CRUISE REPORT: A01/AR07E/A16N
(Updated AUG 2018)










Highlights




                          Cruise Summary Information

               Section Designation  A01/AR07E/A16N
Expedition designation (ExpoCodes)  58GS20150410
                  Chief Scientists  Are Olsen / U. Bergen
                             Dates  2015 APR 10 - 2015 APR 26 
                              Ship  G.O. Sars
                     Ports of call  Torshavn, Denmark to Bergen, Norway

                                                   61° 59' 20" N
              Geographic Boundaries  40° 44' 16.8" W           5° 1' 52.7" E
                                                   57° 42' 0" N

                          Stations  34
      Floats and drifters deployed  0
    Moorings deployed or recovered  0

                            Contact Information:

                     Are Christian Sviggum Olsen, Prof.
                Geophysical Institute • University of Bergen
                    Postboks 7803 • 5020 BERGEN • Norway
               phone: +47 55 58 47 81 • email: Are.Olsen@uib.no












                Report assembled by Jerry Kappa, UCSD/SIO



























                              Cruise report

                               58GS20150410
                    (a.k.a. GOS2015107, SNACS CRUISE)
 



Are Olsen(1,2), Ailin Brakstad(1), Friederike Fröb(1,2), Nil Irvali(3,2), 
Kristin Jackson(1) , Emil Jeansson(4,2), Tor de Lange1, Siv Lauvset(1,2), 
Stig Monsen(3), Ulysses Ninneman(3,2), Tore Onarheim(1), Abdirahman 
Omar(4,2), Balamuralli Rajasakaren(4,2), Jörg Schwinger(4,2), Asgeir 
Steinsland(5), Åse Sudmann(5), Magni Svanevik(1)   

(1)Geophysical Institute, University of Bergen, Bergen, Norway 
(2)Bjerknes Centre for Climate Research, Bergen, Norway 
(3)Department of Earth Sciences, University of Bergen, Bergen, Norway 
(4)Uni Climate, Uni Research, Bergen, Norway 
(5)Institute of Marine Research, Bergen, Norway 
 	
Contents 	
 
1. Introduction and Background                                       3 
 
2. Participants and responsibilities                                 4 
 
3. Watch List                                                        5 
 	 
4. Sampling and instruments 	 
   4.1 Water profile sampling                                        5 
   4.2 Surface sampling                                              8 
   4.3 Sediment coring                                               9 
8 
 
5. Preliminary results 
   5.1 Water profile sampling                                       10 
   5.2 Surface sampling                                             11 
   5.3 Sediment coring                                              12 
 
6. Cruise Diary                                                     14 
 
7. Surface sampling notes                                           20 
 
References                                                          20 
 	 				


1.  Introduction and Background

The cruise was conducted on board the Norwegian research vessel G.O. 
Sars, as part of the Norwegian Research Council funded project SNACS, 
Subpolar Atlantic Climate States. This project focus on North Atlantic 
Subpolar gyre dynamics and carbon cycling in the Holocene, present and 
future. The sampling program was designed to enable carbon budget 
calculations, mapping of sea water chemistry in various water masses, and 
coring at water sampling sites allowing for a direct comparison between 
sedimentary records and water chemistry, in particular focusing on stable 
carbon isotopes, δ13C.

For the cruise we, in particular planned to focus on a hydrographic 
section in the Irminger Sea, the center of the North Atlantic Subpolar 
Gyre. This section covers the western parts of WOCE line AR07E. Further 
we would obtain sediment cores on the western edge of the basin, at a 
site capturing the Denmark Strait Overflow Water and at the western slope 
of Reykjanes Ridge capturing the variability in polar front position. 
Further work was planned along the core of the Iceland Scotland Overflow 
Water from Faeroes-Shetland and southwards (Fig. 1). In particular coring 
at ODP 984 site, and do repeats of A16N stations at 20°W and 61° and 
62°N, this gives us an opportunity to compare our δ13C data with those 
obtained by US groups at the same stations, allowing for calibration of 
data across laboratories.

We also planned to install a new General Oceanics underway pCO2 
instrument on the ship during the cruise as part of the Norwegian Ocean 
Acidification monitoring program funded by the Norwegian Environment 
Agency.

The ship departed from Torshavn, Faeroe Islands, and the plan was to head 
towards Cape Farwell and work our way eastwards, home to Bergen.

The ship was equipped with a Seabird 911+ CTD with temperature, 
conductivity and oxygen sensors, a rosette water sampler. In addition, 
the ship is equipped with a thermosalinograph and a fluorometer that 
carries out underway measurements on water taken from a seawater inlet on 
the drop keel.

For the water sample analysis we brought along instruments for analysis 
of salinity, oxygen concentration, Dissolved Inorganic Carbon (DIC), 
Total Alkalinity (TA), and the transient tracers sulfur hexafluoride 
(SF6) and chlorofluorocarbon-12 (CFC-12). Each of these is described 
later in this document. Further, we took water samples for nutrients, and 
δ13C of DIC to be brought home and analyzed ashore.

For the sediment coring we used a gravity and a multicore from Department 
of Earth Sciences, UiB, and the ship's TOPAS seismic system for mapping 
coring locations.


Fig. 1: Planned sampling locations for 58GS20150510, blue: hydrography 
        and chemistry, red: hydrography, chemistry and potential coring 
        sites.







2.  Participants & responsibilities

Are Olsen                Chief Scientist.
Abdirahman Omar          Dissolved Inorganic Carbon (DIC) & Total 
                         Alkalinity (TA) (PI)
Ailin Brakstad           Bottle salinity sampling and analysis
Asgeir Steinsland        CTD, instrument chief 
Balamuralli Rajasakaren  CFC-12 & SF6
Emil Jeansson            CFC-12 & SF6 (PI) and underway O2/Ar (PI) 
Friederike Fröb          DIC & TA
Jörg Schwinger           Oxygen sampling
Kristin Jackson          Winkler oxygen, sampling and analysis (PI). 
Magni Svanevik           DIC & TA
Nil Irvali               Coring, nutrient and salinity sampling
Siv Lauvset              underway pCO2 and δ13C sampling
Stig Monsen              Coring technician
Tor de Lange             DIC & TA
Tore Onarheim            δ13C sampling
Ulysses Ninnemann        Coring (PI), nutrient sampling 
Åse Sudmann              CTD, instrument






3.  WATCH LIST

Who                      When                   What
———————————————————————  —————————————————————  —————————————————————————
Abdirahman Omar          1200-2400              Carbon
Ailin Brakstad           1200-2400              Salinity
Are Olsen                0800-2000              Chief Scientist
Asgeir Steinsland        0600-1200 & 1800-0000  CTD
Balamuralli Rajasakaren  0000-1200              Freons
Emil Jeansson            1200-0000              Freons
Friederike Frob          1200-2400              Carbon
Kristin Jackson          0000-1200              Oxygen
Magni Svanevik           0000-1200              Carbon
Nil Irvali               0000-1200              Nuts, Salin. sampling, 
                                                sediments      
Siv Lauvset              1200-2400              pCO2, δ13C sampling
Stig Monsen                                     Sediments
Tor de Lange             0000-1200              Carbon
Tore Onarheim            0000-1200              δ13C sampling
Ulysses Ninnemann        1200-2400              Nuts. sampling, sediments
Åse Sudmann              0000-0600 & 1200-1800  CTD








4.  SAMPLING and INSTRUMENTS

4.1  Water profile sampling

We used a 12-bottle rosette equipped with 10 l Niskin bottles from 
General Oceanics. This was done to save time, as this was short, and 
allow work in more adverse conditions than would be allowed with the 24-
bottle rosette.

All water sampling was carried out following GO-SHIP protocols. The 
sampling order was: (1) CFC-12 & SF6 (2) Oxygen (3) DIC & AT in one 
bottle (4) δ13C (5) nutrients (6) salinity.

CTD

Seabird 911+ with two sets of temperature (SBE 3, serial numbers: primary 
4134; secondary 1445) and conductivity sensors (SBE 4, serial numbers: 
primary 2140, secondary 3080) and an SBE 43 dissolved oxygen sensor 
(serial number 0368).

The sensor pairs showed good correspondence throughout the cruise. The 
difference in salinity was typically short of 0.01, with the primary 
sensor higher. The difference in temperature was typically less than 
0.004°C, with the primary being the higher most of the times.

The CTD was set to report temperature on the ITS-68 scale and Salinity on 
the PSS-78 scale. In the bottle data file the tempratures have been 
converted to ITS-90 using t90 = t68 * 0.99976

The oxygen sensor also showed good behavior over the cruise, reporting 
values that were typically around 0.3 ml l^(-1) less than those obtained 
by Winkler titration of water samples.

The CTD salinity and Oxygen data were corrected with respect to the 
bottle salinity and Winkler oxygen data (described below) using GO-SHIP 
recommended practices (Hood et al., 2010). Importantly, for salinity the 
correction was carried out using conductivity. For the bottle files, the 
corrected salinity data are those from sensor 1. For the CTD files 
corrected data from both sensor 1 and 2 are included.

CFC-12 and SF6 analyses

Samples for analysis of CFC-12 and SF6 were collected on all stations 
throughout the cruise. The samples were taken from the Niskin bottles in 
glass syringes (250 ml), which were stored immersed in cold seawater and 
analysis took place within six hours after sampling. The analysis is 
based on purge-and-trap work- up of the water samples followed by gas 
chromatographic separation and electron capture detection of the 
different compounds; the analytical technique is described by Fogelqvist 
(1999).

The standardization was achieved by calibration gas prepared at Deuste 
Steininger GmbH, Mühlhausen, Germany, and cross-calibrated against gas 
prepared at Scripps Institute of Oceanography. The standard gases were 
calibrated against the SIO-93 scale.

Winkler oxygen

Oxygen concentrations in water samples, which were sampled from every 
Niskin were determined using Winkler titration on an instrument designed 
& built at Scripps Institute of Oceanography. The instrument functioned 
seamlessly at the cruise, apart from a few instances when we lost 
connection with the detector.

Density for per l to per kg conversion was determined using draw 
temperature measurements.

Carbon chemistry

Analysis of the DIC and TA in water samples followed standard operating 
procedures as described in Dickson et al. (2007) by using two instruments 
built by MARIANDA in Kiel, VINDTA. The DIC is determined through 
coulometric titration of the gas stream from an acidified water sample of 
known volume following Johnson et al. (1985). The TA is determined using 
potentiometric titration of a water sample with HCl with a known 
concentration and a curve- fitting routine.

The collected samples were first brought to the desired measurement 
temperatures (20°C) and analyzed first for DIC and then for TA (after 
heating further to 25°C). The heating of the samples was carried out by 
storing them in the lab, under a dark plastic sheet to minimize possible 
primary production.

All samples were analyzed within approx. 12 hours of collection, and 
there was no need of conserving these with mercury chloride. All sampling 
bottles had been thoroughly cleaned and baked prior to the cruise.

The accuracy of the DIC and TA measurement systems was kept under control 
by frequent measurements of Certified Reference Material (CRM) supplied 
by Andrew Dickson (Scripps Institute of Oceanography, USA). Typical 
offsets were 4 - 6 µmol kg-1 for both, these offsets are corrected for in 
our final data file.

δ13C

The δ13C samples were drawn from every Niskin into 250 ml serum vials and 
transferred into exitainers preflushed with helium and that contained an 
aliquot of phosphoric acid. The seawater from each sampling depth was 
injected into three exitainers, 1 ml in each, using a new syringe for 
each sample, and making sure there were no air bubbles in the syringe 
when injecting the water into the exitainers. The three exitainers were 
taken from separate flushing batches, for analysis in duplicate at the 
mass spectrometer - Thermoscientific Delta V with Gas Bench prep unit. at 
Department of Earth Sciences at University of Bergen. Standards: IAEA-CO-
8 and NBS 18 and NBS 19 carbonate standards, each in triplicate on 
separate carrousel at start.

Nutrients

Samples for analysis of concentration of phosphate, nitrate and silicate 
were drawn from each Niskin into 24 ml scintillation vials and preserved 
with 0.2 ml chloroform. All samples were stored cold and in the dark 
before analyses on shore by IMR using an autoanalyser within two months 
after the cruise. Crossover analysis with GLODAPv2 data (Olsen et al., 
2016) shows that the phosphate values are likely 12% too high. This has 
not been corrected for. The other nutrient data are consistent with 
GLODAPv2 data.

Salinity

Salinity was determined onboard in bottle samples drawn from every Niskin 
on the rosette at each station, following GO-SHIP recommended practices. 
The samples were allowed to reach recommended analysis temperature by 
storing them in the climate-controlled room on board, before analyzing 
them using a Guildline Portasal. This was also installed in the climate-
controlled room. The stated accuracy of this instrument is 0.003.







4.2  Surface Sampling

Surface sampling was carried out for the following parameters:

Temperature and Salinity

Using the ships TSG, SBE21 from start until end of cruise.

Chlorophyll

Using ships fluorometer, Wet Labs Wet Star from start until end of 
cruise. Note that the data until morning 15/4 are no good, fluorometer 
dirty, see diary.

pCO2

A new underway pCO2 system from GO was installed in the clean seawater 
sampling room during the first days of the cruise. We used the intake on 
the keel, approx. 6 m depth. This was running all the time and used three 
certified standard gasses from NOAA for calibration of the Licor.

Oxygen

An Anderaa optode was hooked up to the underway pCO2 system, and was 
running all the time of the cruise.

Oxygen/Argon

Measurements were carried out, but are not reported.

Discrete samples

Discrete samples were collected at in the clean seawater sampling room 
from April 13. Until evening 15. we used water from the optode overflow, 
after that we used as separate outlet with lesser flow, better accuracy 
many be expected of these later data. Samples for DIC, TA, oxygen and 
salinity were analyzed onboard using methods described above, while 
samples for nutrients and δ13C was brought ashore for analysis at IMR and 
Department of Geosciences, respectively. Each surface station has three 
replicates

In the file with these data:
  • Temperature + Salinity, as read from TSG display, same for all three 
    replicates
  • Btl_Salinity - from samples measured at portasal, 0/2 replicates
  • Oxygen_down - from Winkler measurements of water samples from 
    underway lab. All replicate values are actual replicates. Unit, 
    µmol/kg
  • Oxygen_up - from Winkler measurements of water samples from chemistry 
    lab. Unit, µmol/kg
  • All replicate values are actual replicates
  • Temperature_down, as measured in underway lab during sampling
  • Temperature_up, as measured in chemistry lab during sampling
  • Nitrate, Nitrite, Silicate, Phosphate, all three values per station 
    from actual replicates, Unit, µmol/kg
  • Alkalinity and TCO2, all values at each station are actual 
    replicates, units µmol/kg
  • C13, one 250 ml serum vial per sample. Water injected into three 
    exitainers as for the bottle samples. Mean of measurements of these 
    three exitainers reported in file.

These data have not been quality controlled in any way


4.3  SEDIMENT CORING

TOPAS PS18 (Parametric Sub-bottom Profiler System)

For sub-bottom profiling and siting of sediment cores the SNACS cruise 
employed the TOPAS PS18 system. This is a single, narrow beam sub-bottom 
profiler system with electronic roll, pitch and heave stabilization. The 
range resolution is normally less than 0.3 m, and penetration capability 
is normally more than 150 m. These factors, however, depends on sediment, 
water depth and ambient noise.

There are several types of pulses that can be used, depending on the 
different depth and different use that is needed. High penetration (Chirp 
wavelet with longer wavelengths and greater penetration) was used 
throughout the cruise.


Coring equipment

The multi-corer used on the cruise is a customized KC multi-corer (see 
figure 2). The corer is equipped with 4 tubes, each with a diameter of 
110mm and a length of 600mm. The corer is designed to slowly penetrate 
the sediment after setting down on the seafloor. After sampling the lid 
closes creating a vacuum holding the sediment in place until the core is 
raised free of the sediment triggering the shovel foot to swing into 
place sealing the base of the tube. Further information of the corer can 
be found at KC’s home page at: http://www.kc-denmark.dk/


Fig. 2: KC Multicorer that was used on the cruise, with close up of one 
        of the sampling tubes (photo Stig Monsen). 


The GEO-UoB gravity coring system capable of taking up to 5m long cores 
was also employed. The core liner is rigged directly onto the weighted 
coring head with a cutting head/core catcher combo installed at the base 
of the liner.







5. PRELIMINARY RESULTS

5.1  Water profile sampling

Despite a lot of bad weather we managed to conduct most of the planned 
sampling program. Water was sampled at 34 unique station locations, 
excluding a test station off Torshavn. All but one location was sampled 
using a single CTD cast; at 62°N 20°W, two casts were carried out. Each 
of these was assigned a station number, 192 and 193, in accordance with 
IMRs operating protocols. In our bottle data file 193 has been renamed to 
192 cast 2. The positions of the stations are presented in Fig 4. In 
summary after leaving Torshavn we first sampled the western part of the 
AR07E section, i.e. the Irminger Basin and Reykjanes Ridge. Next we 
sampled the ODP 984 drilling site and watermasses eastwards to 20°E, 
where we repeated the A16N stations at 61° and 62° N. After this we 
sampled 4 stations in the Faroe Bank channel, and 7 stations between 
Faroes and Shetland mapping overflow waters upstream of the FBC. Finally, 
as we had time on our hands we visited 6 locations at the so-called 
Utsira section at 59.28°N in the North Sea, as we headed home to Bergen


Fig. 3: Positions of stations occupied during the cruise.


Fig. 4 (prepared using final data - this is the case for all section 
plots) shows distribution of temperature, salinity and Apparent Oxygen 
Utilization (AOU) at the section across the Irminger Basin. The upper 
1000 m of the water column are occupied by recently ventilated Labrador 
Sea the west and Atlantic waters in the east. Denmark Strait Overflow 
Water is visible towards the bottom in the western parts, while in the 
eastern parts, Northeast Atlantic Deep Water dominates.


Fig. 4: Distribution of temperature, salinity and AOU in the Irminger Sea 
        and right across the Reykjanes Ridge, based on the bottle data 
        from the cruise.  Black points are sampling locations/depths.


Figure 5 shows the DIC and TA distribution along the same section 
displayed above. In the Irminger basin the gradients are fairly small. To 
the east of the Reykjanes Ridge, the high DIC intermediate waters beneath 
the Atlantic waters are the most prominent feature. The TA distribution 
by and large aligns with salinity. DIC beneath 1000 at ~37W appears a tad 
low, but nothing our measurements indicates that these are questionable.


Fig 5: Sections of DIC and TA across the Reykjanes Ridge


Figure 6 shows sections of temperature, salinity and AOU on the section 
eastwards from the ODP 984 site at the eastern flank of the Reykjanes 
Ridge and into the Iceland Basin at approx. 61°N. The upper 500 dbar are 
dominated by Atlantic water, right beneath there is a layer of oxygen 
poor intermediate water. The low salinity core centered at 21.5°W and 
1500 dbar is Labrador Sea Water, and overflow waters in various stages of 
entrainment are found beneath.


Fig. 6: Sections of temperature, salinity and AOU at the section from ODP 
        094 coring site and westwards into the Iceland Basin, preliminary 
        data.


Figure 7 shows sections of temperature, salinity and AOU in the Faroe 
Bank Channel with the saline Atlantic inflow in the upper 500 dbar or so, 
and the fresher and but colder overflow waters beneath. The overflow 
waters have higher AOU, reflecting their less ventilated stage.


Fig. 7: Sections of temperature, salinity and AOU in the Faroe Bank 
        Channel.

Figure 8 shows the distribution of temperature, salinity and AOU in the 
Faroe-Shetland channel, with the warm, saline and oxygen rich Atlantic 
water lying over the colder, fresher and oxygen poor overflow waters.


Fig. 8: Sections of temperature, salinity and AOU across the Faroe-
        Shetland channel.


Finally Figure 9 shows the data obtained along the Utsira section. This 
shows the wedge of coastal current waters, overlying Atlantic Water, over 
the Norwegian trench. A core of waters with negative AOU in the surface a 
2°E witness of high primary production. Over the trench there is a lens 
of colder water. As evaluated from AOU, the waters in the trench are the 
least ventilated at this section.


Fig. 9: Temperature, salinity and apparent oxygen utilisation along the 
        Utsira section.


The Irminger Sea data are further used in Fröb et al. (2016) and Fröb et 
al. (2018)


5.2  Surface sampling

Surface samples were collected at 239 locations (Fig. 10), starting at 
~62°N 20°W, southwest to Greenland, southeast across the Irminger Sea, 
northeast along the Reykjanes Ridge, east to the Faeroes, and then in the 
North Sea. These were analyzed as described above and will be distributed 
in a separate file.


Fig. 10: Surface sampling locations


5.3  Sediment coring

Sediment cores were obtained at three sites, Eirik Drift, Reykjanes Ridge 
and Bjorn Drift, detailed information on each is provided in Table 1, 
while a brief description of each is provided in the following.





Table 1: Sediment cores obtained at 58GS201503410

Station           Core name    Latitude     Depth     Length          Notes        Stat.
                               Longitude  
——————————————  —————————————  ———————————  —————  —————————————  ———————————————  —————
1: Eirik Drift  GS15-196-01MC  59° 37.1 N   2468m  A=23.5cm       Barrel D empty,   175
 SE Greenland                  40° 44.28 W         B=14cm          C drained &  
    (DSOW)                                         C=disturbed      disturbed  
                                                   D=no recovery    

                GS15-196-02GC  59° 37.1 N   2468m  341cm           Soupy at top,    175
                               40° 44.28 W         Sec.I*=150cm     ~5cm oasis  
                                                   Sec. II=150cm   added so Sec.I-  
                                                   Sec.III=41cm       145cm mud  

2: Reykjanes    GS15-196-03GC  58° 28.46 N  2407m  400cm           MC not allowed   182
    Ridge                      33° 52.72 W         Sec.I*=150cm     due to winch  
                                                   Sec. II=150cm        weight  
                                                   Sec.III=100cm    

3: Bjorn Drift  GS15-196-04GC  61° 13.31 N  1735m  500cm           overpenetration  188
   South of                    24° 18.20 W         Sec.I*=150cm     by 2-3cm; in  
   ODP 984                                         Sec. II=150cm     core head.  
    (ISOW)                                         Sec.III=100cm    Sec. I soupy,  
                                                   SecI.V=100cm     oasis in top   
                                                                    and  bottom.  

                GS15-196-05MC  61° 13.31 N  1735m  A=47.5cm         A and B nicest  188
                               24° 18.20 W         B=38cm           tops and clean  
                                                   C=47.5cm           overlying  
                                                   D=no recovery        water  
————————————————————————————————————————————————————————————————————————————————————————————————
*sections ordered from top down (e.g. Section I is top)


Station 1 (Eirik Drift, SE Greenland within DSOW)

Multi and Gravity coring was carried out SE of Greenland in order to 
recover material for reconstructing DSOW variability and its relationship 
to surface climate and changes in Greenland. 2 barrels of the multicore 
were successful in recovering undisturbed sediment water interfaces. 
TOPAS (fig. 11) revealed soft bottom sediments down to approximately 3.4 
m and the gravity core was rigged for 3.5 m length with 342 cm was 
recovered. Core tops were light brown IRD and foram bearing mud. The core 
catcher (GC) was grey IRD, foraminiferal, and diatom rich mud with a 
predominantly polar (Neogloboquadrina pachyderma sinistral) foraminiferal 
assemblage—distinctly more IRD and polar species rich than the core top. 
Ash grains were also observed in the base of the core (CC sample). 
Samples from the foot of the MC also included very high abundances of 
polar Neogloboquadrina pachyderma sinistral and IRD, with only trace 
amounts of subpolar-transitional species Globigerina bulloides.


Fig. 11: TOPAS image of Eirik Drift coring station


Station 2 (Reykjanes Ridge)

A gravity core was taken on the Reykjanes ridge near the edge of the 
subpolar gyre in order to reconstruct shifts in the position of the 
subpolar gyre and Atlantic Water boundary (i.e. subpolar gyre eastward 
extent). The gravity corer was deployed first due to concerns over 
wireline weight on the winch (despite being only 2407m water depth). 
Based on the TOPAS (Fig. 12) , the GC liner was cut at 4m where it 
appeared there was a stronger reflector. 4m of core was recovered with no 
over penetration (@1m/s wireline speed). The top and CC were carbonate 
(foram) ooze with abundant warm water (Atlantic Water) foraminiferal 
species as well as subpolar species such as Neogloboquadrina pachyderma 
dextral, Turborotaloita quinqueloba, Globigerina bulloides, Globigerinita 
glutinata, Globorotalia scitula and Globorotalia inflata. Subtropical 
species such as Orbulina universa, Neogloboquadrina dutertrei, 
Globorotalia hirsuta and Globorotalia crassaformis were also present. 
Trace amounts of polar Neogloboquadrina pachyderma sinistral and high 
amounts of ice rafted detritus were observed. Sponge spicules and 
ostracods were occasionally also present.


Fig. 12: TOPAS image of Rekjanes Ridge coring station


Station 3 south of ODP Site  984

Station 3 was cored near ODP Site 984 near the upper limits of Iceland 
Scotland Overflow Water and just below Labrador Sea Water in the region. 
Based on the soft sediment characteristics inferred from the TOPAS (fig. 
13) a full 5m liner was used for the gravity coring and the winch speed 
lowered to 0.8m/s for penetrating. The gravity core was full with ~3cm 
additional mud in the head of the gravity corer above the core liner. The 
core was dark olive gray silty foraminifera bearing mud. The multicorer 
was deployed next and recovered 3 long cores with well-preserved sediment 
water interfaces. Cores A and B had the clearest bottom water (B was 
pristine) suggesting little sediment entrainment or disturbance and 
barrel B was sampled for 13CDIC. The top of the GC contained subpolar to 
transitional (i.e., Neogloboquadrina pachyderma dextral, Turborotaloita 
quinqueloba, Globigerina bulloides, Globigerinita glutinata, Globorotalia 
scitula and Globorotalia inflata) and subtropical species (such as 
Orbulina universa, Neogloboquadrina dutertrei, Globorotalia hirsuta and 
Globorotalia crassaformis) with trace amounts of polar Neogloboquadrina 
pachyderma sinistral reflecting near modern conditions whereas the CC 
sample from >500cm contained predominantly polar foraminifera 
(Neogloboquadrina pachyderma sinistral), trace amounts of subpolar-
transitional foraminifera (Neogloboquadrina pachyderma dextral and 
Globigerina bulloides) and high amounts of ice rafted detritus. Ostracods 
were occasionally also present at the top of the GC.


Fig. 13: TOPAS image of Bjorn Drift coring station



6. DIARY

Dates and times are local ship (Bergen, UTC+1) time

9/4
Abdirahman Omar, Are Olsen, Emil Jeansson, Kristin Jackson and Tor de 
Lange unpacks and installs our equipment in Torshavn. We also remove the 
old GO underway pCO2 system and get the new one up hanging on the wall. 
Leave for Siv to connect power, water and gas lines when she arrives.

10/4
Left Torshavn 15:00, a bit delayed as the vacuum cleaner at the ship 
needed repair before we left (local service man onboard). Head for Cape 
Farewell.

Do test station before we reach open water, No 174. Will not be included 
in data files. Use 24 btl rosette, all bottles closed and no visible 
leaks. Everybody practice water sampling

11/4.
Morning, at approx. 62°N, 10°W, foul weather, lying essentially still, 
backing against the wind. Heading west at a few knots during the day.

12/4
Morning, at 62°N, 13°W, foul weather. Heading west at 5 knots.
Ulysses and me consider to head for A16N stations at 62°N and 61°N, both 
at 20°W, to see if we can get something done there, and then to ODP 984 
at 61° 25' N, 24°W, while we are waiting for weather to pass.

13/4
Another low-pressure system hits during night. Discard A16 stations, and 
ODP 824, press westwards to get away and into Irminger Sea following a 
northern trajectory on the outskirts of the low-pressure system.
No internet onboard, need to change satellite.

As everybody was impatient go get some work started we start with surface 
sampling on Abdir's initiative. Sample for oxygen, DIC, TA, δ13C and 
nutrients every second hour, at 14:00, 16:00... hrs, ship time from the 
seawater outlet in the clean seawater sampling room, where the pCO2 
system is installed, to map out surface gradients as we move across 
Atlantic waters and into the Arctic Waters in the west. Note that for O2 
we only sampled during daytime the first few days. Note also that for O2 
we also sampled at the seawater outlet in the lab, to evaluate the 
occurrence of respiration in the lines up there, in particular pertinent 
as the oxygen/argon system was hooked up to this outlet.

Do triplicates of all but 13C, if the first two replicates agree for 
DIC/AT and O2, do not measure the third one.

Towards evening we are escaping from low-pressure system, going north of 
it, see Fig. 2, catching up speed. 8 knots.

14/4
Over the night, winds increased again and we were moving slowly. Asgeir 
got the internet back up in the morning, and it seems as if weather will 
clear up and that we can make the Irminger Sea in time. We head towards 
Cape Farewell. Start making speed during evening.

Make the decision to use 12, instead of 24, bottle rosette for 
hydrocasts, to save time, allow use in rougher values and to allow coring 
equipment to be deployed from the main hangar while we are sampling the 
12 btl for water next door.

20:09, ship time, notice that fluorescence sensor returns unrealistically 
high values for this area, around 7-8 mg/m3, - also when we run 
freshwater from ship's supply through it! We decide to clean it. Triton 
and CH3CH2OH. Back online 21:30 ship time. Values of ~20 mg/m3, but 
decreasing slowly.

15/4
Morning. Still steaming towards first station. Data from fluorometer much 
better, around 1.6 mg/m3, which is realistic.

For the 22:00 (ship time) surface sampling I moved the water sampling 
point to a separate outlet. Until now the water had been drawn from the 
optode overflow, which has quite a high flow speed, I moved it to a 
separate outlet with a needle valve regulator and I could get a much more 
reasonable flow. Expect better precision for surface samples beyond this 
point. (This was confirmed by Kristin and Abdir, their gut feeling was 
that agreement among the replicate samples improved after we did this 
modification).

16/4
At ca 13:00 ship time we arrive at the first station. No. 175 at 40°45'W.

We start here because of ice further west, and since strong winds were 
expected in our section's western parts, so we had to get out of this 
area before they reach us in order not spend valuable time waiting here 
for weather to pass.

STATION 175 (~40° 45' W, 59° 37' N)
Wait 2 mins before tripping bottle at each depth, and a few secs after 
(trip confirmation time), agree to do at all stations.
Denmark Strait overflow down deep. Move planned 1500 dbar and 2000 dbar 
to 1800 dbar and 2300 dbar to get this. Very homogenous O2 in upper 1000 
dbar. Some differences in the upper 1000 dbar between down and upcast.
All 12 bottles closed and no apparent leaks.

TOPAS reveals nice sediments with clearly defined layers approaching and 
at station.

Multi corer deployed, 3 out of four tubes filled halfway, one broke off.

Gravity corer deployed. 340 cm of sediments retrieved. This was basically 
according to plan, top was well preserved.

STATION 176 (~39° 45' W, 59° 27' N)
~21:00 ship time
A lot of variability in upper 600 dbar. Spike at just above 900 dbar, in 
salinity and oxygen. Check other sensor. - Checked, spike in sensor 1, 
will be cleaned by Asgeir, but check when you get data.

Move 1500 dbar sampling to 1600 dbar, to avoid sampling in strong 
gradient between upper and deeper water masses.

17/4
STATION 177
02:00 ship time.

15 m/s, gale force winds, seems as if it is picking up, good that we are 
heading east.

Not so much variability in upper water, still strong gradient at beneath 
1000 dbar. 1250 dbar sample right in this, move to just above gradient, 
1100 dbar.

STATION 178
08:00 ship time.
Not so much variability in upper water, still strong gradient at beneath 
1000 dbar.
1500 dbar sample right in this, move to 1450 dbar.

STATION 179
~14:00 ship time.
Not so much variability in upper water, still strong gradient at beneath 
1000 dbar. 1250 dbar sample in gradient, moved to 1120 dbar to get at 
top.

2000 dbar sample shifted to 2100 bar to get low salinity wedge centered 
at this depth.
Niskin 6 & 7 seems to be leaking at the lower cap. STATION 180
19:30 ship time.
Shifted 1250 dbar to 1200 dbar, and 1500 dbar to 1600 dbar in order to 
not sample in the gradient.

No leaks visible, but still O-ring at valve at bottle 7 broken, replaced.

At 22:55 ship time, winds catching up, 24-25 m s-1. If it is not possible 
to sample at next station we will wait until it calms down.

18/4
Winds calm down over the day, and we start again after lunch.

STATION 181
14:23 Ship time
Done 8 minutes east of the intended position, as we were here when the 
winds calmed down.
O2 minimum at 200-600 m.

Less deep than 2500 dbar, planned 2400 dbar sampling point shifted to 200 
dbar instead.

This evening I discovered that there seemed to have been a leak in bottle 
1 at station 175, 176, and 177, as evaluated from offsets between CTD 
sensors and bottle sample data. Niskin 1 replaced.

19/4
STATION 182
~08:00 ship time

Gravity corer deployed 10:40 ship time, targeting small mound with 
sediments. At 58° 28.460' N 33° 52.715' W

STATION 184
20:30 ship time
Dropped planned 300 dbar to 750 dbar, few structures in upper but more in 
intermediate layers.

20/4
STATION 185
01:30 ship time

At 500 m seasave MFC stopped working, error with display program 
Terminate, up on deck, empty bottles
Reset station number and do 185 again.
-repeated with no problems

STATION 186.
08:00 ship time
No issues at this station

STATION 187
13:11 ship time
Final station at this section, we will head northwards to core at ODP 984 
site and sample overflow water at a section ~perpendicular to the ridge 
slope to A16 station at 20 W, 61N and next 62 N, then Faroe Bank Channel. 
No issues at station.

21/4
STATION 188
15:35 ship time
This is close to ODP 984 drilling site where Ulysses planned to core. 
Evaluating TOPAS Ulysses figured that the position we're at 61° 25.507 N 
and 24° 04.939W is a good location so we stop here. CTD first, flawless. 
Many structures in deeper waters, overflow plumes?, so I sampled many 
depths here.

Gravity corer, 5 m of sediment obtained, multi corer, 3 out of 4 tubes 
filled. Here I took a δ13C sample of the water in one of the tubes. 
Labeled as such with the rest of the δ13C samples
Plan for section of four stations from here to (and including) A16N 
repeat at
20°W and 61°N

22/4
STATION 189
00:20 shiptime, 
continue on section from ODP 984 to A16 repeat at ~20°W and 61°N. No 
issues at station, still many overflow features, sample heavily in deep 
waters.

STATION 190
06:11 ship time.
No issues at station, still many overflow features, sample heavily in 
deep waters.

STATION 191
12:06 ship time
A16N, 20°W 61°N repeat
No issues at station, still many overflow features, sample heavily in 
deep waters.

STATION192
20:00 ship time
A16N, 20°W 62°N repeat
Here we do two casts, these are labeled as two stations, one focus on 
deep and the second on waters 600 and above, here we also trip 2 bottles 
at selected depths for tracking our precision. Second cast get unique 
station number.

STATION 193
22:00 ship time
Cast two at 20°W 62°N repeat, 600 dbar and up.

23/4
Steaming towards the Faroes.
Some issues with TA measurements in the evening, returns too high values, 
electrode replaced over night by Kristin.

24/4
Some TA measurements return a value of 0, even though titration seems 
fine. Kristin figures out this is because the first guess E0 value is off 
so curve fit misses the target completely, possible to recalculate values 
by using a more appropriate first guess E0.
06:30 Arrive at first station in the Faroe Bank Channel, STATION 194.
Overflow waters, 10 bottles samples

STATION 195
08:30 Ship time,
still Faroe Bank channel with overflow water, 10 sample depths.

STATION 196
~10:00 Ship time
Third station in Faroe Bank channel, STATION 197

 ~1130 ship time
Last Faroe Bank Channel with overflow. STATION 198
~21:30 ship time
On the slope east of Faroes.

STATION 199
~23:30 ship time
In the basin, sample at every 100 dbar, maintain at next 2 stations, 
which are also 1100 m.

25/4
STATION 200
~02:00 ship time, sample at every 100 dbar.

STATION 201
~04:40 ship time, sample at every 100 dbar.

STATION 202
~07:05 ship time, 830 dbar sample at every 100 dbar.

STATION 203
10:00
Among oil rigs at Shetland Shelf, 224 dbar, sample bottom, 100, 50 and 10 
dbar

Decide to head for Utsira section, we have time to sample at every degree 
along this, purpose, Abdir's North Sea work and map δ13C gradients from 
Atlantic and into coastal waters.

STATION 204
21:20 Ship time
First station at Utsira section.
A bit thermal stratification, and a bit more saline towards bottom. 
Sample 5 depths, bottom, 100, 50, 25 and 10 dbar.

26/4
STATION 205
00:50 ship time,
5 sampling depths, no issues.

STATION 206
03:57 ship time
5 sampling depths, no issues

STATION 207
07:23 ship time
5 sampling depths, no issues.

STATION 208
10:20 ship time.
Above Norwegian trench, some 230 m, 7 sampling depths

STATION 209
13:42 ship time
Final station, 80 m depth, inside Utsira. 4 depths sampled, rest of 
Niskins tripped for fun.







7. Surface sampling notes

Oxygen not sampled at night before 15/4

Ailin draws during salinity samples during day from 16/4

For Carbon we add 1000 to the surface station number, in order to not mix 
up with ordinary stations. Else stations are called S 1- S XXX

Instances:
No 43, no samples, number apparently skipped No 40-41, only salinity was 
sampled.



References:

Fogelqvist E. (1999), Determination of volatile halocarbons in seawater. 
    In: Methods of seawater analysis. 3rd edition, p 501-519. Edited by 
    K. Grasshoff, K. Kremling, M. Ehrhardt. Wiley-VCH.
Fröb, F., A. Olsen. F.F. Pérez, M. I. García-Ibàñez, E. Jeansson, A.M. 
    Omar and S.K. Lauvset (2018), Inorganic carbon and water masses in 
    the Irminger sea since 1991, Biogeosciences, 15, 51-72.
Fröb, F., A. Olsen, K. Våge, G. W. K. Moore, I. Yashayaev, E. Jeansson & 
    B. Rajasakaren (2016). Irminger Sea deep convection injects oxygen 
    and anthropogenic carbon to the ocean interior, Nature 
    Communications, 7:13244.
Happell J.D. and D.W.R. Wallace. (1997) Gravimetric preparation of gas 
    phase working standards containing volatile halogenated compounds for 
    oceanographic applications. Deep-Sea Res. I, 44, 1725-1738.
Hood, E.M., C.L. Sabine, and B.M. Sloyan (2010), The GO-Ship repeat 
    hydrography manual : A collection of expert reports and guidelines. 
    IOCCP report number 14, ICPO Publication Series Number 134, available 
    online at http://www.go-ship.org/HydroMan.html.
Johnson, K.M. et. al. (1985), Coulometric TCO2 analyses for marine 
    studies; an introduction, Marine Chemistry, 16, 61-82.
Olsen, A., R.M. Key, S. van Heuven, S.K. Lauvset, A. Velo, X. Lin, C. 
    Schirnick, A. Kozyr, T. Tanhua, M. Hoppema, S. Jutterström, R. 
    Steinfeldt, E. Jeansson, M. Ishii, F.F. Pérez & T. Suzuki (2016), The 
    Global Ocean Data Analysis Project version 2 (GLODAPv2) - an 
    internally consistent data product for the world ocean, Earth System 
    Science Data, 8, 297-323.





CCHDO Data Processing Notes


• File Merge Carolina Berys
58GS20150410_QCnotes.txt (download) #dac9c 
Date: 2018-08-20 
Current Status: merged


• File Online Carolina Berys
58GS20150410.exc.csv (download) #72745 
Date: 2018-08-20 
Current Status: unprocessed


• File Online Carolina Berys
58GS20150410_surf.csv (download) #47510 
Date: 2018-08-20 
Current Status: unprocessed


• File Online Carolina Berys
59GS20150410_CruiseReport.pdf (download) #9bcb4 
Date: 2018-08-20 
Current Status: unprocessed


• File Online Carolina Berys
58GS20150410_QCnotes.txt (download) #dac9c 
Date: 2018-08-20 
Current Status: merged


• File Online Carolina Berys
58GS20150410_ct1.zip (download) #7a8c2 
Date: 2018-08-20 
Current Status: unprocessed


• File Online Carolina Berys
58GS20150410_nc_ctd.zip (download) #cbba5 
Date: 2018-08-20 
Current Status: unprocessed


• File Online Carolina Berys
58GS20150410_QCnotes.txt (download) #dc72a 
Date: 2018-08-20 
Current Status: unprocessed


• File Submission Robert Key
58GS20150410_QCnotes.txt (download) #dc72a 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
58GS20150410
This file is a replacement for one of the same name I submitted earlier 
today. 
Sorry for the hassle


• File Submission Robert Key
58GS20150410_nc_ctd.zip (download) #cbba5 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain  a DOI 
for these data so that they get appropriate credit. Once known I will 
forward that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.


• File Submission Robert Key
58GS20150410_ct1.zip (download) #7a8c2 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain  a DOI 
for these data so that they get appropriate credit. Once known I will 
forward that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.


• File Submission Robert Key
58GS20150410_QCnotes.txt (download) #dac9c 
Date: 2018-08-09 
Current Status: merged 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain  a DOI 
for these data so that they get appropriate credit. Once known I will 
forward that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.


• File Submission Robert Key
59GS20150410_CruiseReport.pdf (download) #9bcb4 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain a DOI for 
these data so that they get appropriate credit. Once known I will forward 
that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.


• File Submission Robert Key
58GS20150410_surf.csv (download) #47510 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain a DOI for 
these data so that they get appropriate credit. Once known I will forward 
that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.


• File Submission Robert Key
58GS20150410.exc.csv (download) #72745 
Date: 2018-08-09 
Current Status: unprocessed 
Notes
Are Olsen has contacted the Norwegian Marine Data Centre to obtain a DOI for 
these data so that they get appropriate credit. Once known I will forward 
that information. 

For now the pCO2 data is available at the following URL. Once Alex has 
posted at OCADS we can change that.
https://doi.pangaea.de/10.1594/PANGAEA.866724

Sharon reformatted the provided CTD data. I created the bottle file and 
worked with Are to finalize

The file named "58GS20150410_surf.csv" contains additional surface sample 
results.  This file is "as submitted".

I used A01 for the SECTID but other choices would have been as good.
58GS20150410 QC and workup notes
Are Olsen June 2017














This document has three sections, one for Bottle, one for surface and one 
for CTD data
****************************************************************************
BOTTLE
****************************************************************************

Started with /MergedFromRike/Current/data_58GS20150410_current.txt

__________________________

EDITS and NOTES BEFORE QC
__________________________
theta, aou and sigma0-3 columns deleted

Changed format and column headers to WHP EXCHANGE.

Station 193 renamed to 192 Cast 2

BTLNBR_FLAG_W 
for BTLNBR 1 set to 3 by Friederike. Reset to 2, change later.

CTDSAL_FLAG_W 
came with all flags 2.

SALNTY_FLAG_W 
came with all flags 2.

CTDOXY_FLAG_W 
came with all flags 2.

OXYGEN
missing values set from NaN to -999, flag from 4 to 9

SILCAT
below detection level set to  NaN with flag to 2 by Rike. Changes to 0 with 
flag 2 (only two instances, STATION 206 BTL 4 & 5).

NITRAT
came with all flags 2.

NITRIT 
below detection level set to NaN with flag to 5 by Rike. Changed value to 0 
and flag to 2, make a note in header (many instances).

PHSPHT
came with all flags 2.

CFC-12 and SF&
came with QC notes from Emil implemented as flags.

DIC and TALK
181/1
TCARBON changed from 2161 to 2164.5
The Carbon chemistry had three replicates, all three used in Rikes file, but 
final replicate clearly too low so I removed that one and calculated new 
average. 

Otherwise all flagged 2 or 6 

Note, the readme file for TCARBON and ALKALI data notes several values 
should be set to NaN. 

But all TCARBON values appears to have been kept in file, and all flagged 2. 
Checked the carbon 'master file', these had been measured twice and bad 
duplicate removed.

Only two ALKALI values are NaN, these were not present in carbon chemistry 
master file, so obviously not measured

DEL13C
all flags kept. 

All remaining NaNs changed to -999. Set all missing data flags to 9. 

_______________

QUALITY CONTROL
_______________

Flags:
Station 175, 176, 178
Bottle 1, bottle flags set to 3, as leak suspected. Flags for all Niskin 
sampled variables set to 3.
(Note same bottle was used in position 1 for station 175-181, but large 
difference in CTDOXY-OXY only visible for stats 175, 176, 178)

176
btl 5 Oxygen high vs CTDOXY and CTDPRS, flag 3.

177
btl 9 Oxygen high vs CTDOXY and CTDPRS, flag 3.

179
btl 5 Oxygen high vs CTDOXY and CTDPRS, flag 3.

180
btl 9, ALK high vs SALNTY and CTDPRS, flag 3.

185
btls 2,4,7 PO4 low vs NO3 and CTDPRS, flag 3

189
btl 4 Oxygen high vs CTDOXY and CTDPRS, flag 3.

190 
btls 5 & 6 Oxygen likely swapped during work up, swapped.

192, Cast 1
btl 4 Oxygen high vs CTDOXY and CTDPRS, flag 3.

194
btl 4 & 9, ALK very high vs SALNTY and CTDPRS, flag 4.

198
btl 4 Oxygen high vs CTDOXY and CTDPRS, flag 3.

202
btl 3 Oxygen high vs CTDOXY and CTDPRS, flag 3.
btl 4, ALK very low vs SALNTY and CTDPRS, flag 3. 

saved as 58GS20150410_hy1.csv
****************************************************************************
SURFACE
****************************************************************************
Started with MergedFromRike/Current/data/data_58GS20150410surf.csv

added 13C data, from Surface13C_Marie. All data with high standard deviation 
among replicate analysis deleted
All NaN replaced by -999
Changed headers, added units

saved as 58GS20150410_surf.csv

****************************************************************************
CTD
****************************************************************************
Started with MergedFromRike/Current/data/data_58GS20150410ctd_current.csv
did nothing
saved as 58GS20150410_ctd.csv





