparison of hydrographic and 
trace metal data among the two ships, in this case even synoptic, i.e. 
without time delay. The mutual visits to each other's laboratories was 
used for an extensive exchange of experience.


Preliminary/expected results

Our sections across the Barents shelf, Nansen Basin, Amundsen Basin into 
the Makarov Basin (Station 1-101) will provide continuous TEI profiles 
from the northern tip of Norway (Nordkap) to the cross over station in 
the Makarov Basin. In combination with the results of the synoptic US and 
Canadian studies we expect to provide maps of the distribution of TEIs in 
the Arctic including a full section from the Barents Sea to the Bering 
Strait. Comparison with previous data may allow us to determine whether 
distributions have changed, which could be indicative of changes in water 
mass circulation, primary productivity, or particle fluxes. The second 
section across the Lomonosov Ridge (Stations 115-134) will provide a 
second section of the Transpolar Drift. This section can be extended by 
combination with Healy station 21. 

The final section across Bear Island Trough (Sta 147-173) characterizes 
the TEI distribution in the Gateway between Norway of Svalbard. In 
combination with the hydrographical data (chapter 3) and with the mooring 
array with current meters at 20°E (operated by the Institute of Marine 
Research, Norway) it will be possible to calculate TEI fluxes through 
this major inflow pathway of Atlantic water to the Arctic Ocean.


Data management

Data from a crossover station with the US cruise and other 
intercalibration results from duplicate sampling will be submitted to the 
GEOTRACES Standards and Intercalibration Committee for evaluation and 
approval. All data and metadata will be submitted to the international 
GEOTRACES data management office (BODC, www.bodc.ac.uk/geotraces) under 
the data management scheme agreed upon in the GEOTRACES programme 
available at http://www.geotraces.org. Most data and metadata will also 
be submitted to the PANGAEA data base. First data will be presented at 
the AGU Ocean Sciences meeting 2016, we expect to include a large amount 
of data in the second GEOTRACES Intermediate Data Product, due 2017. This 
will be made available through the website www.egeotraces.org where the 
data of the 2007-2009 IPY (International Polar Year) expeditions can also 
be found.


References

Henderson GM, Anderson RF et al. (2007) GEOTRACES - An international 
    study of the global marine biogeochemical cycles of trace elements 
    and their isotopes. Chem Erde-Geochem, 67, 85-131.


Tab. 6.1: GEOTRACES and ancillary parameters sampled during PS94

GEOTRACES parameters      Name                           Institute
————————————————————————  —————————————————————————————  ——————————————————————————
Trace metals              Micha Rijkenberg               NIOZ
Particulate trace metals  Aridane G. Gonzalez            IUEM
Fe Ligands                Loes Gerringa, Hans Slagter    NIOZ
mercury                   Lars-Eric Heimbúrger           MIO Marseille
Fe isotopes               Michael Staubwasser            Uni Kóln
REE, Nd isotopes          Ronja Paffrath                 Uni Oldenburg
230Th/231Pa               Ole Valk,                      AWI, 
                          Sandra Gdaniec                 Swedish Museum of 
                                                         Natural History
234Th, 210Pb/210Po        Viena Puigcorbe                UAB, Barcelona
Radium isotopes, 228Th    Michiel Rutgers van der Loeff  AWI
Artificial radionuclides  Núria Casacuberta              ETH, Zurich
129I, 236U

———————————————————————————————————————————————————————————————————————————————————
Ancillary parameters

Nutrients                 Jan van Ooijen                 NIOZ
CO2 and oxygen            Adam Ulfsbo                    Uni Gothenburg
                          Elisabeth Jones                NIOZ/UK
pCO2, NO3, pH sensors     Daniel Scholz                  AWI
18O                       Dorothea Bauch                 GEOMAR
Dissolved organic matter  Heather Reader                 DTU-Aqua
———————————————————————————————————————————————————————————————————————————————————

Parameters collected for  Name                           Contact person TransArc II
other groups
————————————————————————  —————————————————————————————  ——————————————————————————
N and O isotopes in       Raja Ganeshram                 Michiel vd Loeff
nitrate
Cd, Pb, Cr isotopes       Wafa Abouchami and             Micha Rijkenberg
                          Stephen Galer
Triple oxygen isotopes    Boaz Luz                       Michiel vd Loeff
Si isotopes               Claudia Ehlert                 Ronja Paffrath
CFC                       Bill Smethie                   Michiel vd Loeff
dissolved Ti              Peter Croot                    Micha Rijkenberg
Pu-isotopes               Tim Kenna                      Nuria Casacuberta

———————————————————————————————————————————————————————————————————————————————————
Not-GEOTRACES samples

humic substances          Luis Laglera                   Hans Slagter
rubisco protein           Monica Orellana                Micha Rijkenberg
bPSi, POC/N, Chl a,       Eva-Maria Noethig              Nicole Hildebrandt
Seston
HPLC (pigments)           Ilka Peeken                    Nicole Hildebrandt
Heme                      Maria Nielsdottir              Daniel Scholz       



Tab. 6.2: GEOTRACES Stations with Rosette types and cast numbers

Station    Station  Ultra Clean  Rosette cast  Rosette  ISP   Basin
           type        cast                     type    cast
—————————  ———————  ———————————  ————————————  ———————  ————  —————
PS94/0002  GT                       1 (REE)      S
PS94/0004  Super       2 + 6          3+5        S       4
PS94/0018  Large                     1+3+5       S
PS94/0032  Super         4           5+7+9       S       8
PS94/0040  Large         2            1+3        L
PS94/0050  Super         3          1+4+6+8      S       5       X
PS94/0054  GT            3
PS94/0058  Large         7            1+3        L
PS94/0064  GT            2
PS94/0069  Large         2            4+5        L
PS94/0070  Large         4             1         L
PS94/0081  Super       4 + 10       2+5+7        L       9       X
PS94/0087  GT            1
PS94/0091  GT            2
PS94/0096  Super         4           2+6         L       5       X
PS94/0099  GT           1+3
PS94/0101  Super       4 + 8       2+5+7+9       L       6
PS94/0117  Super         3          2+4+6        L       7
PS94/0119  GT            1
PS94/0121  GT            2
PS94/0125  Super         3           2+5         L       8
PS94/0130  GT            2
PS94/0134  Large         2       1 (deep only)   L
PS94/0147  GT            2
PS94/0149  Large         2           1+4         S
PS94/0153  Super         2           1+4         S       6
PS94/0157  GT            2
PS94/0161  Super         2           1+4         S       5
PS94/0169  Large         3           1+4         S
PS94/0173  Large         2            1          S       



6.1  Nutrients

     Jan van Ooijen                            NIOZ
 

Objective

The nutrients phosphate (Murphy & Riley, 1962), silicate (Strickland & 
Parsons, 1968), nitrite and nitrate (Grasshoff et al., 1983) will be 
measured at all GEOTRACES stations to determine its distribution in the 
Eurasian sector of the Arctic Ocean. The nutrients are important 
parameters allowing other parameters to be related to biological activity 
such as primary production and remineralization. Nutrients function also 
as tracers of water masses.


Work at sea

Equipment and Methods

Nutrients were analysed in an air-conditioned lab container with a, 
Technicon TRAACS 800, continuous flow auto analyser. During this cruise I 
measured about 2,300 samples. Samples originate from CTD 1800, Ice floes 
and related some 300, Surface Waters 50, and lab experiments 150 approx. 
CTD samples were measured unfiltered whereas the ice related and 
experiment samples were 0.2 µm filtered prior to analysis. Measurements 
were made simultaneously on four channels: phosphate, silicate, nitrate 
and nitrite together, and nitrite separately. All measurements were 
calibrated with standards diluted in low nutrient seawater (LNSW), and 
LNSW was used as wash-water between the samples. For the Ice related 
samples having different salinities, all samples were diluted with LNSW 
or demineralised water (18.2 M Ohm) to a salinity of approx. 12 or 26. 
This allows the samples to be analysed all within the same calibration 
salinity.


The colorimetric methods used

Phosphate

Ortho-phosphate is measured by formation of a blue reduced 
Molybdophosphate-complex at pH 0.9-1.1 (Murphy and Riley, 1962). 
Potassium Antimonyltartrate used as the catalyst and ascorbic acid as a 
reducing agent. The absorbency is measured at 880 nm.


Silicate

Measured as a blue reduced Silicomolybdenium-complex at 800 nm 
(Strickland and Parsons, 1972). Ascorbic acid is used as reducing agent 
and oxalic acid is used to prevent interference of phosphate.


Nitrite

Diazotation of nitrite with sulfanylamide and N-(1-naphtyl)-ethylene 
diammonium dichloride to form a pink dye measured at 550 nm (Grasshof, 
1983). 


Nitrate and Nitrite

Nitrate is first reduced in a copperized cadmium-coil using imidazole as 
buffer and is then measured as nitrite at 550 nm (Grasshof, 1983).


Sample handling

The samples were collected in 100 ml high-density polyethylene sample 
bottles, taken directly and unfiltered from the CTD-rosette bottles. The 
samples were kept cool and dark stored in a refrigerator and analysed 
typically within 16 hours as a maximum. Analyses were carried out using 
high-density polyethylene "pony-vials" with a volume of 6 ml as sample 
cups. For duplicate analysis purposes in-between runs, the deepest sample 
at every CTD-station was capped in a pony-vial to be measured for a 
second time in the next run. To avoid evaporation during the runs, all 
vials including the calibration standards used were sealed with 
"parafilm" under tension, so that the sharpened sampler-needle easily 
penetrated through leaving a small hole in the film.


Calibration and Standards

Nutrient primary stock standards were prepared at the laboratory at NIOZ 
by weighing and solute them in demineralised water. All standards are 
kept in a so called 100 % humidity box at lab temperature to prevent 
evaporation.

The calibration standards were prepared daily by diluting the separate 
stock standards, using three electronic pipettes, into four volumetric 
100 ml PP flasks (pre-calibrated at the lab) filled with low nutrient sea 
water LNSW. The background values of the LNSW were measured on board and 
added to the calibration values to get the absolute nutrient values.


Cocktail standard

This standard acts as a lab reference and its use is described under 
"quality control". It is made in the lab containing a mixture of 
phosphate, silicate and nitrate in demineralised water containing 40 mg 
Hg2Cl2 per litre as a preservative. Every time it was used it was diluted 
250 times with the same pipette, and the same volumetric flask.


Quality Control

Our standards have already be proven by inter calibration exercises like 
ICES and Quasimeme, and last years the RMNS exercise organised from Dr. 
Michio Aoyama Meteorological Research Institute (MRI), Japan, to be 
within the best obtainable limits to the mean of the better laboratories. 
To gain some accuracy the Cocktail standard is monitored now since 2008, 
showing in-between runs reproducibility better than 1.0 % , but typically 
0.8% of its average value.


                       Average value    S.D.    N
                       —————————————  ————————  ——
                 PO4     0.901 µM     0.006 µM  70
                 SiO2   13.94 µM      0.06 µM   70
                 NO3    13.66 µM      0.05 µM   70


The advantage of a cocktail standard is like using a reference standard 
with three nutrients mixed in one bulk, giving each run a good overview 
of the machine's output. It also gives you a tool to normalise data from 
run to run for oceanographic purpose from station to station to produce 
transect plots.

Others have reported the use of a real reference sample supplied from 
deep water (2,000 m) but this reference sample is not stable over a 
period longer than three weeks. 

For the semi-final data no corrections (within 0.015 M) were made based 
on normalising on the average cocktail standard value. Final data will be 
ready 2 months after the cruise.


Statistics

Mean Detection Limits: calculated as 2.82 x S.D. of nine 2 % (from the 
full range) spiked samples (EPA norm).


                  µM/l    Used ranges µM/l:  Applied level:
                  ——————  —————————————————  ——————————————
         PO4      0.003         1.75             0.04 M
         SiO2     0.03         24.8              0.50 M
         NO3+NO2  0.04         26.0              0.52 M
         NO2      0.008         1.00             0.02 M 
Precision in single run:  12 sample bottles were measured for this test.

                              Average  Stdev
                              ———————  —————
                     PO4       0.902   0.002
                     SiO2     13.77    0.06
                     NO3+NO2  13.67    0.02
                     NO2       0.028   0.002


Accuracy

To gain accuracy this cruise reference material for nutrients were 
measured parallel to the deep CTD sections containing stable values for 
PO4, SiO2 and NO3 and NO2.

Reference Material for Nutrients in Seawater (RMNS) produced by KANSO lot 
BU and lot BT was used. 


Expected results

During this cruise 2,300 samples were measured. The CTD's provided 1,800 
samples, the ice work some 300 samples, 50 samples of surface waters and 
there were 150 samples originating from on board laboratorium samples. 
The nutrients are important parameters allowing other parameters to be 
related to biological activity such as primary production and 
remineralization. Nutrients can also be used as tracers of water masses. 
Silicate can be used as a tracer of hydrothermal plumes.


Data management

See introduction of chapter 6 for details on GEOTRACES data management. 
All nutrients data are available among all cruise participants. Jan C. 
van Ooijen (Royal NIOZ) should become co-author on any articles that 
comprise nutrient data. If only very few nutrient data are used, and/or 
that the nutrient data is not really pivotal for the scientific 
interpretation, mentioning in Acknowledgments will be adequate. For 
additional information, please contact Micha Rijkenberg (email: 
Micha.Rijkenberg@nioz.nl) or Jan van Ooijen (Jan.van.Ooijen@nioz.nl), 
Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den 
Burg, The Netherlands, Telephone 31 222 369465


References

Murphy J, Riley JP (1962) A modified single solution method for the 
    determination of phosphate in natural waters. Analytica Chim. Acta, 
    27, 31-36.

Strickland JDG, Parsons TR (1968) A practical handbook of seawater 
    analysis, first edition, Fisheries Research Board of Canada, Bulletin 
    no, 167, 65.

Grasshoff K, Ehrhard M, Kremling K (1983) Methods of seawater analysis, 
    2nd ed. Verlag Chemie GmbH, Weinheim.



6.1.1  Stable N & O isotopes of nitrate

       R.S. Ganeshram (not on board)            UE
 

Objectives

To collect water samples for combined O and N stable isotopes of nitrate 
and where possible to collect suspended particles for C and N stable 
isotopes on glass fibre filters (collaboration with Ilka Peeken and Eva-
Maria Noethig).


Work at sea

Water samples were collected with the ultraclean CTD with an online 
Acropak filter into 125ml sample bottles in duplicates after rinsing 3 
times with seawater leaving a headspace. The collected samples were 
stored frozen at -20°C.  Samples were collected at all 40 stations at 
alternative depths starting with the near surface bottle.  


Expected results

The broad scientific aim is to understand what controls N balance in the 
Arctic and the Arctic through flow. Arctic through flow into the North 
Atlantic is depleted in N relative to P. This has significant influence 
on (1) preformed N contents and N:P ratios of North Atlantic Deep water 
and the excess P also drives N-fixation in the Atlantic. By using stable 
N and O isotopes of nitrate, nutrient and water mass information I wish 
to evaluate whether N balance of the  Arctic is controlled by (1) 
Relative proportions of Atlantic and Pacific water masses entering the 
Arctic; or (2) due to terrestrial nutrients sources to the Arctic: or (3) 
nutrient recycling processes within the Arctic Ocean. We will use isotope 
data along with nutrients and water mass information in our 
interpretations. 


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


6.1.2  Biogeochemical cycling of silicon - stable isotopes

       Ronja Paffrath                           ICBM
       C. Ehlert, K. Pahnke (not on board)

 
Objectives

In most oceanic regions, the silicon isotope composition (δ30Si) of water 
masses varies as a function of input from land, diatom primary production 
in surface waters and diatom silica dissolution at greater depth, 
together with physical water mass circulation and mixing.

Therefore, the oceanic δ30Si distribution bears information on the 
dominant pathways and processes by which silicon is cycled within the 
ocean (e.g. de Souza et al., 2012a). However, often the interpretation is 
difficult because the δ30Si always represents a mixed signal of the 
numerous pathways and processes. The Arctic Ocean is a unique system to 
study the silicon cycle, because here the diatom primary productivity and 
silicic acid utilization in the water column is very low and quasi 
restricted to a short season in the year. Therefore, seawater δ30Si 
signatures in the Arctic will mainly represent the input of terrestrial 
dissolved and particulate silicon via rivers, which both have a lighter 
δ30Si signature than the surrounding seawater, and subsequent dissolution 
of the particles and physical water mass mixing. With our applied methods 
we will be able to analyse separately and therefore distinguish the 
silicon isotope composition of the lithogenic (terrestrial derived) 
particles from the in-situ produced diatom biogenic silica. Both particle 
types should have distinctly different silicon isotope compositions 
(higher δ30Si for biogenic particles and low δ30Si for lithogenic 
particles, respectively). This allows us to study the terrestrial input 
and its influence on the seawater δ30Si composition without or very 
little influence from biological fractionation, thus improving our 
understanding of the biogeochemistry of silicon in the ocean. We will 
then further compare the results with data from the Canadian and US 
GEOTRACES cruises (M. Brzezinski, D. Varela, pers. communication), the 
Atlantic (de Souza et al., 2012a), the Pacific (e.g., De Souza et al., 
2012b; Grasse et al., 2013) and in particular the Southern Ocean (e.g. 
Varela et al., 2004, Fripiat et al., 2007) to evaluate and contrast the 
processes affecting silicon biogeochemistry. We will investigate the 
effects of enhanced river input and extended shelf areas in the Arctic 
versus no river discharge and restricted shelf extent in the Southern 
Ocean as well as the different circulation regimes, upwelling (Southern 
Ocean, Equatorial Pacific) versus no upwelling (Arctic), and the 
different particle compositions of opal-rich (Southern Ocean, Equatorial 
Pacific) versus opal-poor (Arctic). 

Although production and subsequent burial of diatom silica is very low in 
the Arctic, the combination of a short growth season before and during 
the time of the cruise and the sampling of suspended particles together 
with sediment samples will provide unique information about the transfer 
of the surface water utilization signal, possibly with a very strong 
fractionation by sea ice diatoms, through the water column to the deep 
ocean and will therefore provide important general information on the 
applicability of diatom δ30Si as a paleo proxy in the global ocean.

Currently, the silicon cycle in the Arctic region is not yet influenced 
by anthropogenic disturbances. However, this will likely change in the 
future. A future temperature increase and an associated decrease in 
permafrost may cause an increase in depth of the weathering active soil 
layer, land plant biomass, atmospheric precipitation, and river 
discharge, which may also increase the river silicon flux and stimulate 
future diatom growth in the Arctic and therefore influence the global 
silicon as well as carbon cycle (Trguer and De La Rocha, 2013). With this 
project we will provide a baseline study on the present day silicon 
isotope distribution in the Arctic Ocean for future evaluation of the 
impact of climate change on the silicon cycle. This project will 
contribute the first δ30Si data from the central and eastern Arctic 
Ocean. Our results will provide information about the main input sources 
of dissolved silicon via the major Siberian rivers by investigating the 
dissolved as well as particulate (suspended particles) δ30Si signatures 
along the wide eastern Arctic shelf regions and the Arctic basin.


Work at sea

The work at sea was conducted by Ronja Paffrath and included mainly 
seawater sampling for dissolved silicon isotopes at 20 stations (up to 16 
depths per station) from the conventional (not trace metal clean) rosette 
and additional surface water samples taken with the ships intake system 
upon leaving each station (see section 5.12 for map). The sample volume 
required per analysis is 1-2 L from the rosette (1 L at depth, 2 L in the 
lower-concentrated upper water column) and 5 L from the ships intake (for 
the highly depleted surface waters). Seawater will be filtered through 
AcroPak filter cartridges (0.8/0.45 µm pore size, Supor pleated membrane) 
directly from the Niskin bottles (same sampling as for Nd isotopes and 
REEs). Afterwards no further onboard treatment is necessary and samples 
will be stored in plastic boxes for the transport to the home laboratory 
in Oldenburg.

Suspended particles were sampled at 10 stations with up to 12 depths 
using in-situ pumps, surface sediments from the multicorer or boxcorer 
were collected at 10 stations for the determination of sedimentary 
biogenic and lithogenic silicon isotope composition. Dirty ice was 
collected at 2 stations using plastic tools. These samples are shared 
among a larger group (see section 5.11) in order to analyse a range of 
parameters on a homogenized sample. The dirty ice will be melted under 
clean conditions and the particles will be collected by filtration over 
the same filter type used for suspended particles.


Expected results

The results will provide unique information about silicon biogeochemical 
cycling under the conditions of high terrestrial input, extensive shelf 
area and low diatom productivity not found in other ocean regions. We 
will study the input of the terrigenous sources to the Arctic and mixing 
with Atlantic and Pacific seawater, trace the transformation processes 
(formation and remineralization) of particulate silicon in the water 
column and the transfer to the underlying sediments.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

De Souza GF, Reynolds BC, Rickli J, Frank M, Saito MA, Gerringa LJA, 
    Bourdon B (2012a) Southern Ocean control of silicon stable isotope 
    distribution in the deep Atlantic Ocean. Global Biogeochemical 
    Cycles, 26(GB2035). doi:10.1029/2011GB004141.

De Souza GF, Reynolds BC, Johnson GC, Bullister JL, Bourdon B (2012b) 
    Silicon stable isotope distribution traces Southern Ocean export of 
    Si to the eastern South Pacific Thermocline Biogeosciences, 9, 
    4199-4213. doi:10.5194/bg-9-4199-2012.

Fripiat F, Cardinal D, Tison JL, Worby A, André L (2007) Diatom-induced 
    silicon isotopic fractionation in Antarctic sea ice Journal of 
    Geophysical Research, 112(G02001). doi:10.1029/2006JG000244.

Grasse P, Ehlert C, Frank M (2013) The influence of water mass mixing on 
    the dissolved Si isotope composition in the Eastern Equatorial 
    Pacific. Earth and Planetary Science Letters, 380, 60-71. 
    doi:10.1016/Jepsl.2013.07.033.

Tréguer PJ, De La Rocha CL (2013) The world ocean silica cycle. Annual 
    Review of Marine Science, 5, 477-501. doi:10.1146/annurev-marine-
    121211-172346.

Varela DE, Pride CJ, Brzezinski M (2004) Biological fractionation of 
    silicon isotopes in Southern Ocean surface waters. Global 
    Biogeochemical Cycles, 18(GB1047). doi:10.1029/2003GB002140.



6.2  CO2 System and dissolved oxygen

     Elizabeth Jones(1), Adam Ulfsbo(2),        1 NIOZ
     L.G. Anderson(2), H.J.W. de Baar(1)        2 UGOT
     (not on board)


Objectives

The overarching objective of this study is to further improve our 
understanding of the carbon system in the rapidly changing Arctic Ocean, 
with an emphasis on the spatial and temporal variability of carbon 
dioxide (CO2) fluxes and net community production (NCP) using novel high-
resolution methods in the surface mixed layer within the central basins. 
More specifically, we aim at improving our understanding of the feedbacks 
by physical and biogeochemical processes on the Arctic Ocean carbon 
system within the surface mixed layer. This also includes carbon 
transformation on the large shelf areas and the exchange with the deep 
central basins, as well as likely changes in the effect by export of 
marine produced organic matter to the deep central Arctic Ocean when the 
sea-ice coverage is absent during the productive summer season. In 
addition, apart from hydrography, a thorough knowledge of the carbon 
system is essential for the understanding of the distribution of trace 
elements in the ocean in terms of their cycling, sources and sinks, 
supporting the on board GEOTRACES programme. 

In addition to the four core marine carbonate system parameters: 
dissolved inorganic carbon (DIC), total alkalinity (TA), pH, and the 
partial pressure of CO2 (pCO2), the participants on board were 
responsible for underway measurements of dissolved O2/Ar (Section 6.2.1) 
and discrete samples for dissolved oxygen (Section 6.2.2.).


Work at sea

Seawater samples were taken from the Niskin bottles mounted to the CTD 
rosette at depths throughout the water column, but with a bias towards 
the upper water column. Ice cores were collected at 8 ice stations and 2 
deployments of the Mummy Chair from the ship. Cores were typically 
sectioned with a stainless saw from the bottom upwards on site or in the 
-20°C container onboard. Core sections were transferred to the laboratory 
in plastic containers and immediately placed in individual 1 L PVF Tedlar 
bags and sealed with plastic clips. Excess air was removed with a Nalgene 
hand pump via Tedlar bag valve and sections were allowed to melt in the 
dark at laboratory temperature. Upon melting, usually within 20-24 hours, 
the bulk ice melt was carefully transferred to 250 ml borosilicate glass 
bottles using Tygon tubing. Samples for under ice water were collected at 
some stations when possible using either a plastic bottle and titanium 
weight on a line or a peristaltic pump.

DIC and TA were determined on all seawater and ice core melt samples. 
Both DIC and TA are measured in parallel with a VINDTA 3C instrument 
(MARIANDA, Kiel). The accuracy is set by internationally recognized and 
widely used certified reference material (CRM), batch 144, obtained from 
Prof. A. Dickson at Scripps Institute of Oceanography (USA). DIC is the 
sum of all dissolved inorganic carbon species and is determined by a 
precise coulometric method (Dickson et al., 2007). For every coulometric 
cell that was used in the coulometer, at least two CRMs were measured in 
duplicate at the beginning and the end of the analyses, where differences 
in the measurements infer the precision of the instrument. The TA 
measurements were made by potentiometric titration with a strong acid 
(HCl) as a titrant. The acid consumption up to the second endpoint is 
equivalent to the titration/total alkalinity. The system uses a highly 
precise Metrohm Titrino for adding acid, a pH electrode and a reference 
electrode. The measurement temperature for both DIC and alkalinity was 
25°C. Analyses were usually carried out immediately after sampling from 
the CTD and upon complete melt of the ice core sections. In a very few 
cases, samples had to be stored prior to analysis and where fixed with 
mercuric chloride solution and were stored in the dark. A total of 57 
stations and 10 ice cores were sampled for DIC and TA (Table 6.2.1), 
totaling about 1,100 samples. The precision for DIC and TA was determined 
from the in-bottle CRM duplicate analyses to be better than 2 µmol/kg. 
The accuracy was checked against frequent analysis of CRMs.

A total of 54 stations were sampled for seawater pH (Table 6.2.1) using 
borosilicate bottles (250mL), having tight plastic screw caps, and were 
rinsed with at least one bottle volume and filled to the rim.  All 
samples were thermostated to 25°C at least 30 min prior to analysis 
directly after sampling. Seawater pH was determined 
spectrophotometrically (Clayton and Byrne, 1993) using the 
sulfonephthalein indicator m-Cresol Purple (mCP). Purified mCP (Liu et 
al., 2011) was purchased from the laboratory of Robert H. Byrne, 
University of South Florida, USA. The indicator solution (0.2 mM) was 
prepared by dissolving pre-weighed mCP indicator in 0.5 L filtered 
seawater (0.20 µm) of about salinity 34. The indicator was adjusted to a 
pH in the same range as the samples, approximately ± 0.2 pH units, by 
adding a small volume of concentrated HCl or NaOH. Before running a set 
of samples, the pH of the indicator was measured using a 0.02 cm cuvette. 
The measurements were performed on board within hours of sampling. The 
shipboard setup is based on the absorption ratios of the indicator at 
wavelengths 434 nm, 578 nm, and 730 nm (background correction) using a 1-
cm flow cuvette and a diode array spectrophotometer (Agilent 8453). Each 
run consists of the three main steps; i) rinsing of tubing and cuvette 
with sample (15 mL) ii) sample blank (25 mL) and iii) sample run (20mL) 
including indicator (0.5 mL). The sample is pumped and mixed using a 
Kloehn V6 syringe pump (Norgren) with a zero-dead volume syringe. Sample 
temperature is measured directly after the cuvette. The magnitude of the 
perturbation of seawater pH caused by the addition of indicator solution 
is calculated and corrected for using the method described in Chierici et 
al. (1999). The instrument setup is controlled by a PC running a LabView 
program (Fransson et al., 2013). The pH values are corrected to 25°C on 
the total scale. The overall precision from duplicate sample analysis was 
better than 0.001 pH units. The accuracy is mainly set by the accuracy of 
the physico-chemical characterizations of the indicator with respect to 
temperature dependence and the determination of the equilibrium constants 
of the indicator, as well as the purity of the indicator (Liu et al., 
2011). The accuracy was checked against Certified Reference Material for 
total alkalinity and total dissolved inorganic carbon, indicating that it 
should be well below 0.01 pH units.  

Surface water partial pressure of CO2 (pCO2) was determined along the 
ships track from the ship's underway seawater supply (Fig. 5.2.1). Sea 
surface pCO2 is obtained with a General Oceanics (GO850) system with an 
infra-red analyser (LiCOR 7000), both for seawater using an water-air 
equilibrator and for the atmosphere, the air being pumped from the crow's 
nest. 


Preliminary/expected results

Across the Arctic Ocean, the vertical profiles of DIC and alkalinity 
typically showed a high consistency. Very low values for DIC and 
alkalinity occurred near the sea ice edge and within other areas of 
recent sea ice melt, consistent with reduced salinity. A minimum in pCO2 
of about 100 µatm also occurred in this region. As alkalinity is thought 
to be conservative, the gradient within the deep water column was 
expected to be very low. This could be confirmed and revealed the high 
precision achieved with the analyses. The values of DIC and alkalinity in 
ice core melts showed variation within the ice profile and between 
different ice stations, with very low values compared to seawater 
samples.


Fig. 6.2.1: Sea surface partial pressure of CO2 (ppm) along the PS94 
            cruise track (white line). The red dashed line indicates the 
            Russian Exclusive Economic Zone.



6.2.1  Net community production using O2/Ar ratios in surface waters

       Elizabeth Jones(1), Adam Ulfsbo(2)       1 NIOZ
                                                2 UGOT
 

Objectives

The objective of this project is to estimate net community productivity 
in the Arctic Ocean using dissolved O2/Ar measurements (Ulfsbo et al., 
2014), investigate the physical and biological controls on oxygen 
saturation variability in the upper Arctic Ocean (Eveleth et al., 2014), 
and constrain the biogeochemical controls on carbon fluxes. Oxygen in the 
mixed layer is influenced by biology, and by physical processes such as 
bubble injection, temperature and pressure changes. Because argon (Ar) 
has similar solubility properties as oxygen, the oxygen derived from 
physical processes can be estimated from the argon concentration relative 
to its saturation ([Ar]sat). The oxygen derived from biology is equal to 
the total oxygen minus the oxygen derived from physical processes.


Work at sea

Biological oxygen supersaturation was measured continuously by 
Equilibrator Inlet Mass Spectrometry (EIMS, Fig. 6.2.2) provided by 
Nicolas Cassar, Duke University, USA, a method previously described 
(Cassar et al., 2009). Briefly, seawater from the ship's underway system 
was pumped through a gas equilibrator, the headspace of which was 
connected to a quadrupole mass spectrometer for continuous elemental 
O2/Ar ratio measurements. The ion current ratio was calibrated by 
periodically sampling ambient air. From the O2/Ar supersaturation, a gas 
exchange rate, and the oxygen concentration at saturation, the net 
biological oxygen flux across the ocean surface will be estimated. The 
oxygen optode (Aanderaa 4835) will be calibrated post-cruise against 
discrete Winkler samples from the ship's underway intake line.


Fig. 5.2.2: Setup of the Equilibrator Inlet Mass Spectrometry. The large 
            seawater reservoir (A) sits in a sink. After going through an 
            inline coarse filter (500 m pore size), seawater flows into 
            the inner reservoir (B) at a rate of 3-5 L min-1 (large 
            arrow). Most of the water running into B overflows into A, 
            which is used as a water bath thermostated to the temperature 
            of ambient seawater. A small fraction (100 mL min-1) of the 
            high flow rate is pulled with a gear pump through a filter 
            sleeve (C), with 100 and 5 m pore size on the outside and 
            inside, respectively. 


From the gear pump, the seawater flows through the equilibrator (D). The 
equilibrator sits in reservoir A to keep its temperature identical to 
that of the incoming seawater. A capillary, attached to the headspace of 
the equilibrator, leads to a multiport Valco valve. This valve alternates 
between admitting gas from the equilibrator and ambient air to the 
quadrupole mass spectrometer. An optode (not shown) in container B 
measures total oxygen saturation. Also not shown is a water flow meter 
located downstream of the equilibrator and thermocouples monitoring 
temperatures through the system (from Cassar et al., 2009).


Preliminary/expected results

Our preliminary observations suggest net autotrophic conditions in the 
deep basins with large biological activity in the marginal sea ice.



6.2.2  Dissolved oxygen

       Elizabeth Jones(1), A. Ulfsbo(2)         1 NIOZ
                                                2 UGOT
 

Dissolved oxygen in seawater was determined by direct spectrophotometry 
of total iodine at 456 nm (Pai et al., 1993). The method is based on the 
classical Winkler method with respect to sampling and pickling reagents 
up to the point of titration with thiosulfate, according to the following 
redox-reactions:

     2 Mn2+  +  2 OH-  --->  2 Mn(OH)2
     2 Mn(OH)2 + O2  ---> 2 MnO(OH)2
     2 MnO(OH)2 + 8 H+ + 6 I-  --->  2 Mn2+  +  2 I3-  +  6 H2O

First an excess of dissolved manganese and a strong base with an excess 
of iodide ions are added to the seawater sample, the Mn2+ is oxidized by 
the dissolved oxygen in the water to higher oxidation states and 
precipitates as MnO(OH)2 to the bottom of the sample bottle. After a few 
hours, an excess of strong acid is added to the sample, to reduce the 
manganese back to the Mn2+ form. With the reduction of manganese the 
iodide ions become oxidized to iodine in the form of I3- ions, which has 
an intense yellow color, and was spectrophotometrically analysed using a 
flow-through cuvette (1 cm) and a peristaltic pump. 


Work at sea

Samples for dissolved oxygen were collected from the specified Niskin 
bottle on the CTD rosette (Table 6.2.1). Samples for sensor calibration 
were generally taken below 400 m depth. Samples were stored under water 
in the dark until analysis within one week of sampling. Standards for the 
calibration curve were prepared before each set of sample analyses using 
seawater from the ship's surface intake line. Pickling reagents and 
sulphuric acid were added in reverse order A pre-prepared potassium 
iodate standard solution (KIO3, 70.16 mM) was added in a step-wise manner 
(0, 200, 300, 400, 500, 650, 750 L). The calibration curve was fitted to 
a quadratic polynomial function since the spectrophotometer in use had a 
slightly non-linear response as determined pre-cruise. A total of 32 
stations were sampled for dissolved oxygen. The precision was determined 
to be on the order of 0.30 mol/L from duplicate sample analysis. The 
accuracy was determined as 0.89 mol/L (0.4 %) by multiple sample analysis 
of a large batch of air-equilibrated deepwater (2,500 m). 


Preliminary/expected results

The dissolved oxygen will be used for post-cruise calibration of the 
oxygen sensors mounted on the small (AWI) and large (NIOZ) CTD-rosettes. 


Data management

The DIC, TA, pH, and pCO2 data will undergo processing after the cruise. 
The final data will be submitted to data centers, as has been done with 
all data of previous cruises with Polarstern. The usual data center for 
carbon research is the Carbon Dioxide Information and Analysis Center 
(CDIAC; Boulder, USA). 

See introduction of chapter 6 for details on GEOTRACES data management.


References

Cassar N, Barnett BA, Bender ML, Kaiser J, Hamme RC, Tilbrook B (2009) 
    Continuous High-Frequency Dissolved O2/Ar Measurements by 
    Equilibrator Inlet Mass Spectrometry. Analytical Chemistry, 81, 1855-
    1864, doi: 10.1021/ac802300u.

Chierici M, Fransson A, Anderson LG (1999) Influence of m-cresol purple 
    indicator additions on the pH of seawater samples: correction factors 
    evaluated from a chemical speciation model. Marine Chemistry, 65(3-
    4), 281-290, doi:10.1016/S0304-4203(99)00020-1.

Clayton TD, Byrne RH (1993) Spectrophotometric seawater pH measurements: 
    total hydrogen ion concentration scale calibration of m-cresol purple 
    and at-sea results. Deep Sea Research Part I, 40(10), 2115-2129, 
    doi:10.1016/0967-0637(93)90048-8.

Dickson AG, Sabine CL, Christian JR (2007) Guide to best practices for 
    ocean CO2 measurements. PICES Special Publication, 173 pp., North 
    Pacific Marine Science Organization (PICES), Sidney, British Columbia

Eveleth R, Timmermans ML, Cassar N (2014) Physical and biological 
    controls on oxygen saturation variability in the upper Arctic Ocean. 
    J GeophyS ReS Oceans, 119, 7420-7432, doi:10.1002/2014JC009816.

Fransson A, Engelbrektsson J, Chierici M (2013) Development and 
    Optimization of a Labview program for spectrophotometric pH 
    measurements of seawater. pHspec ver 2.5, University of GothenburG.

Liu X, Patsavas MC, Byrne RH (2011) Purification and Characterization of 
    meta-Cresol Purple for Spectrophotometric Seawater pH Measurements. 
    Environmental Science & Technology, 45(11), 4862-4868, 
    doi:10.1021/es200665D.

Pai SC, Gong GC, Liu KK (1993) Determination of dissolved oxygen in 
    seawater by direct spectrophotometry of total iodine. Marine 
    Chemistry, 41, 343-351.

Ulfsbo A, Cassar N, Korhonen M, van Heuven S, Hoppema M, Kattner G, 
    Anderson LG (2014) Late summer net community production in the 
    central Arctic Ocean using multiple approaches. Global Biogeochemical 
    Cycles, 28, doi:10.1002/2014GB004833.


Tab. 6.2.2.1: Stations and parameters sampled for DIC, TA, pH, and O2

Year  Month  Day  Station  Cast  DIC, TA  pH  O2  Deployment   Ice core
————  —————  ———  ———————  ————  ———————  ——  ——  ———————————  ————————
2015    8     22      4      1      x      x   x     CTD
2015    8     21     18      3      x      x   x     CTD
2015    8     23     32      2      x      x   x     CTD
2015    8     23     34      1                 x     CTD
2015    8     24     40      1      x      x   x     CTD
2015    8     24     40      3      x      x   x     CTD
2015    8     29     46      4      x      x   x     CTD          x
2015    8     26     50      1      x      x   x     CTD
2015    8     26     50      4      x      x   x     CTD
2015    8     27     50      6      x      x         CTD
2015    8     28     54      2      x      x   x     CTD          x
2015    8     29     58      1      x      x   x     CTD
2015    8     30     58      3      x      x   x     CTD
2015    8     30     58      5      x      x         CTD
2015    8     30     59      1                 x     CTD
2015    9      1     62      1      x      x   x     CTD
2015    9      1     66      1      x      x         CTD
2015    9      2     68      1      x      x   x     CTD
2015    9      2     69      4      x      x   x     CTD          x
2015    9      2     69      5      x      x         CTD
2015    9      3     70      1      x      x   x     CTD
2015    9      4     75      1                 x     CTD
2015    9      4     76      1      x      x   x     CTD
2015    9      5     80      1                 x     CTD
2015    9      6     81      2      x      x   x     CTD          x
2015    9      6     81      5      x      x   x     CTD
2015    9      6     81      7      x      x         CTD
2015    9      7     85      1      x      x   x     CTD
2015   10      5     87      1      x                UCC
2015   10      3     89      1      x      x   x     CTD
2015    9      9     91      1      x      x         CTD
2015    9     10     94      1                 x     CTD
2015    9     11     96      2      x      x         CTD          x


Year  Month  Day  Station  Cast  DIC, TA  pH  O2  Deployment   Ice core
————  —————  ———  ———————  ————  ———————  ——  ——  ———————————  ————————
2015    9     12     96      7      x      x         CTD
2015   10      2     99      2      x      x         CTD
2015    9     15    101      2      x      x   x     CTD          x
2015    9     14    101      5      x      x   x     CTD
2015    9     14    101      7      x      x         CTD
2015    9     14    101      9      x      x         CTD
2015    9           107                           mummy chair      x   
2015    9           112                           mummy chair      x   
2015    9     19    117      2      x      x   x     CTD           x
2015    9     19    117      4      x      x         CTD
2015    9     19    117      7      x      x         CTD
2015    9     20    118      1      x      x         CTD
2015    9     20    119      1      x                UCC
2015    9     21    121      1      x      x   x     CTD
2015    9     23    123      1      x      x   x     CTD
2015    9     22    125      2      x      x   x     CTD           x
2015    9     22    125      5      x      x         CTD
2015    9     22    125      7      x      x         CTD
2015    9     23    128      1      x      x         CTD
2015   10      2    130      1      x      x         CTD
2015    9     24    132      1      x      x   x     CTD
2015    9     24    134      1      x      x         CTD
2015    9     26    134      3      x                UCC
2015   10      7    147      1      x      x         CTD
2015   10      7    149      1      x      x         CTD
2015   10      7    153      1      x      x         CTD
2015   10      7    157      1      x      x         CTD
2015   10      8    161      1      x      x         CTD
2015   10      8    165      1      x      x         CTD
2015   10      9    169      1      x      x         CTD
2015   10      9    173      1      x      x         CTD   



6.2.3  Triple Oxygen isotopes of dissolved O2

       Dorothea Bauch(1)                        1 GEOMAR
       Boaz Luz(2) (not on board)               2 HUJ
 

Objectives

The objective of this study is tracing sources of photosynthetic O2 to 
the depth of the Arctic Ocean. This will give us new insights on 
mechanisms involved in formation of dense deep waters in the Arctic, in 
particular, and more generally, in the world ocean. 


Work at sea

A total of 96 water samples of about 200 mL were taken for triple oxygen 
isotopes of dissolved O2 from the CTD-rosette. For this water was sucked 
by a bubble-free procedure into preevacuated glass flasks. A deep station 
was sampled in each of the visited deep basins in parallel to all 
Geotraces proxies as well as the accompanying parameters δ13CDIC and 
δ18O. About 24 samples were taken in the Nansen, Amundsen and Makarov 
basins (stations 50, 81 and 101, respectively). In addition the upper 500 
m was sampled in the western part of the Makarov basin and a shallow 
station was sampled on the Bear-Island section within the inflow of 
Atlantic Waters into the Barents Sea (station 169). 


Preliminary/expected results

As soon as the samples arrive in Jerusalem, we will follow established 
procedures for seawater removal, gas extraction and purification of O2. 
Then we will start mass spectrometric measurements. The latter will take 
time due to the extreme high precision. I expect to have results by the 
end of April 2016. As explained above, we will use the results for 
tracing sources of photosynthetic O2 to the Deep Arctic Ocean.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.



6.3  Clean sampling of trace metals using an all titanium ultraclean ctd 
     and sampler system

     Sven Ober(1), Micha Rijkenberg(1),             1 NIOZ
     Loes Gerringa(1), Jan van Ooijen(1),           2 UB
     Hans Slagter(1), Lars-Eric Heimbürger(2),      3 IUEM
     Aridane Gonzales(3), Michael Staubwasser(4),   4 UNIK
     H.de Baar (not on board)


Objectives

During this cruise we sampled 28 full depth stations for a suite of bio-
essential trace elements Mn, Fe, Co, Ni, Cu, Zn, Cd and the mostly 
anthropogenic (pollutant and/or potentially toxic) trace metals Hg and 
Pb. Samples were taken in an ultraclean way using the titanium ultraclean 
CTD and sampler system as developed and build at the Royal NIOZ (de Baar 
et al., 2008; Rijkenberg et al., in press).


Work at sea

During this expedition a so called 'Ultra Clean CTD' was used. This 'Ultra 
Clean CTD' is a CTD equipped with 24 polypropylene watersamplers each 
with a volume of 24 liters. The samplers are closed using a butterfly-
type closing mechanism powered using seawater hydraulics (Rijkenberg et 
al. in press). During the first meters of the downcast the samplers open 
automatically and a spring-loaded accumulator is filled with water. This 
process stops at 30 meter depth. During the upcast the bottles are closed 
via a hydraulic multiplexer using the pressurised water in the 
accumulator. This water sampling system is developed and manufactured by 
Royal NIOZ. The frame is made of titanium and lowered by a cable made of 
Dyneema (diameter: 11 mm).  This cable however had no electrical 
conductors so powering and communication with the CTD is not possible 
through this cable. To overcome this problem a SBE17 (S\N 17-0374) in a 
titanium housing was installed. This instrument has a chargeable NiMH-
battery for powering all the electronics in the frame, memory for storing 
the data and a programmemable Auto Firing Module which fires bottles at 
desired depths. The underwater-unit was a SBE9+ (S\N 790). Only a 
thermometer SBE3+ (S\N 032118), a conductivity-sensor SBE4 (S\N 043035) 
and an underwater-pump SBE5 (S\N 050882) were installed due to the 
limited power capacity of the battery. All pressure housings were made of 
titanium.

The UCC has a rectangular frame made of titanium, has wheels and can be 
parked in a clean-air container (de Baar et al., 2008). The container 
provides an ultraclean environment for sub-sampling.  Just prior to a 
cast it can be pushed out of the container on a dedicated pallet. This 
pallet can be moved over deck to the CTD launching spot by using a long 
forklift. After the cast this procedure is reversed.

The software package 'SeatermAF-V2' contains all the functions needed for 
programming and testing of the SBE17. It also provides a function for 
downloading of the CTD-data after a cast. The CTD-data can be processed 
in the usual way using the package 'SBEDataprocessing'.

During the start-up phase we had to overcome a wide variety of problems, 
but after that everything worked fine. An overview of the problems can be 
found in UCC-station-list in de column 'Remarks' of Table 6.3.1. 


Tab. 6.3.1: The UCC station list

Sta.  Cast   Scans    Remarks
            averaged
————  ————  ————————  ———————————————————————————————————————————————————
  4     2     n/a     OK, all bottles closed, but data appeared to be 
                      unreadable.
  4     6     n/a     Failed (Diagnosis: 'Faulty memory-blocks'). 
                      Former cast had the same problem, but this became 
                      only clear after this cast.
  8     2     n/a     First 3 bottles closed, no water-sampling was done, 
                      reason initially unclear, but this became clear 
                      after the next cast.
 30     1     n/a     Failed, due to bad Multivalve-cable. Exchanged by 
                      spare.
 32     4      1      OK, downloading data took 9 hours at highest 
                      speed!, back to default-value 24
 40     2     n/a     Multivalve-main-chip appeared to have corroded 
                      contacts
 50     3     24      OK
 54     3     24      OK, Bottles 22, 23 and 24 open due to a leaking 
                      main-tube of the hydraulics.
 58     7     24      OK
 64     2     24      OK
 69     2     24      OK
 70     4     24      OK
 76     2     n/a     Failed, due to a memory-problem of SBE17 (not 
                      recognized) and a minor problem with Multivalve 
                      (recognized and solved)
 81     1     n/a     Failed, due to a memory-problem of SBE17. This 
                      problem coincided with the problems of the 
                      Multivalve during the former cast.
 81     4     n/a     OK, surface-cast for M. Staubwasser. He didn't want 
                      the CTD data, so no data.
 81    10     24      OK
 87     1     24      OK, Northpole !
 91     2     24      OK
 96     4     24      OK
 99     1     24      OK
 99     3     24      OK
101     4     24      OK
101     8     24      OK
117     3     24      OK
119     1      4      OK
121     2      4      OK
125     4     24      OK
130     2     24      OK
134     2     24      OK
147     2      4      OK
149     2      4      OK
153     2      4      OK
157     2      4      OK
161     2      4      OK
169     3      4      OK
173     2      4      OK   


Preliminary/expected results

Fig. 6.3.1 shows the stations that were successfully sampled with the 
ultraclean CTD sampler system. A total of 28 stations were sampled with 
success resulting in the availability of roughly 16,200 Liters of trace 
metal clean seawater available for sampling for different parameters.


Fig. 6.3.1:  Station map of successful UCC casts


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

de Baar HJW, Timmermans KR, Laan P, De Porto HH, Ober S, Blom JJ, Bakker 
    MC, Schilling J, Sarthou G, Smit MG, Klunder M (2008) Titan: A new 
    facility for ultraclean sampling of trace elements and isotopes in 
    the deep oceans in the international Geotraces program. Mar. Chem., 
    111, 4-21.

Rijkenberg MJA, de Baar HJW, Bakker K, Gerringa LJA, Keijzer E, Laan M, 
    Laan P, Middag R, Ober S, van Ooijen J, Ossebaar S, van Weerlee EM, 
    Smit MG (2015) "PRISTINE" a new high volume sampler for ultraclean 
    sampling of trace metals and isotopes. Mar. Chem., in press.



6.4  Dissolved Fe, Mn, Zn, Ni, Cu, Cd, Pb

     Micha Rijkenberg                           NIOZ
 

Objectives

The Arctic Ocean is rapidly changing due to recent global warming (IPCC 
report 2013). Arctic sea ice declines and exists now mostly of first-year 
sea ice (Haas et al., 2008; Stroeve et al., 2011; Maslanik et al., 2011) 
enabling future economic activities. Warming of Arctic terrestrial areas 
caused increased river discharge which, combined with net loss of the 
Greenland ice-cap and melting of sea ice, resulted in a freshening of 
surface waters and increased stratification. We need to understand how 
climate induced changes will change the biogeochemical cycling and 
therefore the still unknown distribution of many bio-essential and 
pollutant trace metals in the Arctic to understand the consequences for 
the Arctic marine ecosystems. As the Arctic Ocean is part of the 
thermohaline circulation changes in the Arctic will also affect the 
distribution of trace metals in the global oceans (Gerringa et al., 
2015). We are now able to precisely analyze a suite of bio-essential 
trace metal elements Mn, Fe, Co, Ni, Cu, Zn, Cd and the mostly 
anthropogenic potentially toxic trace metals Pb and at high 
concentrations Cu and Zn. This allows us to compare library samples from 
the central Arctic expedition in 2007 (Klunder et al., 2012a, 2012b; 
Middag et al., 2011; Thurczy et al., 2011) with samples of Canadian, US 
and European research cruises in 2015 as well as an expedition to Fram 
Strait (2016) aimed to quantify the exchange of trace metals between the 
Arctic and Atlantic Oceans. The data collected in this project as part of 
the pan-Arctic GEOTRACES effort will also provide a first-ever baseline 
of the pollutant-type metals useful to assess the impact of future 
commercial activities in the Arctic.


Work at sea

At 28 stations, a total of 559 samples for the measurement of dissolved 
trace metals (250 ml, 0.2 µm filtered) and about 280 samples for the 
measurement of total dissolvable trace metals (unfiltered and acidified 
for a period of at least 6 months) were taken from the ultraclean CTD 
sampler system (de Baar et al., 2008; Rijkenberg et al., in press). The 
samples of dissolved trace metals were filtered using the 0.2 Mm 
Sartobran 300 cartridges of Sartorius. The dissolved and total 
dissolvable trace metal samples were acidified with 2ml/L 12M Baseline 
grade Seastar HCl (final pH of 1.8). At NIOZ, the trace metals will be 
extracted from the seawater samples using a seafast system (Lagerstrm et 
al., 2013) and measured by a Thermo Element-II single collector HR-ICP-
MS.

A total of 559 samples were measured on board for their dissolved iron 
(DFe) concentration by automated Flow Injection Analysis (FIA) after a 
modified method of De Jong et al., 1998. Filtered (0.2 µm) and acidified 
(pH 1.8, 2ml/L 12M Baseline grade Seastar HCl) seawater was concentrated 
on a column containing aminodiacetid acid (IDA). This material binds only 
transition metals and not the interfering salts. After washing the column 
with ultrapure water, the column is eluted with diluted hydrochloric 
acid. After mixing with luminol, peroxide and ammonium, the oxidation of 
luminol with peroxide is catalysed by iron and a blue light is produced 
and detected with a photon counter. The amount of iron is calculated 
using a standard calibration line, where a known amount of iron is added 
to low iron containing seawater. Using this calibration line a number of 
counts per nM iron is obtained. Samples were analysed in triplicate and 
average DFe concentrations and standard deviation are given. 

Concentrations of DFe measured during the PS94 cruise ranged from 20 pM 
in the surface of the Nansen basin up to 12.5 nM in a nepheloid layer 
near Svalbard along our Bear Island transect. 

The standard deviation varied between 0% and 37% (the latter being 
exceptional), but was on average 2.9% and generally < 5% in samples with 
DFe concentrations higher than 0.1 nM. The average system blank was 
determined at 0.017 nM 0.02 nM and was defined as a sample loaded for 5 
seconds and measured daily. The average limit of detection was determined 
at 0.06 nM and was defined as 3*standard deviation of the mean blank as 
measured daily. The consistency of the FIA system over the course of the 
day was verified using a drift standard. Drift has been observed and 
seemed to be variable from day to day. All data will be corrected for 
this daily drift. Certified SAFe and GEOTRACES standards (Johnson et al., 
2007) for the long term consistency and absolute accuracy was measured on 
a regular basis.


Preliminary/expected results

As an example of the data collected we present here the depth profile of 
DFe as measured at the North Pole, Fig. 5.4.1. The higher surface 
concentrations of DFe were found in the transpolar drift.


Fig. 5.4.1:  Depth profile of DFe at the North Pole


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

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Gerringa LJA, Rijkenberg, MJA, Schoemann V, Laan P, de Baar HJW (2015) 
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de Jong JTM, den Das J, Bathmann U, Stoll MHC, Kattner G, Nolting RF, de 
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6.5  Organic speciation of Fe

     Hans Slagter, Loes Gerringa, Micha Rijkenberg     NIOZ
 

Outline

Iron is a biologically essential element which is limiting primary 
production in many ocean areas (de Baar et al., 1990; Martin et al., 
1990) and dissolves poorly in seawater. Iron's inorganic solubility in 
seawater of pH 8.1 is between 0.1 and 0.2 nM (Millero et al., 1998) and 
concentrations found above this are recognized to be bound to dissolved 
organic ligands (Gledhill and van den Berg, 1994; Liu and Millero, 2002). 
Many different substances are recognized to bind Iron, making up a pool 
of ligands. However, the relative contributions and interactions at play 
in this ligand pool are still poorly characterized. Work on the 
characterization of this ligand pool is ongoing, employing different 
techniques to identify its constituents (Gledhill and Buck, 2012). 
Examples are different approaches to Competing Ligand Exchange 
РAdsorptive Stripping Voltammetry (CLE-AdCSV) (Rue and Bruland, 1995; 
Croot and Johansson, 2000; van den Berg, 2006), characterization using 
mass-spectrometric methods (McCormack et al., 2003; Mawji et al., 2011; 
Velasquez et al., 2011) and detection and characterization of specific 
functional groups using chemical assays (Macrellis et al., 2001).

Possible contributions to the ligand pool are made by biological 
processes, e.g. bacteria producing siderophores (Haygood et al., 1993) 
and phytoplankton producing exudates such as polysaccharides (Hassler et 
al., 2011). Marine viruses lyse both marine bacteria and phytoplankton, 
releasing cell content and contributing to the dissolved and particulate 
matter pools (Brussaard et al., 2008), also releasing ligands as part of 
these processes (Poorvin et al., 2011). Humic substances (HS) are part of 
the dissolved organic matter (DOM) in seawater with a terrestrial and/or 
riverine origin and are important contributors to the ligand pool in 
estuarine areas (Laglera and van den Berg, 2009). Not much is currently 
known about the composition of the ligand pool in the Arctic Ocean. As 
the Arctic Ocean is a mediterranean sea with major terrestrial inputs, 
the relative contribution to the ligand pool of riverine input is 
expected to be large. The only thorough measurement of organic ligands in 
the Arctic Ocean has been performed during the International Polar Year 
2007 by Thuroczy et al., (2011). This study inventoried organic ligands 
with full depth profiles in the Nansen, Amundsen and Makarov basins. A 
major interest to us on the PS94 TransArcII expedition is the crossing of 
the transpolar drift (TPD), which transports riverine water from the 
Siberian shelf areas and thus the major Arctic rivers within the 
halocline across the arctic basins. The TPD eventually transports these 
waters into the Norwegian Greenland seas through Fram strait (Gordienko 
and Laktionov, 1969; Rudels, 2009; Rutgers van der Loeff et al., 2012) 
and thus transports these riverine fractions eventually into the northern 
North Atlantic. The TPD's drift trajectory changes with the Arctic 
Oscillation (AO) index, shifting further northward towards the Beaufort 
gyre in AO- conditions, and can be traced in a number of ways. Stable 
oxygen isotope analysis (δ18O) indicates the influence of meteoric 
waters that consists mainly of terrestrial runoff introduced into the 
surface waters and transported in the TPD (Bauch et al., 2011). Rutgers 
van der Loeff et al., (2012) were able to infer transfer times of shelf 
waters through 228Th and 228Ra signatures of about 1 to 3 years. Finally 
the TPD may also be identified by the presence of terrestrially sourced 
coloured- or chromophoric DOM (CDOM). CDOM has its origin in the 
breakdown of biological material, with terrestrial and marine sources 
being major contributors (Nelson and Siegel, 2012). In the open ocean the 
signal from marine sources dominates the CDOM pool, however in the TPD in 
which the CDOM pool has a strong terrestrial origin, the terrestrial 
signal dominates (Stedmon et al., 2011; Granskog et al., 2012). CDOM is a 
heterogeneous mix of organic material, some characterization of which is 
possible by the measurement of its absorptive properties (Mopper and 
Schultz, 1993; Stedmon and Markager, 2001), as well as through detailed 
measurement of its fluorescent subset (FDOM) (Stedmon and Markager, 
2005). Humic substances are represented in the CDOM pool as 'gelbstoff', 
with a distinct fluorescence signal (Coble et al., 1990; Mopper and 
Schultz, 1993). This fluorescence signal is also easily measured using an 
in-situ fluorometer mounted on a CTD rosette frame.


Objectives

Crossing into the TPD and its higher terrestrial runoff component, we 
hope to elucidate different contributors to the ligand pool by a 
combination of techniques. Electrochemical measurements were performed to 
ascertain total iron ligand concentrations and binding strengths. Humic 
substances will also be measured electrochemically using fulvic acid as a 
standard. Furthermore, absorbance and fluorescence spectra will be 
measured as an indicator of terrestrial water and humic substances. Given 
the documented influence of biological activity on the organic ligand 
pool, we wish to decouple the contribution of humic substances to the 
iron binding ligand pool from more local biological production of iron 
binding ligands. Therefore, samples were collected for flowcytometric 
enumeration of phytoplankton, bacteria and viruses in the home lab.


Work at sea

Stations sampled

All samples were taken from the Ultra Clean sampling system (UCC). Fe 
Ligands samples were measured on board electrochemically, CDOM samples 
were measured on board spectrophotometrically. Samples will be analysed 
by flow cytometry in the home lab, and samples to measure humics were 
taken for Dr. Luis Laglera (UIB).


Tab. 6.5.1: Overview of stations and samples for analysis of organic 
            speciation of Fe

  Station  Cast  # bottles  Properties to be measured
  ———————  ————  —————————  ————————————————————————————————————————
      4      2        8     Fe Ligands, CDOM, flow cytometry, humics
     32      2       14     Fe Ligands, CDOM, flow cytometry, humics
     40      2        3     Fe Ligands
     50      2       13     Fe Ligands, CDOM, flow cytometry
     64      2       10     Fe Ligands, CDOM, flow cytometry
     69      2       14     Fe Ligands, CDOM, flow cytometry, humics
     70      4        2     Fe Ligands
     81     10       14     Fe Ligands, CDOM, flow cytometry, humics
     87      1       14     Fe Ligands, CDOM, flow cytometry, humics
     91      2        8     Fe Ligands, CDOM, flow cytometry, humics
     96      4       13     Fe Ligands, CDOM, flow cytometry, humics
     99      3       14     Fe Ligands, CDOM, flow cytometry, humics
    101      4       13     Fe Ligands, CDOM, flow cytometry
    117      3       14     Fe Ligands, CDOM, flow cytometry, humics
    119      1        8     Fe Ligands, CDOM, flow cytometry
    121      2        8     Fe Ligands, CDOM, flow cytometry, humics
    125      3       14     Fe Ligands, CDOM, flow cytometry, humics
    130      2        8     Fe Ligands, CDOM, flow cytometry, humics
    134      2       12     Fe Ligands, CDOM, flow cytometry, humics   


Iron binding dissolved organic ligands

The concentration and binding strengths of organic iron binding ligands 
is measured using CLE-AdSV. A known ligand is added to a natural sample, 
which is allowed to equilibrate with increasing iron additions in 
discrete subsamples, constituting a titration with iron. The added ligand 
(AL) is in competition for iron with the natural ligands in the sample. 
As it is added in surplus, the natural ligands will be saturated with 
iron in the higher additions of the titration, whereas the AL will 
continue to take up iron. After equilibration the subsamples are measured 
from low to high additions with a voltammetric scan. The current peak 
recorded is equivalent to the concentration of the iron - AL complex.

0.02 M AL stock solutions were made using 2-(2-Thiazolylazo)-p-cresol 
(TAC) after Croot and Johansson (2000). AL are dissolved in 2 times 
quartz distilled (2QD) methanol. A borate-ammonia buffer was used to 
maintain pH in treated samples during voltammetric scans. The buffer was 
adjusted to keep the pH at 8.05 in a titration subsample consisting of 
seawater, buffer and Fe standard addition. Buffers were prepared at the 
home lab, where they were cleaned of trace metal contaminations using 
equilibration with MnO2 particles after van den Berg and Kramer (1979). 

The voltammetric setup consists of a Metrohm 663 VA stand, control 
hardware (Metrohm Autolab II and IME 663) and a consumer laptop PC 
running Metrohm Autolab's Nova 1.9 as well as GPES 4.9. The VA stand is 
equipped with a Teflon measuring cell containing a Hg drop multimode 
electrode (Metrohm); a reference electrode (double-junction, Ag/AgCl, 3 M 
KCl, Metrohm), an auxiliary electrode (glassy carbon, Metrohm) and a 
Teflon stirrer. The system was connected to an N2 line for purging and Hg 
drop formation pressure. Laminar flow cabinets were used to maintain 
trace metal clean conditions for sample manipulations (Interflow) and 
sample preparation (AirClean systems).

TAC was added to a final concentration of 10 M. The dropsize of the 
mercury drop on the 663 VA stand was set to 1 (smallest). The samples 
were purged for 180 seconds. Deposition lasted for 140 seconds at -0.4 V. 
The sample was left to rest for 5 seconds followed by a differential 
pulse scan from -0.4 to -0.9 V, step size 0.002 V. In order to adjust for 
vibrations equipment was first moved to a less affected location (from 
trockenlabor I to the chemielabor further forward in the ship). 
Subsequently the scan rate of the measurement protocol was increased to 
further minimize the effect of vibration to a point where a sufficiently 
low concentration of the Fe-TAC complex could be discerned. Final scan 
rate was 39 mV s-1, from an interval of 0.05 s, with a modulation of 
0.004 s.

Scan current peaks were manually measured using Nova software. The 
dissolved Fe concentration, as measured on board by dr. Micha Rijkenberg 
using Flow Injection Analysis (FIA), is added to the Fe additions and 
data is parsed into an R script (Micha Rijkenberg) for non-linear 
regression to the Langmuir isotherm (Gerringa et al., 2014) yielding 
natural ligand concentrations and binding strengths.


Humic substances

Humic substances were measured from their complexation with iron through 
cathodic stripping voltammetry (CSV) in the presence of an oxidizer. In 
this method an oxidizer increases the current signal of the dissociating 
iron-humic complex at the electrode, making the signal discernible from 
the system's baseline (Laglera et al., 2007). Samples were buffered by the 
same borate buffer solution used in CLE-AdSV above and humic substances 
were saturated with iron by adding 30 nM from a 3 µM acidified dilution 
of an ISP standard (Fluka). Potassium bromate was used as an oxidizer to 
enhance the reduction peak of the complexed iron, added in a 
concentration of 0.013 M. A fulvic acid standard (Suwannee River Fulvic 
Acid Standard I, International Humic Substances Society (IHSS), St. Paul, 
USA) was used to verify and quantify the presence of humic substances by 
a series standard additions to every sample in a range of 0.1 to 0.4 
mg/L. The in-situ CDOM fluorometer on the CTD rosette frame (dr. Haardt), 
casts of which generally preceded UCC casts, was employed to target a 
sample at the depth of the CDOM maximum. A humic acid standard (Suwannee 
River Humic Acid Standard II, IHSS) was also used as a calibration 
reference for this fluorometer by dr. Heather Reader. 


Spectrophotometry

Chromophoric dissolved organic matter (CDOM) was analysed 
spectrophotometrically after Mopper and Schultz (1993). Depths were 
specifically chosen in parallel to ligand and humic measurements from UCC 
samples in coordination with dr. Heather Reader's CDOM and DOC sampling 
from the normal CTD rosette sampler, also taking CDOM fluorescence from 
the rosette fluorometer into account.

Absorbance spectra were recorded between 200 and 1,000 nm, and 
fluorescent emission spectra were recorded between 360 and 540 nm at an 
excitation wavelength of 250 nm. Samples were measured in a quartz cell 
with a path length of 1cm (Suprasil, Hellma Analytics) using a SpectraMax 
M2 mutimode spectrophotometer (Molecular Devices). Daily measurements of 
a 0.2 mg ᠌-1 quinine sulphate standard dissolved in MQ were made as an 
equivalent reference for the expression of CDOM fluorescence 
measurements.


Preliminary results

A start was made with the analysis of data on board, and offered here is 
the preliminary data for total iron binding ligand concentration (LT) and 
its ratio to dissolved iron as measured in the ligand sample bottles 
(dFe.FeL) for the full depth station on the North Pole (station 87, Figs.  
6.5.1a and 6.5.1b). High concentrations of dFe and LT are observed, 
clearly showing the influence of the TPD in the upper 150 m. The ratio of 
LT over dFe, the amount of excess ligands available for iron to bind to, 
decreases to <1 at the very surface. This means that an excess Fe over 
the ligands exists. An excess of Fe over the solubility product (between 
0.1 and 0.2 nM) is unlikely as this should precipitate (Millero et al., 
1998). The excess iron may also be present in colloidal form, or bound 
irreversible to unknown complexes. Another possibility is that TAC 
underestimates the concentration of LT in the presence of humic 
substances (Laglera et al., 2011). This possibility will be further 
explored in the home lab using a different AL (Abualhaija and van den 
Berg, 2014).

CDOM fluorescence measurements (Fig. 6.5.1c ) at this station, here 
preliminarily expressed in arbitrary units (a.u.), also show the same 
surface increase indicative of the TPD. An unexpected high value for LT 
is observed at 2,000 m (Fig 6.5.1a). While this can be due to the 
preliminary character of this data, an increase at this depth is 
replicated in CDOM fluorescence (Fig. 6.5.1c).

Measurement of humic substances clearly shows a presence of humic 
substances as a defined peak at and around the CDOM max, whereas deep 
samples do not (not illustrated). This further solidifies our belief that 
this station is well within the TPD, where the influence of terrestrial 
water is greatest.


Fig. 6.5.1: Dissolved iron measured from ligand sample bottles (dFe.FeL), 
            total ligand concentration (LT) and the ratio of LT and dFe 
            for the entire depth profile (a) and for the upper 200 m (b). 
            CDOM fluorescence for the entire depth profile and the upper 
            500 m (c).


Acknowledgements

We are most grateful to Captain Schwarze and the crew of Polarstern. We 
are especially thankful to the firm and gentle leadership of chief 
scientist Ursula Schauer. We are also indebted to Aridane Gonzalez, Lars-
Eric Heimbrger and Michael Staubwasser for their efforts as part of the 
UCC sampling team, as well as Sven Ober for operation and maintenance of 
the UCC system.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


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6.6  Organic speciation of copper

     Aridane G. Gonzales                               IUEM
     G. Sarthou(1) (not on board) 
     L.G. Anderson(2), H.J.W. de Baar(1) (not on board)
 
 
Objective

The community structure of phytoplankton in the open ocean can only be 
understood with enough information on the distribution and speciation of 
trace metals (Sunda, 1994, 2012). In the case of copper (Cu), its study 
in natural waters is essential because it is a required element for the 
respiratory proteins and oxidases (Baron et al., 1995), but Cu is also 
toxic according to the free copper concentration and not the total Cu 
levels (Anderson and Morel, 1978; Sunda and Lewis, 1978).

Cu can be supplied to surface seawater by different pathways such as 
atmospheric deposition, resuspension material from sediments, diffusion, 
upwelling and hydrothermal vents. In addition, the exact magnitudes of 
these sources are not exactly known. In this sense, we have also to 
consider the anthropogenic sources of Cu to the ocean via aerosol 
depositions (Jordi et al., 2012) or anti-fouling paint for marine ships 
(Karlsson et al., 2010). The understanding of Cu chemistry is also 
relevant because thermodynamically Cu(II) is favored in seawater, where 
more than 90% is organically complexed with ligands mostly produced 
biologically (Coale and Bruland, 1988; Croot et al., 2000; Moffett et 
al., 1990; van den Berg, 1984, 1987). These ligands have been commonly 
ranked according to their conditional stability constants, as strong 
ligands (L1) with a conditional stability constant of about 1012.5 and 
weaker ligands (L2) from 1010-12.5. The concentration of copper ligands 
in the Arctic can come from the river inputs, both Canadian and Russian. 
In addition, the Transpolar Drift can transport high level of dissolved 
organic matter through the Arctic Ocean that is directly affecting to the 
Cu organic speciation.

In this work, we examine both distribution and speciation of dissolved 
copper along 6 transects across the Arctic Ocean (North Pole included). 
This work is conducted in the framework of the GEOTRACES programme 
(www.geotraces.org).


Work at sea

The samples were always collected in the ultra clean CTD system from 
NIOZ, filtered over a 0.2 µm filter size using N2 overpressure. In 
addition, ice-rafted sediment samples were collected in two different 
locations, which will be used to measure the concentration of copper 
ligands. Ice-cores and seawater in the ice-stations were also collected 
to determine the copper ligand capacity and the diffusion of ligands to 
the surface seawater from the ice cover.


Expected results

The samples will be analyzed in a clean laboratory facilities in Brest 
(LEMAR-IUEM). Dissolved Cu concentrations and the dissolved Cu titrations 
will be carried out by using the voltammetric method of Campos and van 
den Berg (1994) using the artificial ligand Salicylaldoxime (SA). For 
each station we collected 12 samples from the water column and several 
replicates. The data collected during the analysis will be treated by a 
non-linear optimization of a Langmuir isotherm (Guerringa et al., 1995). 
Copper speciation will be performed via competitive ligand 
exchange/cathodic stripping voltammetry (CLE-CSV) measurements in a 
Autolab connected to a Metrohm VA 663 voltammeter used in the static 
mercury drop electrode mode. Each sample is divided in 10 mL aliquots in 
25 mL Teflon bottles, buffered with 200 L of 1 M solution (final 
concentration 0.01 M) of 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic 
acid (EPPS). After, Cu is added with a range of different concentrations 
from 0-90 nM. After one hour SA is added to a final concentration of 1-2 
M (the detection window will be selected before analysis) and keeping at 
least 6 h of equilibrium time (Campos and van den Berg, 1994). The method 
is deposition and initial potential of -0.15 V, deposition time of 60 s, 
modulation time of 0.01 s, interval time of 0.1 s, final potential of 
-0.9 V, modulation amplitude of 50 mV, and scan speed of 20 mV/s (Campos 
and van den Berg, 1994). To determine ligand concentration and 
conditional stability constant data from Cu titrations, the fraction of 
Cu present as the Cu(SA)2 complex at each point on the titration curve 
must be known. Therefore, the system must be calibrated accurately so 
that [Cu(SA)2] can be calculated from the peak current signal generated 
by the cathodic scan.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Anderson DM, Morel FMM (1978) Copper sensitivity of Gonyaulaxtamarensis. 
    Limnol. Oceanogr., 23, 283-295

Baron M, Arellano JB, Gorge JL (1995) Copper and photosystem-II - a 
    controversial relationship. Physiol. Plant., 94 (1), 174-180.

Campos MLAM, van den Berg CMG (1994) Determination of copper complexation 
    in sea water by cathodic stripping voltammetry and ligand competition 
    with salicylaldoxime. Anal. Chim. Acta., 284, 481-496.

Coale KH, Bruland KW (1990) Spatial and temporal variability in copper 
    complexation in the North Pacific. Deep-Sea Res. A Oceanogr. Res. 
    Pap., 37 (2), 317-336.

Croot PL, Moffett JW, Brand L (2000) Production of extracellular Cu 
    complexing ligands by eucaryotic phytoplankton in response to Cu 
    stress. Limnol. Oceanogr., 45, 619-627.

Gerringa LJA, Herman PMJ, Poortvliet TCW (1995) Comparison of the linear 
    van den Berg/Ruzic transformation and a non-linear fit of the 
    Langmuir isotherm applied to Cu speciation data in the estuarine 
    environment. Mar. Chem., 48, 131-142.

Jordi A, Basterretxea G, Tovar-Sánchez A, Alastuey A, Querol X (2012) 
    Copper aerosols inhibit phytoplankton growth in the Mediterranean 
    Sea. Proc. Natl. Acad. Sci., 109 (52), 21246-21249.

Karlsson J, Ytreberg E, Eklund B (2010) Toxicity of anti-fouling paints 
    for use on ships and leisure boats to non-target organisms 
    representing three trophic levels. Environ. Pollut., 158 (3), 681-
    687.

Moffett JW, Zika RG, Brand LE (1990) Distribution and potential sources 
    and sinks of copper chelators in the Sargasso Sea. Deep-Sea Res., 37,
    27-36.

Sunda WG (1994) Trace metal/phytoplankton interactions in the sea. In: 
    Bidoglio, G, Stumm, W (Eds.), Chemistry of Aquatic Systems: Local and 
    Global Perspectives. Kluwer Academic, Dordrecht, pp. 213-247.
    
Sunda WG, Lewis JAM (1978) Effect of complexation by natural organic 
    ligands on the toxicity of copper to a unicellular alga, 
    Monochrysislutheri. Limnol. Oceanogr., 23, 870-876.

Sunda W (2012) Feedback interactions between trace metal nutrients and 
    phytoplankton in the ocean. Front. Microbiol., 3.

van den Berg CMG (1984) Determination of the complexing capacity and 
    conditional stability constants of complexes of Cu(II) with natural 
    organic ligands in seawater by cathodic stripping voltammetry of 
    copperУatechol complex ions. Mar. Chem., 15, 1-18.

van den Berg CMG, Merks AGA, Duursma EK (1987) Organic complexation and 
    its control of dissolved concentrations of copper and zinc in the 
    Scheldt Estuary. Estuar. Coast. Shelf Sci., 24 (6), 785-797.



6.7  Mercury

     Lars Eric Heimbrger                        UB
 

Objectives

Mercury levels in Arctic biota are among the highest in aquatic 
ecosystems and impact the health of Arctic wildlife and human populations 
(AMAP 2011). The idea has taken hold that the Arctic is a global mercury 
sink and that its main entry route is via the atmosphere (AMAP 2011). A 
recent three-dimensional GEOS-Chem model run by Fisher et al., (2013) 
puts both ideas into question and argues that the Arctic Ocean is net 
source and boreal rivers to be the major input (Sonke and Heimbrger 
2012). Their findings shift current paradigms of the Arctic mercury 
research that has focused for the past 20 years on atmospheric phenomena 
and cycling (e.g. atmospheric mercury depletion events). It has been 
shown for the Arctic (Beattie et al., 2014) and for Antarctica (Cossa et 
al., 2011) that sea ice, in particular brine formation is a major player 
in polar Hg budgets. Yet, the Arctic Ocean itself remains undersampled. 
No central Arctic Ocean mercury profiles have been published thus far. 
This is why the following key questions remain to be answered:
	
• Is the Arctic Ocean a global sink or a source for mercury?

• What is the cause for the high mercury concentrations in Arctic marine 
  biota: anthropogenic Hg emissions or is that a "normal natural" 
  phenomenon?

• What is the impact of boreal rivers: how much of the dissolved and 
  particulate mercury is transported to the central Arctic Ocean?

• How much of the rapidly deposited mercury during atmospheric mercury 
  depletion events is re-emitted to the atmosphere and which portion of 
  it is bioavailable (bioamplified along the marine food chain)?

• What is the overall impact of warming climate to the Arctic Mercury 
  cycle? Will warming climate shift Hg's biogeochemical cycle and the 
  functioning of the Arctic ecosystems in a way that we should expect 
  even higher methylmercury levels in marine biota? Our few preliminary 
  results from the 2011 Polarstern Arctic cruise show that:

• Methylmercury concentrations in the Arctic Ocean are highest in the 
  marginal sea ice zone and just below the halocline (~200 m-depth)

• Methylmercury concentrations are among the highest observed (together 
  with the Mediterranean Sea (Heimbrger et al., 2010) and the Southern 
  Ocean (Cossa et al., 2011)) in the Global Ocean

• Total mercury concentrations of the Central Arctic Ocean are suggest 
  anthropogenic enrichments (Lamborg et al., 2014)


Work at sea

Seawater
	
• We sampled for mercury speciation in seawater at the 28 GEOTRACES UCC 
  stations. 

• Unfiltered total mercury (tHg) was determined on board on 572 samples 
  (typically 24 depths resolution, with the exception of the shallow 
  stations) following a method that we had developed for the 2011 
  TransArc cruise, and validated (Heimbrger et al., 2015).

Unfiltered total methylmercury was sampled at all stations (typically 12 
depths) following also a method that we had developed for the 2011 
TransArc cruise, and validated (Heimbrger et al., 2015). The 
acidification (HCl double-distilled, 0.4 % v:v) rapidly converted 
dimethylmercury into monomethylmercury. We will therefore measure total 
methylmercury as the sum of both. On selected stations we purged off 
dimethylmercury prior to acidification to determine, later on, 
monomethylmercury alone. At selected stations we attempted to sample for 
mercury stable isotopes. At this point we can communicate on the used 
method.


Zooplankton

The Zooplankton group provided samples from 12 stations. The samples 
consist in the pooled material from the multinet sampling. All samples 
were sieved to remove excess water and frozen (-20°C). The samples will 
be freeze-dried and analyzed via CVAAS for total particulate mercury 
(USEPA, 2007), and if the quantity allows for particulate total 
methylmercury as well as mercury stable isotopic signatures.


Sediment

The benthos group provided 12 sediment cores, 9 were subsampled from the 
large diameter multi-corer barrels into smaller ones (d = 9 cm), and 3 
were sliced on board into approximately 5 mm subsamples and stored in 
individual PE plastic bags. All samples were frozen (-20°C). The samples 
will be freeze-dried and analyzed via CVAAS for total particulate mercury 
(USEPA, 2007), and if the quantity allows for particulate total 
methylmercury as well as mercury stable isotopic signatures.


Suspended particles

Eva-Maria Noethig's group (Imke Peterson, Franz Schrter) sampled for 
suspended particles via filtration of about 10L seawater from the Niskin 
bottles from the classic CTD. They provided a total of 44 GFF filters (47 
mm) of various depths, mostly within the upper 200 m. The samples will be 
analyzed via CVAAS for total particulate mercury (USEPA, 2007), and if 
the quantity allows for particulate total methylmercury.

Viena Puigcorbe sampled for suspended particles via in situ pumps (McLane 
LV08). She provided a total of 17 QMA filters (142 mm) sampled at 50 and 
100 m-depth (see section 5.13). The samples will be analyzed via CVAAS 
for total particulate mercury (USEPA, 2007). The large filtered volume 
should allow measuring mercury stable isotope signatures as well.


Sea-ice

The sea ice biogeochemistry group provided ice cores for all ice 
stations. The cores were sliced on the ice into approximately 10 cm 
sections, melted on board and transferred into individual sample bottles 
for later determination of tHg and MeHg.


Expected results

Our results, and those of our Canadian and American counterparts, will 
largely contribute to the understanding of mercury in the arctic, and we 
may say that the Arctic Ocean is not undersampled anymore. The shipboard 
tHg indicate consistent surface enrichments, which is contrary to the 
global ocean.

Methylmercury in seawater will be measured early 2016. 


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Heimbürger LE, Sonke JE, Cossa D, Point D, Lagane C, Laffont L, Galfond 
    BT, Nicolaus M, Rabe B, van der Loeff MR (2015) Shallow methylmercury 
    production in the marginal sea ice zone of the central Arctic Ocean. 
    Sci. Rep. 5.USEPA (2007). Method, 7473.



6.8  Fe Isotopic composition

     Michael Staubwasser                        UNIK
 

Objectives

The objectives are: 1) To sample depth profiles across the Transpolar 
drift and the Siberian shelf to analyze the Fe isotope composition of 
dissolved Fe and particulate Fe and map the Fe isotope distribution in 
the Arctic Sea. 2) To trace a potential Fe-isotopic signature in the 
water column from sedimentary diagenetic Fe reflux and/or resuspension 
from shelf sediments. 3) To study the impact of isotopic exchange between 
dissolved Fe and particle surface-bound Fe on marine particles in order 
to clarify to what extend the isotopic composition of dissolved Fe can be 
considered conservative Рwhich is a requirement for using Fe isotopes as 
a source tracer.


Work at sea

Seawater samples were filtered (0.22 m) partly within the routine N2-
pressured sampling procedure used in the NIOZ Clean Container (2 L 
samples, see section 5.3), partly in a flow cabinet (4L) with a 
peristaltic pump. On-board measurements of filtered seawater performed by 
M. J.A. Rijkenberg yielded comparable results for both methods. Seawater 
samples were acidified (HCl, pH 2) and stored for on-shore mass 
spectrometry analysis. From the peristaltic pump filtration the filter 
discs were also stored. Four transects (1a, 2, 4, 6) were sampled during 
the cruise. Except for Transect 4 the entire water column was sampled at 
up to 12 depths. Additionally, a small number of samples from under-ice 
water, and from molten ice cores were taken for complementary analysis. 
Transect 2 comprises two sites from the Gakkel Ridge, a slow-spreading 
volcanic ridge, where during the cruise two hydrothermal plumes could be 
identified by their temperature anomalies in the CTD profiles. In 
addition an isotope exchange experiment was conducted with three 20 L 
samples of surface layer water from the Transpolar Drift. A 58Fe enriched 
spike (98 % purity) was added. Samples were filtered (0.22 µm) and ultra-
filtered (10 kDa) after 3 days and 3 weeks, respectively. A final set of 
samples will be filtered on-shore three weeks after the cruise. A large 
volume sample was also taken from bottom water with resuspended material 
Рaccording to transmissivity sensor data Рon the Barents Sea shelf for a 
similar experiment to be undertaken on-shore. 


Expected results

I expect to find a distinct isotopic signature for at least two of the 
three largest sources of Fe to the Arctic Seas, i.e. Fe from hydrothermal 
sources and Fe transported from the Arctic Russian rivers into the 
Transpolar Drift (Klunder et al., 2012a, 2012b). The third source 
Рresuspension along the continental slope Рcannot be addressed due to the 
withheld permission to sample the Laptev Sea shelf and slope within the 
Russian economic zone. I expect to detect an isotopic signature from the 
Gakkel Ridge plumes comparable to observations on the Atlantic Ocean mid-
ocean ridge, where a hydrothermal plume could be identified by its 
distinct negative δ56Fe signature compared to deep water in the rest of 
the ocean (Conway & John, 2014). Fe in the Transpolar Drift derived from 
Arctic rivers is likely to show a more complex isotopic signature. Given 
the large concentration in the range of an order of magnitude higher than 
expected from thermodynamic equilibrium of inorganic species (see section 
5.5), the principal source must be colloidal Fe discharged from the 
rivers. Organically bound colloidal Fe in Artic Rivers has a negative δ
56Fe signature, whereas hydroxide-bound Fe has a positive δ56Fe 
signature (Ingri et al. 2006). It is possible that the latter may 
proportionally increase in abundance if redox cycling occurs on the 
shelf. In this case, the isotopic signature will likely be altered due to 
the preferential removal of light isotopes during oxidative precipitation 
of sedimentary Fe in the water column (Staubwasser et al., 2013). Because 
open ocean δ56Fe profiles obtained so far indicate that dissolved Fe has 
a higher δ56Fe value than any of the major sources (Conway & John, 
2014), it is likely that dissolved and suspended Fe undergo isotopic 
exchange. The purpose of the Fe-spike enriched exchange experiment is to 
determine the equilibrium fractionation factor (if applicable) between 
dissolved, colloidal and particulate Fe. 


Data management

See chapter 5 for details on data management.


References

Conway TM, John SG (2014) Quantification of dissolved iron sources to the 
    North Atlantic Ocean. Nature, 511, 212-215.

Ingri J et al. (2006) Iron Isotope Fractionation in River Colloidal 
    Matter. Earth Plan. Sci. Lett., 245 792-798.

Klunder MB et al. (2012a) Dissolved iron in the Arctic shelf seas and 
    surface waters of the central Arctic Ocean: Impact of Arctic river 
    water and ice-melt. J. Geophys. Res., 117, C01027, 
    doi:10.1029/2011JC00713.

Klunder et al. (2012b) Dissolved iron in the Arctic Ocean: Important role 
    of hydrothermal sources, shelf input and scavenging removal. J. 
    Geophys. Res., 117, C04014, doi:10.1029/2011JC007135.

Staubwasser M et al. (2013) Isotope fractionation between dissolved and 
    suspended particulate Fe in the oxic and anoxic water column of the 
    Baltic Sea Biogeosciences, 10, 233-245.



6.9  Cd, Cr, and Pb isotopes

     S. Galer (not on board)	                   MPIM


Objectives

A Multi-Trace Metal Isotope Study of the Arctic Ocean - Cycling and 
isotope fractionation of Cd, Cr and Pb in the Arctic Ocean

Recent studies have documented that the Cd isotopic composition of 
seawater exhibits mass-dependent isotope fractionation, thought to be due 
to uptake of Cd by phytoplankton (Ripperger et al., 2007; Abouchami et 
al., 2011, 2014; Gault-Ringold et al., 2012; Yang et al., 2012; Xue et 
al., 2013; Conway and John, 2015). Our Cd isotope data from the Southern 
Ocean, Northwest Atlantic and Southwest Atlantic have shown that Cd 
isotopic variations in cadmium-depleted surface waters track changes in 
biological productivity while deeper waters show relatively uniform 
isotopic compositions, although Cd concentrations increase along the 
great conveyor (Abouchami et al., 2011, 2014; Xie et al., 2013; Janssen 
et al., 2014). By contrast, the few Cd isotope data available for the 
Arctic Ocean show limited isotopic fractionation in the surface layer 
compared to deeper waters, despite being cadmium depleted (Ripperger et 
al., 2007).

Our objective is to investigate, in detail, the stable Cd isotope 
fractionation in the Arctic Ocean by acquiring concentration and isotope 
data at high resolution along the cruise track and in the water column.  
Surface waters and several depth profiles at key stations allow us to 
assess the degree of isotope variability associated with contributions 
from various sources - river runoff, precipitation, evaporation, sea ice 
and exchanges with the North Pacific and Atlantic Basins - to the Arctic 
Ocean's freshwater budget. 

Chromium (Cr), in contrast to Cd, is a redox sensitive element - with two 
oxidation states Cr(VI) and Cr(III) - whose isotopic fractionation has up 
until now mainly been used to trace the oxygenation levels of the past 
oceans (Frei et al., 2009). In oxic seawater, Cr(VI) is highly soluble 
while Cr(III) is particle reactive and forms insoluble (oxy-)hydroxide 
compounds. Chromium concentration data are abundant and are at nanomolar 
levels in seawater (1-7 nM), but Cr isotope data are restricted to a 
single profile (5 samples) in the Argentine Basin and show isotopically 
"heavier" chromium than average continental crust (Bonnand et al., 2013). 
Our aim is to obtain the first measurements of the Cr isotopic 
composition of Arctic seawater and establish a mass balance of the Cr 
budget for sources to the Arctic Ocean.

Lead isotope measurements will be performed to document the distribution 
and cycling of Pb in the water column, identify anthropogenic (shallow) 
and natural (deep) sources of Pb in the Arctic Ocean Basin, and assess 
ventilation rates and mixing in the surface gyres. Important goals are to 
investigate the extent of downward penetration of anthropogenic lead in 
the thermocline, particle reactive behaviour in the shelf regions, and 
evaluate the influence of hydrothermal lead inputs in the deeper Arctic 
Ocean near to the Gakkel Ridge.


Work at sea

Five full vertical profiles were taken, distributed along the cruise 
track, at Stations 4, 50, 81 and 101, covering most of the Arctic Basin, 
and Station 161 on the continental shelf between Norway and Spitzbergen. 
In addition, a surface transect was sampled between Stations 117-134 in 
the eastern Artic sector. Each profile consists of 8 to 11 depths, 
collected on board using the Ultraclean Titan frame (de Baar et al., 
2008) by our NIOZ colleagues. Seawater volumes varied between 20 L for 
surface waters, 4 L for intermediate depth and 1 L for deep waters. The 
samples were filtered into double-bagged, polyethylene bottles and 
canisters (acid cleaned in Mainz prior to the cruise) and acidified to pH 
of 2 using ultra-clean Seastar HCl (low level Cd blank). The returned 
samples will be analysed in the clean-room laboratories of the Max Planck 
Institute for Chemistry in Mainz (Germany) by thermal ionization mass 
spectrometry (TIMS) using proven double-spike technology already 
established for Pb, Cd and Cr isotopes.


Expected results

The isotope and concentration data, combined with historical data, may 
shed light on the effect of the increase of the Arctic Ocean's freshwater 
content over the past few decades, predominantly in the west, on the 
trace metal budget of the Arctic Ocean.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Abouchami W, Galer SJG., de Baar HJW, Alderkamp AC, Middag R, Laan P, 
    Feldmann H, Andreae MO (2011) Modulation of the Southern Ocean 
    cadmium isotope signature by ocean circulation and primary 
    productivity.  Earth Planet. Sci. Lett., 305, 83-91.

Abouchami W, Galer SJG, de Baar HJW, Middag R, Vance D, Zhao Y, Klunder 
    M, Mezger K, Feldmann H, Andreae MO (2014) Biogeochemical cycling of 
    cadmium isotopes in the Southern Ocean along the Zero Meridian. 
    Geochim. Cosmochim. Acta, 127, 348-367.

Bonnand et al. (2013) The chromium isotopic composition of seawater and 
    marine carbonates. Earth Planet. Sci. Lett. 382, 10-20.

Conway TM, John SG (2015) Biogeochemical cycling of cadmium isotopes 
    along a high-resolution section through the North Atlantic Ocean. 
    Geochim. Cosmochim. Acta, 148, 269-283.

De Baar HJ et al. (2008) Titan: A new facility for ultraclean sampling of 
    trace elements and isotopes in the deep oceans in the international 
    Geotraces program. Mar. Chem., 11, 4-21.

Frei R, Gaucher C, Poulton SW, Canfield DE (2009) Fluctuations in 
    Precambrian atmospheric oxygenation recorded by chromium isotopes. 
    Nature, 461, 250-253.

Galer SJG, Abouchami W, Xie RC, Janssen DJ, Rickenberg M, Gerringa L, 
    Cullen JT, de Baar HJW (2014) Global oceanic cadmium isotope 
    distribution. Goldschmidt Conference, Sacramento.

Gault-Ringold M, Adu T, Stirling CH, Frew RD, Hunter KA (2012) Anomalous 
    biogeochemical behavior of cadmium in subantarctic surface waters: 
    mechanistic constraints from cadmium isotopes. Earth Planet. Sci. 
    Lett., 341-344, 94-103.

Janssen DJ et al. (2014) Undocumented water column sink for cadmium in 
    open ocean oxygen-deficient zones. Proceedings of the National 
    Academy of Sciences, 11, 6888-6893.

Janssen DJ, Cullen JT, Abouchami W, Galer SJG, de Baar HJW (2014) Cadmium 
    Isotopes along the Line-P transect in the Northeast Subarctic 
    Pacific. Goldschmidt Conference, Sacramento.

Ripperger S, Rehkämper M, Porcelli D, Halliday AN (2007) Cadmium isotope 
    fractionation in seawater Рa signature of biological activity. Earth 
    Planet. Sci. Lett., 261, 670-684.

Xue Z, Rehkämper M, Horner TJ, Abouchami W, Middag R, van de Flierdt T, 
    de Baar HJW (2013) Cadmium isotope fractionation in the Southern 
    Ocean. Earth Planet. Sci. Lett., 382, 161-172.

Xie RC, Galer SJG, Abouchami W, Rijkenberg M, de Jong J (2014) Cadmium 
    isotope distribution along the western boundary of the South 
    Atlantic. Ocean Sciences Meeting, Honolulu.

Yang SC, Lee DC, Ho TY (2012) The isotopic composition of cadmium in the 
    water column of the South China Sea. Geochim. Cosmochim. Acta, 98, 
    66-77.



6.10  Particulate trace metals

      Aridane G. Gonzalez                       IUEM
      H. Planquette (not on board)

 
Objective

The main sources of particulate trace metal to the ocean are the 
atmospheric deposition (Jickells et al., 2005; Sarthou et al., 2003; 
Mahowald et al., 2009), rivers (Lam et al., 2006; 2012), hydrothermal 
(Tagliabue et al., 2010), sediments (Kalnejais et al., 2007), ice and 
sea-ice (Raiswell et al., 2008).

The distribution of particulate trace metals in the Arctic Ocean will 
help to understand the sources and the scavenging process (Venchiarutti 
and Rutgers Van Der Loeff, 2011), the mixing process in the deep ocean 
(Charette et al., 2007) and the transport from the shelf (Lacan et al., 
2012). On the other hand, chemical speciation of particulate trace metals 
will help to understand the bioavailability of these particles to the 
phytoplankton community.

The goal in this cruise is to study the vertical and spatial distribution 
of particulate trace metals along the Arctic Ocean, quantify the lateral 
transport of particulate trace metals from the Russian rivers by the 
Transpolar Drift. The Artic Ocean is one of the most sensible oceans to 
the thermohaline circulation and physico-chemical properties. In this 
work, we will examine both vertical and spatial distribution of 
particulate trace metals along 6 transects across the Arctic Ocean (North 
Pole included). This work is conducted in the GEOTRACES programme 
(www.geotraces.org) during the expedition PS94 on the German icebreaker 
Polarstern began 17th August (Tromsø) to 15th October 2015 (Bremenhaven).


Work at sea

Particulate trace metals were collected in the ultra clean CTD system 
from NIOZ, filtered over a 0.45 µm filter size using N2 overpressure 
until an optimal volume between 6-10 L during at least 5 hours. 

On the other hand, ice-cores and surface seawater in the ice-stations 
were collected to determine the concentration of particulate trace 
metals. In addition, ice-rafted sediment samples were collected in two 
different locations, which will be used to measure the concentration of 
metals both in particles (sediments) and solution (after filtering).


Expected results

These samples will be analyzed in a clean laboratory facilitie in Brest 
(LEMAR-IUEM). The concentration of metals will be carried out by using an 
Elemental Scientific Sector-Field Inductively Coupled Plasma Mass 
Spectrometry (SF-ICP-MS) with a detection limit of: Al = 0.496 nM; P = 
2.55 nM; Mn=  0.014 nM; Fe = 0.063 nM; Co = 0.003 nM; Cu = 0.089 nM; Zn = 
0.051 nM, Cd = 0.002 nM and Ba = 0.006 nM; Planquette and Sherrell, 
2012).


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Charette MA, Gonneea ME, Morris P, Statham PJ, Fones GR, Planquette H, 
    Salter I, NaveiraGarabato, A (2007) Radium isotopes as tracers of 
    iron sources fueling a Southern Ocean phytoplankton bloom. Deep-Sea 
    Research II, 54, 1989-1998.

Jickells T et al. (2005) Global Iron Connections Between Desert Dust, 
    Ocean Biogeochemistry, and Climate. Science, 308, 67-71.

Kalnejais LH, Martin WR, Signall RP, Bothner MH (2007) Role of sediment 
    resuspension in the remobilisation of particulate-phase metals from 
    coastal sediment. Environmental Science Technology ,41, 2282-2288.

Lacan F, Tachikawa K, Jeandel C (2012) Neodymium isotopic composition of 
    the oceans: a compilation of seawater data. Chemical Geology, 300-
    301, 177-184, 10.1016/j.chemgeo.2012.01.019.

Lam PJ, Ohnemus DC and Marcus MA (2012) The speciation of marine 
    particulate iron adjacent to active and passive continental margins. 
    Geochimica et Cosmochimica Acta, 80, 108-124.

Lam PJ, Bishop JKB, Henning CC, Marcus MA, Waychunas GA, Fung IY (2006) 
    Wintertime phytoplankton bloom in the subarctic Pacific supported by 
    continental margin iron. Global Biogeochemical Cycles 20(1), GB1006.

Mahowald N et al. (2009) Atmospheric Iron deposition: Global 
    distribution, variability and human perturbations. Annual Reviews of 
    Marine Sciences, 1, 245-278.

Planquette H, and Sherrell RM (2012) Sampling suspended particles from 
    rosette-mounted bottles for determination of trace elements: 
    methodology and comparison with in situ pumping. Limnology and 
    Oceanography: Methods, 10, 367-388.

Raiswell R, Benning LG, Tranter M and Tulaczyk S (2008) Bioavailable iron 
    in the Southern Ocean: the significance of the iceberg conveyor belt. 
    Geochemical Transactions, 9, 7.

Sarthou G, Baker AR, Kramer J, Laan P, Laës A, Ussher S, Achterberg EP, 
    de Baar HJW, Timmermans KR, Blain S (2003) Influence of atmospheric 
    inputs on the iron distribution in the subtropical North-East 
    Atlantic Ocean. Marine Chemistry, 104,186-202.

Tagliabue A, Bopp L, Dutay JC, Bowie AR, Chever F, Jean-Baptiste P, 
    Bucciarelli E, Lannuzel D, Remenyi T, Sarthou G, Aumont A, Gehlen M, 
    Jeandel C (2010) Hydrothermal contribution to the oceanic dissolved 
    iron inventory. Nature Geoscience, 3, 252-256.

Venchiarutti C, and Rutgers van der Loeff M (2011) Scavenging of 231Pa 
    and thorium isotopes based on dissolved and size-fractionated 
    particulate distributions at Drake Passage (ANTXXIV-3). Deep-Sea 
    Research II, 58, 2767-2784.



6.11  Ice-rafted sediments

      Aridane G. Gonzalez(1)                    1 IUEM
      Lars-Eric Heimbürger(2)                   2 UB/MIO
      Sandra Gdaniec(3)                         3 SMNH
      Ronja Paffrath(4)                         4 ICBM
      Heather E. Reader(5)                      5 DTU


Objective

The Arctic Ocean presents exceptional conditions to study and 
characterize the continental inputs and extended shelf. The entrainment 
of shelf sediments into sea ice during its formation on the Siberian 
shelf is a unique mechanism for the transport of terrigenous and shelf 
sourced material to the deep basins.  The goal of the sampling effort was 
to collect samples to measure a variety of parameters summarised in the 
table below to characterize the flux and reactivity of elements from the 
shelf to the basins, and better understand the importance of this 
transport mechanism.


Work at sea

The ice-rafted sediment group took samples in two different locations 
with a plastic beaker from the deck. The samples were stored in plastic 
bags at -20°C.


Expected results

These samples will be treated and melted in the clean laboratory 
facilities of LEMAR (Brest) in order to satisfy the necessity of each 
scientist. The different parameters targeted by the ice-rafted sediment 
team are summarized in the table below.


Scientist                          Parameter
—————————————————————————————————  ————————————————————————————————————
Aridane G. Gonzalez (IUEM)         Particulate trace metals and Organic 
                                   Speciation of Copper
 
Micha Rijkenberg (NIOZ)            Dissolved trace metals
 
Heather E. Reader (DTU)            Organic Matter Characterization and 
                                   Dissolved Organic Carbon
 
Loes Guerringa and Hans Slagter    Fe binding Organic Ligands and 
(NIOZ)                             Dissolved Humic Substances

Michael Staubwasser (University    Reactive Fe species and Fe isotopes
of Koeln)
 
Lars-Eric Hamburger (MIO)          Mercury
 
Sandra Gdaniec and Per Andersson   Pa/Th
(SMNH)

RonjaPaffrath and Katharina        Nd and Sr isotopes, Rare Earth 
Pahnke (ICBM)                      Elements
 
*Walter Geibertand Gesine          232Th and 14C
Mollenhauer (AWI)
 
*RonjaPaffrath and Claudia         Si isotopes
Ehlert (ICBM)

*These parameters will be analyzed in the case we have enough sample 
 volume.



6.12  Neodymium isotopes, rare earth element concentrations and long-
      lived natural radionuclides

      Michiel Rutgers van der Loeff(1),         1 AWI 
      Ole Valk(1), Ronja Paffrath(2),           2 ICBM
      Sandra Gdaniec(3), M. Roy-Barman(4),      3 SMNH
      K. Pahnke(2), P. Andersson(3)             4 LSCE
      (not on board)
 

Objectives

The unique conditions in the Arctic of input, removal, and exchange 
processes in relation to particle composition, particle fluxes, and 
circulation are acting on trace element and isotope distributions in the 
Arctic Ocean. These distributions are sensitive to the environmental 
changes already taking place in the Arctic. We propose that the processes 
in this region can be ideally addressed by a combined study of Nd 
isotopes (143Nd/144Nd, εNd), rare earth elements (REE), Th isotopes and 
231Pa, and that the results will add important insights into trace 
element and isotope biogeochemistry in the Arctic. Moreover, the 
simultaneous analysis of the other GEOTRACES key parameters on the same 
cruise and on all cruises of our international partners (US, Canada) will 
provide a solid basis for the evaluation and modelling of biogeochemical 
processes in the Arctic.

Our study will test the following overriding hypothesis: The exceptional 
conditions in the Arctic Ocean of high continental inputs and extended 
shelf areas, contrasting with low particle fluxes and low opal production 
in the deep basins uniquely affect the distribution and budgets of εNd, 
REE, Th isotopes, and 231Pa. A detailed study of these tracers will help 
to understand their behaviour in the Arctic Ocean, with relevance for the 
processes controlling these and other trace element and isotope 
distributions globally.

Specific objectives of the proposed work to test this hypothesis include:
	
• Investigation of the effect of particles on the distribution of εNd, 
  REEs, Th isotopes, and 231Pa (and by extension, on other TEIs) in the 
  water column with a particular focus on particle composition (opal-rich 
  vs. opal-poor), particle fluxes, and terrigenous input.

• Investigation of exchange processes at the margins with exceptionally 
  large shelf areas (εNd for margin-seawater exchange, Th and Pa 
  isotopes for boundary scavenging) and provenance of particles supplied 
  to the Arctic by rivers and ice.

• Determination of whether changes in the circulation of the Beaufort 
  Gyre have led to further changes in the distribution of dissolved 
  230Th, 231Pa, REE, and Nd isotopes in comparison to the situation in 
  1991-2001.

• Investigation of the REE and Nd isotopic composition of the 
  contributions of Siberian rivers and Pacific water to the Arctic.

• Determination of the influence of hydrothermal activity at Gakkel Ridge 
  on seawater

In more detail, we want to exploit the unique boundary conditions in the 
Arctic and their strong contrast to those in other ocean basins, 
particularly those in the Southern Ocean, to improve our understanding of 
biogeochemical processes in the ocean in general and the Arctic in 
particular and to develop a common interpretation of these tracers. We 
particularly hope to see to what extent the large continental inputs in 
the Arctic (river, shelf, dirty ice) affect εNd and REE in the water 
column and how the low opal content in the Arctic compared to the large 
range in opal concentrations in the Southern Ocean influences the 
vertical REE distribution and contributes to a less efficient separation 
between 231Pa and 230Th in the Arctic. Terrigenous particles are 
transported to the central Arctic both in suspension in river water and 
ice rafted in "dirty ice". The combined analysis of Nd and Sr isotopes 
(87Sr/86Sr) on terrigenous river and dirty ice particles will provide 
insight into the provenance of particles as well as particle-seawater 
interactions and lateral transport of particles. In turn, this will 
afford insight into the potential impact of future changes on these 
distributions. We will further investigate the relative contributions of 
Pacific and Atlantic waters in the Arctic using their distinct εNd 
signatures, and investigate whether the recently reported circulation 
changes and freshwater input to the Arctic over the past decade (Karcher 
et al., 2012) have also impacted the trace element and isotope 
distributions in the Arctic since the first studies were carried out 
(samples collected in 2000-2001: 230Th, 231Pa by Bacon et al. (1989), 
Scholten et al. (1995), Edmonds et al. (2004), and ourselves (unpublished 
results), obtained n the years 1983, 1991, 1994, 2007: εNd and REE from 
(Andersson et al., 2008; Porcelli et al., 2009; Zimmermann et al., 2009).

The study of REE, Nd and Th isotopes and 231Pa in the water column and 
particles in the Arctic (this cruise, and US and Canadian cruises) will 
provide a baseline of their distributions for the evaluation of expected 
future changes in this rapidly changing environment.


Work at sea

Water samples were taken at 20 stations (up to 16 depths per station) for 
dissolved Th and Pa isotopes and 21 stations for dissolved REE and Nd 
isotopes (Fig. 6.12.1). The water samples were filtered directly from the 
Niskin bottles (Fig. 6.12.2) using Acropak500 cartridges (0.8/0.45µm pore 
size, Supor pleated membrane). Five to 20 L were sampled for 
determination of dissolved trace element isotopes (Th, Pa, Nd) and 100 ml 
of seawater was sampled for REE concentrations. All samples were 
acidified to pH ~2 using concentrated ultra clean hydrochloric or nitric 
acid (1ml acid per 1 liter of seawater). Samples for Nd isotopes were 
acidified to pH ~3.5 and REEs were pre-concentrated onboard using C18 
cartridges (Waters Inc.) filled with a complexing agent.


Fig. 6.12.1: Station map

Fig. 6.12.2: Sampling of seawater for REE, Si and Th, Pa, Nd isotopes

Fig. 6.12.3: Preconcentration of Nd isotopes using C18 cartridges

 
The study of Pa and Th is shared between the Bremerhaven (AWI) and 
Stockholm (SMNH) labs, with AWI concentrating on the deep basins and SMNH 
on the exchange with the shelves. Water samples for Pa and Th were 
divided accordingly between Ole Valk and Sandra Gdaniec. Three 
intercalibration stations in the central Arctic were sampled, where both 
water and particles were collected for Ole Valk and Sandra Gdaniec. One 
of these stations was the "crossover station" where our American 
colleagues sampled water and particles for REE, Nd isotopes and Pa/Th as 
well. The results from these intercalibration samples will be submitted 
to the GEOTRACES Standards and Intercalibration Committee for evaluation 
and approval.

Suspended particles were sampled at 10 stations at up to 12 depths per 
station using in-situ pumps (Mc-Lane and Challenger). The filters (Supor® 
-0.8µm) were pre-cleaned with 1N HCl and 18 Ω MQ water. Sampled filters 
were cut onboard (Fig. 6.12.3) under a laminar flow hood with HEPA filter 
and stored in plastic sample bags. 230Th, 232Th, 231Pa, REE, trace and 
major elements, and biogenic Si, will be analyzed at our home labs. 234Th 
was analyzed onboard by beta counting (see section 6.13).


Fig. 6.12.4: Dirty ice seen from the working deck


Twice the ship stopped when abundant "dirty ice" was observed from the 
bridge. Five to seven liters of dirty ice were collected at these 2 
stations using plastic tools. These samples are shared among a larger 
group (see section 6.11) in order to analyse a range of parameters on a 
homogenized sample. The dirty ice will be melted under clean conditions 
and the particles will be collected by filtration over the same filter 
type used for suspended particles. Surface sediments (1-2 g dry weight) 
were collected using either MUC or box corer at 10 stations for Nd 
isotopes, 231Pa/230Th and REE analyses on the lithogenic and authigenic 
phases. 


Expected results

The results will provide an unprecedented spatial and vertical resolution 
of dissolved and particulate REE concentrations, Nd and Th isotopes, and 
231Pa distributions in the Central Arctic. The results are expected to 
provide insight into the terrigenous sources to the Arctic, their impact 
on the dissolved trace element and isotope distributions, and the 
influence of rivers and Pacific and Atlantic waters on these 
distributions. Additionally, we expect to be able to evaluate the results 
with respect to data collected on previous expeditions (1991-2001). Ice 
conditions did not allow us to proceed as far south into the Alpha 
Ridge/Canada Basin as in 2007 or 2011. It is therefore questionable 
whether we can confirm the trend of decreasing 230Th activities observed 
2007.


Data management

Data from a crossover station with the US cruise and other 
intercalibration results from duplicate sampling will be submitted to the 
GEOTRACES Standards and Intercalibration Committee for evaluation and 
approval. All data and metadata will be submitted to the international 
GEOTRACES data management office (GDAC at BODC, www.bodc.ac.uk/geotraces) 
under the data management scheme agreed upon in the GEOTRACES programme 
available at http://www.geotraces.org. Most data and metadata will also 
be submitted to the PANGAEA database.


References

Andersson PS, Porcelli D, Frank M, Björk G, Dahlqvist R, Gustafsson Ö 
    (2008) Neodymiumisotopes in seawater from the Barents Sea and Fram 
    Strait Arctic-Atlantic gateways. Geochim. Cosmochim. Acta, 72, 2854-
    2867.

Bacon MP, Huh CA, Moore RM (1989) Vertical profiles of some natural 
    radionuclides over the Alpha Ridge, Arctic Ocean. Earth Planet. Sci 
    Lett., 95, 15-22.

Edmonds HN, Moran SB, Cheng H, Edwards RL (2004) 230Th and 231Pa in the 
    Arctic Ocean: implications for particle fluxes and basin-scale Th/Pa 
    fractionation. Earth Planet. Sci Lett., 227,155-167.

Henderson GM, Anderson RF et al. (2007) GEOTRACES - An international 
    study of the global marine biogeochemical cycles of trace elements 
    and their isotopes. Chem. Erde-Geochem., 67: 85-131.

Karcher M, Smith JN, Kauker F, Gerdes R, Smethie WM (2012) Recent changes 
    in Arctic Ocean circulation revealed by iodine-129 observations and 
    modeling. J. Geophys. Res., 117, C08007.

Porcelli D, Andersson PS, Baskaran M, Frank M, Björk G, Semiletov I 
    (2009) The distribution of neodymium isotopes in Arctic Ocean basins. 
    samples will be collected for: Geochim. Cosmochim. Acta, 73, 2645-2659.

Scholten JC, Rutgers van der Loeff M, 1995 Distribution of 230Th and 
    231Pa in the water column in relation to the ventilation of the deep 
    Arctic basins. Deep Sea Res, II 42, 1519-1531.

Zimmermann B, Porcelli D, Frank M, Andersson PS, Baskaran M, Lee D, 
    Halliday AN (2009) Hafnium isotopes in Arctic Ocean water. Geochim. 
    Cosmochim. Acta, 73, 3118-3233.


Fig. 6.12.1: Station map

Fig. 6.12.2: Sampling of seawater for REE, Si and Th, Pa, Nd isotopes



6.13  Natural radionuclides Рshort lived

      Viena Puigcorbé(1), Nnuria Casacuberta(2),  1 UAB
      Michiel Rutgers van der Loeff(3),           2 LIP
      P. Masqué(1) (not on board)                 3 AWI
 

Objectives

234Th and 210Po as tracers of export production of POC

Part of the carbon dioxide fixed in photosynthesis is transferred to the 
interior of the ocean, mainly by gravitational settling of particulate 
organic carbon (POC). Quantifying this export is essential for 
determining the efficiency of the biological carbon pump, which is a key 
component of the marine and global carbon cycle. Besides carbon, the 
vertical drawdown of particles connects the ocean surface with the deep 
waters, affecting the distribution of nutrients and biominerals and it 
represents an important food source for pelagic but also for benthic 
organisms (Smith et al., 2008), making the study of the particle cycling 
of broad interest for a variety of research fields.

The natural pairs of radionuclides 234Th/238U and 210Po/210Pb have been 
frequently used to provide information on particle export and export 
production (Benitez-Nelson and Moore, 2006; Buesseler et al., 1992; 
Verdeny et al., 2009). In a closed system, a radioactive isotope should 
be in secular equilibrium with its progeny. In the oceanic water column, 
a deficit of the decay product with respect to the concentration of the 
parent is found when its particle affinity is larger, due to removal by 
uptake by particles. Disequilibria among the activities of these tracer 
pairs indicate exportation to deeper waters, and it can be used to derive 
the flux of particles that are removed from the surface layer on time 
scales of weeks (half life of 234Th = 24 days) to months (half life of 
210Po = 138 days), becoming a powerful tool for tracing export events 
occurring on similar time scales such as phytoplankton blooms.

Our objective is to quantify the POC export flux by measuring the 
depletion of these radionuclides with respect to their parents in the 
upper water column. Differences in ice coverage conditions at the sampled 
stations will be examined in order to better assess the influence of ice 
thickness and the timing of the ice melting on particle export. In order 
to convert the radionuclide fluxes to a POC export fluxes, POC/234Th and 
POC/210Po ratios will be determined in sinking particles (e.g. Buesseler 
et al., 2006).


Work at sea

Water samples

Total 234Th was measured at 14 stations (Fig. 1) from 4 L of seawater 
collected at 12-21 discrete depths over the upper 400-500 m. Samples were 
treated following the MnO2 co-precipitation method (Benitez-Nelson et 
al., 2001; Pike et al., 2005) and counted onboard using a gas flow 
proportional low-level RISO beta counter (counting statistics <5 %). 
Uranium-238 activity, due to its conservative behaviour in seawater, is 
typically derived from salinity (Owens et al., 2011). However, additional 
seawater samples were collected to analyze 236U (see section 6.15) from 
which 238U concentrations are obtained as a byproduct, allowing us to 
confirm the U-salinity relationship. 

Lead-210 and 210Po samples were collected in 10 L cubitainers at 4 
stations (Fig.6.13.1). Samples will be processed according to the Co-APDC 
chelate co-precipitation technique, adapted from Boyle and Edmond (1975). 
During the cruise only the precipitation and filtration steps were 
carried out. The rest of the radiochemical procedure will be done at the 
home laboratory, as well as the measurements by alpha spectrometry 
(Rigaud et al., 2013).


Particulate samples

Size-fractionation of particulate samples (large (>53 µm) and small (1-53 
µm)) for analyses of 234Th, 210Po, 210Pb, POC and PON were collected by 
sequential filtration using in-situ filtration pumps (ISP) at 10 stations 
(Fig. 6.13.11). Two pumps were deployed at 50 and 100 m at 10 stations 
(see section 5.12). Pumps filtered on average 400 L during 2.5 h. Large 
particles were retained using a 53 µm mesh screen and removed from the 
screen by rinsing it with 0.2 µm filtered seawater. Small particles were 
collected on a pre-combusted QMA filter. Three subsamples of 25 mm in 
diameter were taken to measure 234Th, 210Po, 210Pb, POC and PON. Six 
additional subsamples (12 mm diameter) will be used to analyze multiple 
trace metals (see section 6.3 and 6.10) and the rest of the filter will 
be dedicated to the analysis of mercury (Hg) and Hg isotopes (see section 
6.7).

Additionally, 6-10 L water samples were collected from the CTD-rosette at 
each station where 234Th profiles were sampled (Fig. 6.13.1). Samples 
were collected over the upper 300 m at 6-9 depths and filtered through 
pre-combusted QMA filter to obtain additional POC/234Th data, which will 
also be compared to the results obtained from the in-situ filtration 
pumps.  


Fig. 6.13.1: Station location for the different parameters analyzed. ISP 
             station correspond to stations where 234 Th:238U profiles 
             where obtained, together with particulate samples collected 
             using ISP. At GEOTRACES crossover station (green star) all 
             the parameters were sampled.


Particulate 234Th activities were also measured on a 25 mm ø subsample of 
the 142 mm Supor® filters dedicated to the analysis of particulate 
230Th/231Pa, Nd isotopes, Rare Earth Elements (REE), together with trace 
and major elements and biogenic Si (see Chapter 6.12). Samples were 
collected at 10 stations (4, 32, 50, 81, 96, 101, 117, 125, 153 and 161) 
along the entire water column using ISP. The 25 mm subsamples of the main 
filters were dried at 50°C overnight and counted on board.


Preliminary results

Results obtained from these samples are expected to provide insights into 
particle export in the central Arctic. This area is known to have low 
export production (Cai et al., 2010; Lalande et al., 2014) but the 
increasing and accelerating melt of the sea ice cover might alter the 
phytoplankton community and increase primary productivity (Arrigo et al., 
2008; Frey et al., 2014), therefore affecting POC export and other 
elements' biogeochemical budgets (Boetius et al., 2013).

In general, low and shallow 234Th deficits were measured from seawater 
samples; therefore we expect to obtain low export fluxes, in agreement 
with previous studies carried out in the Central Arctic Ocean. However, 
differences can be observed between stations, with marked decreases in 
234Th activities at stations near the shelf and those that might be 
influenced by the Transpolar Drift. We will investigate the causes of 
those differences considering factors such as primary productivity, ice 
coverage, water masses, etc., in order to better describe the particle 
fluxes in this region.

Preliminary particulate 234Th concentrations measured in the Supor 
filters along the entire water column are presented in Fig. 6.13.2, where 
higher concentrations can be seen at the shelf and near the bottom of the 
slope, as well as in the surface waters that might be affected by the 
Transpolar Drift.


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Arrigo KR, van Dijken G, Pabi S (2008) Impact of a shrinking Arctic ice 
    cover on marine primary production. Geophys. Res. Lett., 35, L19603.

Benitez-Nelson C, Buesseler KO, Rutgers van der Loeff M, Andrews J, Ball 
    L, Crossin G, Charette MA (2001) Testing a new small-volume technique 
    for determining 234Th in seawater. J. Radioanal. Nucl. Chem., 248, 
    795-799.
Benitez-Nelson CR, Moore WS (2006) Future applications of 234Th in 
    aquatic ecosystems. Mar. Chem., 100, 163-165.

Boetius A, Albrecht S, Bakker K, Bienhold C, Felden J, Fernández-Méndez 
    M, Hendricks S, Katlein C, Lalande C, Krumpen F (2013) Export of 
    algal biomass from the melting Arctic sea ice. Science, 339, 1430-
    1432.

Boyle EA, Edmond JM (1975) Determination of trace metals in aqueous 
    solution by APDC chelate co-precipitation. Anal. Methods Oceanogr., 
    44.

Buesseler KO, Bacon MP, Kirk Cochran J, Livingston HD (1992) Carbon and 
    nitrogen export during the JGOFS North Atlantic Bloom Experiment 
    estimated from 234Th:238U disequilibria. Deep Sea Res Part A 
    Oceanographic Res. Pap., 39, 1115-1137.

Buesseler KO, Benitez-Nelson CR, Moran SB, Burd A, Charette M, Cochra JK, 
    Coppola L, Fisher NS, Fowler SW, Gardner WD (2006) An assessment of 
    particulate organic carbon to thorium-234 ratios in the ocean and 
    their impact on the application of 234Th as a POC flux proxy. Mar. 
    Chem., 100, 213-233.

Cai P, Rutgers van der Loeff M, Stimac I, Nöthig EM, Lepore K, Moran SB 
    (2010) Low export flux of particulate organic carbon in the central 
    Arctic Ocean as revealed by 234Th:238U disequilibrium. J. Res, 115, 
    C10037.

Frey KE, Comiso JC, Cooper LW, Gradinger RR, Grebmeier JM, Saitoh SI, 
    Tremblay JÉ (2014) Arctic Ocean Primary Productivity [in Arctic 
    Report Card 2014], Arctic Report Card, 2014.

Lalande C, Nöthig EM, Somavilla R, Bauerfeind E, Shevchenko V, Okolodkov 
    Y (2014) Variability in under-ice export fluxes of biogenic matter in 
    the Arctic Ocean. Global. Biogeochem. Cycles, 2013GB004735.

Owens SA, Buesseler KO, Sims KWW (2011) Re-evaluating the 238U-salinity 
    relationship in seawater: Implications for the 238U-234Th 
    disequilibrium method. Mar. Chem.r 127, 31-39.

Pike SM, Buesseler KO, Andrews J, Savoye N (2005) Quantification of Th-
    234 recovery in small volume seawater samples by inductively coupled 
    plasma-mass spectrometry. J. Radioanal. Nucl. Chem., 263, 355-360.

Rigaud S, Puigcorbé V, Cámara-Mor P, Casacuberta N, Roca-Martí M, Garcia-
    Orellana J, Benitez-Nelson CR, Masqué P, Church T (2013) A methods 
    assessment and recommendations for improving calculations and 
    reducing uncertainties in the determination of 210Po and 210Pb 
    activities in seawater Limnol. Ocean. Methods, 11, 561-571.

Smith CR, Leo FC De, Bernardino AF, Sweetman AK, Arbizu PM (2008) Abyssal 
    food limitation, ecosystem structure and climate change. Trends Ecol. 
    Evol., 23, 518-528.

Verdeny E, Masqu P, Garcia-Orellana J, Hanfland C, Kirk Cochran J, 
    Stewart GM (2009) POC export from ocean surface waters by means of 
    234Th/238U and 210Po/210Pb disequilibria: A review of the use of two 
    radiotracer pairs. Deep Sea Res. Part II Top. Stud. Oceanogr., 56, 
    1502-5518.


Fig. 6.13.2: (Top) Section plot of 234Th particulate concentrations 
             measured at 10 stations (see text and Fig. 6.13.1 for 
             further information) along the entire water column. (Bottom) 
             Map of station's locations.



6.14  Radium isotopes

      Michiel Rutgers van der Loeff             AWI
 

Objectives

Four natural isotopes of radium (the radium quartet) occur in the ocean. 
228Ra (half life 5.8y) is a known tracer for shelf waters. It is strongly 
enriched in the Arctic shelves and in the Transpolar Drift waters that 
originate in the Siberian shelves (Rutgers van der Loeff et al., 1995). 
223Ra and 224Ra are short lived (11.4 and 3.7 d half life, respectively). 
They can trace near-shore processes (Kadko et al., 2005) but can also be 
used as indirect tracer of the distribution of their parent nuclides, 
228Th (Rutgers van der Loeff et al., 2012) and 227Ac (Geibert et al., 
2008). The fourth isotope, 226Ra (half life 1600yr), is stable on the 
time scale of mixing of the Arctic Ocean and can be used as yield tracer 
for the analysis of other isotopes. Since Pacific and Atlantic source 
waters have distinct 226Ra activities, the isotope can serves as tracer 
for the origin of water masses. In previous expeditions we have studied 
the distribution of the radium quartet in surface waters, we now want to 
include measurements of depth profiles of these isotopes in the water 
column for the study of exchange rates between shelf/slope and open 
ocean.


Work at sea

Water column profiles

At all 10 deployments of the in-situ pumps (ISP, see section 6.12), we 
mounted 75-mm MnO2-coated acrylic cartridges (Henderson et al., 2013) in 
the pumps at 4 to 8 depths to collect dissolved radium and thorium 
isotopes by adsorption on the MnO2. At the three basin stations (54, 81, 
101) we made BaSO4 precipitates of weighed 20-L aliquots for subsequent 
analysis of 226Ra with gamma spectrometry. Additional 1-L samples were 
collected here for mass spectrometric analysis of 226Ra.


Surface water

Throughout the cruise, surface water samples were collected from the 
ship's seawater intake. During PS94 this intake was connected to the 
centrifugal pump with inlet close to the moon pool (Klaus Pumpe) at 11m 
depth and was sampled close to this inlet to avoid possible ingrowth of 
224Ra from 228Th adsrobed to the walls of the tubings. Seawater was 
prefiltered by passing over an uncoated cartridge and then passed over a 
MnO2- absorber for the collection of Radium. As MnO2 absorber we used 
either two columns filled with loose MnO2 fiber in series, or two MnO2-
cartridges identical to the ones used in the in-situ pumps. The 
absorption efficiency of the cartridges (90 ± 7%, even in the ISP with 
flow rates up to around 3 L/min) was clearly superior to that of the 
fiber columns (837 % at flow rates not exceeding 1 L/min) and during the 
last part of the cruise the cartridge method was used exclusively.

The activities of 223Ra and 224Ra were determined by alpha scintillation 
counting of the radon emanation in a delayed coincidence counting system 
(RaDeCC; Moore and Arnold, 1996). 228Th was determined through a new 
generation of its daughter 224Ra by a second RaDeCC count after 20-30 
days. This second count was completed on board for samples up to Sta 120 
(Fig. 6.14.1) and will be continued in the home laboratory for the 
samples collected on the last (Bjørn Øya) transect. The 228Ra/226Ra ratio 
will be determined later in the home laboratory using gamma spectrometry. 


Preliminary and expected results

224Ra and 228Th distributions in the water column must be largely 
supported by parent 228Ra and display the sources in surface water 
(especially from the shelf in the Trans Polar Drift) and at the seafloor. 
The actual distribution of 228Ra awaits further analysis at AWI. 


Fig. 6.14.1: Black, dissolved and blue, particulate 224Ra in surface 
             waters at time of sampling. Red, particulate 228Th as 
             determined from the activity of daughter 224Ra after four 
             weeks of ingrowth. 


Ingrowth of 224Ra into the particulate material collected from the 
surface water with uncoated filters (Fig. 6.14.1) showed that 228Th, not 
224Ra was present in the particulate phase, with a clear maximum at 
station 87-96, likely related to the Trans Polar Drift. Once the 
concentrations of parent 228Ra are available we will investigate whether 
there is a depletion of 228Th with respect to 228Ra in the surface layer, 
which could then be interpreted as a measure of export production on a 
longer timescale (half-life 228Th 1.9 year) than is provided by the study 
of 234Th (24 days)  and 210Po (138 days) (see section 6.13) and 
contribute to resolve the discrepancy between the extremely low export 
production measured 2007 with 234Th by Cai et al. (2010) and the 
observation 2012 of fresh sedimentation at the seafloor of the deep 
basins by Boetius et al. (2013).

From the distribution of radium isotopes we hope to derive exchange rates 
of the shelf and slope with the open ocean at various depths. These 
exchange rates are needed in models describing the distribution of other 
tracers like 230Th and 231Pa. A long recount of the deep radium samples 
will be used to quantify 227Ac. After correction for activity supported 
by 231Pa (see section 6.12), we will investigate whether the excess-227Ac 
activity can be used to derive vertical mixing rates in the deep water. 


Data management

See introduction of chapter 6 for details on GEOTRACES data management.


References

Boetius A, Albrecht S, Bakker K, Bienhold C, Felden J, Fernández-Méndez 
    M, Hendricks S, Katlein C, Lalande C, Krumpen T, Nicolaus M, Peeken 
    I, Rabe B, Rogacheva A, Rybakova E, Somavilla R, Wenzhófer F, Party 
    RPA-SS (2013) Export of Algal Biomass from the Melting Arctic Sea 
    Ice. Science, 339, 1430-1432.

Cai P, Rutgers van der Loeff MM, Stimac I, Nöthig EM, Lepore K, Moran SB 
    (2010) Low export flux of particulate organic carbon in the central 
    Arctic Ocean as revealed by 234Th:238U disequilibrium. Journal of 
    Geophysical Research - Oceans, 115, C10037.

Geibert W, Charette M, Kim G, Moore WS, Street J, Young M, Paytan A 
    (2008) The release of dissolved actinium to the ocean: A global 
    comparison of different end-members. Marine Chemistry, 109, 409.

Henderson PB, Morris PJ, Moore WS, Charette MA (2013) Methodological 
    advances for measuring low-level radium isotopes in seawater. Journal 
    of Radioanalytical and Nuclear Chemistry, 296, 357-362.

Kadko D, Muench R, (2005) Evaluation of shelf-basin interaction in the 
    western Arctic by use of short-lived radium isotopes: The importance 
    of mesoscale processes. Deep Sea Research Part II: Topical Studies in 
    Oceanography, 52, 3227.

Moore WS, Arnold R (1996) Measurement of 223Ra and 224Ra in coastal 
    waters using a delayed coincidence counter. J. Geophys. Res., 101, 
    1321-1329.

Rutgers van der Loeff MM, Key RM, Scholten JC, Bauch D, Michel A (1995) 
    228Ra as a tracer for shelf water in the Arctic Ocean. Deep-Sea Res. 
    II, 42, 1533-1553.

Rutgers van der Loeff MM, Cai P, Stimac I, Bauch D, Hanfland C, Roeske T, 
    Bradley Moran S (2012) Shelf-basin exchange times of Arctic surface 
    waters estimated from 228Th/228Ra disequilibrium. Journal of 
    Geophysical Research - Oceans, 117, C03024, 
    doi:03010.01029/02011JC007478.



6.15  Artificial radionuclides as tracers of water masses

      Nuria Casacuberta(1),                     1 LIP
      Viena Puigcorbé(2),                       2 UAB
      Michiel Rutgers van der Loeff(3)          3 AWI, 
 

Objectives

Artificial radionuclides have been widely used as oceanic tracers to 
study watermass circulation. Radioactive tracers (99Tc, 90Sr, 137Cs and 
129I) dispersed from European nuclear fuel reprocessing plants located at 
Sellafield (formerly Windscale) in the UK and La Hague in France (Kershaw 
& Baxter, 1995) have proved particularly powerful to that aim. The 
discharged radioactive waste in coastal waters of northwest Europe has 
been used to track the water movement through the North Sea (Kershaw & 
Baxter, 1995), the Norwegian Coastal Current (Alfimov, Aldahan et al., 
2004), the Arctic Ocean (Smith, Ellis et al., 1999, Smith, McLaughlin et 
al., 2011, Karcher, Smith et al., 2012) and the Nordic Seas (Alfimov, 
Aldahan et al., 2004). The atmospheric weapon tests performed in the 
1950's and 1960's have been another source of artificial radionuclides to 
the marine environment (Povinec, Aarkrog et al., 2005). Other than 137Cs, 
90Sr, 99Tc, 129I, etc., in recent years, several studies have measured 
the anthropogenic occurrence of 236U (T1/2=23 My) in the ocean and 
pointed out its potential to become a new oceanographic tracer (Steier, 
Bichler et al., 2008, Christl, Lachner et al., 2012, Sakaguchi, Kadokura 
et al., 2012, Eigl, Srncik et al., 2013). Its conservative behavior in 
seawater and the fact that has it not yet reached steady state in the 
oceans, together with new developments in Accelerator Mass Spectrometry, 
proved that the 236U/238U atomic ratio can be used as a marker of water 
masses, particularly in the Arctic and Atlantic Oceans (Casacuberta, 
Christl et al., 2014). Atom ratios between different artificial 
radionuclides can be used to identify the sources of radionuclides in the 
(Kershaw and Baxter, 1995) marine environment (i.e. 240Pu/239Pu and 
90Sr/137Cs) and track the water masses circulation (i.e. 129I/137Cs). For 
example, 129I/137Cs tracer measurements are used in simple 
mixing/advection models to estimate transit times from the North Sea to 
the Arctic Ocean. Similarly, and due to the different input functions of 
129I and 236U from European reprocessing plants, the 129I/236U could 
become a potential tool in tagging the water masses in the North Atlantic 
and Arctic Oceans (Christl et al., 2012). The objective of our work 
during the PS94 cruise is to obtain a comprehensive dataset of artificial 
radionuclides in the Arctic Ocean to: i) constrain the sources of 
artificial radionuclides to the Arctic Ocean (i.e. global fallout, 
reprocessing plants, rivers); ii) use the 236U/238U atom ratio and 
129I/236U to identify water masses in the Arctic Ocean; iii) use the 
129I/137Cs and 129I/236U to constrain the transit times of waters from 
the North Sea to the Arctic Ocean; and iv) use them as tracers of the 
water circulation in the Arctic Ocean.


Work at sea

A total number of 360 seawater samples (131 for 236U and 129I and 98 for 
Pu-isotopes) were taken for artificial radionuclide analysis during the 
PS94 cruise. Full depth profiles of different volumes were collected at 
17 stations during the cruise track, covering the three main deep Arctic 
Basins: Nansen, Amundsen and Makarov Basins, as well as a transect in the 
Barents Sea. All samples were collected from a 24 bottles rosette coupled 
to a three Conductivity Temperature Depth (CTD) system.

For the analysis of 129I, a subsample of 200 Р500 mL was taken and 
processed on board, following the method by Michel et al. (2012). 
Briefly, Woodward iodine was added to the pre-calibrated sample and all 
iodine species were oxidized with Ca(ClO)2 to iodate and subsequently 
reduced with NH3OHCl and NaHSO3 to iodide. After 45 minutes, pH was 
raised to 5-6 and Iodine was extracted with a BioRad 1x8 anion exchange 
resin. Iodine was finally eluted with concentrated potassium nitrate 
solution (2.25 M) and precipitated as AgI. Precipitates were kept in 
filters for its final AMS measurement at ETH AMS Tandy (Zrich).

For the analysis of 236U, 3 to 10 L samples were pre-processed on board. 
Samples were acidified and spiked with 3 pg of 233U immediately after its 
collection. After 24 hours equilibration, uranium isotopes were pre-
concentrated with Fe(OH)3 and kept in 250 mL bottles for its subsequent 
chemical analysis and measurement at ETH Zrich.

5 L samples were taken for Pu-isotopes analysis for Timothy Kenna (LDEO). 
Samples were stored in plastic cubitainers for its further delivery to US 
and its final analysis.

Other than seawater samples, a total of 5 ice stations were sampled 
during the cruise PS94 of RV Polarstern in the central Arctic in 
September 2015. Sea ice cores were retrieved using a standard 9 cm Kovacs 
ice corer, placed in plastic tubes and brought to the -20°C freezer/cold 
lab. Cores were sectioned with a band saw either at discernible 
stratigraphic boundaries possibly related to different ice types or ice 
origin, or in the absence of such features to yield sufficient amounts 
for 129I and 236U analysis. Core sections were melted in cleaned plastic 
drums at room temperature and processed in the chemistry lab within 2 
days. 


Expected results

Distribution of artificial radionuclides in the Arctic Ocean will be used 
as tracers of water circulation in the Arctic Ocean. The 129I/236U atom 
ratio will be used in combination to 236U/238U ratio with the aim to: i) 
constrain the sources of artificial radionuclides to the Arctic Ocean 
(i.e. global fallout, reprocessing plants, rivers); ii) identify water 
masses in the Arctic Ocean; iii) constrain the transit times of waters 
from the North Sea to the Arctic Ocean. 

Pu-isotopes will be used as tracers for understanding sources, pathways, 
dynamics and the fate of pollutants and particles in the Arctic Ocean. 
Due to the well-defined spatial and temporal inputs of Pu, the long half-
lives of 240Pu and 239Pu and its unique chemical properties, Pu can be 
used as tracer for various physical and biogeochemical ocean processes, 
including circulation, sedimentation and biological productivity, and 
hence a means of assessing the impacts of global climate change. 


Data management

See introduction of chapter 6 for details on GEOTRACES data management. 


References

Alfimov V, Aldahan A, Possnert G, Kekli A, Meili M (2004) Concentrations 
    of 129I along a transect from the North Atlantic to the Baltic Sea. 
    Nuclear Instruments and Methods in Physics Research Section B: Beam 
    Interactions with Materials and Atoms, 223в24(0), 446-450.

Alfimov V, Aldahan A, Possnert G, Winsor P (2004) Anthropogenic iodine-
    129 in seawater along a transect from the Norwegian coastal current 
    to the North Pole. Marine Pollution Bulletin, 49(11-22), 1097-1104.

Casacuberta N, Christl M, Lachner J, van der Loeff MR, Masque P, Synal HA 
    (2014) A first transect of U-236 in the North Atlantic Ocean. 
    Geochimica et Cosmochimica Acta, 133, 34-46.

Christl M, Lachner J, Vockenhuber C, Lechtenfeld O, Stimac I, Rutgers van 
    der Loeff M, Synal HA (2012) A depth profile of uranium-236 in the 
    Atlantic Ocean. Geochimica et Cosmochimica Acta, 77(0), 98-107.

Eigl R, Srncik M, Steier P, Wallner G (2013) 236U/238U and 240Pu/239Pu 
    isotopic ratios in small (2ʌ) sea and river water samples. Journal of 
    Environmental Radioactivity, 116(0), 54-58.

Karcher M, Smith JN, Kauker F, Gerdes R, Smethie WM (2012) Recent changes 
    in Arctic Ocean circulation revealed by iodine-129 observations and 
    modeling. Journal of Geophysical Research, Oceans 117(C8), C08007.

Kershaw P, Baxter A (1995) The transfer of reprocessing wastes from 
    north-west Europe to the Arctic. Deep Sea Research Part II: Topical 
    Studies in Oceanography, 42(6), 1413-1448.

Povinec PP, Aarkrog A, Buesseler KO, Delfanti R, Hirose K, Hong GH, Ito 
    T, Livingston HD, Nies H, Noshkin VE, Shima S, Togawa O (2005) 90Sr, 
    137Cs and 239,240Pu concentration surface water time series in the 
    Pacific and Indian Oceans РWOMARS results. Journal of Environmental 
    Radioactivity, 81(1), 63-87.

Sakaguchi A, Kadokura A, Steier P, Takahashi Y, Shizuma K, Hoshi M, 
    Nakakuki T, Yamamoto M (2012) Uranium-236 as a new oceanic tracer: A 
    first depth profile in the Japan Sea and comparison with caesium-137. 
    Earth and Planetary Science Letters, 333-334(0), 165-170.

Smith JN, Ellis KM, Boyd T (1999) Circulation features in the central 
    Arctic Ocean revealed by nuclear fuel reprocessing tracers from 
    Scientific Ice Expeditions 1995 and 1996. Journal of Geophysical 
    Research Oceans, 104(C12), 29663-29677.

Smith JN, McLaughlin FA, Smethie WM, Moran SB, Lepore K (2011) Iodine-
    129, 137Cs, and CFC-11 tracer transit time distributions in the 
    Arctic Ocean. Journal of Geophysical Research Oceans 116(C4), C04024.

Steier P, Bichler M, Fifield KL, Golser R, Kutschera W, Priller A, Quinto 
    E, Richter S, Srncik M, Terrasi P, Wacker L, Wallner A, Wallner G, 
    Wilcken KM, Wild EM (2008) Natural and anthropogenic 236U in 
    environmental samples. Nuclear Instruments and Methods in Physics 
    Research Section B: Beam Interactions with Materials and Atoms, 
    266(10), 2246-2250.





7.  PLANKTON ECOLOGY AND BIOGEOCHEMISTRY IN A CHANGING ARCTIC OCEAN 
    (PEBCAO)

    Nicole Hildebrandt(1), Vanessa S. Köhler(1),  1 AWI
    Ksenia N. Kosobokova(2), Imke Petersen(1),    2 IORAS
    Juliane Riedel(1), Franz Schröter(1) 
    not on board: Katja Metfies(1), 
    Barbara Niehoff(1), Eva-Maria Nöthig(1) 

Grant No. AWI_PS94_00


Objectives 

The Arctic Ocean is strongly affected by climate change, e.g. increasing 
temperatures and shrinking sea ice, which in turn will have large impact 
on the pelagic ecosystem with consequences for the carbon cycle and 
sequestering. Long-term investigations of biogeochemical plankton 
parameters as well community composition analyses for all plankton size 
classes, from pico- to large zooplankton, are thus required to understand 
and predict future ecosystem functioning. Shifts in species composition 
are expected: For example, at the base of the food web smallest algae may 
become more important. At higher trophic levels, zooplankton organisms 
then have to cope with changes in food supply and, thus, have to adjust 
their species-specific patterns in population dynamics, depth 
distribution, and feeding biology. In addition to increasing temperatures 
and shrinking sea ice, recent changes in the circulation (shift of the 
boundary between Atlantic and Pacific water masses) may also alter the 
pelagic system. Also, the increasing advection of relatively warm 
Atlantic water masses inhabited by boreal species could favour the 
distribution of Atlantic communities, which could finally replace the 
Arctic fauna. 

Since the nineties, ecological investigations of phyto- and zooplankton 
biomass, species composition, productivity, sedimentation and biochemical 
parameters (i.e. chlorophyll a, particulate organic carbon & nitrogen, 
carbonate and biogenic silica) have been carried out in the central 
Arctic Ocean with Polarstern (8 cruises between 1993 and 2014). Plankton 
biomass and carbon flux during summer close to and beneath the sea ice do 
not yet appear to have increased, however, marginal ice zones have moved 
closer to the pole. Thus, former ice covered regions are ice-free for 
longer time and allow a different summer population to develop. In 
addition, earlier investigations in the Eurasian Basin demonstrated that 
the composition and distribution of protists and the pelagic fauna in the 
Arctic Ocean are strongly affected at regional and even basin scales by 
Atlantic water from the Fram Strait and from the Barents Sea. The 
ecological niches, e.g. preferences and tolerances, of advected 
zooplankton species then determine their success in inhabiting the Arctic 
basins. 

Molecular biological investigations on biodiversity, HPLC and flow 
cytometry reveal strong gradients of biomass and from diatoms to 
picoplankton-dominated communities from the Atlantic to the Pacific 
sector. Specific hypotheses we intend to test are: 

1. Less sea ice in summer will promote higher production followed by 
   higher sedimentation in regions that have been totally ice covered 
   before. 

2. Shifts in species compositions on different trophic levels will change 
   trophic interactions and change fluxes and export of organic matter. 

3. Changes like the inflow of warmer Atlantic water masses may also alter 
   the pelagic system and export fluxes.

In 2015, specific aims of the zooplankton studies were focused on

1. relating composition, abundance, biomass and spatial distribution of 
   zooplankton communities across the basins and ridges to water 
   circulation patterns and primary productivity and protist composition,

2. understanding the trophodynamic relationships among zooplankton 
   species within the Arctic pelagic communities by continued biochemical 
   analyses (i.e. carbon and nitrogen content, stable isotope ratios),

3. building the DNA sequence library needed for molecular approaches to 
   assess community structure and identifying regional and basin-scale 
   population patterns within the Arctic using molecular markers. 


The results gained during this cruise will be compared to earlier cruises 
to improve projections of future status or change.


Work at sea 

Phytoplankton and protist community

Water samples were taken for analysing unicellular plankton organisms 
distribution and biomass and for biogeochemical measurements (pigments, 
POC/N PbSi) from Niskin bottles attached to a CTD/rosette sampling system 
from 5-7 depths at 25 stations (Table 7.1, Fig. 7.1). Aliquots of 
seawater were filtered for later analysis of particulate organic carbon 
and nitrogen (POC/PON), particulate biogenic silica (PbSi), HPLC 
pigments, fractionated (>10µm; 3µm; 0.4µm) and unfractionated chlorophyll 
a concentration (chl a), and molecular genetic analyses. Ten additional 
stations were exclusively sampled for chl a (Table 7.1, Fig. 7,1). Water 
was generally sampled at depths of 2 m, 10 m, 20 m, 30 m, 50 m, 100 m and 
200 m, however, sampling depths in the upper 50 metres were adjusted to 
match the depth of the chl a maximum whenever present. Samples for 
molecular analyses were collected at three depths in the upper 50 m of 
the water column, including the chl a maximum. Water samples for chl a 
concentration and HPLC pigment analyses were taken within the upper 100 m 
and immediately filtered with Whatman GF/F glass microfibre filters. 
POC/PON and PbSi were generally sampled down to 200 m depth. On stations 
where moorings with attached sediment traps were deployed (see section 
"Export fluxes"), 12 samples in the entire water column were sampled for 
these parameters. POC/PON was filtered on pre-combusted GF/F filters. 
Cellulose acetate filters were used to filter for later PbSi analyses. 
Filters were frozen at -20°C (chl a, POC/PON, PbSi, seston) and -80°C 
(HPLC) to be processed in the home laboratory. Additionally, 200 ml of 
seawater were sampled at 5 depth layers within the upper 50 m and 
preserved with hexamethylentetramine-buffered formaldehyde for later 
identification and enumeration of larger (> 3µm) phyto- and 
protozooplankton cells under the microscope at the home laboratory. 

For molecular analyses of protist community composition and determination 
of fractionated chl a concentrations, water samples were sequentially 
filtered onto Millipore polycarbonate filters with a pore-size of 10µm, 
3µm and 0.4µm. In parallel, filters were collected for analyses of 
ambient bacterial communities according to the same filtration procedure, 
except that the 0.4µm filter was exchanged by an 0.2µm filter. Subsequent 
to filtration, filters were stored at -20°C until further analyses in the 
laboratory.  

After leaving the sea ice - on the way to the Russian EEZ - five underway 
chl a samples were taken in duplicates using the ship's seawater pump. The 
filtration procedure and sample storage were performed as stated above.


Fig. 7.1: Locations of stations sampled by the PEBCAO group


An Apstein net (mesh size 20µm) was deployed at nine ice stations to a 
depth of 10 m. Aliquots of the catches were scanned on board to obtain a 
quick overview of the species composition of unicellular microplankton 
using a Zeiss Axiovert 40°C microscope. Photos were taken with a Zeiss 
AxioCam MRc camera and processed with the respective software. 


Export Fluxes

In order to investigate the vertical particle flux over a one-year 
period, sediment traps (K.U.M.) were deployed on two moorings in the 
Nansen Basin (PS94/058) and at the Gakkel Ridge (PS94/069) close to the 
Karasik Peak (see chapter 3). At both mooring sites, one sediment trap 
was mounted at 200 - 300 m below the sea surface and another one was 
placed ~150 m above the sea floor. This work is part of the AWI FRAM 
project. The mooring in the Nansen Basin will be exchanged in 2016, and 
then deployed for another two years. In addition to the other parameters, 
at these locations 12 water samples were taken with the Niskin bottles 
for the determination of seston (total particulate matter). They were 
filtered on pre-combusted and pre-weighed Whatman GF/F filters which were 
stored frozen at -20°C.


Zooplankton sampling

For the investigation of large-scale distribution and species 
composition, zooplankton was collected by a multiple closing net (Type 
MAXI, 0.5 m2 mouth opening, Hydrobios, Kiel; Fig. 7.2). The multinet was 
equipped with nine nets (150µm mesh size) and provided stratified 
sampling of the entire water column from the bottom to the surface. 

Sampling was carried out in the Arctic Ocean and in the southern Barents 
Sea. In the Arctic Ocean, we sampled a total of 15 stations (Table 7.1, 
Fig. 7.1) on two transects (Fig. 3.1, transect 1+2 and 4) with the 
sampling intervals bottom-3000-2000-1000-500-200-100-50-25-0 m. The 
majority of stations were taken in the deep region (seven of them deeper 
than 3,000 m, plus two deeper than 4,000 m). Three stations were taken at 
the Gakkel and Lomonosov ridges, one in the slope region, and two in the 
shelf region (depths <400 m). Our sampling protocol followed standard 
procedures as applied during previous Polarstern cruises to the deep 
Arctic basins (1993-2012). The comparison of data obtained during PS94 
with these historical data will then be used for assessing changes in the 
Arctic pelagic biota related to ongoing climate change and the entire 
data set can also be considered a starting point for the first 
zooplankton time series in the history of the investigation of the 
Arctic.


Fig. 7.2: Multinet Type Maxi with additional net bag for non-
          quantitative, depth-integrated zooplankton sampling.


In the southern Barents Sea, along the 24°E meridian, five stations were 
taken between 75 and 73°N (Table 7.1, Fig. 7.1). The entire water column 
was sampled at the following depth intervals: bottom-350-300-250-200-150-
100-50-25-0 m. The zooplankton samples were preserved in 4 % 
hexamethylentetramine-buffered formaldehyde for later processing.

To investigate the small-scale distribution of zooplankton species in the 
upper 1,000 m of the water column, the LOKI system (Lightframe On-sight 
Key species Investigation; Fig. 7.3a) was successfully deployed on 11 
stations along the transect from the northern Barents Sea shelf to the 
Makarov Basin (Table 7.1). The LOKI was equipped with a high-resolution 
digital camera and sensors measuring temperature, depth, salinity, 
oxygen, and fluorescence as a proxy for algal abundance. The distribution 
patterns of the zooplankton organisms can thus directly be related to the 
hydrography. Combining both approaches (MN and LOKI) allows us to analyze 
and better understand changes in the zooplankton communities under 
changing environmental conditions. 

In total, approx. 166,000 pictures of zooplankton organisms were taken 
with the LOKI. These pictures (an example is shown in Fig. 7.3b) will be 
analysed at the AWI, and species distribution will be related to the 
environmental parameters and compared with the multinet data.

Live animals for molecular genetics and stable C and N isotope analyses 
were collected by a 60 cm diameter net (300 m mesh-size) attached to the 
outside of the multinet (Fig. 7.2) and from an Apstein net (see section 
"Phytoplankton and protist community"). Representatives of target species 
to be used for molecular genetic analyses were removed from live samples, 
preserved with 96 % ethanol and stored at 0°C for later determination of 
their COI sequences plus some additional mitochondrial or nuclear target 
regions. For the three dominant copepod species - Calanus hyperboreus, C. 
glacialis, and C. finmarchicus - samples were prepared to explore 
population genetics at a high spatial resolution. The relatively low 
availability of most other species will restrict our analysis to a simple 
comparison of the Eurasian to the Amerasian basin populations.

Animals for stable C and N isotope analyses were also sorted out from 
live samples and stored at -20°C for later analyses.

The remainders of the non-quantitative catches were given to Lars-Eric 
Heimbrger (GEOTRACES group) for analyzing the Hg content of the Arctic 
zooplankton at MIO. Subsamples of Thysanoessa sp. (Euphausiacea) were 
given to Ellen Damm (AWI) for analysing DMS.


Fig. 7.3: The LOKI system during deployment (a) and a compilation of 
          photographs taken by LOKI, in clockwise direction: Boroecia sp. 
          (ostracod), Oncaea sp. (cyclopoid copepod), Botrynema ellinorae 
          (jelly fish), Metridia longa (calanoid copepod), Themisto 
          libellula (hyperiid amphipod) and Paraeuchaeta sp. (calanoid 
          copepod).


Tab. 7.1: Biogeochemical and biological parameters

Station   HPLC  Chla  DNA/   bPSi  POC/  Seston  Micros-  Multi-  LOKI  Bongo
                      Chlaf        PON            copy     net           net 
————————  ————  ————  —————  ————  ————  ——————  ———————  ——————  ————  —————
PS94/002   x     x      x     x     x              x
PS94/004   x     x      x     x     x              x
PS94/010                                                    x      x
PS94/018   x     x      x     x     x              x        x
PS94/030                                                    x      x
PS94/032   x     x      x     x     x              x        x      x
PS94/040   x     x      x     x     x              x        x      x
PS94/046   x     x      x     x     x              x        
PS94/050   x     x            x     x                       x      x
PS94/054   x     x      x     x     x              x
PS94/058   x     x      x     x     x      x       x        x      x
PS94/062   x     x      x     x     x              x
PS94/066   x     x            x     x                       x      x
PS94/069   x     x      x     x     x      x       x
PS94/070                                                    x      x
PS94/076   x     x      x     x     x              x
PS94/081   x     x      x     x     x              x        x      x
PS94/091   x     x      x     x     x              x        x      x
PS94/094         x      x                          x
PS94/096   x     x      x     x     x              x        x      x
PS94/099   x     x      x     x     x              x
PS94/101   x     x      x     x     x              x
PS94/105   x     x      x     x     x              x
PS94/115   x     x      x     x     x              x
PS94/117   x     x      x     x     x              x        x
PS94/121   x     x      x     x     x              x
PS94/123   x     x      x     x     x              x
PS94/125   x     x      x     x     x              x        x
PS94/128         x      x                          x
PS94/130   x     x      x     x     x              x        x
PS94/147         x      x                                   x
PS94/149         x      x                                   x
PS94/153         x                                          x             x
PS94/157         x      x                                   x
PS94/161         x      x                                   x
PS94/165                x
PS94/167         x
PS94/169         x
PS94/173         x


Chla: chlorophyll a; Chlaf: fractionated chlorophyll a; bPSi: biogenic 
particulate silica; HPLC: pigment analysis; POC/PON: particulate organic 
carbon & nitrogen. 


Preliminary/expected results

Phytoplankton community

All filters will be analysed in the AWI home laboratory. The survey of 
important microplankton organisms revealed that most commonly copepod 
nauplii belonging to the zooplankton together with large diatoms, 
ciliates and dinoflagellates (protozoa) were found in the 20µm Apstein 
net samples of Arctic surface waters (Fig. 7.4).


Fig. 7.4: Composition of net plankton > 20µm in the upper 10 m surface 
          waters in the Nansen Basin (left) and under the close sea ice 
          in the Amundsen Basin (right) taken by F. Schröter, I. Petersen 
          and J. Riedel.


Protist community

Analyses of all samples will take place subsequent to the cruise in the 
laboratory. 


Zooplankton

LOKI pictures revealed that the mesozooplankton community in the upper 
1,000 m of the water column was clearly dominated by copepods (Calanoida 
and Cyclopoida). Chaetognaths, ostracods, hydrozoan medusa, ctenophores 
and amphipods occurred regularly but in relatively low numbers. In the 
non-quantitative zooplankton samples used for molecular genetics and 
stable isotope analyses, a total of 102 planktonic metazoan and 3 
protozoan (Radiolaria) species were identified. This yield represents >50 
% of the zooplankton species known from the Arctic basins, with only the 
rarest species still remaining unsampled. 

For stable isotope analyses 29 species of most common herbivorous, 
omnivorous and carnivorous copepods (ca. 20 species), ostracods (1 
species), chaetognaths (2 species), amphipods (4 species), pteropods (1 
species), and decapods (1 species) were collected to assess relative 
ratios of grazers versus omnivores and predators. These collections 
include 244 samples from 6 stations (1-3 replicates for each species at 
each station) in the Eurasian Basin and above the Lomonosov Ridge.

Quantitative multinet samples as well as LOKI pictures will be analyzed 
for species abundance and depth distribution at the AWI. The molecular 
genetic samples collected for DNA barcoding will be analyzed in 
cooperation with IORAS at facilities of the White Sea Biological Station 
of the Moscow State University. Stable isotope samples will be analysed 
at UiT (The Arctic University of Norway) in cooperation with the AWI and 
IORAS.


Data management 

Many of the samples (i.e. pigment analyses, particulate matter in the 
water column, etc.) will be analysed at AWI within about two years after 
the cruise. We plan that the full data set will be available at latest 
about three years after the cruise. Most of species samples and samples 
which will not be analysed immediately will be stored at the AWI at least 
for another 10 years. Data will be made available to the public via 
PANGAEA.





8.  ARCTIC IN RAPID TRANSITION (TRACERS, ORGANIC CHEMISTRY, SEA ICE 
    BIOLOGY AND SUSPENDED MATTER)

    Dorothea Bauch(1)                           1 GEOMAR

Grant No. AWI_PS94_00


Introduction

The ART contributions on PS94 are partly connected to the ART work of 
PS92 and thus aim to investigate seasonal signals within the Arctic along 
the Transpolar Drift. The ART programme on PS94 brings together water 
mass tracer work based on stable oxygen and carbon isotopes (δ18O, 
δ13CDIC), suspended particulate matter (SPM), dissolved organic matter 
(DOM, CDOM, FDOM, lignin) and work on sea-ice biology. The work of each 
group is described accordingly in separate sections.

It has recently been shown that coloured dissolved organic matter (CDOM) 
plays a key role in the biogeochemistry and radiant heating of the upper 
layer in the Arctic Ocean (Hill 2008) and enhances the production of 
carbon monoxide in the ice covered Arctic (Tran et al., 2012). Additional 
CDOM will directly influence the light regime in the sea ice and the 
underlying water. Light is one of the key limiting factors for primary 
production in the ocean, particularly in the Arctic where the export of 
turbid waters from rivers and coastal regions enhances the delivery of 
nutrients to micro algal populations, but also impairs photosynthesis by 
scattering and absorbing sunlight (Retamal et al., 2008). 

Therefore it is important to study the pathways of freshwater, suspended 
particulate matter (SPM), and (CDOM) and the possible response to climate 
variations in order to understand their impact on the sensitive Arctic 
ecosystem. In addition, it is important to study these fields with regard 
to sea-ice biology, as differences in sea-ice biological features were 
observed in relation to water mass origin: Due to the decrease of the 
sea-ice thickness, recently new evolving habitats for sea-ice algae were 
observed in melt ponds (Lee et al., 2011). During the cruise TransArc 
2011, particularly in the Atlantic sector of the central Arctic, large 
aggregates of pelagic derived material accumulating on the bottom of the 
melt ponds have been found. These apparently new Arctic melt pond 
ecosystems are likely to have consequences for the carbon budget and thus 
major implications for the cryo-benthic and cryo-pelagic coupling of the 
Arctic Ocean. Nitrate was found to limit the algae standing stocks of all 
habitats (ice, melt ponds und water) in the Pacific sector in contrast to 
the Atlantic sector (Peeken, 2012).


References

Hill VJ (2008) Impacts of chromophoric dissolved organic material on 
    surface ocean heating in the Chukchi Sea. J Geophys Res-Oceans, 113.

Lee SH, Mcroy CP, Joo HM, Gradinger R, Cui XH, Yun MS, Chung KH, Kang SH, 
    Kang CK, Choy EJ,  Son SH, Carmack E, Whitledge TE (2011) Holes in 
    Progressively Thinning Arctic Sea Ice Lead to New Ice Algae Habitat. 
    Oceanography, 24, 302-308. 

Peeken I (2012) Sea ice biology. In Schauer, U., ed. The Expedition of 
    the Research Vessel "Polarstern" to the Arctic in 2011 (ARK-XXVI/3), 
    Reports on Polar and Marine Research, 649, 101-109.

Retamal L, Bonilla S, Vincent WF (2008) Optical gradients and 
    phytoplankton production in the Mackenzie River and the coastal 
    Beaufort Sea. Polar Biology, 31, 363-379.

Tran S, Bonsang B, Gros V, Peeken I, Sarda-Esteve R, Belvisio S (2012) A 
    survey of carbon monoxide and non-methane hydrocarbons in the Arctic 
    Ocean during summer 2010: assessment of the role of phytoplankton. 
    Biogeosciences Discussion, 9, 4727-4792.



8.1  Water mass signatures (δ18O, δ13CDIC)

     Dorothea Bauch(1)                          1 GEOMAR


Objectives

The purpose of the analysis of stable oxygen isotope (d18O) and stable 
carbon isotopes of the total dissolved inorganic carbon (δ13CDIC) is to 
provide an assessment of water mass and freshwater composition within the 
Arctic Ocean and to understand the inter-annual and long-scale variation 
of these signals. The stable oxygen isotope composition (d18O) of the 
water is a conservative tracer and can be used together with hydro-
chemical data to distinguish shelf-derived freshwaters (i.e. river water 
and sea-ice derived melt/brine waters) from Pacific-derived waters and 
other marine waters. Thus contribution of shelf-derived freshwaters to 
the halocline, the Atlantic layer and the deep and bottom waters of the 
Arctic Ocean can be quantified. There are inter-decadal variations in the 
distribution of the Pacific component in the Arctic Ocean but recently 
also strong spatial variations were observed in freshwater distributions 
in the Transpolar Drift in 2007 thus indicating also inter-annual and 
possibly also seasonal variations. It is not known whether these 
variations are a permanent feature and whether they are related to the 
absence of Pacific waters in 2007. The evaluation of freshwater and 
Pacific water in the Arctic Ocean halocline will thus help to further 
understand the impact and the potential feedbacks of the Arctic Ocean 
hydrography on Arctic and global climate change.


Work at sea 

Samples for stable oxygen isotope analysis (δ18O) were taken on all CTD-
rosette stations in parallel to hydro-chemical sampling and CDOM 
sampling. Depths levels are concurrent to the GEOTRACES sampling depth. 
Sampling for δ13CDIC was performed at selected stations parallel to 
hydro-chemical sampling and parallel to Multinet casts. Mostly all depth 
levels over the upper 500 m of the water column were sampled and at a 
selected station down to the bottom. 50 ml of water was taken for each 
δ18O sample. For δ13CDIC 100 ml samples were drawn by minimizing air-
water gas-exchange (without "bubbeling"). Samples were poisoned with 
0.2ml of 0.5-saturated HgCl2.

Samples for δ18O also include ice cores. Sea-ice samples were provided 
from the sea-ice biology group from thawed 10cm section of the salinity 
core (see section on sea-ice biology and section on ice coring sites, 
accordingly).


Expected results

No results were obtained at sea. Samples will be analysed on shore by 
mass-spectrometry. Samples for δ18O and δ13CDIC analysis will be 
transported to Kiel. Analysis will be conducted at the Leibniz Laboratory 
at Kiel University, Kiel, Germany and at the Stable Isotope Facility at 
CEOAS at Oregon State University, Oregon, USA within 1 year. 

Based on hydrological data and stable oxygen isotope analysis (δ18O) the 
influence of mainly shelf-derived meteoric waters and modification by 
sea-ice processes (melting or formation) can be quantified (Bauch et al., 
1995). 

From previous investigations in the Central Arctic Ocean e.g. in summer 
2007 we know that there is spatial and temporal variation of freshwater 
distribution within the Arctic Ocean halocline on an inter-annual to 
potentially seasonal timescale (Bauch et al., 2011). With the samples 
obtained during PS94 we expect to learn more about the inter-annual and 
long-scale variations of freshwater within the different layers of the 
Arctic Ocean halocline.

A comparison with results of freshwater assessment based on CDOM will be 
done and thus we expect to achieve additional information e.g. about the 
ratio of river and other meteoric waters. 


Data management

Data will be stored at the Pangaea data repository and will be made 
public there within three years.


References

Bauch D, Schlosser P, Fairbanks RF (1995) Freshwater balance and the 
    sources of deep and bottom waters in the Arctic Ocean inferred from 
    the distribution of H218O. Progress in Oceanography, 35, 53-80.

Bauch D, Rutgers van der Loeff M, Andersen N, Torres-Valdes S, Bakker K, 
    Abrahamsen EP (2011) Origin of freshwater and polynya water in the 
    Arctic Ocean halocline in summer 2007. Progress in Oceanography, 482-
    495, doi:10.1016/j.pocean.2011.1007.1017.



8.2  Dissolved organic matter

     Heather Reader(1), Colin Stedmon(1)        1 DTU-Aqua
     (not on board),                            2 RSMAS
     Dennis Hansell(2) (not on board),          3 TAMU
     Rainer Amon(3) (not on board)


Objectives
	
• The main goal of sampling effort was to map the distribution and 
  characteristics of dissolved organic matter (DOM) in the Arctic Ocean. 
  One of the goals is to trace the distribution of terrestrially-sourced 
  DOM, which originates in the Siberian rivers, and its mixing with 
  marine waters in the surface layers of the Arctic Ocean, and compare 
  DOM to other water mass tracers, in particular using the optical 
  properties of DOM (coloured and fluorescent DOM, CDOM and FDOM, 
  respectively).  Combining this sampling effort with an on-going 
  monitoring programme in the Fram Strait (see Stedmon et al., 2015), we 
  will evaluate the use of DOM as a new tracer of meteoric water in the 
  Arctic Ocean.

• Further tracing of the influence of the Siberian rivers on the Arctic 
  Ocean ecosystem is achieved by collecting the first detailed vertical 
  profiles of lignin. Lignin is a biomarker that is derived from the 
  tissue of woody plants, and therefore has an exclusively terrestrial 
  source, and can be used as a tracer of river water in marine systems.  
  The sampling of dissolved organic carbon (DOC) will contribute to the 
  concurrent Canadian and US sampling programmes and provide a unique 
  trans-Arctic dataset.  Furthermore, the influence of DOM on sea ice 
  algal communities and vice versa was investigated in collaboration with 
  sea ice biology. 


Work at sea 

Samples were collected for DOC, CDOM and FDOM at all depths concurrent to 
the GEOTRACES sampling stations, and was coordinated with inorganic 
nutrients and stable oxygen isotope sampling.  Additional samples for 
DOC, CDOM and FDOM were taken at each CTD-Large station along section 4, 
focusing on the surface layers (0 - 500 m).  Samples for lignin analysis 
were collected for 3 stations in each basin (Nansen, Amundsen, and 
Makarov), as well as one station on section 6, to collect Atlantic water 
inflow.  

CDOM UV-visible absorbance was measured on board using a Perkin-Elmer 
Lambda-35 spectrophotometer (by agreement with Dr. Piotr Kowalczuk, 
IOPAN). Excitation-emission matrix fluorescence spectra to characterise 
FDOM were also measured on board using a Horiba Aqualog fluorescence 
spectrometer (by agreement with Dr. Astrid Bracher, AWI).  DOC samples 
were frozen for later analysis by Dennis Hansell, RSMAS, Miami, USA.  
Ligning samples were frozen for later analysis by Rainer Amon, Texas A&M 
University, Galveston, USA.

Samples from sea ice cores, melt ponds, and under ice water were sampled 
by the sea ice biology team, and CDOM and FDOM were also measured on 
board.  Sub-samples for DOC from these samples were frozen for later 
analysis at DTU.


Preliminary/expected results 

The DOC measurements will provide a unique basin scale mapping of 
distributions and contribute to the global sampling effort coordinated by 
Hansell (Hansell et al., 2009). The DOM and lignin measurements will 
allow us to develop our understanding of how the quantity and quality of 
Arctic riverine DOM changes during mixing in shelf seas and transport 
across the Arctic in the halocline layer. The DOM and lignin datasets 
will be linked with  previously published data from the Siberian rivers 
(Stedmon et al., 2011; Amon et al., 2012) and with an on-going monitoring 
programme in the Fram Strait that that focuses on water exiting the 
Arctic Ocean along the coast of Greenland (Granskog et al., 2012; Stedmon 
et al., 2015).


Data management

Data from water column DOC measurements will be submitted by Dennis 
Hansell, RSMAS.  Data from lignin measurements will be submitted by 
Rainer Amon, TAMU.  Data from water column CDOM and FDOM will be 
submitted by Heather Reader, DTU.  Data from ice sampling (DOC, CDOM, 
FDOM) will be submitted first to the sea ice biology group to compile 
with the rest of their data and then submitted to PANGAEA by the sea ice 
biology group.  All data will be processed and submitted in a timely 
fashion.


References 

Amon RMW et al. (2012) Dissolved organic matter sources in large Arctic 
    rivers. Geochim. Cosmochim. Acta, 94, 217-237, 
    doi:10.1016/j.gca.2012.07.015.

Granskog MA, Stedmon CA, Dodd PA, Amon RMW, Pavlov AK, de Steur L, Hansen 
    E (2012) Characteristics of colored dissolved organic matter (CDOM) 
    in the Arctic outflow in the Fram Strait: Assessing the changes and 
    fate of terrigenous CDOM in the Arctic Ocean. J. Geophys. Res., 
    117(C12), C12021, doi:10.1029/2012JC008075.

Hansell D, Carlson C, Repeta D, Schlitzer R (2009) Dissolved Organic 
    Matter in the Ocean: A Controversy Stimulates New Insights. 
    Oceanography, 22(4), 202в11, doi:10.5670/oceanog.2009.109.

Stedmon CA, Amon RMW, Rinehart AJ, Walker SA (2011) The supply and 
    characteristics of colored dissolved organic matter (CDOM) in the 
    Arctic Ocean: Pan Arctic trends and differences. Mar. Chem., 124(1-
    4), 108-118, doi:10.1016/j.marchem.2010.12.007.

Stedmon CA, Granskog M, Dodd P (2015) An approach to estimate the 
    freshwater contribution from glacial melt and precipitation in East 
    Greenland shelf waters using colored dissolved organic matter (CDOM). 
    J. Geophys. Res. Oceans, 120, doi:10.1002/2014JC010501.



8.3  Suspended particulate matter (SPM)

     Dorothea Bauch(1)                          1 GEOMAR
     Carolyn Wegner(1) (not on board)


Objectives

The goal of this study is to improve our understanding of the pathways of 
suspended particulate matter (SPM) from the Barents shelf to the Nansen 
Basin which is critical in order to draw the connection between sediment 
dynamics, optical properties and ecosystem dynamics under a changing 
climate. Furthermore quantifying the abundance and composition of SPM, 
and comparing these to sea ice and ocean surface sediment samples is 
required to understand the significance of large-scale lateral transport, 
and how this may affect the reconstruction of ice conditions in the 
geologic past. 


Work at sea and at the ice

Sampling for SPM was conducted over the continental shelf break of the 
Barents Sea at 30°E. For each sample 1L of water was taken from the 
rosette. Water samples were taken over the whole water column for all 
stations with up to about 500 m bottom depth. Samples were filtered 
through pre-weighed HVLP filters by MILLIPORE (0.45 microns), and washed 
carefully with distilled water after filtering. 


Expected results

No results were obtained at sea. To investigate the vertical and 
horizontal distribution of SPM filter samples will be analysed at GEOMAR. 
SPM filter data will be used to calibrate the transmissometer recordings 
from the CTD. In general, losses of light propagating through water can 
be attributed to two causes: scattering and absorption. By projecting a 
collimated beam of light through the water and placing a focused receiver 
at a known distance away, one can quantify these losses. The ratio of 
light gathered by the transmissometer's receiver to the amount originating 
at the source is known as the beam transmittance (Tr), which provides an 
indication of total. 


Data management

Data will be stored in the PANGAEA data repository, and will be made 
publicly available. 



8.4  Sea ice biology

     Andreas Krell(2), Erika Allhusen(1),       1 AWI
     Irina Kryukova(3), Ilka Peeken(1)          2 KOWI
     (not on board)                             3 SIO
 

Objectives

Sea ice associated communities play a major role in the cryo-benthic and 
cryo-pelagic coupling of the Arctic Ocean. The transition from the 
occurrence of multiyear ice (MYI) to the predominance of first year ice 
in the investigation area within the past decades and its implications on 
the sea ice community and associated ecosystem are not well understood.

As a contribution to the German BMBF-project Transdrift, we investigated 
the sea ice and under-ice algal communities in the Atlantic and the 
Pacific sector of the Central Arctic to compare these observations with 
historic data in order to discern long term changes in these habitats. 
Special emphasis will be placed on recent changes in the melt pond 
associated communities and their respective role in the Arctic carbon 
budget. 

The impact of DOM and SPM on the optical properties of sea ice will be 
determined and related to ice algal biomass. The measurement of tracers 
in the sea ice will help to understand the history of the sampled ice 
floes. To understand the seeding processes of the sea ice algae, the 
biodiversity of new ice, particular from the Laptev Sea will be 
determined and compared to sea ice communities sampled along the 
transpolar drift in the framework of the Transdrift project.


Work at sea

The sampling of sea ice for biological properties (chapter 9) involved 
ice-core sections, under-ice water and meltpond water. The depth of the 
sampling under the ice was determined by CTD profiles and fluorescence 
probe measurements prior to the water sampling. On site, environmental 
parameters such as sea ice temperature, snow depth, free board and ice 
thickness were measured. 

Ice core sections were melted in closed plastic barrels filled with 2 L 
of 0.2µm filtered sea water at 4°C. Melted samples were subsequently 
split into 0.5 L aliquots for HPLC, fractionated Chl a and POC 
filtration. Remaining volumes were pooled into an upper and lower part of 
the core for analysis of PBSi, fractionated DNA and Utermhl species 
enumeration. 

Sections of the salinity core were left to melt at 15°C. Salinity was 
determined with a WTW 315i conductivity probe. The total volume of the 
melted section was measured and subsequently aliquots for nutrient and 
18O stable isotope analysis were taken. Remaining samples were again 
pooled into upper and lower part of the ice core and samples for cDOM and 
PABs analysis were taken.


Preliminary results

Average sea ice thickness of the cores was 120 cm and thus in the same 
range as that of biological FYI cores collected during the Transarc 
cruise in 2011 during the same season and region. Compared to 2011, when 
hardly any snow was present, we observed a ubiquitous snow cover on the 
sea ice. All melt ponds had a refrozen surface of up to 15 cm thickness, 
which during the second half of the cruise were also covered with snow. 

Fig.  8.4.1 shows a typical sea ice salinity and temperature plot 
revealing an almost isothermal profile of temperatures ranging between -
1,3°C and -2,5°C. The salinity profile reveals an elevated concentration 
on the surface which reflects brine expulsion after refreezing of the 
surface melt water, which again is reflected by extremely low salinity 
immediately below the surface. The remainder of the core shows typical 
Arctic sea ice salinities corresponding to the temperatures.


Fig. 8.4.1: Temperature and Salinity profile of an ice core (1.51m total 
            length) taken at station PS94_096


Fig. 8.4.2 shows typical salinity and temperature profiles obtained with 
the SEA and SUN CTD deployed through an ice core hole. The strong 
temperature rise and low salinities in the top meter of the water column 
below sea ice is indicative of recent melting.


Fig. 8.4.2: Temperature and salinity profile of the upper 30 m of the 
            water column below the ice at station PS94_054


Filtered samples will be analysed for POC, HPLC, fractionated Chl a, 
fractionated DNA, PBSi and PABs and taxonomic species enumeration will be 
carried out at AWI.


Data management

Data will be stored at the PANGAEA data repository and will be made 
publicly available there within 2 years after the cruise.





9.  BENTHIC BIOGEOCHEMISTRY

    Ulrike Hanz(1), Joshua Kiesel(1),           1 Uni Kiel
    Heike Link(1), Karen von Juterzenka(1),     2 AWI
    Dieter Piepenburg(1),(2), Christina         3 MPI
    Bienhold(3) (last four not on board)

Grant No. AWI_PS94_00


Objectives

Current environmental changes are very likely to heavily impact the 
Arctic marine ecosystem, since warming in the northernmost latitudes is 
considered to be twice or three times the global rate (Wassmann et al., 
2011). Nevertheless, research efforts have mostly focused on terrestrial 
ecosystems, while the marine ecosystem has often been neglected (Wassmann 
et al., 2011). Thus, in order to evaluate and assess current 
environmental changes, large-scale and long-term observations are 
required. 

The benthos plays a major role in the marine ecosystem as it degrades and 
recycles a significant amount of organic matter that enters the seafloor 
from the euphotic zone (Link et al., 2013a; Link et al., 2013b). Benthic 
communities are strongly dependent on this carbon supply, which 
especially counts for deep sea communities (Boetius and Damm 1998). At 
the seafloor these resources will be either recycled by the local fauna, 
or stored in the sediment record. Re-mineralized nutrients will be 
redistributed in the water column and thus, are again available for 
primary production. However, benthic boundary fluxes are not stable and 
re-mineralization fluctuates according to season, functional diversity, 
ice cover, or eventually with changing environmental conditions (Link et 
al., 2013).

During PS94 we determined patterns of benthic ecosystem functioning by 
assessing benthic boundary fluxes among different temporal and spatial 
gradients. This was realized with the help of shipboard microcosm 
incubations, as well as additional porewater oxygen microprofiles and 
sediment samples taken for DNA, total organic carbon (TOC), chlorophyll, 
prokaryotic cell numbers (AODC) and enzymes. Additionally we tried to 
investigate the impact of benthic biodiversity and abundance on re-
mineralization rate, by determining species counts and abundance of the 
communities we observed. Conclusive, the goal was the quantification of 
benthic ecosystem functioning under different resource and diversity 
patterns, while additionally comparing seasonal characteristics (in the 
Barents Sea), annual differences (central Arctic 2015 vs 2011/12 vs 
1993), different sea-ice cover regimes and varying spatial gradients, 
namely shelf seas, slopes, mid oceanic ridges and deep sea basins. We 
thereby hope to assess possible impacts of steadily changing 
environmental conditions on arctic benthic ecosystems. 


Work at sea

Benthic re-mineralization rate and oxygen consumption of benthic 
organisms was studied using ex-situ sediment core incubations and 
additional porewater oxygen microprofiles across the Arctic Ocean. Water 
depths ranged from 377 m in the Barents Sea to 4847 m in the Amundsen 
Basin. Sediment cores were obtained by deploying a multicorer that 
extracts 8 sediment cores from the seafloor. At PS94-66-2, PS94-69-7 and 
PS94-105-2 an additional boxcorer was deployed, since benthic topography 
was likely to cause harm to the more fragile multicorer. Stations 
included deep sea basins, the Barents Sea, the Gakkel Ridge, the 
Lomonosov Ridge and the Karasik Mountain (see Fig. 9.1).


Fig. 9.1: MUC and box corer stations during PS94

 
Thereby we assessed diverse benthic environments of distinct ocean 
basins, mid oceanic ridges, continental slopes and shelf seas. This 
enables us to obtain a more detailed understanding of the arctic benthos 
among different spatial and temporal gradients, as well as varying sea 
ice conditions. 


Tab.9.1: Station list during PS94

Station  Samp-  Date         Latitude     Longitude    Depth    Sea     In-   O2    Mi-   Ma-
         ling                                           [m]     ice     cu-   Pro-  cro-  cro-
         De-                                                  coverage  ba-   file  bio   fau-
         vice                                                   [%]     tion              na
———————  —————  ——————————  ———————————  ————————————  —————  ————————  ————  ————  ————  ————
1-2       MUC   18.08.2015  75°0,055'N    30°0,333'E     378      0       y     y     y     y
2-2       MUC   19.08.2015  76°40,579'N   30°0,213'E     273      0       y     y     y     y
20-2      MUC   21.08.2015  80°59,762'N   28°58,324'E    377              n     y     y     y
32-10     MUC   22.08.2015  81°51,409'N   30°54,656'E   3164     99       y     y     y     y
50-10     MUC   27.08.2015                29°37,426'E   4000     99       n     y     y     y
66-2      GKG   01.09.2015  86°42,756'N   61°21,732'E    644    100       y     n     y     y
69-7      GKG   02.09.2015  87°1,106'N    58°16,327'E   4847    100       n     n     n     y
87-2      MUC   08.09.2015  89°55,482'N  120°33,864'E   4200    100       y     y     y     y
101-10    MUC   14.09.2015  87°29,807'N  179°54,151'E   3941     90       n     y     y     y
105-2     GKG   16.09.2015  86°58,665'N  146°50,676'E  973,4     90       y     y     y     y
123-2     MUC   22.09.2015  85°03,575'N  137°36,566'E   4048     95       n     y     y     n
130-4     MUC   24.09.2015  85°0,926'N   151°45,503'E    833    100       y     y     y     y
149-5/6   MUC   07.10.2015  74°19,132'N   23°48340'E     292      0       y     y     y     y
161-6     MUC   08.10.2015  72°44,062'N   22°49,248'E    385      0       n     y     y     n   


After MUC retrieval, sediment cores were pushed onto a bottom lid and 
then pushed up with an extruder, so that water phase above the sediment 
had a width of about 15cm. Afterwards three cores have been directly 
taken to a temperature controlled water bath of 2°C, where two porewater 
oxygen microprofiles per core have been obtained. Thereby we will assess 
oxygen penetration depth and the diffusive oxygen uptake of the 
respective sediments. Profiles were carried out by using a 
micromanipulator that has been adjusted to a maximum depth of 6.5cm. 
Vertical resolution was 100m and the distance between profiles varied 
between one- and two cm horizontally. After microprofiles have been 
successfully finished, sediment samples have been taken with cut and acid 
cleaned syringes from the respective cores, in order to test for 
microbiological parameters like AODC, chlorophyll, total organic carbon, 
enzymes and DNA. Samples have been immediately frozen at -20°C and will 
be analyzed by Christina Bienhold at the MPI in Bremen. Additionally, one 
core per station was sampled in order to analyze geochemical tracers like 
mercury, as it is described in the geotraces section of this cruise 
report by Lars-Eric Heimbürger. 

Three further cores have been brought to a dark, temperature-controlled 
room of 2 to 4°C, where shipboard microcosm incubations have been carried 
out. We will thereby assess the total sediment oxygen flux by using a 
non-invasive optical probe (Fibox 3 LCD, PreSens, Regensburg, Germany). 
Furthermore, nutrient samples of each respective core enable the 
assessment of re-mineralization rates of nitrate, silicic acid, phosphate 
and nitrite (Link et al., 2013a). 

While working on sediment core incubations, we followed the methodology 
that has been introduced by Link et al., (2013a). Sediment cores were 
topped with a stirring motor that homogenized the water column above the 
sediment. Nutrient samples have been taken with acid cleaned syringes at 
three times during each incubation. The time of sampling has been 
synchronized with the rate of benthic oxygen uptake. At the onset of each 
incubation, sediment cores have been aerated with a bubbling device in 
order to ensure 100 % oxygen saturation. Then, the first nutrient sample 
has been taken. When oxygen levels have dropped by 10 %, midway nutrient 
sampling was conducted while the final sample has been taken when 
remaining oxygen concentration was at 80 %. This was done in order to 
prevent suboxic conditions and therefore chemical alterations during 
final nutrient sampling. After each syringe sample, the taken water has 
been filtered through Gf/f Whatman filters into 15 ml vials. Vials have 
been shock frozen at -80°C. After the third and final nutrient sample, 
syringes have been taken from the sediments of each core, in order to 
test for chlorophyll- and phaeopigments, as they are considered 
indicators of fresh food supply (Link et al., 2013a). Sediment cores have 
been finally sieved under running seawater with 500 m mesh size, in order 
to obtain macrofaunal diversity and abundance. Residues have been 
preserved in 4 % Formalin and will be analyzed in our home labs. 

At stations 66-2 and 105-2 box corer were deployed as bottom topography 
was suspected to harm the multicorer. Directly after box corer retrieval, 
6 subcores for porewater microprofiles and microcosm incubations, as well 
as syringes for microbiological sampling were pushed gently into the 
sediment. Afterwards, cores have been carefully topped with bottom water 
from the rosette, taken at the same station and were treated as described 
above. 

At station 69-7 a boxcorer was deployed for conducting macrofaunal 
analysis in the vicinity of a hydrothermal vent on the Gakkel Ridge. 
Hence, a defined amount of sediment has been taken out of the corer and 
has been sieved over 500 m, in order to obtain macrofaunal diversity and 
abundance. Residues have been preserved for later microscopic analysis in 
4 % Formalin.


Preliminary results

Besides pore water oxygen microprofiles and benthic oxygen consumption of 
microcosm incubation sediments, no further results have yet been 
obtained. 

Nevertheless, we expect significant correlations between water depth, sea 
ice cover and ecosystem functioning in terms of benthic boundary fluxes. 
This has been indicated before by Boetius and Damm (1998) who wrote that 
ice cover as well as an increase in water depth strongly reduces 
abundance and activity of benthic organisms. We additionally hypothesize 
that sediment oxygen fluxes differ significantly among water depth and 
the method that has been used. We will therefore compare fluxes derived 
either from porewater microprofiles (diffusive flux) or from the non-
invasive optical probe (total flux), which we have used during the 
incubations. 


Data management

Data archival will be mainly hosted by the information system PANGAEA at 
the World Data Center for Marine Environmental Sciences (WDC-MARE), which 
is operated by the Alfred Wegener Institute for Polar and Marine 
Research, Bremerhaven and the MARUM, Bremen. As soon as data on 
geotracers, nutrient re-mineralization, oxygen fluxes and microbiological 
parameter are available, we will submit the respective data to PANGAEA 
and protect these via a password. Macrofaunal samples are fixed and will 
be stored at the GEOMAR in Kiel. 


References

Boetius A, Damm E (1998) Benthic oxygen uptake, hydrolytic potentials and 
    microbial biomass at the Arctic continental slope. Deep-Sea Research, 
    45, 239-275. 

Link H, Piepenburg D, Archambault P (2013a) Are Hotspots Always Hotspots? 
    The Relationship between Diversity, Resource and Ecosystem Functions 
    in the Arctic. PLoS ONE, 8 9, 1-18. 

Link H, Chaillou G, Forest A, Piepenburg D, Archambault P (2013b) 
    Multivariate benthic ecosystem functioning in the Arctic Рbenthic 
    fluxes explained by environmental paramteres in the southeastern 
    Beaufort Sea. Biogeosciences, 10, 5911-5929.

Wassmann P, Duarte CM, Augustí S, Sejr MK (2011) Footprints of climate 
    change in the Arctic marine ecosystem. Global Change Biology, 17, 
    1235-1249. 





10.  METHANE AND DMS IN SEA ICE AND SEA WATER

     Ellen Damm(1), Christiane Uhlig(1),        1 AWI
     Elena Vingradova(2) Gerhard Dieckmann(1)   2 SIO
 
Grant No. AWI_PS94_00


Objectives

Summer sea ice retreat alters water mass formation and convection, which 
may have profound effect on natural biogeochemical cycles between sea ice 
and seawater. Especially feedback effects to pathways of climatically 
relevant trace gases will loom large in the equation of change. 
Increasing water stratification during sea ice melting is likely to limit 
nutrient availability in near-surface water, which in turn hampers the 
enhancement of primary production. A characteristic feature of the Arctic 
Ocean is the distinct post-bloom nutrient limitation found in the 
Atlantic-dominated and Pacific-dominated sectors. Nutrient limitation may 
be also a possible regulator of methane production in surface water. 
Methanogens form methane via various pathways commonly classified with 
respect to the type of carbon precursor utilized, e.g. the 
methylothrophic pathway indicates the intact conversion of a methyl group 
to methane. The contribution of methylated substrates is potentially 
large in sea ice, and methylothrophic methanogenis may be a principal 
pathway from which methane is readily formed by microbial activity. 
However, the direct evidence of this role of methylated substrates in sea 
ice is still lacking. In this context the degradation of 
dimethylsulfoniopropionate (DMSP), an abundant methylated substrate in 
surface water and sea ice becomes pivotal. DMSP is produced by marine 
phytoplankton and sea ice algae. Cleavage of DMSP can be carried out by 
bacteria or by phytoplankton, and leads to formation of DMS 
(dimethylsulfide) or methanethiol. DMS, an important climate-cooling gas, 
partly escapes to the atmosphere where it is oxidized to sulphuric acid 
and methanesulfonic acid. Methanethiol is a key reactive intermediate 
utilized as sulphur and carbon sources for biosynthesis or energy 
generation. In anaerobic environments methanethiol act also as precursor 
for methane production. Our goal is to trace methane cycle between sea 
ice and sea water, to distinguish the different degradation pathways of 
DMSP and subsequently to quantify the formation of DMS, methanthiol and 
methane. 

To gain a better understanding on the possible formation of methane from 
the substrate DMSP we will additionally conduct incubation experiments. 
Different treatments will be set up by adding DMSP and varying nutrient 
concentrations to melted sea ice or sea water collected with Niskin 
bottles. During the experiments DMSP, DMS, methanethiol and methane will 
be measured on board. Bacterial abundance and community composition (16S) 
as well as DMSP degradation pathways (degradation genes) will be analysed 
in the home laboratory. Some of the experiments will be conducted with 
13C-labeled DMSP to track the DMSP-derived methyl groups.


Work at sea

Methane, DMS and DMSP were immediately measured on board ship, using gas 
chromatographs equipped with a flame ionization detector (FID) and a 
pulsed flame photometric detector (PFPD), respectively. Methane gas 
samples were stored for analyses of the δ13CCH4 values in the home 
laboratory. 

Water samples for methane analysis have been collected at 50 stations 
distributed along all hydrographic transects. Samples were taken from 
Niskin bottles mounted on a rosette sampler at discrete depths throughout 
the water column at least up to 200 m and on selected stations up to 500 
m water depth. On transect 2 stations 68, 69 and 70 methane concentration 
was measured up to the bottom. The number of sampling depths varied as a 
function of the fluorescence signal and the O2- sensor signal. 

Water samples for DMS and DMSP analysis have been taken from Niskin 
bottles at discrete depths up to 100 m. Samples for DMS analysis were 
carefully alliquoted in glass vials, crimped and measured immediately by 
gas chromatography equipped with a pulsed flame photometer (PFPD) and a 
purge and trap system. DMSP measurements have been conducted on the same 
samples. The vials were opened again and 2 ml sodium hydroxide solution 
was added. After alkaline cleavage the DMSP was measured with the same 
procedure as DMS. 

Ice cores have been taken on 8 ice stations and at 3 mummy chair stations 
(see coring site documentation). The complete ice cores were returned to 
the vessel into the cold (-25°C) container where they were sectioned into 
10 cm slides. One half of each slide was used for the measurement of 
methane concentration and the other one for the analysis of DMS and DMSP 
concentration. For DMS and DMSP measurement a subsample of 10 cm length 
and a cross section of 5x5 mm was cut from the middle half slide. This 
long rectangle was put in a glass vial and immediately crimped with 
rubber lids in the cold container. When the ice in the vials was melted 
DMS was measured with a gas chromatograph (Varian 450) equipped with a 
pulsed flame photometer (PFPD) and a purge and trap system. After DMS 
analysis the glass vials were opened again to add 2 ml sodium hydroxide 
solution to the melted ice. Two hours after closing the vials, the DMSP 
measurement were performed by the same procedure like for DMS. After 
measurement the exact volumes of the ice samples were determined. 

The second half of the slides were putted in a gas tight bag (Kynar bags 
with polypropylene 2-in 1-valve by Keikaventures) and closed. Subsequent 
the air was removed by using a vacuum pump. The melted water was filled 
into 100 ml glass vials where a 20 ml headspace was created after the 
vials were crimped.  The glass vials were shaken for equilibration at 
least half an hour before retrieving a sample from the headspace with a 
syringe. 

To gain a better understanding on the microbial processes involved in 
DMSP conversion to DMS and possibly methane, incubation experiments were 
performed on board. On six different stations (Table 10.1) sea water or 
sea ice cores were collected. The ice core was crushed to small pieces 
inside a plastic bag using a hammer. The ice was melted in the under ice 
water sampled at the same station over night at +5°C. The sea water and 
melted ice was distributed in the experimental bottles. Incubations were 
run for up to two weeks at 0°C temperatures in constant light or dark. 
Control bottles were incubated without any additions in the light. 
Treatment bottles were spiked with different concentrations of DMSP and a 
combination of DMSP and NADPH (ß-Nicotinamide Adenine Dinucleotice 
Phosphate Reduced Form Tetra (Cyclohexylammonium) Salt) hydrogen donor. 
Experimental bottles were kept closed and gas tight during the course of 
the experiment. Gas and liquid samples for all parameters shown in Table 
10.2 were taken with syringes through a septum in the lid of the bottles, 
except for the final sampling when the bottle was opened for the liquid 
sampling. Methane from the headspace as well as DMS and DMSP from the 
liquid phase were measured directly on board using gas chromatographs 
equipped with a flame ionization detector (FID) and pulsed flame 
photometric detector (PFPD), respectively. Samples for the other 
parameters were fixed and stored at the desired temperatures for later 
analysis in the home laboratory. Samples for molecular biology were 
collected onto 0.2 µm Sterivex filtration cartridges filters. 

Water from CTDs PS95/105, PS94/117 and PS94/125, will be transported back 
for further experiments. Additionally, this water was used to prepare 
enrichment cultures with DMSP, methanol and methylphosphonic acid as 
substrate. These will be used to isolate strains able to degrade the 
respective substrates.


Tab. 10.1: Sea ice sampled for microbial incubation experiments

Station     Sample type          comment                Experiment
——————————  ———————————————————  —————————————————————  ——————————
PS94/34-1   CTD bottles 23+24    5+10m depth                1
PS94/81     sea water + sea ice  under ice water            2
                                 sampled with Kemerer-      
                                 bottle,  bottom 10 cm      
                                 from 13cm core             
PS94/101-8  Ultra clean CTD      20m depth                  3
PS94/105-1  CTD bottle 22        10m depth                  4
PS94/117-6  CTD bottle 11        10m depth                  5
PS94/125-7  CTD bottle 7+9       30m depth, cDOM max        6
PS94/125-7  CTD bottle 17        10m depth                  7   
    

Tab.10.2: Parameters that were or will be measured on board or in the 
          home laboratory. Except for methane all parameters were 
          determined from the liquid phase.

On board                                           Experiment
—————————————————————————————————————————————————  ——————————————————————————
Methane (headspace)                                1, 2, 4, 5, 6, 7
DMS and DMSP                                       1, 2, 3
Nutrients (Silikate, Nitrate, Nitrite, Phosphate)  1, 2, 4-7 (only start)
Home laboratory(1)
Living samples (liquid)                            1, 2, 4-7 (only start)
Total counts (bacteria)                            1, 2, 4-7 (only start)
Bacterial diversity (Fluorescence-in-situ-         1, 2, 4-7 (only start)
hybridization, 16S sequencing, denaturing 
gradient gel electrophoresis)
DMSP conversion genes (qPCR)                       1, 2, 4-7 (only start)
Enrichment cultures                                4-7 (from start community)
—————————————————————————————————————————————————————————————————————————————
1 Processing of these samples in the home laboratory are subject to 
  funding and will start in 2017.


Preliminary results

Methane in sea water and sea ice

In the study area, methane concentrations are heterogeneous and 
correspond to both a clear under-saturation and a clear super-saturation 
with respect to the atmospheric equilibrium concentration. The 
equilibrium concentration is calculated as a function of the gas 
solubility on the basis of the measured temperature and salinity 
properties and varies between 3.2 to 3.9nM. Methane super-saturation was 
detected in surface water at all transects (Fig.10.1). Methane under-
saturation was often revealed below the halocline except for transect 1 
and 4. At transect 1 enhanced methane concentration was detected in 
inflowing Atlantic water between 100 and 400 m water depth (Fig.10.2). 

In most ice cores (10) methane concentrations varied between 2.1 and 8.5 
nM. In one ice core methane concentration was clearly below this range 
(0.2-1.8 nM) and in one ice core clearly above this range (3.3-55.1nM).


Fig. 10. 1: Methane concentration at transect 2 
Fig. 10. 2: Methane concentration at transect 1


DMS and DMSP concentrations in sea water and sea ice 

DMS and DMSP concentrations are highest on transect 1 and decrease on 
transects 2 and 3 while both components remain correlated. A mismatch 
between DMS and DMSP is present at transect 4 which means that DMS 
concentrations continue to be as low as at transect 3 but DMSP 
concentrations increase (Fig. 10.3).

Concentrations are significantly higher in ice cores than in seawater. 

In general concentrations are highest at the bottom of sea ice and DMS 
and DMSP are correlated in most ice cores. However, there also exists a 
mismatch between the two in some ice cores. 


Fig. 10.3: DMS and DMSP concentration at transect 4


Experiments

The experiment with water from station PS81/34 first showed an increase 
in DMSP levels in the treatments and control which was followed by a 
decrease. DMSP in the controls was low and DMS was close to the detection 
limit. Methane formation was not detected. The seawater used for the 
first experiments was depleted in nutrients.

In the second experiment (sea ice and under ice water PS94/81) we 
observed DMSP degradation with simultaneous DMS formation in the control 
as well as DMSP and DMSP-plus-NADPH spiked treatments. Methane 
concentrations did not differ between controls and treatments. Sea water 
used for this experiment was depleted in nitrate and had low phosphate 
levels (0.2 µM).

The third experiment was a contribution to a mercury spike experiment 
with seawater from 20 m depth from the ultra clean CTD by Lars-Eric 
Heimbrger. Only DMS and DMSP were measured in this experiment. Due to the 
short incubation time of only 24h only a very small increase in DMS 
concentration was observed.

Experiments 4 to 7 were set up in 125 mL crimp-top bottles to only follow 
methane concentrations. In all experiments methane concentrations were 
decreasing over time indicating methane oxidation. Clear differences 
between controls, treatments with addition of DMSP or incubation in the 
dark were not observed. Few data points indicate slightly higher methane 
oxidation in DSMP-spiked bottles and in light compared to dark 
incubations. 


Data management

All data collected during the expedition will be stored in the PANGAEA 
data repository at the AWI within three years after the cruise. 





11.  SEA ICE FIELD WORK FOR GEOCHEMISTRY AND BIOLOGY

     Andreas Krell(1), Erika Allhusen(2),        1 KOWI
     Irina Kryukova(3), Gerhard Dieckmann(2),    2 AWI
     Christiane Uhlig(2), Elena Vinogradova(3),  3 SIO
     Ellen Damm(2)

Grant No. AWI_PS94_00


Sea ice coring and under-ice sampling was carried out in a coherent way 
for the groups "Production and Cycling of Climate Relevant Trace Gases" 
(chapter 10) and ART (chapter 8). In addition ice cores and under ice 
water samples were taken for various other groups and/or parameters. In 
this chapter the sea ice coring and processing on the ice is documented. 
Scientific objectives and further processing for individual parameters is 
described in the respective chapters accordingly.


Work at sea

Ice station summary

11 ice stations were sampled during PS94. 8 were full-length ice stations 
of more than 6 hours duration and 3 were mummy-chair stations (Table 
11.1).


Table 11.1: List of sea ice stations sampled, mc=mummy chair

            Station Nr.  Date        Latitude  Longitude
            ———————————  ——————————  ————————  —————————
            PS94-046     2015.08.25  83.7163    30.3775
            PS94-054     2015.08.28  85.086     42.6052
            PS94-069     2015.09.02  87.0068    58.6628
            PS94-081     2015.09.05  88.9857    60.9663
            PS94-096     2015.09.11  88.3607  -125.1147
            PS94-098mc   2015.09.12  88.3385  -144.315
            PS94-101     2015.09.14  87.5007   179.8043
            PS94-107mc   2015.09.16  86.6297   133.8762
            PS94-112mc   2015.09.17  85.2148   118.395
            PS94-117     2015.09.19  84.4875   115.718
            PS94-125     2015.09.22  85.0808   139.9132
 

Sea ice cores were retrieved using a standard 9 cm Kovacs ice corer, 
driven by a Makita powerhead. The cores were subsequently processed 
according to and depending on the requirements for the different 
parameters to be analyzed (Table 11.2). Some cores were sectioned on-site 
for bulk ice measurements using a stainless steel butcher's saw. Full-
length cores for different parameters were placed in plastic tubing and 
returned to the ship's cold storage room. CTD depth profiles down to 40 m 
were conducted through the ice holes and water samples were taken 
directly under the ice (immediately underneath the ice and at the 
chlorophyll maximum) using a Kemmerer bottle. Meltponds were sampled 
where present. 

Attempts were made to collect sea-ice brine from sackholes, but failed 
due to the high porosity of the sea-ice which caused immediate flooding 
of the sack holes with water from below. 


Table 11.2: List of parameters to be analyzed and responsible scientists 

Parameter                  For scientist                Responsible PI
—————————————————————————  ———————————————————————————  —————————————————
Methane                    Ellen Damm/Christiane Uhlig  Ellen Damm
DMSP, DMS                  Ellen Damm/Christiane Uhlig  Ellen Damm
Archive                    Ellen Damm                   Ellen Damm
Texture, temperature       Ilka Peeken                  Ilka Peeken
POC, HPLC, Chl a, DNA,     Ilka Peeken                  Ilka Peeken
PBSi, Taxonomy  
Neodym                     Georgi Laukert               Ilka Peeken
Salinity, nutrients, PABs  Ilka Peeken                  Ilka Peeken
18O                        Dorothea Bauch               Dorothea Bauch
Microplastics              Gunnar Gerdts                Ilka Peeken
DIC                        Elisabeth Jones              Micha Rijkenberg/ 
                                                        Leif Anderson
Hg, Hg species             Lars-Eric Heimbrger          Ellen Damm
cDOM/DOC                   Heather Reader               Ilka Peeken/
                                                        Dorothea Bauch
236U, 129I                 Nria Casacuberta             Michiel vd Loeff
Trace metals               Aridane G. Gonzalez          Micha Rijkenberg
Argon, N2O                 Bruno DeLille                Ellen Damm   


Preliminary results

On-site processing

A total of 13 to 15 cores were taken at each coring site of the full-
length ice stations. A thorough site description was carried out and 
entailed ambient air temperature, snow temperature, snow depth, ice 
conditions and weather conditions. The first core was taken to record 
temperature at 5 cm intervals by drilling 4 mm holes to the centre of the 
core and inserting a Testo 720 temperature probe. Cores for biological 
parameters, salinity, DIC and methane were sawed into 10 cm sections and 
placed in plastic containers or in the case of methane, in specially 
sealed plastic bags. All other cores were placed into plastic tubes, 
sealed with cable ties and taken on board for either storage or in case 
of DMS for further processing in the freezer lab.

Kemmerer water samplers were deployed through the core holes for water 
samples for analyses corresponding to the ice core analyses.

At the first 4 stations ice and snow covered meltponds were present in 
the later course of the cruise no discernible meltponds were found. 
Sampling of meltponds included the measurement of temperature, salinity, 
meltpond depth and thickness of the ice cover. Meltpond water was sampled 
for the same parameters as on the sea ice cores.


On-board processing

For textural analysis 5 mm thick sections were cut from the DMS core in 
the cold container using a band saw, cleaned and photographed against a 
black background.





12.  OVERVIEW OF PARAMETERS ANALYSED FROM ROSETTE SAMPLES


TransARCII 
Particiption GEOTRACS

Berth  Name                    PI-Transarc       Function    Institute   parameters  
—————  ——————————————————————  ————————————————  ——————————  ——————————  ———————————————————————
   1   Michiel Rutgers         Michiel vd Loeff  scientist   AWi         Radium isotopes,  
       van der Loeff                                                     228Th
   
   2   Ole Valk (PhD           Michiel vd Loeff  PhD         AWi         230Th/2l1Pa  
       Michiel vd loeff)                         Student  
   
   3   Viena Puigcorbe         Michiel vd Loeff  scientist   Uni         234Th  
                                                             Barcelona   
   
   4   Nuria Casacuberta       Michie! vd Loeff  scientist   Uni         210Pb/210Po, 1291, 2l6U  
                                                             Barcelona   

   5   Ronja Paffrath  I       Katharina Pahnke  PhD         Uni         REE, Nd isotopes  
       (PhD Katharina Pahnke)                    Student     Oldenburg   

   6   Sandra Gdaniec          Michiel vd Loeff  PhD         Uni         230Th/2l1Pa  
                                                 Student     Stockholm 

   7   Michael Staubwasser     Michael           scientist   Uni Koln    trace metal isotopes  
                               Staubwasser  

   8   Lars-Eric Heimburger    Lars-Eric         scientist   Bremen      Hg  
                               Heimburger  

   9   Adam Ulfsbo             Leif Anderson     scientist   Uni         CO2  
                                                             Gothenburg  

  10   Micha Rijkenberg        Micha Rijkenberg  scientist   NIOZ        trace metals  

  11   loes Gerringa           Micha Rijkenberg  scientist   NIOZ        FeL  

  12   Hans Slagter            Micha Rijkenberg  PhD         NIOZ        FeL  
                                                 Student  

  13   Aridane Gonzales        Micha Rijkenberg  France      NIOZ        part trace metals  

  14   SvenOber                Micha Rijkenberg  technician  NIOZ        ultraclean CTD  

  15   Janvan Ooijen           Micha Rijkenberg  technician  NIOZ        nutrients  

  16   Elisabeth Jones         Micha Rijkenberg/ scientist   NIOZ/UK     CO2 and oxygen   
                               Leif Anders                               [Winkler)

  17   Daniel Scholz           Michiel vd Loeff  technician  AWI         sensors  


ancillary data 

       Dorothea Bauch          Dorothea Bauch    scientist   GEOMAR      180 


samples will be collected for:

       name                                      sampling by             parameters 
       ————————————————————————————————————————  ——————————————————————  ———————————————————————————
       Raja Ganeshram          Michiel vd Loeff  UCC team                N and O isotopes in nitrate 

       Wafa Aboudlami and      Micha Rijkenberg  UCC team                Cd, Pb, Cr isotopes 
       Stephen Galer

       Boaz Luz                Michiel vd Loeff  Dorothea Baum           triple oxygen 

       Claudia Ehlert          Katharina Pahnke  Ronja Paffrath          Si isotopes 

       Bi11 Smethie            Michiel vd Loeff  Oceanogphy/             CFC
                                                 Geotraces

       Dennis Hansell          Ilka Peeker       UCC team or
       Rainer Amon             Colin Stedmon     Colin Stedmon           DOC, CDOM, lignin

       Peter Croot             Micha Rijkenberg  NIOZ team               dissolved TI





13.  SEMINARS 


The following talks were given in the seminar "TransArc II lectures".

Michael Staubwasser (UNIK):           Isotope composition of dissolved 
                                      and particulate Fe

Michiel Rutgers van der Loeff (AWI):  Tracers of river and shelf inputs 
                                      in the Trans-Polar Drift

Dorothea Bauch (GEOMAR):              Freshwater sources in the Arctic 
                                      Ocean: Stable oxygen isotopes of 
                                      the water as tracer of Siberian 
                                      shelf waters

Joshua Kiesel (CAU):                  Dynamics and Spatial Variation of 
                                      Intertidal Seagrass Beds in the 
                                      Northern Wadden Sea

Loes Gerringa (NIOZ):                 Iron in the Ross Sea Polynya

Aridane Gonzalez (IUEM):              The effect of organic exudates on 
                                      the Fe redox chemistry

Micha Rijkenberg (NIOZ):              Iron in the Arctic Ocean

Franz Schrter (AWI):                  Ecuador РLand der Extreme, Teil 1

Ursula Schauer (AWI):                 TransArc II Рdem arktischen Wandel 
                                      auf der Spur

Myriel Horn (AWI):                    Links between the freshwater 
                                      budgets of the Arctic Ocean and the 
                                      subpolar North Atlantic

Nuria Casacuberta (LIP):              U-236 and I-129 in the Arctic Ocean

Stefan Hendricks (AWI):               Die Vermessung von Meereis

Sergey Pisarev (SIO):                 Russian seasonal ice camp Barneo

Ulrike Hanz (CAU):                    Structure of benthic communities 
                                      from the Kattegat in relation to 
                                      environmental drivers and 
                                      historical data

Dorothea Bauch (GEOMAR):              Source waters of the lower 
                                      halocline

Benjamin Rabe (AWI):                  Arctic Ocean circulation Рincl. 
                                      preliminary results from PS94

Robert Ricker (AWI):                  Arctic Sea Ice Thickness derived 
                                      from CryoSat-2

Gerhard Dieckmann (AWI):              Von Plttcheneis zu grnen Eisbergen

Ursula Schauer (AWI)                  Using Polarstern for observational 
                                      polar science

Ksenia Kosobokova (SIO):              Wonderworld of Zooplankton

Franz Schroeter (AWI):                Ecuador, Teil 2: Amazonien und 
                                      Galapagos

Michael Staubwasser (Uni Kln)         Climate change and ancient 
                                      civilisations

Ellen Damm (AWI)                      Sea ice Рa blackbox for Arctic 
                                      methane cycling

Ole Valk (AWI)                        230Th and 231Pa, tracer for 
                                      particle fluxes and deep water 
                                      circulation in the Arctic Ocean

Nicole Hildebrandt                    Zooplankton-Zusammensetzung in der 
                                      Framstrae im Licht des Klimawandels 
                                      (+ LOKI-Fotos)

Heather Reader (NTU)                  Dynamics of dissolved organic 
                                      matter

Larysa Istomina  (IUB)                All you wanted to know about melt 
                                      ponds but never dared to ask

Andreas Krell (KOWI)                  EU Funding opportunities for early 
                                      career scientists"

Lars-Eric Heimbrger (UB)              Mercury in the Arctic Ocean Hans 
                                      Slagter (NIOZ) Catching the players 
                                      in the iron game of catch"

Ronja Paffrath (ICBM)                 Rare Earth Elements in pore water 
                                      from Spiekeroog Island

Elisabeth Jones (UGro)                Rothera research station: life, 
                                      science and a little CO2 chemistry










APPENDIX

A.1  PARTICIPATING INSTITUTIONS
A.2  CRUISE PARTICIPANTS
A.3  SHIP'S CREW
A.4  STATION LIST





A.1  TEILNEHMENDE INSTITUTE / PARTICIPATING INSTITUTIONS

             Address
             ———————————————————————————————————————————————————
AWI          Alfred-Wegener-Institut Helmholtz-Zentrum für 
             Polar- und Meeresforschung 
             Postfach 120161 27515 
             Bremerhaven, Germany 

CAU          Institute for Ecosystem Research of Kiel University 
             Christian-Albrechts-Universitt zu Kiel 
             Olshausenstr. 75 
             24118 Kiel, Germany 

DTU          Technical University of Denmark  
             National Institute of Aquatic Resources (AQUA) 
             Kavalergården 6, 
             2920 Charlottenlund, Denmark 

DWD          Deutscher Wetterdienst,  
             Geschftsbereich Wettervorhersage 
             Seeschifffahrtsberatung 
             Bernhard-Nocht-Straße 76 
             20359 Hamburg, Germany 

FMI          Finnish Meteorological Institute 
             PL 503 
             00101 Helsinki, Finland 

GEOMAR       GEOMAR Helmholtz Centre for Ocean Research Kiel 
             Wischhofstr. 1-3 
             D-24148 Kiel, Germany 

HeliService  HeliService International GmbH 
             Gorch-Fock-Straße 103 
             26721 Emden, Germany 

HUJ          Institute of Earth Sciences 
             The Hebrew University of Jerusalem 
             Jerusalem 91904, Israel 

ICBM         Max Planck Research Group for Marine Isotope 
             Geochemistry  
             Institute for Chemistry and Biology of the Marine 
             Environment  
             University of Oldenburg 
             Carl-von-Ossietzky-Straße 
             Oldenburg, Germany 

IUEM         LabexMer РLEMAR, Technopole Brest Iroise 
             Place Nicolas Copernic 
             F - 29280 Plouzane, France 

KoWi         Kooperationsstelle EU der Wissenschaftsorganisationen 
             Rue du Trne 98 
             1050 Bruxelles, Belgium 

LDEO         Lamont-Doherty Earth Observatory 
             Department of Geochemistry 
             61 Rt. 9W 
             Palisades, NY 10964, USA 

LIP          Laboratory of Ion Beam Physics 
             ETH-Zürich 
             Otto-Stern-Weg 5 
             8093 Zürich, Switzerland 

LOCEAN       Université Pierre et Marie Curie 
             Tour 45-46 5E 
             4 place Jussieu 
             75005 Paris, France 

LSCE         Laboratoire des Sciences du Climat et de 
             l'Environnement 
             Universit Paris-Saclay 
             CNRS - LSCE-bt 12 
             Avenue de la Terrasse 
             91198 Gif-sur-Yvette cedex, France 

MIO          CNRS/Mediterranean Institute of Oceanography 
             Chemin de la Batterie des Lions 
             13007 MARSEILLE, France 

MPI          Max Planck Institute for Marine Microbiology 
             Celsiusstrasse 1  
             28359 Bremen, Germany 

MPIM         Max Planck Institut Mainz 
             Hahn-Meitnerweg 1 
             55128 Mainz, Germany 

NIOZ         Royal Netherlands Institute for Sea Research 
             't Horntje  
             Texel, the Netherlands 

SIO          P.P. Shirshov Institute of Oceanology, 
             Nakhimovskiy prospekt, 36, 
             Moscow, 117997, Russia 

SMNH         Swedish Museum of Natural History, Department of 
             Geosciences 
             Frescativgen 40 
             Stockholm, Sweden 

UAB          Universitat Autnoma de Barcelona, 
             Institut de Ciència i Tecnologia Ambientals & 
             Department of Physics 
             08193-Cerdanyola del Valls, Spain 

UAIB         University of Alberta 
             1-26 Earth Sciences Building 
             Edmonton, Alberta, T6G 2E3, Canada 

UB           University of Bremen, Geochemistry and 
             Hydrogeology, Department of Geosciences,  
             Klagenfurter Straße 
             28359 Bremen, Germany 

UE           School of GeoSciences, University of Edinburgh 
             Sir James Hutton Road  
             Edinburgh, UK, EH9 3FE 

UGOT         Department of Chemistry & Molecular Biology, 
             University of Gothenburg, Medicinaregatan 9 c 
             40530 Gteborg, Sweden 

UGR          Centre for Energy and Environmental Sciences, 
             University of Groningen, Nijenborgh 
             49747 AG Groningen, The Netherlands 

UNIK         Institute of Geology and Mineralogy, 
             University of Cologne 
             Greinstraße 4-6 
             Köln, Germany   





A.2  FAHRTTEILNEHMER / CRUISE PARTICIPANTS

Name/         Vorname/    Institut/    Beruf/
Last name     First name  Institute    Profession
————————————  ——————————  ———————————  ———————————————————————————————————
Schauer       Ursula      AWI          Chief scientist, Phys. Oceanography

Alhusen       Erika       AWI          Technician, Biogeochemistry

Bauch         Dorothea    GEOMAR       Scientist, Geochemistry

Beckers       Justin      AWI          PhD student, Sea Ice Physics

Casacuberta   Nuria       LIP          Scientist, Geochemistry

Damm          Ellen       AWI          Scientist, Biogeochemistry

Dieckmann     Gerhard     AWI          Scientist, Biogeochemistry

Gdaniec       Sandra      SMNH         PhD Student, Geochemistry

Gerringa      Loes        NIOZ         Scientist, Geochemistry

Gonzalez      Aridane     IUEM         Scientist, Geochemistry

Graupner      Rainer      AWI          Technician, Phys. Oceanography

Hampe         Hendrik     AWI          Student, Phys. Oceanography

Hanz          Ulrike      CAU          Student, Biology

Heim          Thomas      HeliService  Technician

Heimburger    Lars-Eric   UB           Scientist, Geochemistry

Hempelt       Juliane     DWD          Technician, Meteorology

Hendricks     Stefan      AWI          Scientist, Sea Ice Physics

Hildebrandt   Nicole      AWI          Scientist, Biology

Hoppmann      Mario       AWI          Scientist, Phys. Oceanography

Horn          Myriel      AWI          PhD Student, Phys. Oceanography

Istomina      Larysa      AWI          Scientist, Sea Ice Physics

Jager         Harold      HeliService  Pilot


Name/         Vorname/    Institut/    Beruf/
Last name     First name  Institute    Profession
————————————  ——————————  ———————————  ———————————————————————————————————
Jenkins       Hazel       AWI          PhD student, Sea Ice Physics
                Hartman  
Jones         Elisabeth   NIOZ         Scientist, Geochemistry

Kiesel        Joshua      CAU          Student, Biology

Khler         Vanessa     AWI          Student, Biology

Korhonen      Meri        FMI          PhD student, Phys. Oceanography

Kosobokova    Ksenia      SIO          Scientist, Biology

Krell         Andreas     KOWI         Scientist, Biogeochemistry

Kryukova      Idrina      SIO          Scientist, Sedimentology

Miller        Max         DWD          Scientist, Meteorology

Ober          Sven        NIOZ         Technician, Geochemistry

Paffrath      Ronja       ICBM         PhD Student, Geochemistry

Petersen      Imke        AWI          Student, Biology

Pisarev       Sergey      SIO          Scientist, Phys. Oceanography

Puigcorbe     Viena       UAB          Scientist, Geochemistry

Rabe          Benjamin    AWI          Scientist, Phys. Oceanography

Reader        Heather     DTU          Scientist, Biology

Richter       Roland      HeliService  Technician

Ricker        Robert      AWI          Scientist, Sea Ice Physics

Riedel        Juliane     AWI          Student, Biology

Rijkenberg    Micha       NIOZ         Scientist, Geochemistry

Rutgers van   Michiel     AWI          Scientist, Geochemistry
  der Loeff  

Savy          Jean-       LOCEAN       Scientist, Phys. Oceanography
                Philipe   

Scholz        Daniel      AWI          Technician, Biochemistry

Schrter       Franz       AWI          Student, Biology

Slagter       Hans        NIOZ         PhD Student, Geochemistry




Name/         Vorname/    Institut/    Beruf/
Last name     First name  Institute    Profession
————————————  ——————————  ———————————  ———————————————————————————————————
Staubwasser   Michael     UNIK         Scientist, Geochemistry

Uhlig         Christiane  AWI          Scientist, Biogeochemistry

Ulfsbo        Adam        UGOT         Scientist, Geochemistry

Valk          Ole         AWI          PhD Student, Geochemistry

Van Ooijen    Jan         NIOZ         Technician, Geochemistry

Villacieros   Nicolas     LOCEAN       Scientist, Phys. Oceanography
  Robineau   

Vaupel        Lars        HeliService  Pilot

Vinogradova   Elena       SIO          Scientist, Biogeochemistry   





A.3  SCHIFFSBESATZUNG / SHIP'S CREW

                No. Name                     Rank
                ——  ——————————————————————   ————————————
                 1  Schwarze, Stefan         Master
                 2  Pohl, Klaus              Doctor
                 3  Langhinrichs, Moritz     Chief Mate
                 4  Hering, Igor             2nd  Mate
                 5  Lauber,  Felix           2nd Mate
                 6  Peine, Lutz G.           2nd Mate
                 7  Farysch, Bernd           Chief Eng.
                 8  Grafe, Jens              2nd Eng.
                 9  Krinfeld, Oleksandr      2nd Eng.
                10  Holst, Wolfgang          3rd Eng.
                11  Redmer, Jens             E Eng.
                12  Fröb, Martin             Chief  ELO
                13  Christian, Boris         ELO
                14  Himmel, Frank            ELO
                15  Hüttebräucker, Olaf      ELO
                16  Nasis, Ilias             ELO
                17  Loidl, Reiner            Boatsw.
                18  Reise, Lutz              Carpen.
                19  Bäcker, Andreas          A.B.
                20  Brickmann, Peter         A.B.
                21  Brück, Sebastian         A.B.
                22  Hagemann, Manfred        A.B.
                23  Michaels, Jürgen-Dieter  A.B.
                24  Scheel, Sebastian        A.B.
                25  Wende, Uwe               A.B.
                26  Winkler, Michael         A.B.
                27  Preußner, Jörg           Storek.
                28  Lamm, Gerd               MM
                29  Pinske, Lutz             MM
                30  Rhau, Lars-Peler         IVIM
                31  Schünemann, Mario        MM
                32  Teichert, Uwe            IVIM
                33  Redmer,  Klaus-Peter     Cook
                34  Martens, Michael         Cooksmate
                35  Silinski, Frank          Cooksmate
                36  Czyborra, Bärbei         Chief Stew
                37  Wöckener, Martina        Stwdss/Nurse
                38  Arendt, Rene             2nd Stew.
                39  Dibenau,Torsten          2nd Stew.
                40  Möller, Wolfgang         2nd Stew.
                41  Silinski, Carmen         2nd Stew.
                42  Sun, Yong Sheng          2nd Stew.
                43  Yu, Kwok Yuen            Laundrym.   





A.4  PS94 STATIONSLISTE / STATION LIST

Station      Date       Time       Gear     Action          Position       Position      Water  
                                                            Lat            Lon           depth  
                                                                                          [m]
——————————   ————————   ————————   ——————   —————————————   ————————————   ———————————   —————
PS94/001-1   18.08.15   20:10:00   CTD/RO   on ground/      74°59.94' N    30°0.27' E    373.0
                                            max depth
PS94/001-2   18.08.15   20:46:00   MUC      on ground/      74°59.91' N    30°0.24' E    372.0
                                            max depth
PS94/002-1   19.08.15   05:23:00   CTD/RO   on ground/      76°40.54' N    30°0.34' E    265.0
                                            max depth
PS94/002-2   19.08.15   05:56:00   MUC      on ground/      76°40.58' N    30°0.23' E    265.0
                                            max depth
PS94/003-1   19.08.15   06:34:00   CTD/UW   profile start   76°45.45' N    30°2.79' E    261.5
PS94/003-1   19.08.15   06:42:59   CTD/UW   profile end     76°46.70' N    30°3.61' E    259.5
PS94/003-2   19.08.15   07:25:00   CTD/UW   profile start   76°53.51' N    30°7.79' E    265.7
PS94/003-2   19.08.15   07:34:59   CTD/UW   profile end     76°54.94' N    30°8.64' E    259.0
PS94/003-3   19.08.15   07:35:00   CTD/UW   profile start   76°55.10' N    30°8.72' E    259.0
PS94/003-3   19.08.15   07:43:59   CTD/UW   profile end     76°56.38' N    30°9.48' E    255.7
PS94/003-4   19.08.15   07:44:00   CTD/UW   profile start   76°56.53' N    30°9.58' E    256.0
PS94/003-4   19.08.15   07:52:59   CTD/UW   profile end     76°57.80' N    30°10.42' E   250.0
PS94/003-5   19.08.15   07:53:00   CTD/UW   profile start   76°57.97' N    30°10.54' E   249.7
PS94/003-5   19.08.15   08:02:59   CTD/UW   profile end     76°59.41' N    30°11.42' E   248.0
PS94/003-6   19.08.15   08:03:00   CTD/UW   profile start   76°59.57' N    30°11.51' E   246.2
PS94/003-6   19.08.15   08:11:59   CTD/UW   profile end     77°0.85' N     30°12.22' E   245.5
PS94/003-7   19.08.15   08:12:00   CTD/UW   profile start   77°1.00' N     30°12.31' E   247.0
PS94/003-7   19.08.15   08:21:59   CTD/UW   profile end     77°2.42' N     30°13.25' E   244.7
PS94/003-8   19.08.15   08:22:00   CTD/UW   profile start   77°2.58' N     30°13.35' E   240.0
PS94/003-8   19.08.15   08:30:59   CTD/UW   profile end     77°3.85' N     30°14.11' E   235.2
PS94/003-9   19.08.15   08:31:00   CTD/UW   profile start   77°4.00' N     30°14.20' E   238.2
PS94/003-9   19.08.15   08:39:59   CTD/UW   profile end     77°5.27' N     30°14.99' E   225.0
PS94/003-10  19.08.15   08:40:00   CTD/UW   profile start   77°5.43' N     30°15.11' E   224.7
PS94/003-10  19.08.15   08:46:59   CTD/UW   profile end     77°6.38' N     30°15.65' E   213.0
PS94/003-11  19.08.15   08:47:00   CTD/UW   profile start   77°6.54' N     30°15.74' E   213.2
PS94/003-11  19.08.15   08:55:59   CTD/UW   profile end     77°7.80' N     30°16.59' E   208.2
PS94/003-12  19.08.15   08:56:00   CTD/UW   profile start   77°7.96' N     30°16.68' E   208.5
PS94/003-13  19.08.15   09:02:00   CTD/UW   profile start   77°8.91' N     30°17.26' E   206.0
PS94/003-12  19.08.15   09:02:59   CTD/UW   profile end     77°8.91' N     30°17.26' E   206.0
PS94/003-13  19.08.15   09:07:59   CTD/UW   profile end     77°9.71' N     30°17.71' E   206.2
PS94/003-14  19.08.15   09:08:00   CTD/UW   profile start   77°9.86' N     30°17.80' E   205.0
PS94/003-14  19.08.15   09:13:59   CTD/UW   profile end     77°10.65' N    30°18.29' E   205.7
PS94/003-15  19.08.15   09:14:00   CTD/UW   profile start   77°10.80' N    30°18.40' E   209.5
PS94/003-16  19.08.15   09:22:00   CTD/UW   profile start   77°12.06' N    30°19.17' E   202.0
PS94/003-15  19.08.15   09:22:59   CTD/UW   profile end     77°12.06' N    30°19.17' E   202.0
PS94/003-17  19.08.15   09:28:00   CTD/UW   profile start   77°13.00' N    30°19.74' E   205.5
PS94/003-16  19.08.15   09:28:59   CTD/UW   profile end     77°13.00' N    30°19.74' E   205.5
PS94/003-17  19.08.15   09:34:59   CTD/UW   profile end     77°13.94' N    30°20.30' E   189.0
PS94/003-18  19.08.15   09:35:00   CTD/UW   profile start   77°14.10' N    30°20.39' E   191.7
PS94/003-18  19.08.15   09:40:59   CTD/UW   profile end     77°14.88' N    30°20.99' E   198.5
PS94/003-19  19.08.15   09:41:00   CTD/UW   profile start   77°15.04' N    30°21.08' E   199.2
PS94/003-20  19.08.15   09:47:00   CTD/UW   profile start   77°15.99' N    30°21.67' E   191.0
PS94/003-19  19.08.15   09:47:59   CTD/UW   profile end     77°15.99' N    30°21.67' E   191.0
PS94/003-20  19.08.15   09:53:59   CTD/UW   profile end     77°16.95' N    30°22.23' E   183.7
PS94/003-21  19.08.15   09:54:00   CTD/UW   profile start   77°17.10' N    30°22.32' E   191.0
PS94/003-22  19.08.15   09:59:00   CTD/UW   profile start   77°17.89' N    30°22.84' E   198.2
PS94/003-21  19.08.15   09:59:59   CTD/UW   profile end     77°17.89' N    30°22.84' E   198.2
PS94/003-22  19.08.15   10:05:59   CTD/UW   profile end     77°18.85' N    30°23.43' E   198.7
PS94/003-23  19.08.15   10:06:00   CTD/UW   profile start   77°19.01' N    30°23.55' E   200.5
PS94/003-23  19.08.15   10:12:59   CTD/UW   profile end     77°19.99' N    30°24.15' E   198.0
PS94/003-24  19.08.15   10:13:00   CTD/UW   profile start   77°20.16' N    30°24.22' E   198.0
PS94/003-25  19.08.15   10:19:00   CTD/UW   profile start   77°21.13' N    30°24.78' E   202.0
PS94/003-24  19.08.15   10:19:59   CTD/UW   profile end     77°21.13' N    30°24.78' E   202.0
PS94/003-26  19.08.15   10:26:00   CTD/UW   profile start   77°22.28' N    30°25.54' E   200.5
PS94/003-25  19.08.15   10:26:59   CTD/UW   profile end     77°22.28' N    30°25.54' E   200.5
PS94/003-27  19.08.15   10:32:00   CTD/UW   profile start   77°23.25' N    30°26.21' E   197.0
PS94/003-26  19.08.15   10:32:59   CTD/UW   profile end     77°23.25' N    30°26.21' E   197.0
PS94/003-28  19.08.15   10:38:00   CTD/UW   profile start   77°24.21' N    30°26.75' E   210.5
PS94/003-27  19.08.15   10:38:59   CTD/UW   profile end     77°24.21' N    30°26.75' E   210.5
PS94/003-28  19.08.15   10:44:59   CTD/UW   profile end     77°25.15' N    30°27.42' E   192.2
PS94/003-29  19.08.15   10:45:00   CTD/UW   profile start   77°25.31' N    30°27.52' E   192.2
PS94/003-30  19.08.15   10:51:00   CTD/UW   profile start   77°26.25' N    30°28.07' E   206.0
PS94/003-29  19.08.15   10:51:59   CTD/UW   profile end     77°26.25' N    30°28.07' E   206.0
PS94/003-30  19.08.15   10:58:59   CTD/UW   profile end     77°27.33' N    30°28.74' E   208.7
PS94/003-31  19.08.15   10:59:00   CTD/UW   profile start   77°27.48' N    30°28.84' E   210.0
PS94/003-31  19.08.15   11:05:59   CTD/UW   profile end     77°28.40' N    30°29.44' E   205.0
PS94/003-32  19.08.15   11:06:00   CTD/UW   profile start   77°28.55' N    30°29.56' E   210.2
PS94/003-33  19.08.15   11:13:00   CTD/UW   profile start   77°29.61' N    30°30.25' E   217.5
PS94/003-32  19.08.15   11:13:59   CTD/UW   profile end     77°29.61' N    30°30.25' E   217.5
PS94/003-33  19.08.15   11:21:59   CTD/UW   profile end     77°30.82' N    30°30.99' E   217.2
PS94/003-34  19.08.15   11:22:00   CTD/UW   profile start   77°30.97' N    30°31.11' E   217.7
PS94/003-35  19.08.15   11:29:00   CTD/UW   profile start   77°32.03' N    30°31.72' E   225.5
PS94/003-34  19.08.15   11:29:59   CTD/UW   profile end     77°32.03' N    30°31.72' E   225.5
PS94/003-35  19.08.15   11:36:59   CTD/UW   profile end     77°33.09' N    30°32.38' E   225.5
PS94/003-36  19.08.15   11:37:00   CTD/UW   profile start   77°33.24' N    30°32.47' E   223.0
PS94/003-36  19.08.15   11:44:59   CTD/UW   profile end     77°34.30' N    30°33.16' E   225.5
PS94/003-37  19.08.15   11:45:00   CTD/UW   profile start   77°34.45' N    30°33.25' E   226.5
PS94/003-37  19.08.15   11:56:59   CTD/UW   profile end     77°36.12' N    30°34.33' E   228.2
PS94/003-38  19.08.15   13:09:00   CTD/UW   profile start   77°47.26' N    30°41.53' E   234.0
PS94/003-39  19.08.15   13:21:00   CTD/UW   profile start   77°49.12' N    30°42.72' E   247.7
PS94/003-38  19.08.15   13:21:59   CTD/UW   profile end     77°49.12' N    30°42.72' E   247.7
PS94/003-40  19.08.15   13:29:00   CTD/UW   profile start   77°50.37' N    30°43.61' E   241.5
PS94/003-39  19.08.15   13:29:59   CTD/UW   profile end     77°50.37' N    30°43.61' E   241.5
PS94/003-40  19.08.15   13:37:59   CTD/UW   profile end     77°51.61' N    30°44.46' E   241.7
PS94/003-41  19.08.15   13:38:00   CTD/UW   profile start   77°51.77' N    30°44.55' E   241.0
PS94/003-42  19.08.15   13:46:00   CTD/UW   profile start   77°53.04' N    30°45.29' E   234.2
PS94/003-41  19.08.15   13:46:59   CTD/UW   profile end     77°53.04' N    30°45.29' E   234.2
PS94/003-43  19.08.15   13:54:00   CTD/UW   profile start   77°54.29' N    30°46.10' E   262.5
PS94/003-42  19.08.15   13:54:59   CTD/UW   profile end     77°54.29' N    30°46.10' E   262.5
PS94/003-43  19.08.15   14:03:59   CTD/UW   profile end     77°55.72' N    30°47.07' E   265.7
PS94/003-44  19.08.15   14:04:00   CTD/UW   profile start   77°55.88' N    30°47.16' E   268.0
PS94/003-45  19.08.15   14:14:00   CTD/UW   profile start   77°57.47' N    30°48.28' E   242.5
PS94/003-44  19.08.15   14:14:59   CTD/UW   profile end     77°57.47' N    30°48.28' E   242.5
PS94/003-46  19.08.15   14:22:00   CTD/UW   profile start   77°58.74' N    30°49.04' E   255.5
PS94/003-45  19.08.15   14:22:59   CTD/UW   profile end     77°58.74' N    30°49.04' E   255.5
PS94/003-47  19.08.15   14:32:00   CTD/UW   profile start   78°0.32' N     30°50.11' E   260.5
PS94/003-46  19.08.15   14:32:59   CTD/UW   profile end     78°0.32' N     30°50.11' E   260.5
PS94/003-48  19.08.15   14:41:00   CTD/UW   profile start   78°1.76' N     30°51.07' E   248.2
PS94/003-47  19.08.15   14:41:59   CTD/UW   profile end     78°1.76' N     30°51.07' E   248.2
PS94/003-49  19.08.15   14:50:00   CTD/UW   profile start   78°3.18' N     30°51.99' E   219.2
PS94/003-48  19.08.15   14:50:59   CTD/UW   profile end     78°3.18' N     30°51.99' E   219.2
PS94/003-50  19.08.15   14:59:00   CTD/UW   profile start   78°4.61' N     30°52.94' E   234.7
PS94/003-49  19.08.15   14:59:59   CTD/UW   profile end     78°4.61' N     30°52.94' E   234.7
PS94/003-50  19.08.15   15:06:59   CTD/UW   profile end     78°5.71' N     30°53.66' E   231.5
PS94/003-51  19.08.15   15:07:00   CTD/UW   profile start   78°5.87' N     30°53.77' E   233.5
PS94/003-52  19.08.15   15:14:00   CTD/UW   profile start   78°6.96' N     30°54.57' E   242.2
PS94/003-51  19.08.15   15:14:59   CTD/UW   profile end     78°6.96' N     30°54.57' E   242.2
PS94/003-53  19.08.15   15:23:00   CTD/UW   profile start   78°8.36' N     30°55.49' E   243.0
PS94/003-52  19.08.15   15:23:59   CTD/UW   profile end     78°8.36' N     30°55.49' E   243.0
PS94/003-54  19.08.15   15:31:00   CTD/UW   profile start   78°9.62' N     30°56.38' E   231.7
PS94/003-53  19.08.15   15:31:59   CTD/UW   profile end     78°9.62' N     30°56.38' E   231.7
PS94/003-55  19.08.15   15:39:00   CTD/UW   profile start   78°10.88' N    30°57.13' E   239.7
PS94/003-54  19.08.15   15:39:59   CTD/UW   profile end     78°10.88' N    30°57.13' E   239.7
PS94/003-56  19.08.15   15:47:00   CTD/UW   profile start   78°12.12' N    30°58.06' E   241.5
PS94/003-55  19.08.15   15:47:59   CTD/UW   profile end     78°12.12' N    30°58.06' E   241.5
PS94/003-57  19.08.15   15:55:00   CTD/UW   profile start   78°13.36' N    30°58.84' E   272.2
PS94/003-56  19.08.15   15:55:59   CTD/UW   profile end     78°13.36' N    30°58.84' E   272.2
PS94/003-57  19.08.15   16:03:59   CTD/UW   profile end     78°14.60' N    30°59.69' E   253.7
PS94/003-58  19.08.15   16:04:00   CTD/UW   profile start   78°14.76' N    30°59.77' E   255.7
PS94/003-59  19.08.15   16:12:00   CTD/UW   profile start   78°16.02' N    31°0.58' E    249.2
PS94/003-58  19.08.15   16:12:59   CTD/UW   profile end     78°16.02' N    31°0.58' E    249.2
PS94/003-60  19.08.15   16:21:00   CTD/UW   profile start   78°17.44' N    31°1.57' E    260.0
PS94/003-59  19.08.15   16:21:59   CTD/UW   profile end     78°17.44' N    31°1.57' E    260.0
PS94/003-61  19.08.15   16:30:00   CTD/UW   profile start   78°18.86' N    31°2.62' E    257.7
PS94/003-60  19.08.15   16:30:59   CTD/UW   profile end     78°18.86' N    31°2.62' E    257.7
PS94/003-62  19.08.15   16:39:00   CTD/UW   profile start   78°20.28' N    31°3.60' E    251.0
PS94/003-61  19.08.15   16:39:59   CTD/UW   profile end     78°20.28' N    31°3.60' E    251.0
PS94/003-63  19.08.15   16:48:00   CTD/UW   profile start   78°21.73' N    31°4.50' E    258.5
PS94/003-62  19.08.15   16:48:59   CTD/UW   profile end     78°21.73' N    31°4.50' E    258.5
PS94/003-64  19.08.15   16:57:00   CTD/UW   profile start   78°23.15' N    31°5.54' E    257.2
PS94/003-63  19.08.15   16:57:59   CTD/UW   profile end     78°23.15' N    31°5.54' E    257.2
PS94/003-65  19.08.15   17:06:00   CTD/UW   profile start   78°24.57' N    31°6.54' E    271.2
PS94/003-64  19.08.15   17:06:59   CTD/UW   profile end     78°24.57' N    31°6.54' E    271.2
PS94/003-65  19.08.15   17:15:59   CTD/UW   profile end     78°26.01' N    31°7.42' E    278.5
PS94/003-66  19.08.15   17:16:00   CTD/UW   profile start   78°26.17' N    31°7.57' E    280.5
PS94/003-66  19.08.15   17:25:59   CTD/UW   profile end     78°27.58' N    31°8.58' E    300.5
PS94/003-67  19.08.15   17:26:00   CTD/UW   profile start   78°27.73' N    31°8.70' E    300.0
PS94/003-68  19.08.15   17:35:00   CTD/UW   profile start   78°29.16' N    31°9.66' E    299.2
PS94/003-67  19.08.15   17:35:59   CTD/UW   profile end     78°29.16' N    31°9.66' E    299.2
PS94/003-69  19.08.15   17:45:00   CTD/UW   profile start   78°30.73' N    31°10.74' E   306.2
PS94/003-68  19.08.15   17:45:59   CTD/UW   profile end     78°30.73' N    31°10.74' E   306.2
PS94/003-70  19.08.15   17:56:00   CTD/UW   profile start   78°32.46' N    31°11.96' E   311.7
PS94/003-69  19.08.15   17:56:59   CTD/UW   profile end     78°32.46' N    31°11.96' E   311.7
PS94/003-71  19.08.15   18:07:00   CTD/UW   profile start   78°34.18' N    31°13.06' E   315.2
PS94/003-70  19.08.15   18:07:59   CTD/UW   profile end     78°34.18' N    31°13.06' E   315.2
PS94/003-71  19.08.15   18:18:59   CTD/UW   profile end     78°35.90' N    31°14.24' E   307.0
PS94/003-72  19.08.15   18:19:00   CTD/UW   profile start   78°36.05' N    31°14.34' E   311.5
PS94/003-72  19.08.15   18:28:59   CTD/UW   profile end     78°37.44' N    31°15.35' E   307.7
PS94/003-73  19.08.15   18:29:00   CTD/UW   profile start   78°37.59' N    31°15.49' E   305.2
PS94/003-73  19.08.15   18:38:59   CTD/UW   profile end     78°38.97' N    31°16.50' E   310.7
PS94/003-74  19.08.15   18:39:00   CTD/UW   profile start   78°39.12' N    31°16.60' E   311.0
PS94/003-74  19.08.15   18:49:59   CTD/UW   profile end     78°40.67' N    31°17.60' E   289.0
PS94/003-75  19.08.15   18:50:00   CTD/UW   profile start   78°40.83' N    31°17.75' E   286.7
PS94/003-75  19.08.15   18:59:59   CTD/UW   profile end     78°42.22' N    31°18.77' E   267.5
PS94/003-76  19.08.15   19:00:00   CTD/UW   profile start   78°42.37' N    31°18.86' E   269.7
PS94/003-76  19.08.15   19:09:59   CTD/UW   profile end     78°43.77' N    31°19.75' E   265.5
PS94/003-77  19.08.15   19:10:00   CTD/UW   profile start   78°43.92' N    31°19.88' E   256.7
PS94/003-78  19.08.15   19:19:00   CTD/UW   profile start   78°45.30' N    31°20.90' E   242.0
PS94/003-77  19.08.15   19:19:59   CTD/UW   profile end     78°45.30' N    31°20.90' E   242.0
PS94/003-78  19.08.15   19:28:59   CTD/UW   profile end     78°46.69' N    31°21.82' E   244.2
PS94/003-79  19.08.15   19:29:00   CTD/UW   profile start   78°46.84' N    31°21.93' E   238.0
PS94/003-79  19.08.15   19:37:59   CTD/UW   profile end     78°48.07' N    31°22.84' E   160.7
PS94/003-80  19.08.15   19:38:00   CTD/UW   profile start   78°48.23' N    31°22.92' E   147.7
PS94/003-80  19.08.15   19:46:59   CTD/UW   profile end     78°49.45' N    31°23.85' E   134.7
PS94/003-81  19.08.15   19:47:00   CTD/UW   profile start   78°49.60' N    31°23.97' E   134.0
PS94/003-81  19.08.15   19:55:59   CTD/UW   profile end     78°50.81' N    31°24.76' E   128.5
PS94/003-82  19.08.15   19:56:00   CTD/UW   profile start   78°50.97' N    31°24.86' E   124.0
PS94/003-82  19.08.15   20:02:59   CTD/UW   profile end     78°51.87' N    31°25.53' E   110.5
PS94/003-83  19.08.15   20:03:00   CTD/UW   profile start   78°52.02' N    31°25.64' E   108.0
PS94/003-83  19.08.15   20:12:59   CTD/UW   profile end     78°53.38' N    31°26.58' E   147.5
PS94/003-84  19.08.15   20:13:00   CTD/UW   profile start   78°53.53' N    31°26.69' E   151.2
PS94/003-84  19.08.15   20:20:59   CTD/UW   profile end     78°54.58' N    31°27.50' E   173.7
PS94/003-85  19.08.15   20:21:00   CTD/UW   profile start   78°54.73' N    31°27.60' E   177.2
PS94/003-85  19.08.15   20:27:59   CTD/UW   profile end     78°55.64' N    31°28.23' E   202.7
PS94/003-86  19.08.15   20:28:00   CTD/UW   profile start   78°55.79' N    31°28.33' E   202.0
PS94/003-86  19.08.15   20:34:59   CTD/UW   profile end     78°56.68' N    31°29.05' E   202.2
PS94/003-87  19.08.15   20:35:00   CTD/UW   profile start   78°56.83' N    31°29.08' E   201.7
PS94/003-87  19.08.15   20:40:59   CTD/UW   profile end     78°57.59' N    31°29.65' E   227.0
PS94/003-88  19.08.15   20:41:00   CTD/UW   profile start   78°57.74' N    31°29.72' E   228.7
PS94/003-88  19.08.15   20:47:59   CTD/UW   profile end     78°58.64' N    31°30.39' E   247.2
PS94/003-89  19.08.15   20:48:00   CTD/UW   profile start   78°58.78' N    31°30.52' E   251.0
PS94/003-89  19.08.15   20:56:59   CTD/UW   profile end     78°59.96' N    31°31.42' E   241.0
PS94/003-90  19.08.15   21:00:00   CTD/UW   profile start   79°0.53' N     31°31.73' E   181.2
PS94/003-90  19.08.15   21:06:59   CTD/UW   profile end     79°1.40' N     31°32.44' E   154.7
PS94/003-91  19.08.15   21:07:00   CTD/UW   profile start   79°1.55' N     31°32.51' E   160.0
PS94/003-91  19.08.15   21:11:59   CTD/UW   profile end     79°2.13' N     31°32.86' E   140.2
PS94/003-92  19.08.15   21:12:00   CTD/UW   profile start   79°2.28' N     31°33.00' E   138.0
PS94/003-92  19.08.15   21:16:59   CTD/UW   profile end     79°2.86' N     31°33.49' E   147.7
PS94/003-93  19.08.15   21:17:00   CTD/UW   profile start   79°3.01' N     31°33.60' E   136.2
PS94/003-93  19.08.15   21:21:59   CTD/UW   profile end     79°3.60' N     31°33.97' E   118.0
PS94/003-94  19.08.15   21:22:00   CTD/UW   profile start   79°3.74' N     31°34.07' E   119.5
PS94/003-94  19.08.15   21:25:59   CTD/UW   profile end     79°4.19' N     31°34.37' E   115.0
PS94/003-95  19.08.15   21:26:00   CTD/UW   profile start   79°4.34' N     31°34.47' E   118.7
PS94/003-95  19.08.15   21:36:59   CTD/UW   profile end     79°5.83' N     31°35.57' E   118.7
PS94/004-1   20.08.15   00:45:00   CTD/RO   on ground       79°15.07' N    30°2.87' E    234.0
                                            max depth
PS94/004-2   20.08.15   01:23:00   CTD/UC   on ground       79°15.20' N    30°2.77' E    228.2
                                            max depth
PS94/004-3   20.08.15   02:51:00   CTD/RO   on ground       79°14.97' N    30°2.49' E    230.0
                                            max depth
PS94/004-4   20.08.15   03:52:00   ISP      on ground       79°14.97' N    30°2.17' E    227.2
                                            max depth
PS94/004-5   20.08.15   08:26:00   CTD/RO   on ground       79°14.91' N    30°2.10' E    224.5
                                            max depth
PS94/004-6   20.08.15   09:17:00   CTD/UC   on ground       79°14.96' N    30°1.93' E    226.2
                                            max depth
PS94/005-1   20.08.15   10:23:00   CTD/UW   profile start   79°16.42' N    30°2.51' E    252.5
PS94/005-1   20.08.15   10:34:59   CTD/UW   profile end     79°18.07' N    30°2.72' E    292.7
PS94/005-2   20.08.15   11:16:00   CTD/UW   profile start   79°24.52' N    30°0.77' E    332.5
PS94/005-3   20.08.15   11:30:00   CTD/UW   profile start   79°26.77' N    30°0.56' E    296.0
PS94/005-2   20.08.15   11:30:59   CTD/UW   profile end     79°26.77' N    30°0.56' E    296.0
PS94/005-3   20.08.15   11:46:59   CTD/UW   profile end     79°29.35' N    29°59.72' E   273.5
PS94/006-1   20.08.15   12:13:00   CTD/RO   on ground       79°29.98' N    29°59.99' E   259.0
                                            max depth
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PS94/007-1   20.08.15   13:07:59   CTD/UW   profile end     79°35.63' N    29°59.98' E   258.5
PS94/007-2   20.08.15   13:08:00   CTD/UW   profile start   79°35.80' N    29°59.95' E   256.5
PS94/007-3   20.08.15   13:20:00   CTD/UW   profile start   79°37.82' N    29°59.97' E   262.5
PS94/007-2   20.08.15   13:20:59   CTD/UW   profile end     79°37.82' N    29°59.97' E   262.5
PS94/007-3   20.08.15   13:31:59   CTD/UW   profile end     79°39.69' N    30°0.07' E    259.7
PS94/007-4   20.08.15   13:32:00   CTD/UW   profile start   79°39.86' N    30°0.05' E    256.2
PS94/007-5   20.08.15   13:42:00   CTD/UW   profile start   79°41.57' N    29°59.95' E   269.5
PS94/007-4   20.08.15   13:42:59   CTD/UW   profile end     79°41.57' N    29°59.95' E   269.5
PS94/007-5   20.08.15   13:55:59   CTD/UW   profile end     79°43.75' N    29°59.61' E   235.7
PS94/008-1   20.08.15   14:20:00   CTD/RO   on ground       79°45.04' N    30°0.37' E    218.7
                                            max depth
PS94/008-2   20.08.15   14:42:00   CTD/UC   on ground       79°45.00' N    30°0.02' E    222.2
                                            max depth
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PS94/009-1   20.08.15   15:22:59   CTD/UW   profile end     79°48.70' N    29°59.94' E   143.5
PS94/009-2   20.08.15   15:23:00   CTD/UW   profile start   79°48.85' N    29°59.95' E   141.7
PS94/009-2   20.08.15   15:28:59   CTD/UW   profile end     79°49.64' N    30°0.06' E    173.5
PS94/009-3   20.08.15   15:29:00   CTD/UW   profile start   79°49.80' N    30°0.06' E    210.2
PS94/009-4   20.08.15   15:36:00   CTD/UW   profile start   79°50.90' N    30°0.05' E    263.7
PS94/009-3   20.08.15   15:36:59   CTD/UW   profile end     79°50.90' N    30°0.05' E    263.7
PS94/009-5   20.08.15   15:46:00   CTD/UW   profile start   79°52.44' N    30°0.08' E    243.2
PS94/009-4   20.08.15   15:46:59   CTD/UW   profile end     79°52.44' N    30°0.08' E    243.2
PS94/009-6   20.08.15   15:55:00   CTD/UW   profile start   79°53.81' N    29°59.94' E   245.2
PS94/009-5   20.08.15   15:55:59   CTD/UW   profile end     79°53.81' N    29°59.94' E   245.2
PS94/009-6   20.08.15   16:03:59   CTD/UW   profile end     79°55.03' N    29°59.96' E   253.7
PS94/009-7   20.08.15   16:04:00   CTD/UW   profile start   79°55.19' N    29°59.98' E   252.2
PS94/009-7   20.08.15   16:12:59   CTD/UW   profile end     79°56.40' N    29°60.00' E   250.2
PS94/009-8   20.08.15   16:13:00   CTD/UW   profile start   79°56.55' N    29°59.96' E   244.7
PS94/009-9   20.08.15   16:22:00   CTD/UW   profile start   79°57.92' N    29°59.94' E   272.5
PS94/009-8   20.08.15   16:22:59   CTD/UW   profile end     79°57.92' N    29°59.94' E   272.5
PS94/009-9   20.08.15   16:33:59   CTD/UW   profile end     79°59.58' N    30°0.83' E    293.2
PS94/010-1   20.08.15   16:53:00   CTD/RO   on ground       79°59.92' N    29°59.96' E   292.0
                                            max depth
PS94/010-2   20.08.15   17:37:00   MN       on ground       79°59.95' N    29°59.88' E   294.2
                                            max depth
PS94/010-3   20.08.15   18:20:00   LOKI     on ground       79°59.92' N    29°60.00' E   293.0
                                            max depth
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PS94/010-3   20.08.15   18:30:00   LOKI     profile end     79°59.89' N    29°59.99' E   292.2
PS94/011-1   20.08.15   19:32:00   CTD/UW   profile start   80°9.01' N     30°0.03' E    297.5
PS94/011-2   20.08.15   19:37:00   CTD/UW   profile start   80°9.82' N     29°59.98' E   284.0
PS94/011-1   20.08.15   19:37:59   CTD/UW   profile end     80°9.82' N     29°59.98' E   284.0
PS94/011-2   20.08.15   19:49:59   CTD/UW   profile end     80°11.77' N    29°59.96' E   296.7
PS94/011-3   20.08.15   19:50:00   CTD/UW   profile start   80°11.93' N    29°60.00' E   298.7
PS94/011-3   20.08.15   20:04:59   CTD/UW   profile end     80°14.18' N    30°0.01' E    253.0
PS94/012-1   20.08.15   20:24:00   CTD/RO   on ground       80°15.01' N    29°59.29' E   248.2
                                            max depth
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PS94/013-2   20.08.15   20:51:00   CTD/UW   profile start   80°17.86' N    30°0.06' E    205.2
PS94/013-1   20.08.15   20:51:59   CTD/UW   profile end     80°17.86' N    30°0.06' E    205.2
PS94/013-2   20.08.15   20:59:59   CTD/UW   profile end     80°19.17' N    30°0.07' E    150.2
PS94/013-3   20.08.15   21:00:00   CTD/UW   profile start   80°19.34' N    30°0.05' E    149.7
PS94/013-4   20.08.15   21:06:00   CTD/UW   profile start   80°20.31' N    29°59.96' E   193.7
PS94/013-3   20.08.15   21:06:59   CTD/UW   profile end     80°20.31' N    29°59.96' E   193.7
PS94/013-4   20.08.15   21:17:59   CTD/UW   profile end     80°22.13' N    30°0.02' E    202.0
PS94/013-5   20.08.15   21:18:00   CTD/UW   profile start   80°22.30' N    29°60.00' E   198.0
PS94/013-5   20.08.15   21:26:59   CTD/UW   profile end     80°23.65' N    29°59.93' E   234.2
PS94/013-6   20.08.15   21:27:00   CTD/UW   profile start   80°23.81' N    29°59.92' E   235.5
PS94/013-6   20.08.15   21:36:59   CTD/UW   profile end     80°25.30' N    30°0.07' E    219.5
PS94/013-7   20.08.15   21:37:00   CTD/UW   profile start   80°25.47' N    30°0.02' E    175.2
PS94/013-7   20.08.15   21:44:59   CTD/UW   profile end     80°26.64' N    30°0.04' E    364.2
PS94/013-8   20.08.15   21:45:00   CTD/UW   profile start   80°26.81' N    30°0.07' E    338.0
PS94/013-8   20.08.15   21:53:59   CTD/UW   profile end     80°28.16' N    30°0.01' E    346.7
PS94/014-1   20.08.15   22:22:00   CTD/RO   on ground       80°29.98' N    29°59.19' E   378.2
                                            max depth
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PS94/015-2   20.08.15   23:06:00   CTD/UW   profile start   80°32.94' N    29°35.46' E   314.0
PS94/015-1   20.08.15   23:06:59   CTD/UW   profile end     80°32.94' N    29°35.46' E   314.0
PS94/015-3   20.08.15   23:18:00   CTD/UW   profile start   80°34.07' N    29°25.94' E   173.7
PS94/015-2   20.08.15   23:18:59   CTD/UW   profile end     80°34.07' N    29°25.94' E   173.7
PS94/015-3   20.08.15   23:25:59   CTD/UW   profile end     80°34.73' N    29°20.44' E   228.5
PS94/015-4   20.08.15   23:26:00   CTD/UW   profile start   80°34.82' N    29°19.66' E   257.5
PS94/015-5   20.08.15   23:36:00   CTD/UW   profile start   80°35.75' N    29°11.76' E   190.7
PS94/015-4   20.08.15   23:36:59   CTD/UW   profile end     80°35.75' N    29°11.76' E   190.7
PS94/015-6   20.08.15   23:44:00   CTD/UW   profile start   80°36.48' N    29°5.48' E    326.2
PS94/015-5   20.08.15   23:44:59   CTD/UW   profile end     80°36.48' N    29°5.48' E    326.2
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PS94/015-7   20.08.15   23:54:00   CTD/UW   profile start   80°37.39' N    28°57.69' E   260.7
PS94/015-8   21.08.15   00:03:00   CTD/UW   profile start   80°38.24' N    28°50.79' E   305.2
PS94/015-7   21.08.15   00:03:59   CTD/UW   profile end     80°38.24' N    28°50.79' E   305.2
PS94/015-9   21.08.15   00:13:00   CTD/UW   profile start   80°39.14' N    28°42.95' E   484.7
PS94/015-8   21.08.15   00:13:59   CTD/UW   profile end     80°39.14' N    28°42.95' E   484.7
PS94/015-9   21.08.15   00:26:59   CTD/UW   profile end     80°40.35' N    28°32.87' E   444.7
PS94/015-10  21.08.15   00:27:00   CTD/UW   profile start   80°40.45' N    28°32.13' E   444.2
PS94/015-10  21.08.15   00:44:59   CTD/UW   profile end     80°41.88' N    28°21.71' E   51.2
PS94/016-1   21.08.15   01:26:00   CTD/UW   profile start   80°45.02' N    28°28.47' E   80.2
PS94/016-2   21.08.15   01:31:00   CTD/UW   profile start   80°45.00' N    28°31.78' E   120.7
PS94/016-1   21.08.15   01:31:59   CTD/UW   profile end     80°45.00' N    28°31.78' E   120.7
PS94/016-3   21.08.15   01:35:00   CTD/UW   profile start   80°44.99' N    28°34.62' E   190.7
PS94/016-2   21.08.15   01:35:59   CTD/UW   profile end     80°44.99' N    28°34.62' E   190.7
PS94/016-3   21.08.15   01:41:59   CTD/UW   profile end     80°44.98' N    28°40.56' E   365.2
PS94/016-4   21.08.15   01:50:00   CTD/UW   profile start   80°45.00' N    28°49.89' E   492.0
PS94/016-5   21.08.15   01:58:00   CTD/UW   profile start   80°44.99' N    28°58.32' E   500.5
PS94/016-4   21.08.15   01:58:59   CTD/UW   profile end     80°44.99' N    28°58.32' E   500.5
PS94/016-5   21.08.15   02:18:59   CTD/UW   profile end     80°45.00' N    29°19.37' E   484.2
PS94/017-1   21.08.15   02:26:59   XCTD     on ground       80°45.01' N    29°27.83' E   495.7
                                            max depth
PS94/017-2   21.08.15   02:46:59   XCTD     on ground       80°45.01' N    29°49.11' E   267.0
                                            max depth
PS94/017-3   21.08.15   02:55:59   XCTD     on ground       80°45.01' N    29°58.60' E   257.7
                                            max depth
PS94/017-4   21.08.15   03:03:59   XCTD     on ground       80°45.01' N    30°7.07' E    259.0
                                            max depth
PS94/017-5   21.08.15   03:14:59   XCTD     on ground       80°45.27' N    30°17.34' E   201.7
                                            max depth
PS94/017-6   21.08.15   03:30:59   XCTD     on ground       80°45.65' N    30°4.82' E    248.2
                                            max depth
PS94/017-7   21.08.15   03:56:59   XCTD     on ground       80°45.36' N    29°40.95' E   354.7
                                            max depth
PS94/018-1   21.08.15   04:18:00   CTD/RO   on ground       80°45.29' N    29°40.66' E   367.0
                                            max depth
PS94/018-2   21.08.15   05:00:00   LOKI     on ground       80°45.30' N    29°40.22' E   378.2
                                            max depth
PS94/018-2   21.08.15   05:00:02   LOKI     profile start   80°45.30' N    29°40.22' E   378.2
PS94/018-2   21.08.15   05:12:01   LOKI     profile end     80°45.29' N    29°40.16' E   384.5
PS94/018-3   21.08.15   05:48:00   CTD/RO   on ground       80°45.26' N    29°39.85' E   393.7
                                            max depth
PS94/018-4   21.08.15   06:31:00   MN       on ground       80°45.24' N    29°39.54' E   403.0
                                            max depth
PS94/018-5   21.08.15   07:29:00   CTD/RO   on ground       80°45.23' N    29°38.85' E   418.5
                                            max depth
PS94/019-1   21.08.15   08:01:00   CTD/UW   profile start   80°47.35' N    29°33.84' E   423.0
PS94/019-1   21.08.15   08:16:59   CTD/UW   profile end     80°49.70' N    29°27.00' E   407.5
PS94/019-2   21.08.15   08:17:00   CTD/UW   profile start   80°49.86' N    29°26.69' E   398.5
PS94/019-2   21.08.15   08:34:59   CTD/UW   profile end     80°52.52' N    29°20.45' E   431.0
PS94/019-3   21.08.15   08:35:00   CTD/UW   profile start   80°52.68' N    29°20.02' E   431.2
PS94/019-3   21.08.15   08:52:59   CTD/UW   profile end     80°55.34' N    29°12.47' E   420.5
PS94/020-1   21.08.15   09:00:59   XCTD     on ground       80°56.55' N    29°8.90' E    409.5
                                            max depth
PS94/021-1   21.08.15   09:47:00   CTD/RO   on ground       80°59.72' N    28°59.45' E   390.0
                                            max depth
PS94/021-2   21.08.15   10:22:00   MUC      on ground       80°59.79' N    28°58.17' E   389.5
                                            max depth
PS94/022-1   21.08.15   11:17:59   XCTD     on ground       81°4.66' N     29°3.16' E    376.0
                                            max depth
PS94/023-1   21.08.15   12:02:59   XCTD     on ground       81°10.41' N    29°7.28' E    352.0
                                            max depth
PS94/024-1   21.08.15   12:40:59   XCTD     on ground       81°14.82' N    29°10.09' E   334.0
                                            max depth
PS94/025-1   21.08.15   13:27:00   CTD/RO   on ground       81°18.08' N    29°13.52' E   327.7
                                            max depth
PS94/026-1   21.08.15   14:47:59   XCTD     on ground       81°22.17' N    29°43.48' E   296.5
                                            max depth
PS94/027-1   21.08.15   15:30:59   XCTD     on ground       81°25.80' N    30°4.58' E    268.0
                                            max depth
PS94/028-1   21.08.15   16:14:59   XCTD     on ground       81°29.17' N    30°26.04' E   646.7
                                            max depth
PS94/029-1   21.08.15   18:01:00   MOR      on ground       81°32.65' N    30°50.83' E   883.5
                                            max depth
PS94/030-1   21.08.15   20:02:00   CTD/UC   on ground       81°31.78' N    30°47.55' E   831.5
                                            max depth
PS94/030-2   21.08.15   21:12:00   CTD/RO   on ground       81°31.96' N    30°46.89' E   841.0
                                            max depth
PS94/030-3   21.08.15   22:14:00   MN       on ground       81°32.19' N    30°48.71' E   852.0
                                            max depth
PS94/030-4   21.08.15   23:41:00   LOKI     on ground       81°32.03' N    30°50.22' E   842.5
                                            max depth
PS94/030-4   22.08.15   00:06:00   LOKI     profile end     81°32.18' N    30°51.52' E   848.0
                                            max depth
PS94/030-4   22.08.15   00:07:01   LOKI     profile start   81°32.19' N    30°51.58' E   847.2
                                            max depth
PS94/031-1   22.08.15   02:57:00   CTD/RO   on ground       81°41.66' N    30°55.02' E  2716.2
                                            max depth
PS94/032-1   22.08.15   07:49:00   MN       on ground       81°51.71' N    30°48.83' E  3175.2
                                            max depth
PS94/032-3   22.08.15   11:13:00   HN       on ground       81°51.59' N    30°49.76' E  3172.5
                                            max depth
PS94/032-2   22.08.15   11:45:00   CTD/RO   on ground       81°51.58' N    30°50.32' E  3172.0
                                            max depth
PS94/032-4   22.08.15   14:35:00   CTD/UC   on ground       81°51.24' N    30°53.60' E  3169.0
                                            max depth
PS94/032-5   22.08.15   16:06:00   CTD/RO   on ground       81°50.90' N    30°54.27' E  3166.5
                                            max depth
PS94/032-6   22.08.15   17:20:00   LOKI     on ground       81°50.63' N    30°53.85' E  3165.5
                                            max depth
PS94/032-6   22.08.15   17:20:02   LOKI     profile start   81°50.63' N    30°53.85' E  3165.5
                                            max depth
PS94/032-6   22.08.15   17:52:01   LOKI     profile end     81°50.50' N    30°53.55' E  3165.7
                                            max depth
PS94/032-7   22.08.15   19:23:00   CTD/RO   on ground       81°50.49' N    30°51.26' E  3167.5
                                            max depth
PS94/032-8   22.08.15   22:06:00   ISP      on ground       81°50.83' N    30°51.09' E  3168.5
                                            max depth
PS94/032-8   23.08.15   03:01:59   ISP      on ground       81°51.38' N    30°55.03' E  3162.2
                                            max depth
PS94/032-9   23.08.15   03:30:00   CTD/RO   on ground       81°51.39' N    30°54.94' E  3162.7
                                            max depth
PS94/032-10  23.08.15   05:12:00   MUC      on ground       81°51.46' N    30°53.80' E  3166.7
                                            max depth
PS94/033-1   23.08.15   07:32:59   XCTD     on ground       81°57.85' N    30°53.56' E  3194.2
                                            max depth
PS94/034-1   23.08.15   09:33:00   CTD/RO   on ground       82°2.47' N     30°55.54' E  3224.2
                                            max depth
PS94/035-1   23.08.15   11:32:00   XCTD     on ground       82°6.56' N     30°47.78' E  3283.7
                                            max depth
PS94/035-1   23.08.15   11:45:00   XCTD     on ground       82°7.69' N     30°46.83' E  3305.0
                                            max depth
PS94/035-1   23.08.15   12:00:59   XCTD     on ground       82°8.10' N     30°50.77' E  3302.5
                                            max depth
PS94/036-1   23.08.15   14:17:00   CTD/L    on ground       82°13.07' N    30°54.06' E  3326.7
                                            max depth
PS94/036-2   23.08.15   16:25:00   CTD/RO   on ground       82°13.33' N    30°53.46' E  3332.2
                                            max depth
PS94/037-1   23.08.15   18:29:59   XCTD     on ground       82°18.52' N    30°54.68' E  3400.0
                                            max depth
PS94/038-1   23.08.15   20:50:00   CTD/L    on ground       82°23.56' N    30°54.96' E  3464.5
                                            max depth
PS94/039-1   23.08.15   23:32:59   XCTD     on ground       82°33.34' N    30°53.01' E  3605.5
                                            max depth
PS94/040-1   24.08.15   02:15:00   CTD/L    on ground       82°42.39' N    30°55.06' E  3686.2
                                            max depth
PS94/040-2   24.08.15   05:25:00   CTD/UC   on ground       82°42.42' N    30°49.79' E  3695.2
                                            max depth
PS94/040-3   24.08.15   07:19:00   CTD/L    on ground       82°42.53' N    30°47.01' E  3701.0
                                            max depth
PS94/040-4   24.08.15   08:26:00   LOKI     profile start   82°42.64' N    30°44.17' E  3706.7
                                            max depth
PS94/040-4   24.08.15   08:26:01   LOKI     on ground       82°42.64' N    30°44.17' E  3706.7
                                            max depth
PS94/040-4   24.08.15   08:27:00   LOKI     profile end     82°42.64' N    30°44.12' E  3706.7
                                            max depth
PS94/040-5   24.08.15   11:06:00   MN       on ground       82°43.20' N    30°37.15' E  3722.5
                                            max depth
PS94/041-1   24.08.15   15:25:59   XCTD     on ground       82°54.11' N    30°55.40' E  3805.7
                                            max depth
PS94/042-1   24.08.15   18:55:00   CTD/L    on ground       83°2.66' N     30°50.46' E  3893.0
                                            max depth
PS94/043-1   24.08.15   22:15:59   XCTD     on ground       83°13.28' N    30°58.43' E  3957.0
                                            max depth
PS94/044-1   25.08.15   02:23:00   CTD/L    on ground       83°22.68' N    30°49.85' E  3969.5
                                            max depth
PS94/045-1   25.08.15   05:50:59   XCTD     on ground       83°33.07' N    30°57.78' E  4031.7
                                            max depth
PS94/046-2   25.08.15   10:34:00   HN       on ground       83°42.88' N    30°20.58' E  4052.5
                                            max depth
PS94/046-3   25.08.15   13:13:00   CTD/L    on ground       83°42.29' N    30°15.14' E  4052.7
                                            max depth
PS94/046-4   25.08.15   16:03:00   CTD/RO   on ground       83°41.48' N    30°5.55' E   4053.7
                                            max depth
PS94/046-1   25.08.15   17:33:00   ICE      on ground       83°41.16' N    29°58.53' E  4054.7
                                            max depth
PS94/047-1   25.08.15   21:17:59   XCTD     on ground       83°53.17' N    31°0.27' E   4013.5
                                            max depth
PS94/048-1   26.08.15   00:52:00   CTD/RO   on ground       84°2.29' N     30°45.52' E  4056.7
                                            max depth
PS94/049-1   26.08.15   04:39:59   XCTD     on ground       84°13.11' N    30°53.88' E  4056.0
                                            max depth
PS94/050-1   26.08.15   09:05:00   CTD/RO   on ground       84°23.92' N    30°42.91' E  4055.7
                                            max depth
PS94/050-2   26.08.15   09:26:00   HN       on ground       84°23.90' N    30°41.69' E  4055.5
                                            max depth
PS94/050-3   26.08.15   12:21:00   CTD/UC   on ground       84°23.64' N    30°32.65' E  4055.7
                                            max depth
PS94/050-4   26.08.15   14:41:00   CTD/RO   on ground       84°23.29' N    30°24.85' E  4055.7
                                            max depth
PS94/050-5   26.08.15   17:23:00   ISP      on ground       84°23.02' N    30°13.80' E  4055.7
                                            max depth
PS94/050-6   26.08.15   23:02:00   CTD/RO   on ground       84°23.20' N    29°55.83' E  4056.2
                                            max depth
PS94/050-7   26.08.15   23:58:00   LOKI     on ground       84°23.19' N    29°54.10' E  4056.5
                                            max depth
PS94/050-7   27.08.15   00:28:00   LOKI     profile start   84°23.18' N    29°53.15' E  4056.2
                                            max depth
PS94/050-7   27.08.15   00:28:01   LOKI     profile end     84°23.18' N    29°53.15' E  4056.2
                                            max depth
PS94/050-8   27.08.15   00:57:00   CTD/RO   on ground       84°23.15' N    29°52.19' E  4056.7
                                            max depth
PS94/050-9   27.08.15   03:13:00   MN       on ground       84°23.00' N    29°46.50' E  4056.5
                                            max depth
PS94/050-10  27.08.15   07:10:00   MUC      on ground       84°23.08' N    29°33.70' E  4039.5
                                            max depth
PS94/051-1   27.08.15   15:33:59   XCTD     on ground       84°37.07' N    33°33.47' E  3876.5
                                            max depth
PS94/052-1   27.08.15   19:50:59   XCTD     on ground       84°46.96' N    37°31.00' E  4027.0
                                            max depth
PS94/053-1   28.08.15   00:43:59   XCTD     on ground       84°58.57' N    41°19.37' E  4022.5
                                            max depth
PS94/054-1   28.08.15   06:33:00   ICE      on ground       85°5.11' N     42°37.05' E  4016.2
                                            max depth
PS94/054-2   28.08.15   08:28:00   CTD/L    on ground       85°5.47' N     42°31.97' E  4017.0
                                            max depth
PS94/054-3   28.08.15   11:43:00   CTD/UC   on ground       85°5.91' N     42°26.39' E  4017.2
                                            max depth
PS94/054-4   28.08.15   13:40:00   CTD/RO   on ground       85°6.04' N     42°22.96' E  4018.0
                                            max depth
PS94/055-1   28.08.15   21:17:59   XCTD     on ground       85°5.08' N     46°57.59' E  3943.5
                                            max depth
PS94/056-1   29.08.15   01:36:59   XCTD     on ground       85°12.33' N    50°20.12' E  3986.0
                                            max depth
PS94/057-1   29.08.15   07:17:59   XCTD     on ground       85°14.35' N    54°49.22' E  3963.5
                                            max depth
PS94/058-1   29.08.15   15:24:00   CTD/L    on ground       85°16.79' N    60°2.97' E   3928.0
                                            max depth
PS94/058-2   29.08.15   19:28:00   MOR      on ground       85°17.52' N    60°0.85' E   3928.5
                                            max depth
PS94/058-3   29.08.15   20:19:00   CTD/L    on ground       85°17.81' N    59°56.08' E  3929.2
                                            max depth
PS94/058-4   29.08.15   21:29:00   LOKI     on ground       85°18.02' N    59°56.14' E  3929.5
                                            max depth
PS94/058-4   29.08.15   21:59:00   LOKI     profile end     85°18.03' N    59°56.16' E  3929.2
                                            max depth
PS94/058-4   29.08.15   21:59:01   LOKI     profile start   85°18.03' N    59°56.16' E  3929.2
                                            max depth
PS94/058-5   29.08.15   22:51:00   CTD/L    on ground       85°18.08' N    59°56.53' E  3929.2
                                            max depth
PS94/058-6   30.08.15   01:05:00   MN       on ground       85°18.10' N    59°55.26' E  3929.7
                                            max depth
PS94/058-7   30.08.15   05:15:00   CTD/UC   on ground       85°18.58' N    59°49.32' E  3930.5
                                            max depth
PS94/059-1   30.08.15   12:03:00   CTD/L    on ground       85°31.01' N    60°22.15' E  3935.5
                                            max depth
PS94/060-1   30.08.15   20:21:59   XCTD     on ground       85°39.05' N    60°1.56' E   3935.5
                                            max depth
PS94/061-1   31.08.15   02:08:00   CTD/L    on ground       85°50.15' N    60°3.05' E   3929.2
                                            max depth
PS94/062-1   31.08.15   17:14:00   CTD/L    on ground       86°8.16' N     59°51.55' E  3914.2
                                            max depth
PS94/062-2   31.08.15   21:25:00   CTD/UC   on ground       86°7.37' N     59°48.58' E  3914.5
                                            max depth
PS94/062-3   31.08.15   23:15:00   CTD/L    on ground       86°6.89' N     59°48.46' E  3915.2
                                            max depth
PS94/063-1   01.09.15   02:55:01   XCTD     on ground       86°17.65' N    59°25.58' E  2583.0
                                            max depth
PS94/063-1   01.09.15   03:04:59   XCTD     on ground       86°17.84' N    59°34.01' E  2549.7
                                            max depth
PS94/064-1   01.09.15   07:13:00   CTD/L    on ground       86°24.99' N    60°12.41' E  2108.5
                                            max depth
PS94/064-2   01.09.15   08:56:00   CTD/UC   on ground       86°24.92' N    60°9.12' E   2104.2
                                            max depth
PS94/065-1   01.09.15   12:10:59   XCTD     on ground       86°33.29' N    61°21.78' E  2553.7
                                            max depth
PS94/066-1   01.09.15   15:26:00   CTD/L    on ground       86°42.75' N    61°21.65' E   674.0
                                            max depth 
PS94/066-2   01.09.15   16:30:00   GBG      on ground       86°42.61' N    61°19.02' E   655.7
                                            max depth 
PS94/066-3   01.09.15   18:22:00   LOKI     on ground       86°42.72' N    61°9.58' E    712.5
                                            max depth
PS94/066-3   01.09.15   18:23:01   LOKI     profile start   86°42.72' N    61°9.55' E    718.0
                                            max depth 
PS94/066-3   01.09.15   18:44:00   LOKI     profile end     86°42.68' N    61°9.09' E    679.2
                                            max depth 
PS94/066-4   01.09.15   19:22:00   MN       on ground       86°42.60' N    61°8.49' E    622.0
                                            max depth
PS94/067-1   02.09.15   00:06:59   XCTD     on ground       86°51.04' N    60°1.79' E   3293.7
                                            max depth
PS94/068-1   02.09.15   05:11:00   CTD/L    on ground       86°59.81' N    58°36.90' E  4908.2
                                            max depth
PS94/069-1   02.09.15   08:05:00   ICE      on ground       87°0.45' N     58°39.53' E  4752.0
                                            max depth
PS94/069-1   02.09.15   08:16:00   ICE      on ground       87°0.41' N     58°39.77' E  4753.0
                                            max depth
PS94/069-2   02.09.15   10:17:00   CTD/UC   on ground       86°59.89' N    58°43.84' E  4826.0
                                            max depth
PS94/069-3   02.09.15   11:17:00   HN       on ground       86°59.59' N    58°46.47' E     0.0
                                            max depth
PS94/069-4   02.09.15   12:38:00   CTD/L    on ground       86°59.17' N    58°49.01' E  4838.5
                                            max depth
PS94/069-5   02.09.15   14:50:00   CTD/L    on ground       86°58.49' N    58°50.37' E  4627.5
                                            max depth
PS94/069-6   02.09.15   20:22:00   MOR      on ground       87°0.97' N     58°15.52' E  4669.2
                                            max depth
PS94/069-6   02.09.15   20:22:01   MOR      on ground       87°0.97' N     58°15.52' E  4669.2
                                            max depth
PS94/069-7   02.09.15   22:19:00   GKG      on ground       86°59.72' N    58°10.23' E  4815.2
                                            max depth
PS94/070-1   03.09.15   03:55:00   CTD/L    on ground       86°57.19' N    55°49.57' E  3086.5
                                            max depth
PS94/070-2   03.09.15   06:25:00   LOKI     on ground       86°57.17' N    55°39.17' E  3113.0
                                            max depth
PS94/070-2   03.09.15   06:26:00   LOKI     profile start   86°57.17' N    55°39.14' E  3114.2
                                            max depth
PS94/070-2   03.09.15   06:57:00   LOKI     profile end     86°57.18' N    55°37.86' E  3113.7
                                            max depth
PS94/070-3   03.09.15   08:40:00   MN       on ground       86°57.25' N    55°34.19' E  3179.5
                                            max depth
PS94/070-4   03.09.15   12:07:00   CTD/UC   on ground       86°57.21' N    55°26.21' E  3253.7
                                            max depth
PS94/070-5   03.09.15   14:29:00   GKG      on ground       86°56.93' N    55°16.02' E  3652.2
                                            max depth
PS94/070-6   03.09.15   16:18:00   GKG      on ground       86°56.80' N    55°5.46' E   3653.7
                                            max depth
PS94/071-1   03.09.15   20:37:59   XCTD     on ground       87°11.25' N    57°58.77' E  3861.0
                                            max depth
PS94/072-1   04.09.15   00:08:00   CTD/L    on ground       87°21.78' N    59°39.80' E  3917.2
                                            max depth
PS94/073-1   04.09.15   03:52:59   XCTD     on ground       87°31.41' N    60°0.55' E   4180.0
                                            max depth
PS94/074-1   04.09.15   07:18:00   CTD/L    on ground       87°41.54' N    59°59.80' E  4075.7
                                            max depth
PS94/075-1   04.09.15   10:41:59   XCTD     on ground       87°51.97' N    60°15.66' E  4418.5
                                            max depth
PS94/076-1   04.09.15   13:56:00   CTD/L    on ground       88°1.75' N     59°52.76' E  4424.5
                                            max depth
PS94/076-2   04.09.15   17:28:00   CTD/UC   on ground       88°1.83' N     59°33.02' E  4424.0
                                            max depth
PS94/076-3   04.09.15   19:32:00   CTD/RO   on ground       88°1.98' N     59°27.24' E  4424.7
                                            max depth
PS94/077-1   04.09.15   21:49:59   XCTD     on ground       88°10.34' N    60°43.50' E  4422.2
                                            max depth
PS94/078-1   05.09.15   01:25:00   CTD/L    on ground       88°21.05' N    59°47.72' E  4418.5
                                            max depth
PS94/079-1   05.09.15   06:29:59   XCTD     on ground       88°30.36' N    60°50.39' E  4419.7
                                            max depth
PS94/080-1   05.09.15   10:53:00   CTD/L    on ground       88°41.63' N    60°10.71' E  4414.5
                                            max depth
PS94/081-1   05.09.15   18:00:00   ICE      on ground       88°59.14' N    60°57.98' E  4401.2
                                            max depth
PS94/081-2   05.09.15   20:04:00   CTD/L    on ground       88°59.37' N    61°3.80' E   4401.2
                                            max depth
PS94/081-3   05.09.15   20:09:00   HN       on ground       88°59.38' N    61°4.12' E   4401.2
                                            max depth
PS94/081-4   05.09.15   23:19:00   CTD/UC   on ground       88°59.70' N    61°14.76' E  4401.7
                                            max depth
PS94/081-5   06.09.15   01:29:00   CTD/L    on ground       88°59.93' N    61°16.76' E  4400.2
                                            max depth
PS94/081-6   06.09.15   02:55:00   LOKI     on ground       89°0.13' N     61°17.58' E  4400.0
                                            max depth
PS94/081-6   06.09.15   02:55:01   LOKI     profile start   89°0.13' N     61°17.58' E  4400.0
                                            max depth
PS94/081-6   06.09.15   03:28:00   LOKI     profile end     89°0.22' N     61°18.19' E  4400.0
                                            max depth
PS94/081-7   06.09.15   04:00:00   CTD/L    on ground       89°0.30' N     61°19.15' E  4399.7
                                            max depth
PS94/081-8   06.09.15   06:18:00   MN       on ground       89°0.62' N     61°26.15' E  4399.5
                                            max depth
PS94/081-9   06.09.15   11:14:00   ISP      on ground       89°0.89' N     61°44.12' E  4399.5
                                            max depth
PS94/081-9   06.09.15   16:24:59   ISP      on ground       89°0.69' N     61°43.50' E  4399.5
                                            max depth
PS94/081-10  06.09.15   18:08:00   CTD/UC   on ground       89°0.58' N     61°46.71' E  4399.5
                                            max depth
PS94/082-1   06.09.15   22:11:59   XCTD     on ground       89°9.93' N     59°56.74' E  4390.5
                                            max depth
PS94/083-1   07.09.15   02:18:00   CTD/L    on ground       89°19.71' N    58°45.16' E  4372.0
                                            max depth
PS94/084-1   07.09.15   05:57:59   XCTD     on ground       89°30.16' N    60°2.44' E   4352.2
                                            max depth
PS94/085-1   07.09.15   11:17:00   CTD/L    on ground       89°38.95' N    58°17.12' E  4329.7
                                            max depth
PS94/086-1   07.09.15   16:27:59   XCTD     on ground       89°50.18' N    46°52.51' E  4306.2
                                            max depth
PS94/087-1   08.09.15   04:28:00   CTD/UC   on ground       89°55.81' N   120°11.69' W  4263.5
                                            max depth
PS94/087-2   08.09.15   07:25:00   MUC      on ground       89°54.97' N   121°45.05' W  4262.2
                                            max depth
PS94/088-1   08.09.15   12:07:59   XCTD     on ground       89°48.47' N   113°16.01' W  4251.0
                                            max depth
PS94/089-1   09.09.15   01:26:00   CTD/L    on ground       89°34.00' N   119°27.46' W  4239.7
                                            max depth
PS94/090-1   09.09.15   05:28:59   XCTD     on ground       89°24.14' N   119°17.06' W  2306.7
                                            max depth
PS94/091-1   09.09.15   09:38:00   CTD/L    on ground       89°10.00' N   116°49.82' W  1342.7
                                            max depth
PS94/091-2   09.09.15   11:01:00   CTD/UC   on ground       89°9.80' N    116°40.79' W  1331.0
                                            max depth
PS94/091-3   09.09.15   12:22:00   MN       on ground       89°9.59' N    116°26.11' W  1323.2
                                            max depth
PS94/091-4   09.09.15   14:16:00   LOKI     on ground       89°9.23' N    116°0.87' W   1317.0
                                            max depth
PS94/091-4   09.09.15   14:16:02   LOKI     profile start   89°9.23' N    116°0.87' W   1317.0
                                            max depth
PS94/091-4   09.09.15   14:48:01   LOKI     profile end     89°9.13' N    115°53.76' W  1317.7
                                            max depth
PS94/092-1   09.09.15   18:19:59   XCTD     on ground       88°57.17' N   112°41.18' W  1376.2
                                            max depth
PS94/093-1   09.09.15   19:24:00   ICE      on ground       88°54.60' N   112°55.37' W  1710.2
                                            max depth
PS94/093-1   09.09.15   19:41:00   ICE      on ground       88°54.59' N   112°52.73' W  1691.2
                                            max depth
PS94/094-1   10.09.15   09:12:00   CTD/L    on ground       88°42.53' N   118°54.42' W  3996.0
                                            max depth
PS94/095-1   10.09.15   17:14:59   XCTD     on ground       88°32.21' N   121°2.99' W   3994.5
                                            max depth
PS94/096-1   11.09.15   06:10:00   ICE      on ground       88°21.79' N   125°10.06' W  3614.0
                                            max depth
PS94/096-2   11.09.15   07:37:00   CTD/L    on ground       88°21.59' N   125°5.65' W   3611.5
                                            max depth
PS94/096-3   11.09.15   09:09:00   HN       on ground       88°21.38' N   125°0.82' W   3597.0
                                            max depth
PS94/096-4   11.09.15   10:43:00   CTD/UC   on ground       88°21.18' N   124°55.77' W  3586.7
                                            max depth
PS94/096-5   11.09.15   13:51:00   ISP      on ground       88°20.84' N   124°46.60' W  3583.5
                                            max depth
PS94/096-6   11.09.15   20:29:00   MN       on ground       88°20.25' N   124°31.82' W  3579.2
                                            max depth
PS94/096-7   11.09.15   23:02:00   CTD/L    on ground       88°20.29' N   124°21.76' W  3574.2
                                            max depth
PS94/096-8   12.09.15   00:11:00   LOKI     on ground       88°20.30' N   124°16.36' W  3572.0
                                            max depth
PS94/096-8   12.09.15   00:45:00   LOKI     profile start   88°20.29' N   124°13.67' W  3570.5
                                            max depth
PS94/096-8   12.09.15   00:45:01   LOKI     profile end     88°20.29' N   124°13.67' W  3570.5
                                            max depth
PS94/097-1   12.09.15   11:47:59   XCTD     on ground       88°19.29' N   143°43.71' W  3804.0
                                            max depth
PS94/098-1   12.09.15   13:22:59   ICE      on ground       88°20.17' N   144°7.96' W   3806.5
                                            max depth
PS94/099-1   12.09.15   20:59:00   CTD/UC   on ground       88°10.89' N   155°49.49' W  3765.5
                                            max depth
PS94/099-2   12.09.15   22:43:00   CTD/L    on ground       88°10.78' N   155°45.58' W  3761.5
                                            max depth
PS94/099-3   13.09.15   01:51:00   CTD/UC   on ground       88°10.96' N   155°39.60' W  3763.0
                                            max depth
PS94/100-1   13.09.15   11:09:01   XCTD     on ground       87°54.40' N   170°0.11' W   3979.0
                                            max depth
PS94/101-1   13.09.15   20:42:00   ICE      on ground       87°29.71' N   179°54.70' E  3995.5
                                            max depth
PS94/101-1   13.09.15   21:05:00   ICE      on ground       87°29.73' N   179°53.72' E  3995.5
                                            max depth
PS94/101-2   13.09.15   22:26:00   CTD/L    on ground       87°29.84' N   179°50.47' E  3995.7
                                            max depth
PS94/101-3   13.09.15   23:31:01   HN       on ground       87°29.96' N   179°48.61' E  3995.7
                                            max depth
PS94/101-4   14.09.15   01:23:00   CTD/UC   on ground       87°30.19' N   179°47.89' E  3995.7
                                            max depth
PS94/101-5   14.09.15   03:49:00   CTD/L    on ground       87°30.31' N   179°50.78' E  3995.5
                                            max depth
PS94/101-6   14.09.15   06:27:00   ISP      on ground       87°30.14' N   179°52.45' E  3995.5
                                            max depth
PS94/101-7   14.09.15   12:13:00   CTD/L    on ground       87°30.13' N   179°49.96' E  3995.7
                                            max depth
PS94/101-8   14.09.15   14:23:00   CTD/UC   on ground       87°30.15' N   179°55.92' E  3995.5
                                            max depth
PS94/101-9   14.09.15   16:15:00   CTD/L    on ground       87°29.95' N   179°56.84' W  3995.2
                                            max depth
PS94/101-10  14.09.15   17:46:00   MUC      on ground       87°29.70' N   179°52.73' W  3995.2
                                            max depth
PS94/102-1   15.09.15   07:50:00   ICE      on ground       87°15.92' N   164°36.92' E  4006.2
                                            max depth
PS94/103-1   15.09.15   09:40:59   XCTD     on ground       87°12.14' N   162°2.13' E   3979.5
                                            max depth
PS94/104-1   15.09.15   15:55:59   XCTD     on ground       87°2.99' N    153°56.98' E  1925.5
                                            max depth
PS94/105-1   15.09.15   22:34:00   CTD/L    on ground       86°58.66' N   146°50.62' E  1000.7
                                            max depth
PS94/105-2   15.09.15   23:54:00   GKG      on ground       86°58.61' N   146°48.61' E  1001.0
                                            max depth
PS94/106-1   16.09.15   06:03:59   XCTD     on ground       86°50.26' N   140°16.06' E  2152.2
                                            max depth
PS94/107-1   16.09.15   11:18:59   XCTD     on ground       86°39.89' N   134°38.68' E  3380.7
                                            max depth
PS94/107-2   16.09.15   13:47:59   ICE      on ground       86°37.66' N   133°51.90' E  3701.7
                                            max depth
PS94/108-1   16.09.15   17:28:59   XCTD     on ground       86°24.59' N   131°2.67' E   4285.2
                                            max depth
PS94/109-1   16.09.15   22:45:59   XCTD     on ground       86°3.11' N    126°40.28' E  4381.2
                                            max depth
PS94/110-1   17.09.15   04:11:59   XCTD     on ground       85°44.09' N   123°37.91' E  4399.0
                                            max depth
PS94/111-1   17.09.15   09:28:59   XCTD     on ground       85°24.82' N   120°49.32' E  4417.7
                                            max depth
PS94/112-2   17.09.15   13:22:59   XCTD     on ground       85°12.88' N   118°23.83' E  4410.0
                                            max depth
PS94/112-1   17.09.15   14:20:59   ICE      on ground       85°12.76' N   118°25.59' E  4410.2
                                            max depth
PS94/113-1   17.09.15   19:31:59   XCTD     on ground       84°54.26' N   115°29.49' E  4425.0
                                            max depth
PS94/114-1   17.09.15   23:42:59   XCTD     on ground       84°38.11' N   113°22.67' E  4220.2
                                            max depth
PS94/115-1   18.09.15   06:37:00   CTD/L    on ground       84°16.30' N   110°41.30' E  4046.5
                                            max depth
PS94/116-1   18.09.15   11:42:59   XCTD     on ground       84°24.76' N   112°44.54' E  3181.2
                                            max depth
PS94/117-1   18.09.15   18:24:00   ICE      on ground       84°33.80' N   115°59.76' E  4380.7
                                            max depth
PS94/117-2   18.09.15   20:06:00   CTD/L    on ground       84°33.62' N   115°59.74' E  4400.2
                                            max depth
PS94/117-3   18.09.15   23:37:00   CTD/UC   on ground       84°32.55' N   115°57.65' E  4320.2
                                            max depth
PS94/117-4   19.09.15   01:44:00   CTD/L    on ground       84°31.74' N   115°53.22' E  4272.0
                                            max depth
PS94/117-5   19.09.15   04:24:00   MN       on ground       84°30.88' N   115°45.44' E  4240.2
                                            max depth
PS94/117-6   19.09.15   07:28:00   CTD/L    on ground       84°30.41' N   115°40.75' E  4217.2
                                            max depth
PS94/117-7   19.09.15   09:31:00   ISP      on ground       84°29.84' N   115°42.29' E  4214.7
                                            max depth
PS94/117-8   19.09.15   11:50:01   HN       on ground       84°28.78' N   115°42.70' E  4170.0
                                            max depth
PS94/117-9   19.09.15   16:00:59   ICE      on ground       84°31.36' N   116°8.95' E   350.7
                                            max depth
PS94/118-1   19.09.15   23:58:00   CTD/L    on ground       84°39.72' N   119°47.53' E  4395.5
                                            max depth
PS94/119-1   20.09.15   10:20:00   CTD/UC   on ground       84°48.77' N   123°53.59' E  4385.5
                                            max depth
PS94/119-2   20.09.15   13:42:59   ICE      on ground       84°51.64' N   124°11.71' E  4385.5
                                            max depth
PS94/120-1   20.09.15   17:59:59   XCTD     on ground       84°55.52' N   128°23.42' E  4358.2
                                            max depth
PS94/121-1   21.09.15   00:22:00   CTD/L    on ground       85°0.85' N    132°55.90' E  4318.0
                                            max depth
PS94/121-2   21.09.15   04:14:00   CTD/UC   on ground       85°0.74' N    132°43.92' E  4322.0
                                            max depth
PS94/122-1   21.09.15   12:35:59   XCTD     on ground       85°6.71' N    135°21.88' E  4281.2
                                            max depth
PS94/123-1   21.09.15   18:24:00   CTD/L    on ground       85°3.85' N    137°38.09' E  4089.5
                                            max depth
PS94/123-2   21.09.15   21:19:00   MUC      on ground       85°3.18' N    137°33.08' E  4113.0
                                            max depth
PS94/124-1   22.09.15   02:57:59   XCTD     on ground       85°5.12' N    140°0.47' E   3904.2
                                            max depth
PS94/125-1   22.09.15   04:07:00   ICE      on ground       85°4.96' N    139°57.38' E  3913.0
                                            max depth
PS94/125-2   22.09.15   05:44:00   CTD/L    on ground       85°5.13' N    139°58.72' E  3906.0
                                            max depth
PS94/125-3   22.09.15   09:40:00   CTD/UC   on ground       85°4.85' N    139°54.12' E  3919.5
                                            max depth
PS94/125-4   22.09.15   11:10:00   HN       on ground       85°4.87' N    139°48.07' E  3923.0
                                            max depth
PS94/125-4   22.09.15   11:13:00   HN       on ground       85°4.88' N    139°47.88' E  3923.7
                                            max depth
PS94/125-5   22.09.15   11:38:00   CTD/L    on ground       85°4.93' N    139°46.37' E  3920.2
                                            max depth
PS94/125-6   22.09.15   13:45:00   MN       on ground       85°5.37' N    139°40.83' E  3910.0
                                            max depth
PS94/125-7   22.09.15   16:30:00   CTD/L    on ground       85°5.87' N    139°37.60' E  3904.5
                                            max depth
PS94/125-8   22.09.15   18:53:00   ISP      on ground       85°5.86' N    139°36.09' E  3905.5
                                            max depth
PS94/126-1   23.09.15   06:22:59   XCTD     on ground       85°4.20' N    143°1.86' E   3292.7
                                            max depth
PS94/127-1   23.09.15   08:01:59   XCTD     on ground       85°4.67' N    144°43.83' E  2595.7
                                            max depth
PS94/128-1   23.09.15   11:19:00   CTD/L    on ground       85°3.84' N    146°56.54' E  1252.0
                                            max depth
PS94/129-1   23.09.15   16:50:59   XCTD     on ground       85°1.39' N    149°13.40' E  1734.5
                                            max depth
PS94/130-1   23.09.15   21:34:00   CTD/L    on ground       85°0.93' N    151°45.35' E  860.5
                                            max depth
PS94/130-2   23.09.15   22:45:00   CTD/UC   on ground       85°1.02' N    151°41.23' E  868.0
                                            max depth
PS94/130-3   23.09.15   23:47:00   MN       on ground       85°1.22' N    151°38.00' E  867.0
                                            max depth
PS94/130-4   24.09.15   01:05:00   MUC      on ground       85°1.58' N    151°35.41' E  866.5
                                            max depth
PS94/131-1   24.09.15   04:45:59   XCTD     on ground       84°58.40' N   153°51.88' E  1614.2
                                            max depth
PS94/132-1   24.09.15   07:26:00   CTD/L    on ground       85°1.37' N    155°13.15' E  2509.2
                                            max depth
PS94/133-1   24.09.15   12:34:59   XCTD     on ground       84°58.47' N   157°14.15' E  2503.7
                                            max depth
PS94/134-1   24.09.15   15:40:00   CTD/L    on ground       84°50.66' N   159°1.48' E   3170.2
                                            max depth
PS94/134-2   24.09.15   18:26:00   CTD/UC   on ground       84°50.53' N   159°2.68' E   3180.7
                                            max depth
PS94/135-1   25.09.15   06:26:00   ICE      on ground       83°30.07' N   154°56.58' E  2779.0
                                            max depth
PS94/135-2   25.09.15   06:45:59   XCTD     on ground       83°29.99' N   154°55.75' E  2778.5
                                            max depth
PS94/136-1   25.09.15   08:01:59   XCTD     on ground       83°19.66' N   154°44.94' E  2785.5
                                            max depth
PS94/137-1   25.09.15   10:06:59   XCTD     on ground       83°2.04' N    154°11.40' E  2800.2
                                            max depth
PS94/138-1   25.09.15   13:45:59   XCTD     on ground       82°41.05' N   151°52.20' E  2790.2
                                            max depth
PS94/139-1   25.09.15   15:44:59   XCTD     on ground       82°22.93' N   150°31.22' E  2796.5
                                            max depth
PS94/140-1   25.09.15   18:56:59   XCTD     on ground       82°1.03' N    148°24.31' E  2665.5
                                            max depth
PS94/141-1   25.09.15   21:23:59   XCTD     on ground       81°42.44' N   146°59.68' E  2557.2
                                            max depth
PS94/142-1   25.09.15   23:23:59   XCTD     on ground       81°21.32' N   145°49.49' E  2291.7
                                            max depth
PS94/143-1   26.09.15   01:28:59   XCTD     on ground       80°58.52' N   144°31.91' E  1871.5
                                            max depth
PS94/144-1   04.10.15   17:36:59   FLOAT    on ground       74°0.06' N      6°21.61' E  2225.7
                                            max depth
PS94/145-1   05.10.15   06:54:00   GLD      on ground       75°33.35' N     2°39.66' W  3715.7
                                            max depth
PS94/146-1   05.10.15   10:27:00   GLD      on ground       75°23.44' N     1°8.56' W   3749.7
                                            max depth
PS94/147-1   06.10.15   18:13:00   CTD/RO   on ground       75°0.46' N     24°15.10' E   150.7
                                            max depth
PS94/147-2   06.10.15   18:43:00   CTD/UC   on ground       75°0.39' N     24°15.43' E   151.5
                                            max depth
PS94/147-3   06.10.15   19:15:00   MN       on ground       75°0.37' N     24°15.75' E   150.7
                                            max depth
PS94/148-1   06.10.15   22:20:59   XCTD     on ground       74°36.04' N    23°57.66' E   209.5
                                            max depth
PS94/149-1   07.10.15   00:35:00   CTD/RO   on ground       74°19.14' N    23°48.38' E   303.0
                                            max depth
PS94/149-2   07.10.15   01:16:00   CTD/UC   on ground       74°19.40' N    23°48.24' E   305.0
                                            max depth
PS94/149-3   07.10.15   01:57:00   MN       on ground       74°19.37' N    23°47.63' E   304.5
                                            max depth
PS94/149-4   07.10.15   02:51:00   CTD/RO   on ground       74°19.28' N    23°46.31' E   303.2
                                            max depth
PS94/149-5   07.10.15   03:25:00   MUC      on ground       74°19.32' N    23°45.25' E   301.5
                                            max depth
PS94/149-6   07.10.15   03:54:00   MUC      on ground       74°19.43' N    23°44.18' E   300.5
                                            max depth
PS94/150-1   07.10.15   05:15:59   XCTD     on ground       74°9.81' N     23°43.52' E   415.7
                                            max depth
PS94/151-1   07.10.15   06:19:59   XCTD     on ground       74°0.45' N     23°36.15' E   456.5
                                            max depth
PS94/152-1   07.10.15   07:21:59   XCTD     on ground       73°51.38' N    23°28.48' E   466.2
                                            max depth
PS94/153-1   07.10.15   08:47:00   CTD/RO   on ground       73°42.44' N    23°21.65' E   460.0
                                            max depth
PS94/153-2   07.10.15   09:35:00   CTD/UC   on ground       73°42.45' N    23°21.60' E   460.0
                                            max depth
PS94/153-3   07.10.15   10:17:00   MN       on ground       73°42.42' N    23°21.49' E   460.2
                                            max depth
PS94/153-4   07.10.15   11:18:00   CTD/RO   on ground       73°42.42' N    23°21.57' E   459.2
                                            max depth
PS94/153-5   07.10.15   12:24:00   BN       profile start   73°42.46' N    23°21.74' E   459.0
                                            max depth
PS94/153-5   07.10.15   12:24:01   BN       profile end     73°42.46' N    23°21.74' E   459.0
                                            max depth
PS94/153-6   07.10.15   13:16:01   ISP      on ground       73°42.31' N    23°21.82' E   461.7
                                            max depth
PS94/154-1   07.10.15   18:06:59   XCTD     on ground       73°35.33' N    23°18.21' E   450.2
                                            max depth
PS94/155-1   07.10.15   18:48:59   XCTD     on ground       73°29.13' N    23°13.72' E   445.5
                                            max depth
PS94/156-1   07.10.15   19:33:59   XCTD     on ground       73°22.57' N    23°8.74' E    427.2
                                            max depth
PS94/157-1   07.10.15   20:43:00   CTD/RO   on ground       73°15.15' N    23°4.27' E    415.0
                                            max depth
PS94/157-2   07.10.15   21:28:00   CTD/UC   on ground       73°15.24' N    23°4.42' E    415.2
                                            max depth
PS94/157-3   07.10.15   22:17:00   MN       on ground       73°15.20' N    23°4.34' E    416.7
                                            max depth
PS94/158-1   07.10.15   23:30:59   XCTD     on ground       73°7.80' N     23°1.14' E    409.5
                                            max depth
PS94/159-1   08.10.15   00:18:59   XCTD     on ground       73°0.39' N     22°57.57' E   410.2
                                            max depth
PS94/160-1   08.10.15   01:17:59   XCTD     on ground       72°51.57' N    22°53.23' E   405.5
                                            max depth
PS94/161-1   08.10.15   02:32:00   CTD/RO   on ground       72°44.08' N    22°49.27' E   395.2
                                            max depth
PS94/161-2   08.10.15   03:18:00   CTD/UC   on ground       72°44.06' N    22°49.30' E   395.0
                                            max depth
PS94/161-3   08.10.15   04:03:00   MN       on ground       72°44.08' N    22°49.22' E   394.2
                                            max depth
PS94/161-4   08.10.15   04:48:00   CTD/RO   on ground       72°44.07' N    22°49.24' E   395.0
                                            max depth
PS94/161-5   08.10.15   10:03:00   ISP      on ground       72°44.09' N    22°49.38' E   395.2
                                            max depth
PS94/161-6   08.10.15   10:20:00   MUC      on ground       72°44.04' N    22°49.56' E   394.7
                                            max depth
PS94/162-1   08.10.15   11:30:59   XCTD     on ground       72°36.96' N    22°46.35' E   382.2
                                            max depth
PS94/163-1   08.10.15   12:43:59   XCTD     on ground       72°27.16' N    22°41.11' E   333.5
                                            max depth
PS94/164-1   08.10.15   13:46:59   XCTD     on ground       72°18.72' N    22°35.99' E   317.2
                                            max depth
PS94/165-1   08.10.15   15:19:00   CTD/RO   on ground       72°9.42' N     22°29.81' E   328.7
                                            max depth
PS94/166-1   08.10.15   17:02:59   XCTD     on ground       71°59.31' N    22°24.28' E   372.0
                                            max depth
PS94/167-1   08.10.15   18:10:59   XCTD     on ground       71°49.93' N    22°18.58' E   374.5
                                            max depth
PS94/168-1   08.10.15   19:13:59   XCTD     on ground       71°41.21' N    22°13.46' E   372.5
                                            max depth
PS94/169-1   08.10.15   20:36:00   CTD/RO   on ground       71°33.93' N    21°54.44' E   357.5
                                            max depth
PS94/169-2   08.10.15   22:29:00   CTD/RO   on ground       71°34.04' N    21°54.75' E   358.2
                                            max depth
PS94/169-3   08.10.15   23:11:00   CTD/UC   on ground       71°34.00' N    21°54.57' E   356.7
                                            max depth
PS94/170-1   09.10.15   01:02:59   XCTD     on ground       71°21.62' N    21°52.01' E   315.5
                                            max depth
PS94/171-1   09.10.15   01:53:59   XCTD     on ground       71°14.75' N    21°38.76' E   299.7
                                            max depth
PS94/172-1   09.10.15   02:46:59   XCTD     on ground       71°7.42' N     21°25.91' E   218.0
                                            max depth
PS94/173-1   09.10.15   03:56:00   CTD/RO   on ground       70°59.98' N    21°11.96' E   174.5
                                            max depth
PS94/173-2   09.10.15   04:27:00   CTD/UC   on ground       70°59.96' N    21°11.57' E   175.5   
                                            max depth




Gear abbreviations: 

Argo    Deployment of Argo float
CTD/L   Large Conductivity/Temperature/Depth and water sampler system
CTD/RO  Conductivity/Temperature/Depth system with water sampler 
        caroussel
CTD/UC  Ultra-clean Conductivity/Temperature/Depth and water sampler 
        system
CTD/UW  Towed Underway Conductivity/Temperature/Depth system
GKG     Box corer
Glider  Recovery of glider
HN      Hand net
ICE     Ice station
ISP     In-situ pumps
LOKI    Lightframe On-sight Key species Investigation system
MN      Multi-net
MOR     Mooring deployment
MUC     Multi corer
XCTD    Expandable CTD




Band 377-568, von 2000 bis 2008) sowie der früheren Berichte zur 
Polarforschung (ISSN 0176-5027, Band 1-376, von 1981 bis 2000) befindet 
sich im electronic Publication Information Center (ePIC) des Alfred-
Wegener-Instituts, Helmholtz-Zentrum für Polar- und Meeresforschung 
(AWI); see http://epic.awi.de. Durch Auswahl “Reports on Polar- and 
Marine Research“ (via “browse”/”type”) wird eine Liste der Publikationen, 
sortiert nach Bandnummer, innerhalb der absteigenden chronologischen 
Reihenfolge der Jahrgänge mit Verweis auf das jeweilige pdf-Symbol zum 
Herunterladen angezeigt.


(ISSN 1866-3192) are available as open access publications since 2008. A 
table of all volumes including the printed issues (ISSN 1618-3193, Vol. 
377-568, from 2000 until 2008), as well as the earlier Reports on Polar 
Research (ISSN 0176- 5027, Vol. 1-376, from 1981 until 2000) is provided 
by the electronic Publication Information Center (ePIC) of the Alfred 
Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI); 
see URL http://epic.awi.de. To generate a list of all Reports, use the 
URL http://epic.awi.de and select “browse”/”type” to browse ”Reports on 
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Zuletzt erschienene Ausgaben: / Recently published issues:

703 (2016) The Expedition PS94 of the Research Vessel POLARSTERN to the 
central Arctic Ocean in 2015, edited by Ursula Schauer

702 (2016) The Expeditions PS95.1 and PS95.2 of the Research Vessel 
POLARSTERN to the Atlantic Ocean in 2015, edited by Rainer Knust and 
Karin Lochte

701 (2016) The Expedition PS97 of the Research Vessel POLARSTERN to the 
Drake Passage in 2016, edited by Frank Lamy

700 (2016) The Expedition PS96 of the Research Vessel POLARSTERN to the 
southern Weddell Sea in 2015/2016, edited by Michael Schröder

699 (2016) Die Tagebcher Alfred Wegeners zur Danmark-Expedition 1906/08, 
herausgegeben von Reinhard A. Krause

698 (2016) The Expedition SO246 of the Research Vessel SONNE to the 
Chatham Rise in 2016, edited by Karsten Gohl and Reinhard Werner

697 (2016) Studies of Polygons in Siberia and Svalbard, edited by Lutz 
Schirrmeister, Liudmila Pestryakova, Andrea Schneider and Sebastian 
Wetterich

696 (2016) The Expedition PS88 of the Research Vessel POLARSTERN to the 
Atlantic Ocean in 2014, edited by Rainer Knust and Frank Niessen

695 (2016) The Expedition PS93.1 of the Research Vessel POLARSTERN to the 
Arctic Ocean in 2015, edited by Ruediger Stein

694 (2016) The Expedition PS92 of the Research Vessel POLARSTERN to the 
Arctic Ocean in 2015, edited by Ilka Peeken

693 (2015) The Expedition PS93.2 of the Research Vessel POLARSTERN to the 
Fram Strait in 2015, edited by Thomas Soltwedel





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CCHDO Data Processing Notes


• File Merge Carolina Berys
BzPM_0703_2016.pdf (download) #70915 
Date: 2019-07-29 
Current Status: merged


• File Merge Jerry Kappa
06AQ20150817_do.pdf (download) #e8468 
Date: 2019-07-29 
Current Status: dataset


• File Submission Jerry Kappa
06AQ20150817_do.pdf (download) #e8468 
Date: 2019-07-25 
Current Status: dataset 
Notes
The pdf version of TransArc-II's cruise report is ready to be added to 
the CCHDO Dataset.  It includes all of the PI-provided data reports as 
well as CCHDO summary pages and data processing notes.


• File Merge CCHSIO
06AQ20150817_ct1.zip (download) #a24af 
Date: 2019-06-28 
Current Status: merged


• As Received processed into Dataset CCHSIO 
Date: 2019-06-28 
Data Type: CTD 
Action: Website Update 
Note: 
2015 06AQ20150817 processing - CTD/merge - 
CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDXMISS,CTDFLUOR,CTDFLUOR_Haardt
2019-06-28

CCHSIO

Submission

filename             submitted by   date       id  

-------------------- -------------- ---------- -----

06AQ20150817_ct1.zip James Swift    2019-06-27 14567

Changes
-------
	
06AQ20150817_ct1.zip

	- CTDFLUOR_Haardt not a defined variable in Exchange.

Conversion
----------

file                    converted from       software               
----------------------- -------------------- -----------------------
06AQ20150817_nc_ctd.zip 06AQ20150817_ct1.zip hydro 0.8.2-57-g8aa7d7a


Updated Files Manifest
----------------------

file                    stamp            
----------------------- --------------
06AQ20150817_ct1.zip    20190627CCHSIO
06AQ20150817_nc_ctd.zip 20190627CCHSIO

:Updated parameters: 
CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDXMISS,CTDFLUOR,CTDFLUOR_Haardt

opened in JOA 5.2.1 with no apparent problems:
     06AQ20150817_ct1.zip
     06AQ20150817_nc_ctd.zip

opened in ODV with no apparent problems:
     06AQ20150817_ct1.zip


• File Online Carolina Berys
06AQ20150817_ct1.zip (download) #a24af 
Date: 2019-06-27 
Current Status: merged


• File Submission CCHDO for J.Swift
06AQ20150817_ct1.zip (download) #a24af 
Date: 2019-06-27 
Current Status: merged 
Notes
data downloaded from https://doi.pangaea.de/10.1594/PANGAEA.859558,  
converted to Exchange.   Oxygen not calibrated.


• File Online Carolina Berys
06AQ20150817.exc.csv (download) #c6aa4 
Date: 2018-01-24 
Current Status: unprocessed


• File Online Carolina Berys
BzPM_0703_2016.pdf (download) #70915 
Date: 2018-01-24 
Current Status: merged


• File Submission Robert Key
BzPM_0703_2016.pdf (download) #70915 
Date: 2018-01-22 
Current Status: merged 
Notes

Robert Key

See header for aliases

This cruise is the one that met up with Healy at the N.Pole. All data 
files from PANGAEA

This is a new cruise for CCHDO


• File Submission Robert Key
06AQ20150817.exc.csv (download) #c6aa4 
Date: 2018-01-22 
Current Status: unprocessed 
Notes

Robert Key

See header for aliases

This cruise is the one that met up with Healy at the N.Pole. All data 
files from PANGAEA

This is a new cruise for CCHDO


