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CRUISE REPORT: SR04
(Updated OCT 2013)



HIGHLIGHTS

CRUISE SUMMARY INFORMATION

          WOCE Section Designation  SR04
Expedition designation (ExpoCodes)  06AQANTIX_2
                  Chief Scientists  Eberhard Fahrbach / AWI
                             Dates  1990 NOV 17 - 1990 DEC 30
                              Ship  POLARSTERN
                     Ports of call  Punta Arenas, Chile  - Cape Town, S. Africa

                                                     54°19'59" S
             Geographic Boundaries  58°53'12" W                         3°20'42" W
                                                     71°6'47" S
                          Stations  82
      Floats and drifters deployed  0
    Moorings deployed or recovered  21 deployed, 7 recovered

                                Contact Information:

                                  Eberhard Fahrbach
                Alfrd Wegener Institut für Polar und Meeresforschung
                         D-2850 Bremerhaven, F.R. • Germany
            Tel: 49-471-4831-501 • Fax: 49-471-4831-149   49-471-4831-425
                         Email: efahrbach@awi.bremerhaven.de




FOREWORD
V.Smetacek, U. Bathmann (AWI)


The ninth research cruise of RV "Polarstern" to the Antarctic (ANT IX) 
consisted of 4 Legs. The first Leg addressed chemical interactions 
between ocean and atmosphere during the southward voyage. The second 
Leg carried out investigations of the Weddell Gyre within the 
framework of the World Ocean Circulation Experiment (WOCE). The third 
Leg was planned as a broad-based, interdisciplinary study of the 
hitherto unexplored southwestern Weddell Sea but had to be reorganized 
with a new scientific program for the Lazarev Sea because of 
exceptionally heavy ice conditions in the Weddell Sea. The fourth Leg 
was the return journey and was primarily devoted to the geology of the 
South Atlantic.

RV "Polarstern" departed from Bremerhaven on October 20, 1990 and 
arrived in Punta Arenas on November 14. The intensive chemical 
research Programme was a continuation of previous Atlantic crossings 
and addressed hemispheric variability of metals and various natural 
and anthropogenic compounds in atmosphere and ocean.

The second Leg commenced on November 17 and proceeded first to King 
George Island where personnel and supplies were dropped off at the 
Bellingshausen station. From there, the transect across the Weddell 
Gyre first performed in the winter of 1989, was repeated. Twenty one 
current meter moorings were deployed and the 7 in the field since 1989 
were successfully recovered and equipped with new Instruments. Water 
column measurements of physical, chemical and biological parameters 
were carried out; the data will aid in assessing seasonal differences 
in hydrography and their influence on the ecology of the Gyre. The 
current meter data will enable quantification of bottom water 
formation and transport of water out of and into the Gyre. Sediment 
traps attached to three of the current meter moorings were also 
serviced. The data obtained from them, together with results of 
specific studies on silica cycling, will further our knowledge on 
vertical particle flux and cycling of matter in the Weddell Sea. At 
the end of the cruise, equipment was dropped at the Georg-von-Neumeyer 
Station (GvN). Cape Town was reached on December 30, 1990.

The third leg left Cape Town on January 3, 1991 with personnel and 
equipment for GvN On board. Shortly after disembarkation and unloading 
of supplies at GvN, "Polarstern" helicopters rescued 5 South-African 
personnel who were stranded at 3,000 m elevation and 300 km inland. 
The unusually heavy and extensive ice cover prevented "Polarstern"'s 
southward journey and the ship was forced to drift for 2 weeks 
entrapped in thick, soft ice named "porridge ice" by Capt. Lawrence of 
RRS "Bransfield". Ice and under-ice physics and biology were 
investigated during the period of drift, and as ice conditions did not 
irnprove till the beginning of February alternate plans had to be made 
for work in the Lazarev Sea between GvN and Georg-Forster stations. On 
several transects along the shelf and into the deep-sea, all 
disciplines participating on this cruise - oceanography, biology and 
geology - investigated in closely interlocked programmes water rnass 
distribution, water chemistry as well as the morphology of the sea 
floor and cornposition of the sediments. GvN was visited on the return 
journey and personnel from here as well as the Georg-Forster-Station 
further to the East transported to Cape Town where "Polarstern" 
arrived on March 28, 1991.

The fourth Leg departed from Cape Town on March 30 and proceeded to 
Bouvet Island. The aim of this predorninantly geological Leg was to 
rnap and sample submarine elevations - the Agulhas Ridge, the Meteor 
Rise and the eastern flank of the southernrnost Mid-Atlantic Ridge - 
in order to refine existing models of the paleoceanography of the 
South Atlantic. "Polarstern" arrived in Brernerhaven on May 13, 1991. 




1.  ITINERARY AND SUMMARY
    E. Fahrbach (AWI)

On 17 November 1990 "Polarstern" left Punta Arenas. In Drake Passage 
physical oceanography work was started with an XBT-transect 
(Expendable Bathythermograph) across the Antarctic Circumpolar 
Current. An Acoustic Doppler Current Profiler (ADCP) recorded the 
current field in the upper few hundred meters. The bathymetry and 
geology Programmes began with soundings of Hydrosweep and Parasound 
which were continued during the complete cruise. Chemical 
investigations from the first leg were continued with underway 
measurements. They concentrated on biogenic sulfur compounds and their 
reaction products in sea water and the marine atmosphere with 
particular interest in DMS (dimethyl sulfide). Concentrations of 
nitric acid, ammonia and ammonium nitrate and organobromine compounds 
were investigated in the marine atmosphere.

We reached the Polar Front on 19 November at 57°23'S, 61°14'W. The 
first logistic task of the cruise was to deposit three German 
scientists with more than 8 tons of supply goods at the Soviet station 
"Bellingshausen" on King George Island. One scientist returned with us 
after an eleven months stay. After measuring the first CTD-profile 
(conductivity, temperature, depth) and making a catch with the 
multinet, we approached Joinville Island at the northeastern tip of 
the Antarctic Peninsula. There, two hauls with the Agassiz-trawl 
provided material for comparative studies on the temperature 
dependence and kinetics of digestive enzymes in crustaceans.

Still in open water we reached the western end of our main 
hydrographic transect crossing the Weddell Gyre towards Kapp Norvegia 
(Figure 2.1) where the first of 21 current meter moorings was deployed 
and the first of seven recovered. On the shelf the first biology 
station took place including measurements with quantameter and Secchi 
disk, two CTD casts combined with a rosette water sampler and catches 
with multinet, bongo net, and plankton net. The water samples were 
used for biogeochemical investigations with special emphasis on the 
silica and nitrogen cycles. For this reason incubations were carried 
out to measure the uptake of radioactive 14C, 32Si and 32P and stable 
15N. The nitrogen flux in the Antarctic food web could be determined 
from the water column to the zooplankton. In this context the 
phytoplankton biomass and species distribution as well as reproduction 
and life cycles of dominant copepods were studied.

On 22 November at about 150 km from the coast we met at 63°30'S, 
51°30'W the ice edge. The winds calmed down with increasing distance 
from the coast and air temperatures did not drop below -4°C. Rather 
quickly the swell disappeared and the floes increased in size. 
However, due to a system of leads, we could proceed along our course 
as planned.

On 26 November at 65°34'S, 38°52'W we reached a deep sea channel which 
was surveyed with hydrosweep and parasound along 500-km profiles over 
a distance of 144 km. The structure is 1 to 3 km wide with a depth of 
60 to 100 m below the adjacent sea level of about 4650 m. It extends 
with large meanders from westnorthwest to eastnortheast. Due to the 
heavy ice cover, consisting of floes a few kilometers in diameter and 
up to a meter thick, the track line could not be maintained as 
straight as desirable. Bottom samples were collected with a minicorer 
which was hung under the CTD. This instrument was newly developed. 
During initial trials a procedure was achieved which allowed its use 
without significant additional shiptime. After this phase it was used 
routinely on 37 stations.

The first recovery of a current meter mooring (208) within the ice 
(70% ice cover) occurred on 29 November. Before the acoustic release 
of the mooring the floes of up to 500 m in diameter were broken into 
smaller pieces to allow the floats to reach the surface. After the 
release 40 minutes of intensive search were necessary to sight a float 
before the recovery could be successfully finished. At mooring 209 on 
3 December no float reached the surface and a time consuming acoustic 
ranging and breaking of ice floes finally permitted the detection and 
consequent recovery after 8 hours. This tedious technique had to be 
applied during all further recoveries, whereas the deployment of 
moorings could be accomplished without any problem.


Figure 2.1:  Cruise track of "Polarstern" during ANT IX/2


The center of the Weddell Gyre at about 66°16'S, 30°18' is marked by a 
relatively shallow surface mixed layer. It was reached on 2 December. 
For a better localization of the center a transect of 150 nm length 
consisting of 7 CTD-stations perpendicular to the main transect was 
carried out. On the basis of those data absolute velocities will be 
determined using the Beta spiral concept. During the Winter Weddell 
Gyre Study (WWGS) '89 higher mixed layer temperatures and more intense 
biological activity were found in that area. This was not observed 
during the present cruise possibly due to the different season. On 7 
December the investigations in the "beta cross" area were terminated 
and the main transect was continued to the southeast with CTD-
profiles, biology stations, mooring recoveries and deployments. The 
ice conditions became less favourable due to larger floes of less 
friable ice and closed leads because of colder temperatures. 
The transect was finished on 15 December. The coastal polynya was only 
poorly established and highly variable. Because the biologists noted 
that there was no sign of a spring bloom, the planned stations were 
cancelled. The desert-like conditions in the water column, evidenced 
by a Secchi depth of 54 m were in sharp contrast to the abundant algae 
growth in the ice which gave rise to all coulors from yellow to brown. 
Although small the narrow polynya was large enough for a haul with the 
Agassiz-trawl. The offshore ice belt of the polynya confirmed the term 
"icefactory". It provided the heaviest ice conditions during the 
cruise and made the recovery of mooring 214 impossible. The last 
station on the transect was located in an inlet of 1 km length and 400 
m width. In this inlet casts with CTD, multi- and bongo net were 
carried out in Open water in the vicinity of the 25 m high shelf ice 
front. After a hydrosweep survey of the continental slope in the area 
of the Explorer-Escarpment we left On 16 December towards the 
Georgvon- Neumayer-Station (GvN). 

The work along the transect between Joinville Island and Kapp Norvegia 
amounted to 82 CTD and rosette stations, 7 biology stations, 21 
mooring deployments and 7 recoveries. The established mooring network 
represents a gigantic flow meter which measures the volume of water 
and its heat content entering the Weddell Gyre in the northeast and 
leaving it in the northwest. South of our transect, cooling due to 
contact with the atmosphere and the shelf ice, together with salt 
release through ice formation, induces vertical descent of water 
masses to the bottom. Glacial meltwater has to be taken into account 
for a quantitative understanding of those processes. Because of the 
significance of deep reaching vertical mixing for the global abyssal 
circulation, our measurements are part of the World Ocean Circulation 
Experiment (WOCE).

The biogeochemical investigations of the cycles and budgets of various 
constituents represent a contribution to the international Joint 
Global Ocean Flux Study (JGOFS). They aim to explain the special role 
of the Weddell Gyre in the Southern Ocean and to estimate the 
significance of this area to the global carbon cycle. The contrast 
between the high nutrient availability and the low production remains 
unresolved. A chemical-biological project allowed for the first time, 
direct measurement of DMS-production of Antarctic phytoplankton and 
determination of the contributions of different species. 

On 17 December we reached Atka-Bight. In the early morning 
"Polarstern" rammed into the fast ice to provide a safe platform for 
the unloading of about 100 tons of supply goods for the GvN-Station. 
First contacts with the female overwintering team had been established 
by a helicopter visit on 13 December to prepare the unloading 
procedure. The first trek with unloaded material left in the early 
afternoon towards the shelf ice edge and the station. Due to 
favourable conditions all loading was finished in the evening. 
"Polarstern" left the Atka-Bight at midnight of 18 December. On the 
way north air chemistry, XBT, hydrosweep and parasound measurements 
were continued. The ice edge was met at 68°00'S, 3°58'W where the ice 
concentration dropped within 30 nm from 70% to 10%. Here the last 
biology station was carried out. On 23 December we reached 54°20'S, 
3°23'W about 200 nm west of Bouvet Island were mooring BO1 was 
deployed with two sediment traps. The Polar Front was crossed on 24 
December at 51°45'S 2°24'E. Christmas Eve was celebrated with a merry 
ceremony in the "Blue Saloon" and a delightful buffet. The recovery of 
the last mooring PF3 and deployment of PF4 was achieved in the morning 
of the 25 December. When we reached the 200 nm limit research was 
terminated. On 30 December 1990 at 01.00 "Polarstern" reached the 
bunker pier of Cape Town. 


Cruise Participants

Name                          Institution*
----------------------------  ------------
Baumann, Marcus               AWI
Behmann, Thomas               AWI
Bluszcz, Thäddaus             AWI
Brandini, Frederico           AWI
Brosin, Hans-Jürgen           IfMW
Buxhoeveden, Cristina Isabel  ITBA
Corradi, Pio Ante             AF
Dehn, Joachim                 AWI
Dittrich, Birgit              AWI
Erdmann, Holger               DWD
Frhrback, Eberhard            AWI
Goeyens, Leo                  VUB
Goldkamp, Ulrich              AWI
Harder, Markus                FPB
Heitmüller, Karl-Heinz        HSW
Hillebrandt, Oliver           HSW
Hinrichsen, Hans-Harald       FPB
Knoche, Martin                AWI
Köhler, Herbert               DWD
Krest, Jim                    OSU
Kubrjeweit, Frank             AWI
Lengacher, Dieter             AF
Leynaert, Ande                IEM
Lindenmaier, Patrick          AF
Lindner, Louis                RUU
Markus, Thorsten              AWI
Monk, Jürgen                  AWI
Papenbrock, Thomas            RUB
Pauls, Margarete              AWI
Pfeiffenberger-PertI, Hans    AWI
Plugge, Rainer                AWI
Quéguiner, Bernard            IEM
Ragueneau, Olivio             IEM
Rauschert, Martin             FiW to K.G.I
Riewesell, Christian          HSW
Ross, Andy                    OSU
Schäfer, Hartmut              FPB
Schlumpf, Hans-Ulrich         AF
Schmidt, Martin               IfMW
Schoch, Roland                FPB
Schöffmann, Erhard            FGB
Schrerns, Otto                AWI
Schütt, Ekkehard              FPB
Segl, Monika                  FGB
Simon, Bernd                  FiW to K.G.I
Sonnabend, Hartrnut           DWD
Staubes, Regina               IfMG
Sterr, Uta                    FPB
Stiller, Michael              AWI to K.G.I
Strass, Volker                AWI
Tins, Wolfgang                TA
Vucelic, Sonja                AWI
Wasserthal, Claus             HSW
Weber, Michael                AWI
Wisotzki, Andreas             FPB
Zippel, Detlev                FiW from K.G.I


List of Institutions

Abbreviation  Institution
------------  --------------------------------------------
AWI           Alfred-Wegener-Institut für
              Polar- und Meeresforschung
              Columbusstrasse
              2850 Bremerhaven
              Germany

DWD           Deutscher Wetterdienst
              Seewetteramt
              Bernhard-Nocht-Str. 76
              2000 Hamburg 4
              Germany

FGB           Universität Bremen
              Fachbereich Geowissenschaften FB5
              Postfach 33 04 40
              2800 Bremen 33
              Germany

FiW           Forschungsstelle für Wirbeltierforschung
              Alfred-Kowalke-Str. 17
              O-1136 Berlin
              Germany

FPB           Universität Bremen
              Fachbereich Physik FB1
              Postfach 33 04 40
              2800 Bremen 33
              Germany

HSW           Helicopter-Service
              Wasserthal GmbH
              Kätnerweg 43
              2000 Hamburg 65
              Germany

IfMG          Johann Wolfgang Goethe-Universität
              Institut für Meteorologie und Geophysik
              Feldbergstr. 47
              Postfach 11 19 32
              6000 Frankfurt am Main 11
              Germany

IfMW          Institut für Meereskunde
              Akademie der Wissenschaften der DDR
              Seestr. 15
              O-2530 Rostock-Warnemünde
              Germany

RUB           Ruhr-Universität Bochum
              Fakultät für Chemie / Physikalische Chemie I
              Postfach 10 21 48
              4630 Bochum 1
              Germany

TA            TERRAQUA
              Indersdorfer Str. 16
              8061 Arnbach
              Germany

ITBA          Instituto Technologico de Buenos Aies
              Avda Enardo Madero 351/99
              1106 Buenos Aires
              Argentina

VUB           Vrije Universiteit Brussels
              Laboratory for Analytical Chemistry
              Pleinlaan 2
              B-1050 Brussels
              Belgium

CBM           Centro de Biologia Marinha/UFPR
              AV. Beira Mar,
              Ponta do Sul
              Paranagua 83200 Pr
              Brazil

IEM           Institut d'Etudes Marines
              Université de Bretagne Occidentale
              6 Avenue le Gorgeu
              F-29287 Brest Cedex
              France

RUU           Rijksuniversiteit te Utrecht
              Faculteit der natuur en sterrenkunde
              Princetonplein 5
              NL-3508 TA Utrecht
              Netherlands

AF            Arian Film AG
              Postfach 835
              CH-8025 Zürich
              Switzerland

OSU           Oregon State University
              College of Oceanography
              Oceanography Administration Building 104
              Corvallis, Oregon 97331-5503




2.  PHYSICAL OCEANOGRAPHY

2.1.  Water masses and circulation
      T. Behmann, E. Fahrbach, J. Dehn, M. Knoche, T. Markus,  
      R. Plugge, V. Strass (AWI), C. Buxhoeveden (ITBA), M. Harder, 
      H.-H. Hinrichsen, H. Schäfer, U. Sterr, A. Wisotzki (FPB); 
      E. Schütt (FGB), H.-J. Brosin, M. Schmidt (IfMW)


Objectives

The aim of the physical oceanography programme is to further 
understand the circulation in the Weddell Gyre and the related 
distribution of water masses. The operations contribute to a multiyear 
project, the Weddell Gyre Study, which is part of the World Ocean 
Circulation Experiment (WOCE). During this period a hydrographic 
survey along a transect from the northern tip of the Antarctic 
Peninsula to Kapp Norvegia (Figure 2.2) will be repeated four times, 
twice in summer and twice in winter, to measure the water mass 
distribution with its seasonal and interannual variability. The 
programme was initiated with a winter survey in 1989, the Winter 
Weddell Gyre Study (WWGS) '89, and will be continued with further 
surveys in austral winter 1992 and summer 1992/1993.


Figure 2.2:  Schematic representation of the Weddell Gyre and the transect 
             from Joinville Island to Kapp Norvegia (KN).


Simultaneously an extensive current meter mooring programme began with 
the deployment of seven current meter moorings. The data from those 
moorings will be used to estimate the volume transport in the Weddell 
Gyre. Direct current measurements are essential because they are the 
only way to obtain the barotropic flow which determines the net volume 
transport. From the measured mass, heat, and salt transports across 
the transect we can derive water mass formation rates.

The transformation of Winter Water (WW) and Warm Deep Water (WDW) in 
the inflow to Antarctic and Weddell Sea Bottom Water (AABW, WSBW) in 
the outflow is of special interest, because it results from a deep 
vertical exchange which is relevant to the large scale abyssal 
circulation of the world ocean. Present estimates show that about 70% 
of the Antarctic Bottom Water spreading into the world ocean obtains 
its water mass characteristics in the Weddell Sea. Because the salt 
budget of the area is strongly influenced by ice formation and 
melting, special interest is focused on the ice transport across the 
transect. Interaction with the ice shelves has to be taken into 
account for a quantitative understanding.


Figure 2.3:  Station map of "Polarstern"-cruise ANT IX/2. Small dots stand 
             for CTD-stations, circles for recovered and Squares for deployed 
             moorings.


Work at sea

In order to obtain the water mass distribution, a hydrographic section 
was carried out with 74 CTD-profiles (conductivity, temperature, 
depth) and discrete casts for temperature, salinity, oxygen, nutrients 
and tracers (helium, tritium and (^18)O). For the location of the stations 
see Figure 2.3 and the station list. On the eastern slope the station 
distance was small enough (Figure 2.4) to resolve topographic features 
such as the Explorer-Escarpment Seven current meter moorings were 
recovered and 21 were laid (Table 2.1 and 2.2, Figure 2.3). On six of 
them ice thickness will be measured by upward-looking Sonars (ULS). 
The moorings will stay in position for two years. Vertical temperature 
and electrical conductivity profiles were measured with a Neil Brown 
Mark III B CTD. The quality of the CTD-measurements was assured by 
reference measurements with a rosette sampler. Water samples were 
taken with a General Oceanic rosette composed of 24 bottles with 12 l 
volume each. Each time a water bottle was closed 50 cycles of 
pressure, temperature and conductivity were recorded with the CTD, 
quality controlled and averaged.


Figure 2.4:  Cruise-track and location of CTD-stations off Kapp Norvegia 
             during "Polarstern"-cruise ANT IX/2.


Pressure and temperature measurements were corrected by means of a 
laboratory calibration carried out in the Scripps Institution of 
Oceanography before the cruise. A second calibration will be done 
after the cruise. Both calibrations will lead to a more elaborate 
correction of the data. However, the control by electronic as well as 
mercury reversing thermometers and pressure meters gives us confidence 
that the preliminary data have errors of less than 5 mK in temperature 
and 5 db in pressure.

The salinity data are given in PSU. They are based on the CTD 
conductivity measurements from which salinity was calculated using the 
Unesco Practical Salinity Scale (PSS78). The values were compared with 
salinities from water bottle samples measured with a Guildline Autosal 
8400 A in reference to I.A.P.S.O. Standard Seawater. The number of 
samples per profile, the mean difference between the samples and the 
CTD measurements as well as its standard deviation are shown in Figure 
2.5. Preliminary data presented in this report were corrected with a 
constant offset of 0.023 to an accuracy of 0.005. The final data will 
be corrected in conductivity for time and depth dependence of the 
deviations. Afterwards salinity will be recalculated.


Figure 2.5:  Comparison between salinity measurements from water bottles with 
             those from the CTD. Stars give the mean difference for each 
             station between the bottle and CTD salinities, squares the 
             standard deviation, and dots the number of samples per station.


Oxygen was determined with an automatic titration unit, using the 
Winkler method with a photometric endpoint determination. The error in 
the oxygen determination is estimated to 1%. This results from 
intercomparisons at selected stations between the chemical 
oceanography group from the Oregon State University and the AWI group 
both using different instruments. Duplicate samples from the same 
water bottle were analysed during the complete cruise as a measure of 
precision. The obtained data are given in ml/l.


Table 2.1:  Moorings recovered during "Polarstern"-cruise ANT IX/2

Mooring  Latitude     Date      Water Depth     Instrument
         Longitude    Time       (m,corr.)   Type       Depth
-------  -----------  --------  -----------  ----       -----
206      63°29.6' S   13.09.89      946      AVT        229
         52°07.4' W   11.13                  S          349
                      22.11.90               AVT        876
                      08.52                     
207      63°45.8' S   14.09.89     2503      AVTPC      263
         50°54.3' W   10.39                  AVTPC      952
                      23.11.90               AVT       2162
                      00.41                  AVT       2410
208      65°36.3' S   24.09.89     4768      AVTPC      288
         36°29.9' W   18.30                  AVTPC     1037
                      29.11.90               S         1090
                      13.00                  (AVT)     2610
                                             S         4122
                                             AVT       4631
209      66°36.8' S   01.10.89     4863      AVTC       293
         27°07.4' W   10.28                  AVTPC      993
                      03.12.90               (AVT)     2653
                      09.16                  (AVT)     4725
210      69°38.9' S   05.10.89     4751      AVTC       289
         15°44.5' W   21.11                  AVTPC      988
                      11.12.90               AVT       2547
                      14.29                  AVT       4617
211      70°29.5' S   6./7.10.89   2402      AVTC       247
         13°07.0' W   00.13                  AVTPC      856
                      14.12.90               AVT       2066
                      14.28                  AVT       2313
212      70°59.2' S   08.10.89     1069      AVTPC      309
         11°49.4' W   16.55                  AVT        999
                      13.12.90                     
                      22.50                     
PF3      50°07.6' S   09.11.89     3785      S          625
         05°50.0' E   10.34                  AVT        645
                      25.1 2.90              S         3200
                      08.30                  AVT       3220
                                                  
AVTPC:  Aanderaa current meter with temperature, pressure and conductivity 
        sensor. In brackets instruments with poor data quality.
S:      Sediment trap


Table 2.2:  Moorings deployed during "Polarstern"-cruise ANT IX/2.

Mooring  Latitude  (S)  Date      Water depth  Type      Instrument
         Longitude (W)  Time      (m,uncorr.)           No.     Depth
-------  -------------  --------  -----------  -----  ------    -----
215      63°19.89'      21.11.90      448      AVTP    10001     291
         52°59.07'      20:14                  AVTP     9996     396
                                               WLR      1155     447
206/2    63°29.55'      22.11.90      942      AVTP     8402     253
         52°06.27'      14:54                  AVTP     9786     891
207/2    63°45.05       23.11.90     2498      ULS      9/90     165
         50°54.32'      06:52                  AVTP     9206     326
                                               TK       1569     
                                               ATR      1100     578
                                               AVTPC    8395    1037
                                               AVT      8417    2187
                                               TK       1570    
                                               ATR      1102    2439
                                               AVT      8418    2447
216      63°56.96'      24.11.90     3477      AVT      9182    2968
         49°09.21       00:34                  AVT      9184    3426
217      64°25.10'      24.11.90     4424      ULS     13/90     141
         45°50.97'      21:26                  AVTPC    9192     250
                                               S      890107     796
                                               AVTC     9211    1010
                                               AVT      9185    2510
                                               ACM-2    1281    4373
218      64°48.87'      25.11.90     4688      AVTP    10005     252
         42°29.28       21:15                  TK       1427     
                                               ATR       944     505
                                               AVTP     9212     993
                                               AVT      9186    2503
                                               ACM-2    1284    4636
219      65°39.87'      28.11.90     4732      AVT      9187    4226
         37°42.45'      13:36                  AVT      9188    4674
                                               AVT      9190    4722
208/2    65°38.14'      29.11.90     4776      ULS     11/90     171
         36°30.20'      18:27                  AVTPC    9194     281
                                               AVTPC    9213    1040
                                               S      890106    1123
                                               AVT      9191    2533
                                               S      890108    4165
                                               ACM-2    1285    4725
220      65°58.19'      30.11.90     4799      AVT      9767    4300
         33°20.33'      15:43                  AVT      9768    4748
221      66°16.63'      02.12.90     4784      ADCP              236
         30°17.78'      10:49                  AVTPC    9195     247
                                               TK       1426     
                                               ATR       943     499
                                               AVTPC    9214     985
                                               AVTPC    9215    2499
                                               ACM-2    1288    4732
209/2    66°37.35'      03.12.90     4862      ULS     14/90     147
         27°07.10'      20:50                  AVTP     9202     279
                                               AVTPC    9216    1015
                                               AVTPC    9217    2526
                                               ACM-2    1289    4809
222      67°03.56'      07.12.90     4836      AVT      9769    4336
         24°52.11'      22:54                  ACM-2    1282    4785
223      67°59.84'      09.1 2.90    4885      AVTPC    9205     251
         19°57.64'      17:24                  AVTPC    9218    1010
                                               AVT      9208    2520
                                               ACM-2    1290    4834
224      68°49.65'      10.12.90     4740      AVT      9770    4239
         17°54.49'      13:38                  ACM-2    1291    4689
210/2    69°39.63'      11.12.90     4745      ULS     10/90     151
         15°42.90'      16:50                  AVTP     9201     270
                                               TK       1571     
                                               ATR      1103     523
                                               AVTP     9995    1012
                                               AVT      9391    2521
                                               ACM-2    1297    4694
225      70°19.11'      12.12.90     4329      AVTP    10002     275
         13°39.61'      18:19                  AVT      9783    1124
                                               AVT      9997    2625
                                               AVT      9782    4278
226      70°22.84       13.12.90     2943      AVTP    10003     231
         13°32.53       00:57                  AVTP     9998     980
                                               AVT      9207    2892
212/2    70°54.67'      14.12.90     1555      ULS     12/90     135
         11°57.80'      07:34                  AVTP     8367     254
                                               AVTC     9401     759
                                               AVT      9402    1504
211/2    70°29.67'      14.12.90     2381      AVTP    10004     270
         13°08.85'      22:17                  TK       1572     
                                               ATR      1104     523
                                               AVTP     8396    1012
                                               AVT      9999    2222
                                               AVT      9392    2329
KN4      70°59.51'      15.12.90      892      S      860019     328
         11°46.86'      09:55                  AVTP     9209     333
                                               S      860020     782
                                               AVTPC    9210     810
                                               UCM               811
214/2    71°02.93'      15.12.90      378      AVTP     8370     213
         11°41.25'      12:56                  AVT      9403     318
                                               WLR      1044     377
BO1      54°20.3' S     23.12.90     2734      S      860024     423
         03°22.6' W     16.43                  AVT      7727     474
                                               S      890005    2196
                                               AVT      8037    2217
PF4      50°07.6' S     25.12.90     3807      S      860038     625
         05°52.0' E     10.31                  AVT      9803     646
                                               S      890009    3267
                                               AVT      9805    3290


Abbreviations:  

ACM-2  Acoustic current meter, Neil Brown
ADCP   Acoustic doppler current meter
ATR    Recording unit for thermistor chain
AVTPC  Aanderaa current meter with temperature.pressure and conductivity 
       sensor
S      Sediment trap
UCM    Acoustic current meter, Simtronics
ULS    Upward looking sonar
WLR    Water level recorder



2.2.  CTD Measurements

 CTD Measurements during AQANTIX/2                                             
 Instrument : Neil Brown CTD, Mark IIIB, Sn: 1069, BJ: 1984                    
                                                                              
              CTD temperature sensor : Rosemount Platinum                     
                                       Thermometer                            
              resolution :     0.0005 deg C                                   
              accuracy   : +/- 0.005  deg C                                    
              CTD pressure sensor    : Paine Model                             
              resolution :     0.1 dbar                                        
              accuracy   : +/- 6.5 dbar                                        
              CTD conductivity sensor : EG&G NBIS                              
              resolution :     0.001 mmho                                      
              accuracy   : +/- 0.005 mmho                                      
                                                                               
 Software   : EG&G Oceansoft MkIII/SCTD Aquisition Version 2.01                
                                CTD postprocessing Version 1.12                
 Time lag   : 0.13 s                                                           
                                                                               
 Pressure pre-cruise calibration coefficients                                  
 a1 = -1.1552376e+1                                                            
 a2 =  7.014388e-3                                                             
 a3 = -1.236572e-5                                                             
 a4 =  7.641595e-9                                                             
 a5 = -2.052136e-12                                                            
 a6 =  2.544142e-16                                                            
 dp = a1 +a2*p +a3*p**2 +a4*p**3 +a5*p**4 +a6*p**5                             
  p = p + dp                                                                   
                                                                               
 Temperature pre-cruise calibration coefficients                               
 a1 = -2.99299                                                                 
 a2 = -7.18462e-4                                                              
 a3 =  4.44174e-5                                                              
 a4 = -1.43668e-6                                                              
 a5 =  2.67305e-8                                                              
 dt = a1 +a2*t +a3*t**2 +a4*t**3 +a5*t**4                                      
  t = t + dt                                                                   
 the post-cruise calibration data are the same                                 
                                                                               
 correction of the CTD-conductivity data with the bottle-samples               
 ( conductivity of the salinometer data )                                      
 evaluation of the coefficients of each station                                
 --------------------------------------                                        
 CD = ( CONDUCTIVITY SALINO - CONDUCTIVITY CTD ) * 1000                        
 COND :== CONDUCTIVITY SALINOMETER                                             
 --------------------------------------                                        
 CD = A0 + A1*COND + A2*PRES + A3*PRES**2                                      
 --------------------------------------                                        
 station                                                                       
    no.            A0            A1            A2            A3                
                                                                               
    03501   -0.51872E+02   0.24728E+01  -0.63940E-02   0.79995E-05             
    03601   -0.51872E+02   0.24728E+01  -0.63940E-02   0.79995E-05             
    03901   -0.51872E+02   0.24728E+01  -0.63940E-02   0.79995E-05             
    04001   -0.51872E+02   0.24728E+01  -0.63940E-02   0.79995E-05             
    04101   -0.51872E+02   0.24728E+01  -0.63940E-02   0.79995E-05             
    04201   -0.59161E+02   0.26925E+01  -0.35827E-02  -0.59052E-05             
                                                                               
 dc = A0 + A1*COND + A2*PRES + A3*PRES**2                                      
 C(ctd) = C(ctd) + dc/1000.                                                    
                                                                               
 correction of the CTD-conductivity data with the bottle-samples               
 evaluation of the coefficients with the running mean of 10 stations           
 --------------------------------------                                        
 CD = A0 + A1*PRES + A2*PRES**2 + A3*PRES**3 + A4*PRES**4                      
 --------------------------------------                                        
station                                                                       
  no.          A0            A1            A2            A3            A4   
 4301     0.16057E+02  -0.53003E-02   0.36477E-05  -0.77356E-09   0.43815E-13
 4401     0.16057E+02  -0.53003E-02   0.36477E-05  -0.77356E-09   0.43815E-13
 4501     0.16057E+02  -0.53003E-02   0.36477E-05  -0.77356E-09   0.43815E-13
 4601     0.16060E+02  -0.52277E-02   0.35370E-05  -0.75885E-09   0.44722E-13
 4701     0.16060E+02  -0.52277E-02   0.35370E-05  -0.75885E-09   0.44722E-13
 4801     0.16275E+02  -0.59179E-02   0.41748E-05  -0.97715E-09   0.69451E-13
 4901     0.16108E+02  -0.60083E-02   0.49328E-05  -0.13678E-08   0.12189E-12
 5001     0.16102E+02  -0.54978E-02   0.43413E-05  -0.11653E-08   0.99760E-13
 5101     0.16899E+02  -0.77574E-02   0.66678E-05  -0.20257E-08   0.20231E-12
 5201     0.16881E+02  -0.59944E-02   0.44888E-05  -0.13842E-08   0.14902E-12
 5501     0.17761E+02  -0.70108E-02   0.56046E-05  -0.17661E-08   0.19017E-12
 5601     0.17937E+02  -0.75108E-02   0.63627E-05  -0.20726E-08   0.22755E-12
 5701     0.18022E+02  -0.64782E-02   0.53523E-05  -0.16870E-08   0.17910E-12
 5801     0.18156E+02  -0.62368E-02   0.50660E-05  -0.15814E-08   0.16690E-12
 5901     0.18156E+02  -0.62368E-02   0.50660E-05  -0.15814E-08   0.16690E-12
 6001     0.18178E+02  -0.63440E-02   0.54099E-05  -0.17589E-08   0.19218E-12
 6101     0.18370E+02  -0.59355E-02   0.48751E-05  -0.15619E-08   0.16985E-12
 6201     0.18148E+02  -0.42419E-02   0.30712E-05  -0.86105E-09   0.82874E-13
 6301     0.17937E+02  -0.26588E-02   0.15897E-05  -0.37211E-09   0.30423E-13
 6401     0.17782E+02  -0.17227E-02   0.63312E-06   0.26379E-11  -0.17070E-13
 6501     0.17723E+02  -0.12923E-02   0.25428E-06   0.12091E-09  -0.28589E-13
 6601     0.17461E+02  -0.67162E-03   0.21007E-06  -0.21894E-10   0.11939E-14
 6701     0.17694E+02  -0.13889E-02   0.65721E-06  -0.12674E-09   0.94644E-14
 6801     0.17450E+02  -0.97850E-03   0.27286E-06  -0.15240E-10  -0.48745E-15
 6901     0.17563E+02  -0.15356E-02   0.71896E-06  -0.15865E-09   0.15453E-13
 7001     0.17563E+02  -0.15356E-02   0.71896E-06  -0.15865E-09   0.15453E-13
 7101     0.17479E+02  -0.96447E-03  -0.73640E-07   0.16015E-09  -0.23761E-13
 7201     0.17006E+02  -0.11719E-03  -0.62758E-06   0.27564E-09  -0.29867E-13
 7301     0.16916E+02  -0.78963E-03  -0.29516E-07   0.39261E-10  -0.17887E-15
 7401     0.16904E+02  -0.21073E-02   0.12650E-05  -0.40022E-09   0.48944E-13
 7501     0.16726E+02  -0.18753E-02   0.10196E-05  -0.34344E-09   0.46267E-13
 7601     0.16753E+02  -0.19489E-02   0.99166E-06  -0.30502E-09   0.39144E-13
 7701     0.16940E+02  -0.26189E-02   0.15238E-05  -0.44051E-09   0.49389E-13
 7801     0.16764E+02  -0.97997E-03  -0.79946E-08   0.76954E-10  -0.96646E-14
 7901     0.16953E+02  -0.13147E-02   0.11905E-06   0.74029E-10  -0.12693E-13
 8001     0.16250E+02  -0.28762E-03  -0.63608E-06   0.30982E-09  -0.38113E-13
 8101     0.16592E+02  -0.93415E-03  -0.59756E-07   0.10940E-09  -0.14970E-13
 8201     0.16592E+02  -0.93415E-03  -0.59756E-07   0.10940E-09  -0.14970E-13
 8301     0.16971E+02  -0.19752E-02   0.84813E-06  -0.16722E-09   0.12449E-13
 8401     0.17508E+02  -0.21779E-02   0.61323E-06   0.24780E-10  -0.18108E-13
 8501     0.17608E+02  -0.13212E-02  -0.44565E-06   0.46132E-09  -0.74966E-13
 8601     0.17806E+02  -0.95871E-03  -0.10371E-05   0.69309E-09  -0.10154E-12
 8701     0.17901E+02  -0.50715E-03  -0.16823E-05   0.97189E-09  -0.13764E-12
 8801     0.17782E+02  -0.15468E-03  -0.16149E-05   0.82369E-09  -0.10936E-12
 8901     0.17752E+02  -0.12688E-02  -0.54494E-06   0.46368E-09  -0.68610E-13
 9001     0.17595E+02  -0.44907E-03  -0.13521E-05   0.75085E-09  -0.10213E-12
 9101     0.17818E+02   0.10371E-02  -0.27966E-05   0.12559E-08  -0.16210E-12
 9201     0.17739E+02   0.92340E-03  -0.21876E-05   0.93502E-09  -0.11655E-12
 9301     0.17696E+02   0.18375E-02  -0.32648E-05   0.13364E-08  -0.16358E-12
 9401     0.17379E+02   0.36388E-02  -0.52546E-05   0.21307E-08  -0.26343E-12
 9501     0.16627E+02   0.44116E-02  -0.55975E-05   0.21872E-08  -0.26592E-12
 9601     0.16501E+02   0.44658E-02  -0.55051E-05   0.21473E-08  -0.26200E-12
 9701     0.16684E+02   0.44739E-02  -0.55477E-05   0.21310E-08  -0.25597E-12
 9801     0.17031E+02   0.31220E-02  -0.38486E-05   0.14558E-08  -0.17342E-12
 9901     0.16900E+02   0.39229E-02  -0.47820E-05   0.17983E-08  -0.21271E-12
10001     0.16896E+02   0.38833E-02  -0.53216E-05   0.21346E-08  -0.26184E-12
10101     0.16874E+02   0.37733E-02  -0.54502E-05   0.22433E-08  -0.27886E-12
10201     0.16902E+02   0.37003E-02  -0.55233E-05   0.23019E-08  -0.28783E-12
10301     0.17029E+02   0.29472E-02  -0.48717E-05   0.21078E-08  -0.26871E-12
10401     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
10501     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
10601     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
10801     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
10802     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
10901     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
11301     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
11401     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
11402     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
11501     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
11502     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
12001     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
12101     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
12102     0.16995E+02   0.16188E-02  -0.32527E-05   0.15057E-08  -0.19816E-12
04502     0.16057E+02  -0.53003E-02   0.36477E-05  -0.77356E-09   0.43815E-13
04802     0.16275E+02  -0.59179E-02   0.41748E-05  -0.97715E-09   0.69451E-13
05602     0.17937E+02  -0.75108E-02   0.63627E-05  -0.20726E-08   0.22755E-12
06302     0.17937E+02  -0.26588E-02   0.15897E-05  -0.37211E-09   0.30423E-13
07502     0.16726E+02  -0.18753E-02   0.10196E-05  -0.34344E-09   0.46267E-13
09402     0.17379E+02   0.36388E-02  -0.52546E-05   0.21307E-08  -0.26343E-12
                                                                               
                                                                               
--------------------------------------                                         
dc = A0 + A1*PRES + A2*PRES**2 + A3*PRES**3 + A4*PRES**4                       
C(ctd) = C(ctd) + dc/1000.                                                     
 --------------------------------------                                        
                                                                               
 CTD-Files column 5 : number = -9 :== unknown data , it                        
                      was not possible to restore this data                    
                                                                               
                                                                               
                                                                               
                                                                               
NOTES ON THE NUTRIENT DATA FILES FOR SWGS 90 (ANTIX/2)                         
                                                                               
From:                                                                          
M. Consuelo Carbonell-Moore                                                    
Joe C. Jennings, Jr.                                                           
Louis I. Gordon                                                                
                                                                               
STATIONS WITH MISSING NUTRIENTS:                                               
                                                                               
STATION     MISSING NUTRIENT        BOTTLE                                     
                                                                               
040         NH4                     ALL                                        
043         PO4                     3;13-16                                    
044         NH4                     1-4                                        
046         NH4                     ALL                                        
062         NH4                     3                                          
066         NH4                     14                                         
067         PO4                     6                                          
067         N + N                   6                                          
072         PO4                     ALL                                        
073         PO4                     5,6                                        
075         N + N                   14                                         
078         Si(OH)4                 10,11                                      
083         NH4                     ALL                                        
084         PO4                     ALL                                        
087         N + N                   4                                          
087         NH4                     1-8                                        
090         N + N                   6                                          
090         NH4                     4,6                                        
091         PO4                     ALL                                        
092         PO4                     ALL                                        
092         NH4                     4,7                                        
093         NH4                     21                                         
096         PO4                     18,19                                      
098         NH4                     ALL                                        
099         NH4                     ALL                                        
105         PO4                     ALL                                        
106         PO4                     ALL                                        
106         NH4                     1-4                                        
115         PO4                     ALL                                        
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
                                                                               
NOTES ON NITRITE (NO2) AND AMMONIUM (NH4):                                     
                                                                               
Because deep ocean  nitrite and ammonium values are usually near the limit
of detection, small shifts in baseline and/or blank levels can lead to the     
calculation of concentrations which are negative.  Although these negative     
nitrite and ammonium  values are physically impossible, we report them as an   
indication of the imprecision associated with the analysis.                    
                                                                               
NOTES ON PHOSPHATE (PO4):                                                      
                           
                                                
Low phosphate values in stations 050 and 051 might be doubtful as there   
was and equipment change after station 049.  Values at station 053 agree with  
those at station 049.                                                          
                                                                               
There is a wide spread in deep  phosphate values: 2.19 micromol/liter to 2.42 
micromol/liter, many stations showing high values, higher than those from 
Wepolex and Ant V/2 cruises in the same region, but lower than WWGS 89. Deep   
phosphates increase in concentration from station 60 through station 83, 
increase which we can not account for.  These high values might be an 
artefact from a change in blank values due to changes in either the deionized 
water or in the low nutrient seawater used to prepare standards.  There is no 
information in the laboratory notebooks, logs or recorder charts that allows 
us to either correct or delete these data.  However, they are of doubtful 
quality.  The increase of phosphate values in these stations is 0.1 
micromol/liter.  Nitrate concentration values did not show the same trend.                              



PRELIMINARY RESULTS

The hydrographic features measured along the transect are presented as 
sections of potential temperature and salinity (Figure 2.6). Below a 
shallow surface layer of WW which deepens significantly towards the 
shelf edge, a temperature and salinity maximum due to the WDW is 
found. It is more pronounced at the boundaries than in the interior 
with temperatures up to 0.8% in the east and 0.4% in the west 
evidencing the inflow in the east and the outflow in the west. The 
largest part of the water column with potential temperatures between 0 
and -0.8°C and salinities from 34.67 to 34.64 is classified as AABW. 
Below we find WSBW with temperatures colder than -0.8°C which extends 
in the West in a shallow layer over the continental slope indicating 
the outflow of this freshly formed water mass. The young age of this 
water mass is suggested by the high oxygen content (Figure 2.7). In 
the forthcoming analysis we will quantify the transformation which 
occurs south of our transect of inflowing water masses in the east 
into the outflowing ones in the west.

Seasonal changes on that transect are most evident in the near surface 
layers. Relatively warm air temperatures (Figure 2.8 top) and weak 
winds (Figure 2.8 bottom) indicate the onset of spring.

A comparison of surface layer temperatures and salinities measured in 
September and October during WWGS '89 with the ones obtained during 
the present cruise indicates a much more pronounced springtime warming 
in the west than in the east (Figure 2.9 top). The salinity decrease 
due to ice melting was more intense in the east than in the west 
(Figure 2.9 bottom). In the deeper layers fluctuations of a wide 
spectral range are expected to be at least as intense as the seasonal 
cycle. Consequently no seasonal change can be identified in the 
comparison of the two sections.

From CTD data on a straight section only geostrophic current shear can 
be estimated. Absolute currents can be obtained by the use of mass 
conservation of geostrophic currents in and out of a closed area or by 
the Beta-spiral method. Therefore, in the area of the gyre centre, 
which is indicated by the doming of the isotherms, a second section 
normal to the main section was carried out with a length of about 275 
km (Figure 2.10, top).

The estimate of absolute geostrophic current velocities by use of the 
Beta-spiral method will yield additional information on the location 
of the gyre center complementary to the moored current meter data. 
However, this method requires the calculation of the second derivative 
of isopycnals with respect to horizontal and vertical coordinates and 
is very sensitive to fluctuations. Thus, quantitative estimates need 
to be carried out with the final data.

The transects of the potential temperature along the Beta-cross 
(Figure 2.10, top) show smoothly inclined isolines which seem to 
reflect the doming of the Weddell Gyre. The temperature maximum of the 
WDW increases towards the north. This can be taken as an indication 
that there is a southward component in this level and consequently the 
center of the gyre has to be located further to the west.

The interaction with the ice shelf was studied by means of a CTD 
profile which was measured in an inlet of the Quarisen northeast of 
Kapp Norvegia (Figure 2.1 1, top). The temperature profile shows cold 
WW above a slightly warmer layer centered at 200 m depth which tops a 
colder bottom layer (Figure 2.1 1, bottom). The salinity increases 
from top to bottom. Presently it is not possible to conclude if the 
deeper layer is the remnant of a WW-layer which reached to the bottom 
and is separated from a slightly warmed surface layer by an intrusion 
of warmer water from offshore, or if it represents water which 
emanates from under the ice shelf. Tracer data measured from the water 
samples will be used to answer this question. 


Figure 2.6:  Vertical section of potential temperature (top) and salinity 
             (bottom) from Joinville Island (left) to Kapp Norvegia (right) 
             carried out during Polarstern"-cruise ANT IX/2.

Figure 2.7:  Vertical section of dissolved oxygen from Joinville Island 
             (left) to Kapp Norvegia (right) carried out during "Polarstern"-
             cruise ANT IX/2.

Figure 2.8:  Three-hour averages of air temperature (top) and wind speed 
             (bottom) measured during CTD-stations on "Polarstern" during ANT 
             IX/2.

Figure 2.9:  Surface layer temperatures (top) and salinities (bottom) 
             measured with the CTD in 10 m water depths during winter 1989 
             (WWGS '89, dotted line) and spring 1990 (ANT IX/2, solid line).

Figure 2.10: Cruise track and station locations in the "Beta-cross" area 
             during "Polarstern"-cruise ANT IX/2 (top) and vertical sections 
             of potential temperature (bottom) along the track lines.

Figure 2.11: Location of the station in the inlet of the Quarisen during 
             "Polarstern"-cruise ANT IX/2 (top) and vertical profiles of 
             potential temperature (stippled line) and salinity (solid line) 
             in the inlet (bottom). 



2.3.  Distribution of dissolved inorganic nutrients in the water column
      J.M. Krest, A.A. ROSS (OSU)


Objectives

By obtaining high quality nutrient data from late winter and early 
spring, we will improve on the sparse historical data set of the 
central Weddell Sea. The repeated "Polarstern" transects should permit 
the seasonal and interannual variability of the major water masses to 
be assessed. This data set will be used to study the evolution of WW 
which is the mixed layer beneath the seasonal pack ice. WW properties 
change with length of time under the ice due to continuous mixing of 
warmer, higher nutrient waters (WDW) from just below the pycnocline. 
From the analysis of nutrients in this surface layer, we plan to 
extend and refine our earlier estimates of net primary productivity in 
the Weddell Sea.

Work at sea

At 88 CTD casts, water samples were taken and analyzed for silicic 
acid, phosphate (Ortho-Phosphate), nitrate + nitrite (N+N), nitrite, 
and ammonium. Analyses were performed using the ALPKEM RFA-300 
continuous flow analysis System. The entire water column was sampled 
for nutrients, but at this time, only the surface water in the primary 
northwest-to-southeast transect has been examined for silicic acid, 
phosphate and N+N.

Preliminary Results

Contour plots of nutrients in the upper 500 meters (Figure 2.12) show 
a fairly well defined layer of WW from approximately 50°W to 14°W. In 
the WW-layer which occupies the top 100 meters of the water column 
silicic acid concentrations range from 70 to 80 µM, N+N concentrations 
from 28 to 30 µM, and phosphate concentrations from about 2.0 to 2.1 
µM. Underlying this WW-layer is a reasonably strong nutricline, 
varying in depth from 100 to 150 meters. In this nutricline, silicic 
acid increases in concentration to 110 micromolar, N+N increases to 33 
µM, and phosphate increases to 2.3 µM. For all three nutrients, 
concentrations are most elevated in the center of this gyre, 
indicating a general upwelling trend. At two locations, 40° and 32°W, 
the contour plots for all three nutrients indicate strong vertical 
mixing between the WW and the underlying water mass. At the Western 
and eastern boundaries, intense vertical mixing causes nearly vertical 
nutrient isolines. In the WSBW a tongue of low concentration silicic 
acid can be seen which extends laterally more than halfway across the 
Weddell Sea Basin at a depth of approximately 4500 to 5000 meters. 
Initial comparisons were made with data obtained by Oregon State 
University's group during WWGS '89 and show good agreement.


Figure 2.12: Vertical sections of nutrients from Joinville Island to Kapp 
             Norvegia carried out during "Polarstern'-cruise ANT IX/2. 



2.4.  Tritium and Helium measurements
      R. Well (FPB)


Objectives

Within the scope of the physical oceanography programme the tritium 
and helium-isotope contents of the water samples serve as tracers for 
water mass characteristics. In addition, they can yield information 
about the time scales of exchange of the water masses within the 
Weddell Gyre. On this cruise - for the first time - we degassed water 
samples at sea. This procedure is expected to reduce the contamination 
caused by longtime storage and can simplify the handling of the sample 
containers. For this purpose we tested new degassing equipment on 
board and will compare the results with those obtained with the 
traditional method.

Work at sea

We took water samples at 6 CTD-stations on the shelf and continental 
slope of the Antarctic Peninsula in water depths of about 400, 1000, 
2200, 2500, 3550 and 4200 m, at 3 CTD-stations in the central Weddell 
Sea at water depths of about 4700, 4760 and 4860 m and at 4 CTD-
stations on the eastern continental slope off Kapp Norvegia in water 
depths of about 4400, 2400, 1600 and 500 m. Altogether about 50 
double-samples were taken. One half of them were degassed on board, 
the other half will be degassed after our return in the laboratory, 
the helium- and neon-isotope contents will be compared.

Preliminary Results

As the measurements of the samples have to be done with a mass 
spectrometer in the laboratory we can not present data or quantitative 
results of the intercomparison here. The degassing technique on board 
did not show serious technical problems. Some problems occurred with 
the melting off procedure of the glass ampoules so that presently we 
can not generally guarantee that the extracted gas is well caught in 
the glass ampoule. 



2.5.  Water level measurements
      C. Buxhoeveden (ITBA), E. Fahrbach, R. Plugge (AWI), E. Schütt


Objectives

Water level measurements and deployments of water level recorders were 
carried out during ANT IX/2 for two reasons: to obtain further 
information on the tides in the Weddell Sea and to study low frequency 
fluctuations such as coastal trapped waves or basin modes, for a 
better understanding of the fluctuations observed in the moored 
current meter records.

Work at sea

To obtain time series long enough for a detailed tidal analysis and to 
study lower period fluctuations, two current meter moorings on the 
western and the eastern shelf respectively (215, 214/2) were equipped 
with Aanderaa water level recorders (WLR). It was planned to recover 
mooring 214/1 with a WLR, but due to the heavy ice conditions off the 
eastern shelf, this was not possible and the mooring had to be 
recovered during the following leg. During the stay in the Atka-Bight 
a short period study took place to check a tidal prediction made by 
members of the Meeresphysik section at AWI on the basis of previous 
measurements. With this aim soundings of the navigational echo sounder 
were evaluated and a current meter was moored 50m below the hull of 
"Polarstern" through the moon pool (Figure 2.13).

Preliminary results

The short term study over 36 hours allowed us to compare the predicted 
and observed tidal range as well as the times of high and low water. 
It appears that they agree to the accuracy of the measurements. The 
times of the extrema can be determined to about 10 min which 
corresponds to the difference in the predictions. The determination of 
the tidal range is affected by the influence of lower period 
fluctuations of the sea level and the motion of the ship due to the 
unloading and later ballasting which changes the location and 
inclination of the echosounder. Both effects add up to an uncertainty 
of about 15 cm in the determination of the tidal range which is about 
10% of the observed range. Within this range predicted and measured 
data correlate. The correlation between tidal current and sea level is 
less clear. Whereas during 18 December high and low water seems to 
correlate with maximum and minimum tidal current, on the 17th no 
correlation is found. This agrees with observations from moored 
current meters where nontidal current variability is as strong as the 
tidal one.


Figure 2.13: Records of the current speed (open circles) in 50 m water depth 
             and the navigational echo sounder from "Polarstern" during the 
             visit to Atka-Bight. 


2.6.  Optical properties of sea water
      R. Plugge, V. Strass (AWI)


Objectives

The optical properties of sea water vary with its constituents of 
biological origin. Observational methods based on the variations of 
the optical properties allow measurements of biological variables at 
the same high sampling rate as temperature and salinity, and thus can 
be used for underway data recording. Data sets including both 
biological and physical variables collected in this way allow for 
statistical studies of the dependency of the biological realm on the 
physical environment. During the present cruise a sensor package for 
measuring temperature, salinity, chlorophyll, fluorescence, Mie 
backscatter and yellow substance was employed; the optical 
measurements allow determination of the concentration of phytoplankton 
biomass and particles and zooplankton concentration/activity.

Work at sea

The hydrographic-optical sensor package (named COMED, developed in the 
Meeresphysik section at the AWI) was mounted in the ship's well at 
hull depth (11 m), where the data were collected at a rate of 1 cycle 
per 10 seconds. Measurements were taken during two periods: the first 
starting on 18 November and ending on 22 November, the second period 
starting on 20 December and ending on 29 December. During both periods 
the ship crossed the Antarctic Circumpolar Current with the Polar 
Front: the first time on the southward leg from Punta Arenas towards 
Bellingshausen-Station, the second time on the northward leg from GvN-
Station towards Cape Town. During the period in between the ice 
conditions required the COMED System to be switched off and to cover 
the sensor package with a protective lid in order to avoid damages.


2.7.  Underway measurements of current profiles, XBTs and the thermosalinograph 
      T. Behmann, J. Dehn, E. Fahrbach, M. Knoche, T. Markus,  
      V. Strass (AWI), H.-J. Brosin, M. Schmidt (IfMW), C. Buxhoeveden (ITBA),
      M. Harder, H.-H. Hinrichsen, H. Schäfer U. Sterr, A. Wisotzki (FPB)


Objectives

The Antarctic Circumpolar Current is subject to a wide range of 
temporal and spatial variability. The repeated crossings of 
"Polarstern" are used to obtain a data set which is suitable to 
address longer term variability of the thermal field and spatial 
variability of the velocity field. The temperature profiles are 
inserted in the Integrated Global Ocean Services System (IGOSS).

Work at sea

This goal is approached by usage of the Vessel Mounted Acoustic 
Doppler Current Profiler (VM-ADCP, manufactured by RD Instruments, San 
Diego) which allows us to monitor the current profile in the upper 
350m of the water column from the ship moving at full speed. The 
corresponding thermal structures were measured by means of XBTs using 
T-7 probes. Sea surface temperature and salinity is recorded by a 
thermosalinograph.

By use of the ADCP a cross section of the upper ocean velocity profile 
through the Circumpolar Current was recorded through Drake Passage to 
the Antarctic Peninsula. A set of calibration data were collected by 
running a cross-shaped course pattern on the shelf of the Antarctic 
Peninsula. During the calibration courses the ADCP was operated in its 
bottom track mode; a variety of control parameter settings were used 
during the measurements in order to optimise the instrument's 
performance. The data sampled were transferred to the ship's VAX 
Computer for processing and plotting. During the measurements the ADCP 
was run without the occurrence of major problems. However, during a 
later phase of the cruise no more data were obtained for two reasons. 
First, in its mode of operation the ADCP's transducer sits at hull 
depth (approx. 11 m) in the ship's well without any protection against 
mechanical damage by ice floes pushed under the ship. When the ship 
moves through the ice the transducer is protected by a lid consisting 
of two stainless steel sheets of 8 mm thickness. With the transducer 
behind the protective lid the ADCP not able to function. Consequently, 
no ADCP measurements of current profiles could be obtained along the 
Weddell Sea cross section. Second, it appeared that the protective lid 
was not strong enough to withstand the collisions with ice floes. When 
we tried to reactivate the ADCP in ice-free waters after having left 
the GvN-Station, we noticed that the lid was deformed by the impacts 
from ice floes and the transducer assembly was severely damaged. All 
four transducer heads were scoured off at their outer periphery, and 
in one case the metal cage embedding the transducer face was torn. 
Moreover, two of the transducer heads were loosened from their proper 
connection to the transducer electronics housing because the 
connecting bolts had been lengthened by leverage, leading to gaps of 
up to 3 mm wide between the transducer heads and the electronics 
housing. Through these gaps sea water flooded the electronics housing. 
Because of the severeness of the damages, there was no way of 
repairing the transducer assembly on board of the ship and to employ 
the ADCP during the further parts of the cruise.

The thermal structure of the upper 700 to 800 meters was measured by 
194 XBT-profiles which were recorded with a Nautilus-system. Times and 
locations of the individual profiles are given in Table 2.3 and 2.4. 
Comparison between 8 XBT and CTD measurements at the same stations 
confirmed the accuracy of 0.2 K given by the manufacturer. The data 
obtained are depicted as vertical sections in Figure 2.14.

Sea surface temperature and salinity were recorded continuously in the 
bow thruster channel at about 5 m depth with a thermosalinograph 
supplied by Meerestechnik-Electronik (ME). The data were controlled by 
salinity samples taken at the inlet to the instrument and the 
temperature measurements of the CTD. The following corrections have to 
applied to the recorded data:

Ttrue=0.921 Trecorded- 0.253 
Strue=0.949 Srecorded- 1.772

The corrected data will then be accurate to 0.03 K and 0.03. However, 
it has to be taken into account that occasionally a water-ice mixture 
is flowing in sensor head which results in erroneous data. The error 
is obvious by the reduced conductivity due to the ice. Therefore we do 
not use the thermosalinograph data along the transect but refer to the 
CTD-data in 10 m depth (Figure 2.9). The T/S-profiles across Drake 
Passage and from Antarctica to South Africa are shown in Figure 2.15. 


Table 2.3:  XBT-Section C. San Juan - King George Island

St.  Date       Time       Position      Depth   
No.             GMT      Lat    Long       m   
                          S       W     (uncorr.)
------------------------------------------------
 1  18.11.90    2357    54°39'  63°31'     122   
 2  19.11.90    0112    54°54'  63°19'   >1800  
 3              0203    55°07'  63°08'    2639  
 4              0307    55°20'  62°57'    4171  
 5              0403    55°34'  02°48'    4141  
 6              0518    55°48'  62°35'    4090  
 7              0625    56°01'  62°25'    3953  
 8              0745    56°15'  62°11'    4040  
 9              0850    56°29'  62°00'    4100  
10              0958    56°42'  61°48'    3000  
11              1058    56°56'  61°39'   >3000 
12              1158    57°09'  61°27'    3819  
13              1258    57°23'  61°14'    3845  
14              1405    57°38'  61°02'    3631  
15              1456    57°50'  60°52'    3601  
16              1601    58°04'  60°42'    4305  
17              1739    58°28'  60°21'    3073  
18              1831    58°31'  60°12'    3600  
19              1930    58°44'  60°03'    3715  
20              2035    58°58'  59°50'    6428
21              2135    59°11'  59°39'    4090
22              2250    59°25'  59°27'    4298
23  20.11.90    0004    59°40'  59°13'    2142
24              0108    59°52'  59°02'    5930
25              0209    60°06'  58°49'    3490
26              0321    60°20'  58°36'    3868
27              0421    60°33'  58°23'    3912
28              0526    60°47'  58°11'    4266
29              0633    61°00'  57°58'    4910
30              0739    61°14'  57°45'    2499
31              0840    61°27'  57°33'     903
32              0945    61°41'  57°18'     399
33              1042    61°54'  57°10'     259
34              1201    62°06'  57°26'     743
35              1315    62°13'  58°02'    1280
36              1403    62°17'  58°24'    1100
37              1501    62°17'  58°44      464


Table 2.4:  XBT-Section Antarctica - South Africa

St.  Date      Time       Position      Depth   
No.            GMT      Lat    Long       m   
                         S       W    (uncorr.)
------------------------------------------------
106  20.12.90  0406  68°11'  04°28'     4086
107            1000  67°45'  03°09'     4283
108            1435  67°32'  01°04'    >4000
109            1717  67°15'  00°24'     3451
110            1920  67°00'  00°52'    >4500
111            2220  66°30'  01°49'     4080
112  21.12.90  0005  66°15'  02°21'     3680
113            0155  66°00'  02°51'     3390
114            0340  65°45'  03°17'     3669
115            0625  65°15'  03°21'     2627
116            0744  65°00'  03°23'     2530
117            0906  64°45'  03°26'
118            1031  64°30'  03°29'     2177
119            1157  64°15'  03°31'     2600
120            1316  64°00'  03°34'     3159
121            1411  63°45'  03°36'     4365
122            1601  63°30'  03°37'     4940
123            1722  63°15'  03°41'     5055
124            1844  63°00'  03°44'     5360
125            2001  62°45'  03°31'     5340
126            2125  62°30'  03°16'     5378
127            2240  62°15'  03°02'     5372
128            2355  62°00'  02°49'     5380
129  22.12.90  0120  61°45'  02°34'     5378
130            0230  61°30'  02°20'     5376
131            0350  61°15'  02°07'     5122
132            0510  61°00'  01°53'     3341
133            0607  60°48'  01°42'     5400
134            0745  60°30'  01°27'     4181
135            0902  60°15'  01°15'     4303
136            1136  59°45'  00°51'     4924
137            1245  59°30'  00°39'    >4200
138            1517  59°00'  00°14'     4488
139            1637  58°45'  00°02'     4599
140            1800  58°29'  00°12'     4428
141            1905  58°15'  00°22'     3885
142            2010  58°00'  00°34'     3900
143            2135  57°45'  00°45'     4210
144            2250  57°30'  00°58'     3905
145  23.11.90  0006  57°15'  01°10'     3368
146            0235  56°45'  01°33'     3563
147            0350  56°30'  01°44'     4187
148            0504  56°15'  01°55'     4045
149            0640  55°58'  02°09'     3386
150            0745  55°44'  02°18'     3371
151            0855  55°30'  02°29'     2640
152            1013  55°15'  02°41'     2460
153            1124  55°01'  02°51'     3143
154            1244  54°45'  03°03'     2645
155            1356  54°30'  03°14'     2606
156            1835  54°20'  03°24'     2702
157            1915  54°15'  03°15'     2400
156            2120  54°00'  02°36'     2495
157            2317  53°45'  01°59'     2040
158  24.12.90  0110  53°30'  01°25'     2658
159            0305  53°15'  00°50'     2358
160            0416  53°05'  00°29'     2600
161            0454  53°00'  00°19'     2481
162            0645  52°45'  00°15'     2720
163            0820  52°30'  00°46'     2800
164            1015  52°15'  01°19'     2800
165            1204  52°00'  01°52'     2600
166            1355  51°45'  02°24'     3053
167            1545  51°30'  02°57'     3485
168            1735  51°15'  03°28'     3390
169            1825  51°00'  04°00'     3608
170            1950  50°57'  04°06'     3553
171            2125  50°45'  04°30'     3231
172            2314  50°30'  05°02'     3349
173  25.12.90  0145  50°15'  05°33'     3659
174            1120  50°00'  05°58'     3711
175            1300  49°45'  06°11'     3519
176            1440  49°30'  06°23'     3500
177            1625  49°13'  06°37'     3464
178            1830  49°00'  06°48'     3684
179            2036  48°45'  07°02'     3890
180            2245  48°29'  07°15'     2182
181  26.12.90  0039  48°15'  07°27'     2465
182            0247  47°59'  07°43'     4158
183            0430  47°45'  07°53'     3090
184            0630  47°30'  08°05'     2550
185            0819  47°15'  08°18'     1837
186            1004  47°00'  08°31'     3452
187            1152  46°45'  08°43'     3685
188            1337  46°30'  08°55'     4420
189            1520  46°15'  09°07'     4680
190            1655  46°01'  09°19'     4650
191            1850  45°45'  09°32'     4563
192            2230  45°30'  09°43'     4513
193            2220  45°15'  09°55'     4610
194  27.12.90  0005  45°00'  10°08'     4710
195            0144  44°45'  10°20'     4748
196            0321  44°30'  10°31'     4981
197            0509  44°15'  10°43'     4231
198            0647  44°00'  10°55'     4305
199            0930  43°45'  11°07'     4409
200            1120  43°28'  11°19'     4980
201            1250  43°15'  11°31'     4591
202            1430  43°00'  11°43'     4703
203            1610  42°45'  11°55'     4505
204            1742  42°30'  12°06'     4606
205            1933  42°13'  12°20'     3239
206            2048  42°00'  12°29'     5102
207            2217  41°45'  12°40'     3329
208            2349  41°30'  12°51'     2930
209  28.12.90  0013  41°15'  13°02'     2100
210            0140  41°00'  13°10'     4500
211            0322  40°45'  13°22'     4626
212            0506  40°30'  13°36'     4934
213            0652  40°15'  13°48'     4842
214            0835  40°00'  13°59'     4135
215            1010  39°45'  14°10'     4679
216            1321  39°29'  14°21'     4760
217            1453  39°13'  14°31'     4730
218            1514  39°00'  14°40'     4744
219            1657  38°57'  14°51'     4853
220            1830  38°29'  15°04'     4856
221            2253  37°51'  15°33'     4866
222            2335  37°45'  15°37'     4396
223  29.12.90  0104  37°30'  15°49'     4788
224            0229  37°15'  15°58'     4708


Figure 2.14: XBT sections across Drake Passage (top) and from Antarctica to 
             South Africa (bottom) carried out during ANT IX/2. For location 
             see Figure 2.1.

Figure 2.15: T/S-profiles across Drake Passage (top) and from Antarctica to 
             South Africa (bottom) measured with a thermosalinograph during 
             ANT IX/2. For location see Figure 2.1.




3.  CHEMISTRY

3.1.  Measurements of biogenic sulfur compounds and their reaction 
      products in sea water and the marine atmosphere
      R. Staubes (IfMG)


Objectives

Oceanic emissions of biogenic sulfur gases like dimethyl sulfide 
(DMS), carbonyl sulfide (COS), carbon disulfide (CS2) and methyl 
mercaptan (CH3SH) constitute a major flux of sulfur to the atmosphere, 
a source which is believed to be responsible for the background levels 
of SO2, non-sea salt sulfate and methanesulfonic acid. These compounds 
are important factors in cloud chemistry and global climate as 
contributors to cloud condensation nuclei. The dominant sulfur 
compound released from the oceans and thus the most important 
precursor of non-sea salt sulfate is considered to be DMS which is 
produced from metabolic processes in certain algae.

Work at sea

During ANT IX/2 we performed simultaneous measurements of dimethyl 
sulfide (DMS), carbonyl sulfide (COS), carbon disulfide (CS2) and 
methyl mercaptan (MeSH) in sea water and the atmospheric boundary 
layer. The concentrations of the main reaction products sulfate and 
methanesulfonate in aerosols in the atmosphere were determined. The 
air samples were collected at the front of the ship's upper deck; to 
minimize the influence of the ship two outriggers were fixed at the 
rail. Aerosols were sampled on filters; the analysis of the ion 
concentration in the aerosols will be carried out in the laboratory in 
Frankfurt. The seawater samples were taken from the ship's continuous 
seawater pumping System. The concentration of atmospheric and 
dissolved DMS, COS, CS2 and MeSH were analyzed by means of a gas 
chromatographic system equipped with a flame photometric detector. 
Biological data of the seawater have been collected during the cruise 
to aid the Interpretation of the findings. Due to our participation in 
the cruise legs ARK Vll/2, ANT IX/1 and ANT IX/2 of "Polarstern" the 
concentration profiles of atmospheric and dissolved DMS, COS, CS2 and 
MeSH could be examined from 82°N to 71°s.

Preliminary results

The data show that DMS is the dominant sulfur gas in all sea water 
samples examined, with smaller amounts of COS, CS2 and MeSH in sum 
accounting for less than 20% of the observed sulfur in seawater. 
Atmospheric DMS in the boundary layer was characterized by a 
significant spatial variability, while COS was distributed fairly 
homogeneously along the cruise. Traces of biogenic sulfur gases other 
than DMS and COS were found only in a limited number of atmospheric 
samples.


3.2.  Measurements of the concentration of Nitric acid, Ammonia and 
      Ammonium Nitrate in the marine atmosphere
      T. Papenbrock (RUB)

Objectives

Nitric acid (HNO3) is a final, stable product of atmospheric NOx and 
HOx chemistry. One third of the acid rain is caused by nitric acid. 
Hence, nitric acid is an important indicator for two of the most 
important cycles in clean and polluted air. Ammonia (NH3), one of the 
most important bases in air, is mainly produced by biological 
processes, It has been found in clean and polluted air, even in the 
marine atmosphere, for example in the Sargasso Sea. Ammonium nitrate 
participates in the acid-base equilibrium with gaseous nitric acid and 
ammonia. This equilibrium depends on temperature and relative humidity 
of the air masses. For a better understanding of the concentration 
distribution of these three components and the equilibrium in the 
atmosphere, it is important to do simultaneous measurements.

Work at sea

Our method for measuring the concentration of nitric acid and ammonia 
in air is based on laser photolysis yielding excited OH and NH 
radicals. The fluorescence intensities of the two species are taken as 
a measure for the nitric acid and ammonia mixing ratios in the 
atmosphere. At present the detection limits for long integration times 
(one hour) is 0.04 ppbv for nitric acid and 0.3 ppbv for ammonia, 
respectively. Our method allows direct and continuous measurements. To 
examine the concentration of ammonium nitrate in air we took Denuder 
probes with sampling times between 40 and 64 hours. The air was 
sampled at the front of the ship's upper deck and pumped through an 8-
meter long Teflon tube to the photolysis cell. The analysis of the 
samples will be performed in our home laboratory after the cruise.

Preliminary results

The highest nitric acid and ammonia concentrations were measured in 
the Strait of Magellan after leaving Punta Arenas. The maximum values 
were 250 pptv for nitric acid and 600 pptv for ammonia, respectively. 
During the following days the concentrations slowly decreased with 
north-westerly winds. Then the wind changed direction and we measured 
air masses coming from the east. The concentrations decreased very 
quickly with the values often below the detection limits. Due to our 
participation in the cruise legs ARK VII/2 and ANT IX/1 and 2 of 
"Polarstern" in 1990, the concentration profiles of atmospheric 
gaseous nitric acid and ammonia could be examined from 82°N to 70°s.


3.3.  Organobromine compounds in the ocean and atmosphere
      T. Bluszcz, O. Schrems (AWI)


Objectives

A considerable amount of the bromine which is present in the 
atmosphere originates from natural sources. The oceans are important 
sources for methyl bromide (CH3Br) and bromoform (CHB3). These are 
compounds which are produced by marine macro-algae. Anthropogenic 
emissions of organobromine compounds like the halons 1301 (CF3Br) and 
1211 (CF2ClBr), however, are responsible for the increase of the 
bromine concentration in the stratosphere due to their long life 
times. So far, halons have very low concentrations in the atmosphere, 
but show an increasing tendency. Increasing production and emission 
rates of these chemicals can be expected in the future. Therefore, 
these anthropogenic source gases are a potential reservoir for 
stratospheric bromine radicals which are efficiently involved in the 
catalytic ozone depletion cycles. On the other hand a significant 
ozone depletion potential of the biogenic organobromine compounds has 
to be considered for the lower stratosphere. The objective of our work 
is to obtain horizontal concentration profiles of various volatile 
organobromine compounds during legs 1, 2 and 4 of the "Polarstern"-
cruise ANT/IX. The profiles will provide information about the global 
distribution of these compounds, as well as information about the 
biogenic and anthropogenic contributions to stratospheric ozone 
depletion catalyzed by bromine radicals. In order to investigate the 
air-sea exchange of bromine compounds we collected also surface water 
samples for later analysis.

Work at sea

The air samples were taken 20 m above sea level through a short 1/4" 
Teflon tube. Gas chromatographic analyses of the samples were 
performed in the air chemistry container at the upper deck of the 
ship. During sampling the wind direction was carefully checked in 
order to avoid contamination of the air samples by the ship. The 
applied sampling method was cryogenic preconcentration of the samples 
by means of liquid argon as coolant. The air was pumped at a constant 
flow rate through a U-tube (filled with silylated glass wool) which 
was kept in a dewar containing liquid argon. In this way the trace 
gases were frozen out inside the U-tube. Prior to the condensation of 
the trace gases the air moisture was removed by means of a permeation 
gas dryer or a cold trap kept at -20°C The samples were transferred 
from the U-tube to a focusing column and from there injected into the 
GC. The gas chromatographic separation of the components was achieved 
with a fused silica capillary column. For the analyses of these 
halogen-containing samples the GC was equipped with a highly sensitive 
electron capture detector (ECD). During the leg ANT IX/2 about 120 air 
samples were directly measured with the gaschromatograph installed in 
the air chemistry container. For control measurements and application 
of other analytical methods in the home laboratories an additional air 
sample was collected daily, sealed and stored at low temperature. Gas 
chromatography-mass spectrometry (GC-MS) coupling and GC-FTIR coupling 
will be applied at home for the complete identification of the peaks 
in the gaschromatogrammes. For the investigation of the air-sea 
exchange of the bromine species water samples have been taken from the 
seawater line at about 60 stations and also kept at low temperature. 
These samples will also be analysed in the home laboratory.

Preliminary results

At the beginning of the cruise we tested several variations of our air 
sampling technique. Removal of the air moisture by means of a cold 
trap (-20°C) prior to the condensation of the trace gases turned out 
to be the most suitable procedure for preparing the air samples. By 
comparison with calibrated standards of CH3Br, CHBr3, CF3Br and CF2ClBr 
we could perform a preliminary quantification of the samples. It was 
found that these compounds are present in the marine troposphere at 
concentrations in the low pptv range. A listing of the compounds 
according increasing concentrations provides the following order: CF3Br 
< CF2CIBr < CH3Br < CHBr3. The final evaluation and statistical 
treatment of the gaschromatogrammes will be performed in the home 
laboratory. 



3.4.  Biogeochemistry of Silica
      L. Goeyens (VUB), J. Krest, A. ROSS (OSU), A. Leynaert, 
      B. Quéguiner, O. Ragueneau (IEM), L. Lindner (RUU)


Objectives

During EPOS Leg 2, high biogenic silica production rates have been 
measured in the marginal ice zone of the western part of the Weddell 
Sea and at one station in the Scotia Sea. Comparison with previous 
studies conducted in the Antarctic Circumpolar Current and in the Ross 
Sea indicated that the dynamics of silicon in the above mentioned 
subsystems are quite different. The present study was initiated to 
bring more information on the importance of the Weddell Sea ecosystem 
in the silicon budget of the Southern Ocean.

Work at sea

Eleven stations were sampled in the Weddell Sea (from 63°12'S, 53°41'W 
to 71°06'S, 11°23'W) at depths ranging from 0 to 300 m. For production 
experiments, sampling depths were determined with reference to 
quantameter profiles (respectively 100%, 25%, 10%, 3%, 1% and 0.1% of 
surface incident light measured as PAR). 24h incubations were 
conducted in a deckincubator where in situ light was simulated by 
using different transmission neutral filters. The deck-incubator was 
cooled by running surface water.

Additional depths were sampled to obtain complete profiles of 
particulate organic carbon, particulate organic nitrogen, biogenic 
silica, chlorophyll a and nutrients (silicate, nitrate, nitrite, 
ammonium, phosphate) in the upper 300 m at each station. At each 
photometric depth the production of biogenic silica was measured by 
means of stable silicon (30Si) and radioactive silicon (32Si) uptake 
experiments. For the latter, size-fractionation (on 0.4 and 10 µm 
filters) was performed at the 25% light level. The radioactive 32Si-
silicate enables us to measure phosphorus uptake rates also because it 
decays into radioactive 32P-phosphate. Dissolution rates of biogenic 
silica were followed in parallel with production measurements by using 
the stable 29Si method. The carbon production was measured with the 
classical 14C method. The nitrogen production was measured only in 
surface water using the 15N procedure. Phytoplankton samples were 
collected (lugol fixation) only at depths where production experiments 
were done and further phytoplankton samples were taken by means of a 
vertical net in order to estimate the Al/Si content of diatoms.

Preliminary results

For most of the stations production results must be considered as 
maximum potential production rates because of the importance of ice 
cover during the cruise (especially for Sta. B3 to B9). In those 
conditions natural phytoplankton populations experience a different 
light regime (with periods of darkness under ice) from the one used 
during incubations.

The distribution of major nutrients indicates weak biological activity 
during the study period. Surface water silicate, nitrate and phosphate 
concentrations were respectively about 80 µM Si-Si(OH)4, 30 µM N-NO3, 2 
µM P-PO4. As far as ammonium is concerned the measured concentrations 
were always very low. They almost never amount more then 0.2 µM N-NO4; 
some stations, near 65°S - 66°S, show, however, a slight increase in 
ammonium concentration and a corresponding decrease in surface 
nitrate. But still nitrate concentrations are as high as 27 µM N-NO3 in 
this area. In general these stations were also characterized by a 
slightly increased phytoplankton production. Preliminary results of 14C 
uptake experiments indicate low levels of primary production. Maximum 
uptake rates in a given depth were encountered in surface waters 
(range : 0.15-0.54 mmol C.m-3d-1). The lowest rates were observed at the 
ice-shelf station where the euphotic layer reached down to 138 m. 
Maximum rates were measured at station B5 (31°47' W, 66°07' S) and 
ice-edge station B11 (03°57' W, 68°00' S). Depth-integrated production 
rates (Table 2.5) ranged between 12.2 and 26.2 mmol C m-2d-1 (146-314 mg 
C m-2d-1). These low values can be related both to the importance of the 
ice cover and the low temperatures which must prevent the emergence of 
large phytoplankton developments at this period of the year. First 
results obtained by the 32Si method indicate low uptake rates both for 
phosphorus and silicon (Table 2.5), as well as for carbon uptake. 
Silica production rates range between 0.62-8.02 mmol Si m-2d-1. The 
highest rate was observed at station B1 and must be taken as 
characteristic of coastal water rather than the Weddell Sea. At this 
station the >10 µm fraction accounted for 86.1% of silica uptake 
rates. The other stations fall within the lower part of the range of 
production rates that were measured during EPOS Leg 2. The same trend 
is observed for phosphorus for which the uptake rates range between 
0.08-0.61 mmol P m-2d-1. At station B7 the 32Si/32P uptake experiment was 
conducted on brine (incubated under daylight conditions) and indicated 
uptake rates one order of magnitude higher than in the water column. 
Preliminary assimilation ratios, calculated from depth-integrated 
production rates, are given in Table 2.6. With the exception of 
station B4, C/P ratios range between 101.5-168.8, close to the 
Redfield ratio (C/P = 106). Sta. B1 to B3 exhibit the highest Si/P 
ratios which suggest the dominance of diatoms in phytoplankton 
populations. This is also indicated by the high Si/C ratios measured 
at Sta. B2 and B3. Sta. B5 and B6 are quite different with regards to 
the three ratios and exhibit low silicon uptake as compared to carbon 
and phosphorus which can be related to different phytoplankton 
populations (dominance of non-siliceous phytoplankton). Sta. B4 is 
different from the other stations, showing high phosphorus uptake 
relative to carbon and silicon but the high Si/C ratio which suggests 
the dominance of diatoms in phytoplankton as for the first stations.


Table 2.5:  Depth-integrated carbon, silicon and phosphorus production rates 
            (in mmol C m-2d-1, mmol Si m-2d-1, mmol P m-2d-1, respectively) 

N° Sta.  C prod.   Si prod.*    P prod.(data from 32Si method)
-------  ------    ---------    ------------------------------
B1         -         8.02                     -
B2        13.9       1.64                   0.14
B3        13.0       1.11                   0.08
B4        17.9       2.35                   0.38
B5        22.0       1.17                   0.19
B6        18.1       0.62                   0.11
B7        13.1         -                      -
B8        22.5                              0.33
B9        26.2                              0.33
B10       19.8                              0.38
B11       12.2              


Table 2.6:  C/Si/P assimilation ratios calculated from depth-integrated 
            production rates

No Sta.  Si/C     Si/P      C/P
------   ----     ----     -----
B1         -      13.0       -
B2       0.12     12.0     101.5
B3       0.09     14.4     168.8
B4       0.13      6.1      46.5
B5       0.05      6.1     115.8
B6       0.03      5.4     157.4
  
  
  
3.5.  Biogeochemistry of Barium
      L. Goeyens (VUB)


Objectives

Particulate Ba, as well as other elements like Ca, Sr and Si, trace 
former biological activity in the marine environment. More than for 
particulate carbon or nitrogen, the longer turnover time of 
particulate barium is of interest for its tracer properties. Whether 
Ba is taken up by organisms in an active or passive way is still a 
matter of debate. On the one hand active uptake was described in the 
literature, but on the other hand it was stressed that Ba precipitates 
in small microenvironments of cell and detritus aggregates as barite 
crystals. In any case barite crystals represent the major part of 
particulate Ba in the total suspended matter. During the 
remineralization process the organic matrix (of cells and/or 
aggregates) decays and sets the barite crystals free in the sea water, 
where sedimentation and slow dissolution take place. The presence and 
distribution of particulate Ba in the marine environment is, however, 
very dependent on assimilation and break down processes. In general a 
vertical Ba profile shows peak concentrations in the surface water and 
very often secondary peaks near the oxygen minimum. For this reason 
the study of the biogeochemical cycle of Ba is of interest for other 
parameters such as nutrients, oxygen, particulate carbon and nitrogen, 
chlorophyll a, and species distributions, but also for flux studies 
such as nutrient assimilation and regeneration.

Work at sea

The filtration of total suspended matter for particulate Ba, Ca, Sr, 
AI and Si analysis demands large amounts of sea water. Normally 10 
liters are filtered; on previous cruises even more than 20 l were 
filtered. The total suspended matter (TSM) is collected on membrane 
filters, Millipore cellulose acetate filters or Nuclepore 
polycarbonate filters. They are simply dried at 60°C on board and 
stored in Petri dishes until analysis in the home lab.

During the ANT IX/2 cruise samples for TSM were taken at 9 stations. 
At every station the samples were selected according to the plankton 
distribution study, carried out by Baumann and Brandini. In general 
sampling covered the upper 500 to 600 m. The analyses will be carried 
out in the home lab by dissolution of the samples (filters) after LiBO2 
fusion and determination of the Ba (Ca, Sr, AI and Si) concentrations 
by ICP.




4.  MARINE BIOLOGY

4.1.  Energy flux at the base of the Antarctic food web
      M. Baumann, F. Brandini, F. Kurbjeweit (AWI), L. Goeyens (VUB), 
      J. Krest, A. ROSS (OSU), B. Quéguiner (IEM)


Objectives

The information concerning the Antarctic food web is mostly based on 
descriptive work such as spatiotemporal distributions of nutrients, 
primary production, phytoplankton biomass (chlorophyll), and 
zooplankton. To our knowledge, the energy flux from the primary 
producers to the primary consumers within the pelagic ecosystem is 
estimated only by means of such a descriptive approach. As an attempt 
to gain a more precise picture of the trophic relationships among the 
planktonic communities in Antarctic regions, we focused on the 
quantitative nitrogen transfer at the first and second trophic level 
using the stable isotope 15N as a tracer. This study was carried out in 
terms of unialgal culture experiments using the common Antarctic 
copepod Metridia gerlachei as a primary consumer and six 15N-labelled 
algal species as primary producers.

Work at sea

Five diatoms (Thalassiosira spp., Nitzschia curta, Porosira glacialis, 
Rhizoso- lenia alata, Chaetoceros socialis) and a prymnesiophyte 
(Phaeocystis spp.) were isolated from the plankton in the Weddell Sea. 
The species were grown in natural sea water without the addition of 
nutrients etc., except EDTA as a chelator. To one liter of 0.2 µm 
filtered sea water, 3.72 mg of EDTA were added. The stock cultures 
were stored at 1°C and 30 µE m-2d-1 continuous light. The copepod 
Metridia gerlachei was caught by means of a bongo net with mesh width 
of 100 µm. The animals were transferred by pipette into filtered 
seawater and allowed to starve for 48 hours before starting the 
experiments. The experiments were carried out in 5-1 Duran flasks at 
1°C and 30 µE m-2d-1 continuous light. Every 24 hours the unialgal 
cultures were spiked with about four micromoles of 15NH4+ (97% 15N). It 
was assumed that after three days the algae were labeled through out. 
A mixture of 500-ml aliquots of each experimental vessel served as a 
seventh culture. For the grazing experiment, 20 female copepods were 
added to each bottle. Sampling was performed according to Table 2.7.


Table 2.7:  Sampling scheme during the phytoplankton grazing experiment

Parameter           0h   24h   48h   72h*   96h   120h
------------------  --   ---   ---   ----   ---   ----
POC/PON, NH4+       x                 x            x
nutrients           x     x     x     x      x     x
cell number         x     x     x     x      x     x
Chl a                                 x            x
15N in PON                            x            x
15N in NH4+                           x            x
14C - Assimilation                    x            x
15NH4+ - Addition   x     x     x     x          

* Addition of 20 animals to each culture.


Due to the fact that most of the analyses will be done in the home 
labs, no results can be given here. However, we hope that the 
experiments will provide information on the ammonia uptake of 6 of the 
common Antarctic phytoplankton species and on the extent Metridia 
gerlachei feeds on these species.



4.2.  Phytoplankton biomass and species distribution
      M. Baumann, F. Brandini (AWI)


Objectives

In marine environments, the availability of light and nutrients are 
important preconditions for the onset of phytoplankton development. 
The melting of ice along the marginal ice zones of the Weddell Sea 
during the spring/summer period increases both the mean light 
penetration and the vertical stability of the water column. Therefore, 
phytoplankton cells are maintained within the euphotic layer for 
longer periods, increasing the primary production along the receding 
ice edge. Moreover due to intense upwelling of the Warm Deep Water, 
the Weddell Sea is considered as one of the nutrient-richest waters of 
the World Ocean and there seems to be no evidence that the macro-
nutrient concentrations may ever limit phytoplankton growth. During 
ANT IX/2 our objective was to examine the distributions of 
phytoplankton, chlorophyll, and particulate organic carbon and 
nitrogen (PON and POC) on a large-scale northeast-southwest transect 
across the Weddell Sea with special regard to the marginal ice zone. 
Due to the almost complete ice Cover in the area of the transect we 
could not perform more stations within the ice edge in order to 
resolve precisely the spatial gradients of biological Parameters 
usually observed in these areas. Most of our stations were located in 
heavily ice covered areas (8/10 to 10/10) with very low biological 
activity in the water column compared to the ice edge zones and to the 
ice associated communities.

Work at sea

A total of 21 stations were vertically sampled (10 depths) by means of 
a rosette sampler with an integrated CTD system, to determine 
phytoplankton biomass in terms of chlorophyll, cell counts, and 
PON/POC measurements. For the microscopical analyses of species 
composition, samples were obtained by vertical net hauls, with a mesh 
size of 20 µm. The microscopic analy- ses of unpreserved net samples 
were performed immediately after sampling. Light attenuation was 
estimated at each station with the Secchi-disk, not in order to 
determine the euphotic zone, but to get an idea about cell abundance.

Preliminary results

At three stations (39, 43 and 101) no meaningful estimate of the 
Secchi depth could be determined due to darkness and/or rough sea. The 
lowest value (17 m) was obtained on the western shelf at station 40, 
indicating a more developed state of the phytoplankton community, and 
the highest (55 m) was found on the shelf off the Antarctic Peninsula 
(Figure 2.16). Net samples were very poor during the whole transect 
and usually dominated by diatoms. At the first stations of the 
northeastern Part (e.g. Sta. 40, 45), species were dominated by 
Corethron criophilum, Thalassiosira, Odontella, Nitzschia, Porosira 
glacialis, Rhizosolenia, Chaetoceros, and Coscinodiscus. In the deep 
waters of the gyre, Nitzschia spp, Rhizosolenia alata, Chaetoceros 
socialis and dinoflagellates, such as Gyrodinium and Gymnodinium, were 
most frequent, whereas in the southeastern sector mainly 
Coscinodiscus, Chaetoceros and Rhizosolenia appeared.


Figure 2.16:  Secchi depths measured during ANT IX/2.


The nano-size cells were observed in the middle of the gyre (Sta. 66 
and 75) after filtration of 500 ml of seawater from the euphotic zone 
on membrane filters (Sartorius Inc., 0.8 µm). The material was 
transferred to microscopic slides and observed under x1000 
magnification. It turned out that mainly phytoflagellates of different 
groups (dinoflagellates, cryptophycean, prasinophycean) but also 
zooflagellates (choanoflagellates) dominated the samples. Within the 
smaller size category (< 10 µm) the diatoms were dominated by 
Nitzschia cylindrus. Ice algae samples were obtained at three 
different stations located in deep, near -slope, and the shelf areas 
along the cruise track. Ice algal communities over deep water were 
totally dominated by Phaeocystis spec. - no other algae could be 
found. The near-slope sample contained both Phaeocystis and diatoms, 
mainly Nitzschia longissima, N. curta, and other pennate species; the 
shelf sample was dominated by diatoms, the most characteristic species 
being N. stellata, N. curta, N. closterium, Odontella weissflogii, 
Amphiprora spec.. Phaeocystis could not be found in this sample. It 
might be suggested that species composition in the ice algae 
assemblages are related to depth of the water column, but this should 
be confirmed in further investigations. 



4.3.  DMS - Production by Antarctic phytoplankton species
      M. Baumann, F. Brandini (AWI), R. Staubes (IfMG)


Objectives

It is well established that the oceans are a significant source of 
organic sulfur compounds, which are largely biogenic. The most 
important one is probably dimethyl sulfide (DMS), which is also 
produced by marine phytoplankton. It is suggested that DMS production 
is due mainly to dinophyceae and prymnesiophyceae. However, the 
importance of diatoms in this connection is still unclear and 
especially in polar regions has this aspect not been investigated. 
During ANT IX/2 the DMS production of eight dominant Antarctic 
phytoplankton species under several light- and temperature conditions 
was tested.


Figure 2.17: Production of DMS by 7 Antarctic diatom species at 1°C and 6 
             different light conditions in 36 h. Because the initial value 
             was subtracted, negative values occur in those samples where DMS 
             was not produced.


Work at sea

Seven diatom species (two Thalassiosira spp., Nitzschia curta, 
Porosira glacialis, Rhizosolenia alata, Rhizosoleni spp, Chaetoceros 
socialis) and a prymnesiophyte (Phaeocystis spp.) were isolated from 
the plankton of the Weddell Sea. The species were grown in natural 
seawater without the addition of nutrients etc., except EDTA as a 
chelator. 3.72 mg of EDTA were added. to one liter of sea water 
filtered with 0.2 µm. The stock cultures were stored at 1°C and 30 µEm-
2s-1 continuous light. For the experiments, a 2 I culture medium with 
cells was shaken vigorously and distributed in 100 ml flasks. One 
aliquot was kept for a quantitative cell analysis and another for the 
determination of the initial DMS content. The experiments were carried 
out in an incubator which allowed the choice of six light conditions 
(350, 160, 100, 50, 18, and 3.5 µEm-2s-1) and two temperatures (1°C and 
-1.6°C). The DMS released by the algae after three days was analyzed 
according to the method described in 1.3.1.


Figure 2.18: Production of DMS by Phaeocystis spp. at 1°C and six different 
             light conditions.


Preliminary results

Figure 2.17 shows the preliminary results of DMS produced by the 
diatoms at 1°C Although the values still have to be related to cell 
numbers, one can see that except Thalassiosira- and the Rhizosoleni 
spp., all diatoms produced DMS; Rhizosoleni alata obviously released 
the greatest amount. Compared to diatoms, the prymnesiophyte 
Phaeocystis sp. produces significantly more DMS (Figure 2.18). While 
values for the diatoms range from 0.1 to 1.5 ng DMS/ 10 ml, the 
Phaeocystis culture produced up to 20 ng DMS/10 ml. Later we intend to 
express the results as DMS production per cell surface for better 
comparisons of production rates among species. 



4.4.  Effect of dissolved organic compounds derived from "brown ice" 
      On the development of surface phytoplankton in the Weddell Sea
      M. Baumann, F. Brandini, (AWI); J. Krest, A. ROSS (OSU)


Objectives

The blooming of phytoplankton cells in the ice edge zones of the 
Antarctic Ocean has been associated with a vertical stabilization of 
the surface water layers during ice melting. More recently, the 
seeding hypothesis has been claimed to be crucial for increasing 
phytoplankton biomass in the near surface layers, as algae from the 
brown ice are released in great quantities during the receding of the 
ice in early spring. However, it should be mentioned that the water 
column not only receives particulate material from the ice but also 
dissolved organic compounds making the seeding process much more 
complex than it is assumed.

According to recent studies on spatial distribution of phytoplankton 
in the ice edge zones, the dynamics of the blooming should be analyzed 
at two consecutive stages, starting with the ice associated species 
(Nitzschia spp., Navicula spp., Amphiprora spp., and Fragillaria spp.) 
immediately after the melting of the ice. Due to grazing pressure and 
the rapid sinking of cells - ice algae are strongly silicified and 
therefore heavier than planktonic species - the phytoplankton 
composition in the ice edge shifts from an ice algae characterized 
community to a more holoplanktonic community (Thalassiosira spp., 
Rhizosoleni spp., Chaetoceros spp., and Corethron criophilum). We 
believe that the development of this second stage is strongly related 
to the input of great amounts of dissolved organic compounds, derived 
from the "brown ice" community, into the surface water. The dissolved 
organic material possibly acts as chelators for essential trace metals 
(Fe, Mn, etc.), improving the development of planktonic diatoms. 
Although the stimulating effect of the melted "brown ice" on the 
phytoplankton development was previously mentioned, it seems that 
hitherto no proper attention has been paid to this. Therefore, during 
ANT IX/2 we decided to test the potential stimulating effect of 
dissolved organic material from "brown ice" on the development of the 
natural phytoplankton of the Weddell Sea.

Work at sea

For testing the effect of DOM from melted ice samples on the potential 
growth of natural phytoplankton populations, two different "brown ice" 
(BI 1, BI 2) samples were taken. The analysis of species composition 
and the contents of the macro-nutrients revealed that they differed 
both in microalgal community structure and nutrient contents. BI 1 was 
totally dominated by Phaeocystis colonies and BI 2 by a mixture of 
Phaeocystis and diatoms. The growth potential of natural phytoplankton 
from surface seawater was experimentally tested as follows: 
 
1: 800 ml SSW1) +  200 ml FSW2)
2: 800 ml SSW   +  200 ml FSW            +        EDTA
3: 800 ml SSW   +  200 ml melted BI 1
4: 800 ml SSW   +  200 ml melted BI 2

1) surface seawater
2) filtered seawater

All experiments were done in duplicates (A, B). 200 ml of SSW were 
added to the control (1 A/B) and EDTA flasks to avoid dilution effects 
of initial cell concentrations. The experimental flasks were kept at 
1°C and 30 µEm-2s-1. Sampling for cell counts and nutrient 
concentrations (nitrate, phosphate and silicate) was performed every 
two days for two weeks. Cell numbers were estimated on board after 
filtration of 50 ml culture medium on cellulose acetate filters (pore 
size 0,8 µm). If performed very gently, the cells are not destroyed by 
this procedure and can be counted with a standard microscope directly 
on the filters. Total nano-size and macro-size diatoms were counted in 
the same unit area of the filters and hence results are expressed on a 
relative basis. Nutrient analyses were carried out on board with the 
aid of an autoanalyzer.

Preliminary results

Initial cell concentrations in all experimental flasks averaged 200 
relative units, and were dominated by Nitzschia curta, N. cylindrus, 
N. kerguelensis, Chaetoceros dichaeta, Chaetoceros spp., 
Pseudonitzschia spp., Corethron criophilum, unidentified centric and 
pennate diatoms. Total diatoms and two different size classes of 
Nitzschia spp. were considered to represent biomass development. The 
nano-size Nitzschia cylindrus numerically dominated all the 
experimental approaches. Figure 2.19 shows clearly the stimulating 
effect of DOM, derived from both melted BI 1 and BI 2 on growth rates 
in comparison with the control and EDTA-added flasks. From the 
differences between cell concentrations after 12 days it might be 
assumed that DOM derived from diatom - dominated "brown ice" (4 A,B) 
had a stronger effect on cell doubling rates than DOM from Phaeocystis 
- dominated "brown ice". In contrast to that no significant 
differences can be observed when the control and the EDTA added 
bottles are compared.

Initial nutrient concentrations (Figure 2.20) may not be considered 
limiting for phytoplankton growth as phosphate, silicate, and total 
inorganic nitrogen averaged respectively 2.0, 66.9, and 27.8 µmol l-1. 
Ammonium was significantly higher in the DOMIB II- flasks (4 A,B), but 
decreased to comparatively low concentrations in all experiments after 
48 hours.

From these preliminary results it may be concluded that DOM released 
from the "brown ice" of the Weddell Sea certainly has a stimulating 
effect on cell growth that hitherto has been neglected. We believe 
that these results represent baselines for future experimental 
approaches to provide a more detailed picture of the seeding mechanism 
and its impact on the blooming of the phytoplankton along the receding 
ice edge zones of polar seas. 


Figure 2.19: Cell increase during the DOM - experiment

Figure 2.20: Changes in nutrient concentrations during the DOM -
             experiment



4.5.  Reproduction and life cycles of dominant copepods in the Weddell Sea
      F. Kurbjeweit (AWI)


Objectives

Besides krill (i.e. Euphausia superba) and salps, copepods play the 
most important role as secondary producers in the pelagic System of 
the Antarctic and the Weddell Sea. Several Papers have dealt with the 
distribution and abundance of calanoid copepods in the Antarctic in 
general, but our knowledge about their distribution, abundance, 
reproduction and their life cycles are sparse concerning the Weddell 
Sea. The first aim of this investigation is to examine the 
distribution and abundance of dominant calanoid copepods such as 
Metridia gerlachei, Microcalanus pygmaeus, Stephos longipes, Calanus 
propinquus and Calanoides acutus in space and time in the Weddell Sea 
during spring and summer. Due to the short period of primary 
production in this area, it is of major interest to investigate their 
reproduction Pattern and to obtain if their reproduction is food 
limited quantitatively as well as qualitatively. With additional 
biochemical Parameters and Information about the hydrography it might 
be possible to develop schemes for their life cycles and their role as 
secondary producers in the pelagic System.

Work at sea

During ANT IX/2 on the transect from the Antarctic Peninsula to Atka 
Bay the distribution and abundance of dominant copepods in the upper 
1000m of the water column was examined on 13 stations by means of a 
multinet (100 µm mesh size, 0.25m2 opening area). Samples from five 
depth Strata at each station were preserved in 4% buffered 
formaldehyde for future investigation of Stage distribution of the 
above mentioned copepod species and the examination of gonadal 
development of their females. For the second part of the investigation 
a bongo net (10Opm mesh size; 60cm diameter) was lowered on 10 
stations to 300m for getting undamaged females for reproduction 
experiments. Females from the most abundant copepod species were 
incubated on four stations under in situ conditions in surface water. 
In addition females of C. acutus, M. gerlachei and S. longipes were 
starved in 0.2 pm Nucleopore filtered seawater for up to two weeks. 
Later On, enhancement of reproduction was attempted with high 
concentrations of mixed algae, mainly diatoms and the prymnesiophyte 
Phaeocystis sp.. On two stations respiration of female copepods of S. 
longipes, C. acutus, C. propinquus and M. gerlachei were measured to 
evaluate their metabolic demands. As additional parameters for the 
Interpretation of the reproductive potential of the animals under 
investigation, samples were taken for dry weight, CIN-content, 
digestive enzymes (trypsin and amylase) and lipids, which will be 
examined in the laboratory at home.

Preliminary results

The small copepod species S. longipes was found on merely three 
stations in high numbers, namely on the first station (station 40) on 
the shelf of the Antarctic Peninsula and on the last two stations 
close to the ice shelf in the southeast (Sta. 108, 11 5). M. pygmaeus, 
the other small calanoid copepod of about one millimeter in length, 
was found only on two stations in low numbers (63 and 94), while C. 
acutus and M. gerlachei were abundant on almost all stations. C. 
propinquus was dominant only on stations in the central part of the 
Weddell Gyre. Besides these copepods on almost all stations cyclopoid 
copepods of the genera Oncaea spp. and Oithona spp. were predominant 
in the micro- and smaller meso-zooplankton size classes. However, 
radiolarians were also important on all stations, partly clogging nets 
and acting as a trap for most of the other zooplankton organisms. On 
station 115 in an inlet at the ice shelf juveniles of Pleuragramma 
antarcticum (pers. comm. Kellermann) dominated the haul.

In situ egg production experiments on five stations (63, 87, 94, 108, 
115) carried out for over 24hrs in ambient surface water showed that 
C. acutus, C. propinquus and M. gerlachei produced well in the 
southeastern Weddell Sea close to the ice shelf (Sta. 108 and 115), 
whereas the reproduction of these species decreased with increasing 
distance from it (Figure 1.22). Except on station 63, where none of 
the four incubated copepod species reproduced (M. Iongipes was used 
only here) C. propinquus laid the most eggs followed by C. acutus and 
M. gerlachei (Figure 2.21). The maximum egg production per day of C. 
propinquus was 15.8, of C. acutus 10.1 and for M. gerlachei 7.6, 
respectively. Whether a correlation with chlorophyll concentrations in 
the water column exists, still has to be proved.


Figure 2.21: Intubation of the four dominant copepods Calanus propinquus, 
             Calanoides acutus, Metridia gerlachei and Microcalanus pygmaeus 
             (only on Sta. 63) on a transect from the central part (Sta. 63) 
             of the Weddell Sea to Atka Bay in the southeast (Sta. 115).


Egg production experiments with S. longipes (station 40) under 
starvation in egg separation chambers showed no significant egg 
production within 7 days. After the addition of mixed algae, mainly 
diatoms a) without and b) with Phaeocystis sp., the mortality rate was 
higher in the latter one, but in both incubation series no eggs were 
laid. In contrast, S. longipes was able to produce 2.8 eggs per day 
(sd = ±2.0) in tissue culture vessels of only about 3ml volume for 
three days with Chaetoceros socialis as food source. Its maximum 
clutch size was 8. Furthermore, Microcalanus pygmaeus produced an 
average of 7.5 eggs per day (sd = ±3.0) even without food supply to 
the culture vessels for four days. After that time the mortality rate 
increased dramatically and no eggs were produced anymore. Its maximum 
clutch size was 11.

On two stations, 45 and 48, 16 females of C. acutus were incubated in 
0.2 µm Nucleopore filtered seawater to see for how long they could 
sustain egg production from preconsumed energy reserves. Although 
variability in egg production was high on both stations, the 
cumulative egg production for all females combined for each station 
leveled off after 10 to 11 days (Figure 2.22). The maximum number of 
eggs produced on station 45 and 48 was 1355 and 955, or 253 and 195 as 
maximum numbers for a single female, respectively.


Figure 2.22: Cumulative egg production of pooled females of Calanoides acutus 
             On Sta. 45 (open squares) and 48 (filled squares).

 
The respiration measurements showed that small calanoid copepods such 
as S. longipes respired between 0.065 and 0.081 µI O2 per animal per 
hour, while large animals as C. acutus respired between 0.244 and 
0.456 µI O2 per animal and hour. Respiration of C. propinquus and M. 
gerlachei ranged somewhere in between.

Eggs from all five copepod species under investigation, incubated in 
filtered seawater at 0°C under dim light conditions (5µEm-2s-1) showed 
quite different developments. While eggs of C. acutus needed 8 to 10 
days to reach 50% of the NI population, those of M. gerlachei needed 3 
to 4, and M. pygmaeus only 1 to 2 days. Eggs of C. propinquus from 
several hatches did not develop at all. 



4.6.  Comparative studies on the temperature dependence and kinetics 
      of digestive enzymes in crustaceans
      B. Dittrich (AWI)


Objectives

As mediators between food uptake and metabolic turn-over, enzymes play 
a decisive role in ensuring long-term survival of a species as well as 
of an individual. As highly sensitive proteins their functioning 
depends not only on nutritional factors but also directly on 
environmental conditions. Although a variety of investigations has 
been devoted to nutritional adaptations in zooplankton organisms, few 
studies have been carried out on thermal acclimation of their 
digestive enzymes. Most of the proteases known today show an optimum 
of activity at about 40-50°C Generally, increasing as well as 
decreasing temperatures result in a decrease of activity which is - in 
temperate and tropical species - about zero when approaching the 
freezing point of water and when exceeding 60°C The main interest of 
the present study is focused on the question of how polar species cope 
with these extreme unfavorable conditions that exert a lethal effect 
on all other, not cold-adapted species. The postulation that the 
nutritional adaptability is a function of the metabolic needs is 
obviously valid also for thermal adaptability.

Work at sea

Crustaceans from different systematic groups - decapods, isopods and 
amphipods - as well as pantopods were obtained by means of an Agassiz-
trawl, towed at a depth of 140 - 270 m near King George Island 
(62°35'S, 55°25'W and 62°54'S, 54°24'W) and near Kapp Norvegia 
(71°05'S 11°32'W) After collecting and sorting the animals, a large 
portion was dissected immediately; their midgut glands and gastric 
fluids were deep-frozen at -80°C and will remain stored at this 
temperature until further analyses on temperature dependence and 
kinetics will be carried out at the AWI. After arrival at Cape Town, 
some of the samples were transported on dry-ice to Germany while the 
others remained on board "Polarstern". Several individuals of isopods, 
collected from the Agassiz-trawl off King George Island, were kept 
individually without any food supply in a temperature-controlled 
container at 0°C; a small number of them was prepared after each week 
to obtain information on the resistance to starvation and the 
influence of such unfavorable nutritional conditions On the enzymatic 
equipment and activity.

Preliminary Results

Analysis on midgut glands and digestive fluids in the stomachs of 
crustaceans collected in the course of EPOS 3 in Austral summer 
1988/89, were supplemented by samples from the Skagerrak, the German 
Bight and the coast of Kenya. The results indicate - at least in the 
trypsin-like Protease - characteristic differences in the temperature 
dependence and kinetics, which become obvious especially in the low-
temperature range. Temperature optima of the investigated enzymes do 
not differ significantly from each other and were found at about 40-
50°C. However, the most striking mechanisms of adaptation to permanent 
low temperatures in the predominantly cold-stenothermic Antarctic 
species were found to be (1) the high activity even at temperatures 
near freezing-point which may amount up to 15% of the maximum activity 
at the temperature optimum and (2) the reduction of activation energy 
which was found to be only a third of that in temperate and tropical 
species. Distinct species-specific changes in the enzyme activity 
after application of selected effectors suggest decisive alterations 
in the molecular structure of the enzyme protein. However, further 
detailed analyses on Antarctic species will prove if the results 
characterize a general phenomenon. 



4.7.  32Si applied to marine biology
      M. Baumann, B. Dittrich, F. Kurbjeweit (AWI), L. Lindner (RUU)


Objectives

During EPOS leg 2, pilot experiments had already been carried out to 
underscore the potential of radioactive 32Si. This is a follow-up on 
the previous studies. 32Si is a weak beta emitter (t1/2=174 y) and is 
the parent of radioactive 32P (t1/2=14 d).

Work at sea

Part of the 32Si waste (32Si-silicate in radioactive equilibrium with 
daughter 32P-phosphate contained in filtered sea water) produced in the 
course of the 32Si uptake experiments (c.f. section 3.4 ) was used for 
labeling of a mixed culture of sea algae. This 32Si-32P-labelled culture 
was subsequently used for grazing studies with an amphipod, an isopod 
and a copepod, respectively.

Preliminary results

After 11 days of incubation, the first culture had taken up about one 
third of the available 32P; the uptake of 32Si was considerably less. A 
second culture (the first one with additional, nutrient rich, waste 
water) had after several days of incubation two thirds of the 32P 
incorporated (and seemingly also more 32Si than in case of the first 
culture). The results show again that with an adequate selection of 
the type of culture (preferably of diatoms only) 32Si can be recovered 
from its waste solutions (however, with a lower specific activity). 
The previous EPOS experiments with krill had shown them to be a nearly 
ideal specimen for 32Si studies. Unfortunately, due to the lack of 
krill during this cruise three other animals were tested. Instead we 
used an amphipod, an isopod and a copepod.

Contrary to all expectations, both starved benthic animals were 
happily feeding on (labeled) phytoplankton. Dissection of the animals 
after several days of grazing was followed by radioactive counting of 
the different tissues. The activities measured in the digestive 
systems were low, in contrast to that in the exoskeleton and the 
muscles combined. Only the amphipod produced several greenish slimy 
faecal pellets with considerable activity, much of it 32P but also 32Si.

The copepod (Calanoides acufus, 8 mm) was measured alive at regular 
intervals during the grazing/fasting cycles, counting the Cerenkov 
radiation of 32P taken in. This made it possible to estimate the uptake 
of phytoplankton (on the order of 1% of the available biomass during a 
period of a week). No faecal pellets were observed to be produced.

The earlier hypothesis, given in the above mentioned krill studies, 
that the mechanical and physiological digestive processes of diatoms 
being grazed form a first and possibly important step in the 
remineralization of silicon, seems to find additional support in the 
present observations.




5.  MARINE GEOLOGY

5.1.  Bathymetry 
      U. Goldkamp, J. Monk, S. Vucelic (AWI)

Objectives

During "Polarstern"-cruise ANT V/4 in 1987 a channel-like structure 
was discovered at 65°40'S, 38°45'W by means of Seabeam fansweep 
system. The course of the channel was expected to run from SW to NE; 
accordingly, a rectangular pattern of measurements was planned to 
investigate the extent and the shape of the channel over a larger 
distance. From these data the origin of and significance to 
northeastward bottom water transport will be derived. In addition to 
this area of special interest, the cruise track was used to continue 
charting the Weddell Sea.

Work at sea

Starting November 19th the Hydrosweep system was put in operation and 
worked for more than 9000 profile-kilometers. Due to technical 
problems, no hydrosweep data were recorded from 29 November, 12.00 
until 30 November, 21.30. After leaving the Georg-von-Neumayer-Station 
measurements were continued while passing Maud Rise and heading for 
Cape Town until the end of the leg. After reaching the known position 
of the channel at 65°40'S and 38°45'W and passing the first turning 
points of the survey pattern, the track had to be modified, because 
the ice conditions made it impossible to follow a prescribed course. 
Nevertheless, the width of the channel was recorded in its whole 
extent along the channel axis from east to west which was possible 
because frequently leads were aligned along the channel axis. At the 
eastern part of the survey, large ice floes prohibited following the 
course of the channel. The hydrosweep screen on the bridge allowed 
changes in the course to be made in a way, that the survey of this 
part of the channel was achieved despite the ice cover. The channel 
was surveyed over a total length of 144 kilometers with a track line 
of 500 kilometers.


Figure 2.23: Ships track (heavy line) and axis of the deep sea channel in the 
             northwestern Weddell Sea M219 indicates the location of a 
             current meter mooring and PS stand for minicorer samples.


On the shelf and the continental slope off Kapp Norvegia, several 
hydrosweep profiles could be run in spite of unfavorable ice-
conditions to supplement data in the area east of the Wegener Canyon. 
The route to Atka Bight was used to run a profile parallel to former 
courses. For the passage to Cape Town a course crossing over the 
eastern slope of Maud Rise from south to north was chosen. The online 
constructed isoline-plot showed small cone-like structures in this 
area, even above Maud Rise. During the complete leg, GPS satellites 
could be used for positioning. Offsets, positioning errors and failing 
data were recorded, which were due to changes in position of the 
satellite, inter-satellite constellation and the time free of GPS. 
Offsets and positioning errors were corrected within one day. 
Therefore, post processing resulted in an exact positioning of the 
fansweep profiles and isobaths crossings of Hydrosweep profiles.



5.2.  Sediment distribution 
      M. Weber (AWI)


Objectives

The program can be subdivided in three parts: - a Parasound survey, 
carried out jointly with the bathymetric group, from Bellingshausen to 
the Agulhas Basin. - the investigation of the structure, origin and 
significance of a deep sea channel at 65°40'S, 38°45'W in the 
northwestern Weddell Sea with Hydrosweep and Parasound. - the 
development of a minicorer based on the principle of a multicorer, 
which is fixed under the CTD with a 20 m stainless steel wire, to 
obtain a large number of geological samples in combination with the 
oceanographic station with no need of additional ship time.


Figure 2.24: Minicorer sampling stations during ANT IX/2. Circles stand for 
             geological and triangles for geochemical sampling


Work at sea

Parasound and Hydrosweep surveys were carried out in cooperation with 
the bathymetry group. In addition to the acoustic measurements, two 
sediment samples were taken using the minicorer and also the current 
meter mooring 219 was deployed in the center of the channel to get 
information about the flow velocity (Figure 2.23). This minicorer 
enabled us to take 37 samples from the sediment surface (Figure 2.24, 
Table 2.8), mostly on the transect between Bellingshausen and Kapp 
Norvegia. The use of the minicorer combined with the CTD saved more 
than four days of ship time normally needed for extra geological 
stations.

Preliminary results

Over the length of 144 km (Figure 2.23) the structure occurs at a 
water depth of about 4650 m. The channel depth relative to its 
surroundings increases from 60 m up to 100 m. Most of he channel has 
an asymmetric geometry with a steep and a smooth slope. In the middle 
and eastern part of the studied area it is a rather small meandering 
feature (1 to 3 km wide). In the western part, the channel axis 
straightens and the channel widens to more than 10 km. The quality of 
the surface samples from the minicorer is the same as from the 
multicorer. Further investigations including sedimentological, 
palaeontological and geochemical analysis will be done in the AWI. 


Table 2.8:  Geological sampling during ANT IX/2

Station     AWIGELO     Date     Time     geogr.       geogr.     Water    MIC      MIC     MIC
  Nb.         Nb.                        Latitude    Longitude    depth  Penetra-  Length  stored
Cruise 18/                                                         (m)   tion (m)   (m)     (m)
----------  ---------  --------  -----  -----------  -----------   ----  --------  ------  ------
  042       PS 1952-1  22.11.90  13:40  63°29,92' S  52°08,02' W    924    0,02     0,00    0,00
  044       PS 1953-1  23.11.90  09:33  63°44,59' S  50°55,36' W   2413    0,20     0,20    0,04
  048       PS 1954-1  24.11.90  23:30  64°24,37' S  45°48,21' W   4434    0,28     0,25    0,04
  050       PS 1955-1  25.11.90  22:39  64°49,21' S  42°30,22' W   4684    0,26     0,25    0,25
  053       PS 1956-1  27.11.90  15:07  65°54,32' S  40°15,47' W   4607    0,10     0,01    0,01
  055       PS 1957-1  28.11.90  09:48  65°40,29' S  37°44,63' W   4727    0,12     0,12    0,04
  056       PS 1958-1  28.11.90  20:48  65°11,99' S  39°22,31' W   4757    0,32     0,31    0,04
  057       PS 1959-1  29.11.90  06:38  65°24,71' S  37°54,80' W   4736    0,28     0,25    0,25
  058       PS 1960-1  29.11.90  19:52  65°38,27' S  36°28,42' W   4770    0,24     0,24    0,04
  059       PS 1961-1  30.11.90  02:41  65°43,18' S  35°26,86' W   4777    0,25     0,24    0,04
  061       PS 1962-1  30.11.90  22:34  65°59,51' S  33°24,71' W   4760    0,26     0,25    0,25
  063       PS 1963-1  01.12.90  17:40  66°07,27' S  31°47.09' W   4786    0,25     0,24    0,04
  065       PS 1964-1  02.12.90  06:26  66°16,60' S  30°17,80' W   4800    0,25     0,25    0,04
  067       PS 1965-1  02.12.90  19:46  66°27,98' S  28°45,30' W   4850    0,25     0,25    0,04
  069       PS 1966-1  03.12.90  06:15  66°37,58' S  27°07,48' W   4860    0,25     0,25    0,25
  075       PS 1967-1  05.12.90  10:10  65°57,41' S  30°04,25' W   4847    0,21     0,20    0,04
  079       PS 1968-1  06.12.90  09:31  67°28,70' S  31°06,61' W   4625    0,29     0,25    0,25
  080       PS 1969-1  06.12.90  15:39  67°18,95' S  29°57,50' W   4682    0,25     0,24    0,04
  081       PS 1970-1  06.12.90  22:10  67°08,54' S  28°47,76' W   4815    0,25     0,22    0,04
  082       PS 1971-1  07.12.90  04:46  66°57,20' S  27°36,63' W   4819    0,24     0,23    0,04
  083       PS 1972-1  07.12.90  11:19  66°45,47' S  26°24,15' W   4854    0,18     0,14    0,04
  084       PS 1973-1  07.12.90  17:18  66°53,47' S  25°32,89' W   4841    0,25     0,25    0,04
  086       PS 1974-1  08.12.90  06:59  67°13,33' S  24°08,78' W   4857    0,12     0,11    0,04
  088       PS 1975-1  08.12.90  21:04  67°30,49' S  22°31,29' W   4893    0,27     0,26    0,04
  090       PS 1976-1  09.12.90  09:41  67°50,47' S  20°50,65' W   4919    0,27     0,25    0,25
  092       PS 1977-1  09.12.90  00:40  68°17,06' S  19°20,42' W   4838    0,27     0,25    0,04
  094       PS 1978-1  10.12.90  15:28  68°50,37' S  17°53,60' W   4795    0,10     0,09    0,04
  096       PS 1979-1  11.12.90  04:30  69°22,01' S  16°29,80' W   4735    0,08     0,07    0,04
  098       PS 1980-1  12.12.90  02:29  69°48,23' S  15°14,07' W   4741    0,04     0,00    0,00
  100       PS 1981-1  12.12.90  11:35  70°07,90' S  14°15,21' W   4526    0,26     0,25    0,04
  101       PS 1982-1  12.12.90  19:53  70°18,75' S  13°42,09' W   4366    0,26     0,25    0,04
  102       PS 1983-1  13.12.90  02:16  70°23,27' S  13°32,57' W   2968    0,26     0,25    0,04
  104       PS 1984-1  13.12.90  08:09  70°29,80' S  13°08,31' W   2407    0,26     0,25    0,25
  106       PS 1985-1  13.12.90  16:38  70°47,72' S  12°22,24' W   2074    0,22     0,20    0,04
  108       PS 1986-1  14,12.90  00:25  70°59,39' S  11°50,73' W   1135    0,23     0,21    0,04
  114       PS 1987-1  15.12.90  14:37  71°04,87' S  11°33,72' W    273    0,20     0,19    0,04
  118       PS 1988-1  23.12.90  17:42  54°19,84' S  03°24,10' W   2704    0,17     0,17    0,17



5.3.  Particle flux in the water column
      E. Schöffmann M. Segl (FGB)


Objectives

To quantify the particle flux from the photic layer to the sediment 
and to monitor the seasonality of sediment build-up over several 
years.

Work at sea

At five positions moorings with sediment traps were deployed; two on 
the western and eastern slope (206 and KN4), one in the center of the 
Weddell Sea (208), west of Bouvet Island (B0 1) and in the area of the 
Polar Front (PF 4) (Figure 2.25). Three sediment trap moorings were 
recovered in the western and the central Weddell Sea and at the Polar 
Front (Figure 2.26).

On board, smear slides were prepared from the trap samples. The 
samples were then stored in a cool room at 4°C. Further investigations 
on the sediment trap material including biological, geological and 
isotopic analysis will be carried out at the AWI and at the FGB.

Preliminary results

The sediment traps in the Weddell Sea operated since 20 September 1989 
(mooring 206) and 5 November 1989 (mooring 208), respectively. The 
sample bottles were changed every 15 days in spring and summer and 
every 30 days during the winter. The trap in mooring 206 sampled only 
until May 1990 because of electronic problems. The upper trap in 
mooring 208 worked well, the lower trap did not work at all. The flux 
to the traps showed a maximum during February and March. The traps in 
the Polar Front operated since November 1989. The maximum flux was in 
March. In the upper trap, the cups from the winter months contained 
about 118 to 114 of the material that was collected in the summer 
months. In the lower trap the winter cups were nearly empty. This 
leads to the conclusion that in winter most of the material present in 
the photic zone is reworked in the water column and does not reach the 
sediment.



5.4.  Stable isotopes in the water column 
      E. Schöffmann M. Segl (FGB)


Objectives

Stable oxygen and carbon isotopes are used in marine geology to 
reconstruct the paleoceanographic history by measuring the 18O/16O and 
13C/12C in the shells of marine organisms and the 13C/12C in the organic 
material, and to quantify the influence of bio-activity.

Work at sea

Samples to determine the isotopic composition of the dissolved CO2 
(13C/12C) and of the water itself (18O/16O) were taken from the rosette 
on all biological stations. Samples of 250 ml and 100ml were put into 
glass bottles, avoiding air bubbles in the sample. The 250 ml samples 
for 13C measurements were poisoned with HgCl2 to avoid further CO2 
production. These samples, as well as the 100 ml samples, were then 
sealed with wax and stored in a cool room at 4°C. The isotopic 
composition of the samples will be measured at the stable isotope 
laboratory of the AWI.


Figure 2.25: Schematic representation of the mooring recovered in the Polar 
             Front

Figure 2.26: Schematic representation of moorings deployed in the Polar Front 
             and West of Bouvet Island



5.5.  Natural radioactive isotopes in the water column 
      E. Schöffmann M. Segl (FGB)


Objectives

Investigations on sediment samples from the area off West Africa and 
from the Polar Front show that in areas with high biological activity, 
the flux of radioisotopes such as 10Be and 230Th to the sediments 
increases the production of the isotopes. This is due to scavenging of 
the isotopes by settling particles. This causes a concentration 
gradient of the isotopes from high to less productive areas which 
might allow former biological activity to be deduced.


Work at sea

To quantify these effects, samples for 10Be measurements were taken on 
4 stations of the Weddell Sea transect. The investigations on these 
samples will be linked to investigations on 230Th in the Weddell Sea by 
the geochemistry group of the AWI, and to results of measurements of 
10Be and 230Th in the South Atlantic by the FBG. To get the 30 l of 
water needed for a 10Be analysis, water from different depths within 
the same water layer was combined. A well known amount of 9Be carrier 
was added and Be, together with Mg and other elements, was 
precipitated at a pH of 8 - 9. The water was decanted, and the 
precipitate will be prepared for measurements with the accelerator 
mass spectrometer of the ETH Zürich. Additionally at all the 
minicorer-stations 10Be samples have been taken from the sediment 
surface.




6.  POST INSTALLATION WORK ON THE COMPUTER SYSTEM 
    H. Pfeiffenberger-PertI (AWI)


Objectives

A new central computer system and two local area networks were 
installed aboard "Polarstern" in October 1990. Five VAX-VMS systems of 
different capabilities, configured as a duster, replace one older VAX-
VMS computer. The local area networks, using ethernet and localtalk 
cabling, provide the possibility to connect PCs and Workstations in 
all locations used for scientific purposes to each other, the central 
system and its resources, i.e. printers, plotters, etc. The most 
important objective of the work at sea was to observe this rather 
complex system under real conditions, in order to see - if the 
concepts leading to its hardware and software configuration do work, - 
how the system is utilized by the scientists, how its utility could be 
improved, - which problems are encountered and how to fix them. The 
result of this work should be a users manual for scientists and 
support personnel on board that provides advice on this specific 
installation in the most compact way possible.

Work at sea

The information necessary to meet the objectives was collected while 
giving advice or help to scientific users and support personnel. Some 
programming was necessary to fix problems, support routine operation 
of the system and to meet requests from scientists for access to 
specific data. The documentation most urgently needed was written.

Preliminary results

In general the VAX systems worked as planned. The most important task, 
the quasi-realtime data logging and processing on one of these 
machines, worked without problems. The disc and file services for PCs 
were made available on board in the same way as at the institute. Due 
to a much higher data transfer demand between VAX-, IBM-compatible and 
Macintosh-systems, yet unknown problems appeared. They could be solved 
by a file conversion utility and some documentation giving recipes. 
Observations on the use of publicly available PCs led to the 
conclusion that these will produce more work for the support personnel 
(or less utility to the scientists) than the VAX-systems, if - their 
users are not very disciplined and - they are managed as personal PCs 
Further work has to be done on this problem.




7.  WEATHER CONDITIONS 
    H. Erdmann, H. Köhler, H. Sonnabend (DWD)


At the beginning of the cruise the main cyclonic activity was located 
west of the Antarctic Peninsula. On 17 November, the steering cyclone 
moved slowly eastward with a minimum pressure below 960 hPa. Secondary 
lows passed the Drake Passage quickly and affected "Polarstern" with 
northwesterly winds Bft 8 and seas up to 5 m. South of the Polar 
Frontal Zone, visibility deteriorated due to northerly winds Bft 7. On 
20 November, "Polarstern" reached Bellingshausen Station with 
northwesterly winds Bft 7 and Snow showers. Due to catabatic 
influence, the wind increased up to Bft 9 near the station; in spite 
of the unfavorable weather conditions, helicopter service was 
possible. Due to the permanent influence of the wide-spread and stable 
low-pressure System with minimum pressure still below 960 hPa at the 
southwestern part of Bransfield Strait, wind turned from northwest to 
southeast Bft 5 on 21 November, while "Polarstern" left Bransfield 
Strait heading for the Weddell Sea. Snowfall coming up caused bad 
visibly later on and a decrease of air temperature down to -4°C. In 
the early evening, "Polarstern" approached an area densely covered 
with sea ice. During the following next four days, the ship operated 
within a low pressure area between the steering Weddell Sea cyclone 
and secondary lows in the north and northeast. Therefore, the pressure 
gradient as well as the winds were generally weak. Cold air mass 
advection gave rise to good visibility but was accompanied by some 
snow showers. On 26 and 27 November, the dominant cyclone remained 
stable over the northwestern Part of the Weddell Sea and began to fill 
slowly. Therefore, "Polarstern" was affected by stronger cold air 
advection in the northwestern section accompanied by numerous polar 
cumulonimbus clouds and heavy snow showers.

On 28 November a new gale center developed in the western part of the 
Drake Passage and moved to the South Shetlands. On 29 November its 
frontal systems approached "Polarstern" near 66°S, 37°W while activity 
was decreasing. Therefore, wind turned northeasterly while decreasing 
to Bft 3 to 4. Occasionally occurring snowfall diminished visibility 
until the end of November. At the beginning of December, a flat high 
developed in the central Weddell Sea. Therefore, the wind was light 
and varying, the visibility very good and the clouds dissolved. A 
small-ranged but heavy cyclonic development north of "Polarstern's" 
operating area caused heavy snowfall on 3 December, which was 
accompanied by strong easterly winds up to force Bft 7. Therefore 
helicopter service was not possible on this day. During the night of 4 
December, the cyclone moved south while decreasing and crossed the 
position of "Polarstern" to the west. The wind was backing to the 
north and caused low level warm air advection with rising dew point 
near 0°C. As a consequence, fog persisted for about 4 hours. On the 
same day, another but stronger cyclonic development evolved near South 
Georgia. This new storm center moved quickly southeast; with its rear 
and southerly gales up to force Bft 9 it affected "Polarstern" in the 
central Weddell Sea during 4 December. The maximum wind speed measured 
on board at the marine meteorological station was 55 knots within 
gusts. The chill temperature was -27°C and rendered open air work 
almost impossible. A small wedge within the advanced polar air gave 
rise to better weather conditions on 5 December but caused decreasing 
temperatures with morning minimum temperatures near -8°C. In the 
course of the next 3 days, weather remained fair, sometimes even sunny 
with only light winds generally from west, due to the influence of a 
relatively high pressure center north of. the ship's position. During 
the night hours, ice covering fog patches developed due to heat loss 
and disappeared when sun rose.

In the eastern section of a quasi-stationary but developing low, 
strong warm air advection mainly in the upper troposphere produced 
widespread snowfall also in the operation area of "Polarstern" near 
67°S, 23°W on 9 December. During the next 24 hours, temperatures rose 
to 0°C and wind turned northerly with force up to Bft 7. From 10 to 14 
December, a dynamic high developed above the northern part of the 
Antarctic continent with its center (1004 hPa) near 70°S 05°W. 
Therefore, a strong Inversion near 1000 m-level caused overcast 
stratocumuli with some snow showers and light winds. On 15 December 
"Polarstern" reached Kapp Norvegia in sunshine and light winds 
produced by the still stationary high near Neuschwabenland.

The weather conditions were still good when "Polarstern" was stationed 
at the shelf ice near Georg-von-Neumayer-Station for unloading. In 
spite of overcast sky with a ceiling near 800 feet and occasional 
"whiteout" conditions, helicopter service was not affected. When 
"Polarstern" left for Cape Town on 19 December, the synoptic situation 
changed. The dominant high at Neuschwabenland moved southwest while 
weakening and the low system east of South Georgia moved east. 
Therefore an easterly wind increased up to force Bft 6 accompanied 
with some snowfall and bad visibility.

On 20 December "Polarstern" left the closely packed sea ice near 68°S, 
03°W. On the southern edge of a heavy steering low near 60°S 05°W (958 
hPa), which moved eastsoutheast very slowly, wind increased up to 
force Bft 7 to 8 while turning from east to southeast for some hours. 
Next day wind turned southwest while decreasing slowly. Wind seas and 
swell of about 3 m affected the voyage of "Polarstern" only little. On 
24 December a new low developed northeast of South Georgia moving 
southeast slowly. Its frontal systems affected "Polarstern" on 25 
December north of Bouvet Island with northerly gales Bft 8 to 9 
turning northwest but decreasing slowly. Shortly before arrival in 
Cape Town, light winds, sunshine and warm temperatures were 
encountered.




8.  ICE CONDITIONS 
    H.-J. Brosin, D. Zippel (IfMW)


Visual observations of the ice conditions were performed between 22 
November and 20 December according to instructions given by the 
Glaciological Section of the Alfred-Wegener-Institute. Altogether 236 
observations were realized together with an additional 70 observations 
on the distribution of algae in the ice.

The first iceberg was observed on 20 November at the position 62°12'S, 
57°56'W, the last one on 23 December. The ice edge was crossed at 
63°30'S, 51°30'W 150 km distant from the nearest shoreline on 22 
November. It was passed again at the position 68°S, 04°W on 20 
December. The shelf ice edge was reached for the first time at 
71°07'S, 11°23'W on 15 December.

The portion of white ice amounted to 40 to 100% of the total ice 
cover. The thickness mostly varied between 0.5 and 1.5 m and was 
estimated to be up to 2 m in a few cases. A distinct increase of the 
size of ice floes to a diameter of more than 1 km was observed at the 
position 65°39'S, 39°W, an evident reduction of the floe size occurred 
only close to the end of the observations at 70°25'S 13°25'W. The 
thickness of the snow cover on the ice varied between 20 and 50 cm. 
Marked melting effects at the bottom layers of ice floes were observed 
for the first time at the position 66°22'S, 29°32'W On 2 December. 
Local new ice formation (nilas, grey-white ice) were repeatedly 
observed after a larger decrease in air temperature.

A wide spread occurrence of icebergs was observed particularly at the 
western edge of the working area between 64° and 65°50'S, 49° and 40°W 
(up to 41 icebergs within the field of view) and at the southeastern 
edge from 69°15' to 70°30'S, 16°45' to 10°W (up to 52 icebergs seen 
simultaneously).




9.  ACKNOWLEDGEMENTS

When we left "Polarstern" in Cape Town, we felt that we had had an 
extremely successful cruise and an enjoyable life on board. We are 
aware that master Jonas together with officers and crew took good care 
of our needs with a dedication and patience which guaranteed efficient 
work and good humour.




10.  REFERENCES

Unesco, 1983. International Oceanographic tables. Unesco Technical Papers in 
    Marine Science, No. 44.

Unesco, 1991. Processing of Oceanographic Station Data. Unesco memorgraph
    By JPOTS editorial panel.




11.  WHPO SUMMARY

Several data files are associated with this report. They are the 
ANTIX.sum, ANTIX.hyd, ANTIX.csl and *.wct files. The ANTIX.sum file 
contains a summary of the location, time, type of parameters sampled, 
and other pertinent information regarding each hydrographic station. 
The ANTIX.hyd file contains the bottle data. The *.wct files are the 
ctd data for each station. The *.wct files are zipped into one file 
called ANTIX.wct.zip. The ANTIX.csl file is a listing of ctd and 
calculated values at standard levels.

The following is a description of how the standard levels and 
calculated values were derived for the ANTIX.csl file:
Salinity, Temperature and Pressure: These three values were smoothed 
from the individual CTD files over the N uniformly increasing pressure 
levels. using the following binomial filter-

     t(j) = 0.25ti(j-1) + 0.5ti(j) + 0.25ti(j+1) j=2....N-1

When a pressure level is represented in the *.csl file that is not 
contained within the ctd values, the value was linearly interpolated 
to the desired level after applying the binomial filtering.  
Sigma-theta(SIG-TH:KG/M3), Sigma-2 (SIG-2: KG/M3), and Sigma-4(SIG-4: 
KG/M3): These values are calculated using the practical salinity scale 
(PSS-78) and the international equation of state for seawater (EOS-80) 
as described in the Unesco publication 44 at reference pressures of 
the surface for SIG-TH; 2000 dbars for Sigma-2; and 4000 dbars for 
Sigma-4.

Gradient Potential Temperature (GRD-PT: C/DB 10-3) is calculated as 
the least squares slope between two levels, where the standard level 
is the center of the interval. The interval being the smallest of the 
two differences between the standard level and the two closest values. 
The slope is first determined using CTD temperature and then the 
adiabatic lapse rate is subtracted to obtain the gradient potential 
temperature. Equations and Fortran routines are described in Unesco 
publication 44.

Gradient Salinity (GRD-S: 1/DB 10-3) is calculated as the least 
squares slope between two levels, where the standard level is the 
center of the standard level and the two closes values. Equations and 
Fortran routines are described in Unesco publication 44.
Potential Vorticity (POT-V: 1/ms 10-11) is calculated as the vertical 
component ignoring contributions due to relative vorticity, i.e. 
pv=fN2/g, where f is the coriolius parameter, N is the buoyancy 
frequency (data expressed as radius/sec), and g is the local 
acceleration of gravity. 

Buoyancy Frequency (B-V: cph) is calculated using the adiabatic leveling 
method, Fofonoff (1985) and Millard, Owens and Fofonoff (1990). Equations 
and Fortran routines are described in Unesco publication 44.

Potential Energy (PE: J/M2: 10-5) and Dynamic Height (DYN-HT: M) are 
calculated by integrating from 0 to the level of interest. Equations 
and Fortran routines are described in Unesco publication 44.
Neutral Density (GAMMA-N: KG/M3) is calculated with the program GAMMA-
N (Jackett and McDougall) version 1.3 Nov. 94.  




12.  CTD DATA QUALITY EVALUATION
     Robert Millard
     November 27, 1995


ANTIX: CTD Data Quality Comments

General:

The range of potential temperature for the ANTIX data set is 
narrow (-1.87 to 1.89°C) and salinity varies from 33.92 to 34.72 psu. 
The potential temperature versus salinity plot for all stations is 
shown in figure 1. Removing station 121 reduces temperature/salinity 
range further with the warmest temperature below 0.9°C and the 
minimum salinity increased to 34.1 psu. I found the 2 decibar CTD 
data to be well calibrated to the water sample data and the data was 
also well edited to remove questionable data values.

The informal CTD data documentation (I'm not referring to the Cruise 
report 17 edited by Eberhard Fahrbach) that accompanied the CTD data 
was sketchy and contained little information on processing procedures. 
It would be helpful to have more information on calibration and 
processing methods used with this data set. Perhaps there is a 
technical report available that can be referenced? An overall 
assessment of the quality of the CTD and water sample data, including 
a few plots, would be helpful. There is one figure (2.5) in the cruise 
report (17) comparing the Autosal and CTD salinities. The data 
assessment might have information such as which water sample data were 
used in for the CTD conductivity calibration. A more detailed data 
report along with more extensive use of the quality word to flagged 
data that are either questionable or altered both in the water sample 
file and individual 2 decibar station files would be helpful to 
secondary users of the data.

There are no CTD oxygens in either the water sample or individual 
2 decibar CTD data files. There is no assessment of the oxygen data 
in this report.

The down profile 2 decibar CTD data are free of spurious data values 
as the density inversion check below indicate. The data quality word 
in the 2 decibar CTD data files is not always utilized. For example, 
an interpolation on station 50 for salinity is carried out between 
4000 & 4500 decibars without flagging in the quality word. The CTD 
salinity observations are very well matched to the water sample data 
except as noted below. The CTD salinity in the water sample file 
differs from the down-profile salinity data and water sample 
salinities for many stations, particularly in the deep water.


Specific comments on the CTD data processing documentation:

Note: This is a separate document from the formal cruise Report 17 
      (July 1991) edited by Eberhard Fahrbach.

The CTD conductivity calibration is varied on a station by station 
basis to matched the individual station water sample data. The 
conductivity calibration coefficients are smoothed over 10 stations 
without explanation. The correction of the CTD conductivity to match 
the water samples involves up to a fourth order polynomial in 
pressure. The coefficients of the conductivity correction polynomial 
are tabulated in the data documentation. I don't understand why it was 
necessary to use such a high order polynomial in pressure to obtain 
well calibrated CTD salinities. Are all of the pressure correction 
terms of these polynomials significant? Was the CTD conductivity cell 
geometry correction applied (see the formula below)? Were these 
corrections used and found not to work well? Again, more detailed in 
the data report would be useful.

CTD Conductivity Cell geometry corrections as recommended by the 
manufacture. Were these applied to this data set along with a fourth 
order polynomial in pressure??

The CTD conductivity cell pressure and temperature deformation 
effects for the Mark III with an alumina conductivity cell are:

C = G* (1+alpha* (T-T0) +beta* (P-P0))

where

G     = CTD conductance 
alpha = -6.5E-6 
beta  =  1.5E-8

T0 and P0 are expansion values. 2.8°C and 3000 dbars typically.

We find that the conductance G drift can be modeled with a linear 
station dependent change conductivity slope variation (not always 
necessary)

 G  = A+ B*g+C*g*s
"g" = is the observed CTD conductance and "s" is station related.
 A  = bias, B = slope and C = station dependent term.

I found the data report description of the terms in the formula (see 
below) to be confusing. The conductivity correction term is referred 
to as both "CD and "dc'). What is the definition of CONDUCTIVITY 
SALINO: Is it the conductivity of the lab salinometer or is it an 
"instu conductivity derived from the water sample salinity by using 
the CTD temperature and pressure? 

------------------- from informal CTD document ------------------

The following is taken from the ANTIX data report section that I found 
to be confusing as indicated by (????).

    dp = al +a2*p +a3*p**2 +a4*p**3 +a5*p**4 +a6*p**5
    p  = p + dp???? : This implies that dp = 0.0. (i.e. p-p=dp=0.0.)
	
The same is true for t-t+dt ????.

I think these corrections were meant to be p = pu + dp; where Pu 
is the uncorrected pressure.

correction of the CTD-conductivity data with the bottle-samples 
(conductivity of the salinometer data)
evaluation of the coefficients of each station

-------------------------------------------------
CD = ( CONDUCTIVITY SALINO ???? - CONDUCTIVITY CTD ) * 1000
COND :== CONDUCTIVITY SALINOMETER
-------------------------------------------------
CD = A0 + A1*COND + A2*PRES + A3*PRES**2
-------------------------------------------------
    station
      no.          A0            Al             A2          A3

     03501    -0.51872E±02  0.24728E±01  -0.63940E-02  0.79995E-05


dc     = A0 + A1*COND + A2*PRES + A3*PRES**2
C(ctd) = C(ctd) + dc/1000.

correction of the CTD-conductivity data with the bottle-samples

evaluation of the coefficients with the running mean of 10 
stations

-------------------------------------------------
CD = A0 + A1*PRES + A2*PRES**2 + A3*PRES**3 + A4*PRES**4


Water sample file:

The CTD salinity data in the water sample file is compared to the 
water sample salinities (CTD minus WS) and displayed versus station 
number for all depth levels in figure 2a and for those below 900 
decibars in figure 2b. Individual stations such as stations 46, 47, 
69, 75, 76, and 93 show large differences but a closer examination 
indicates that the problem is with the water sample data as the 
potential temperature/salinity plot shown in figure 3 for stations 
68-78 indicates. It is difficult to know which water sample data were 
used for the CTD calibration as all water sample salinity data (i.e. 
column labeled "SALNTY" are flagged with "3" indicating that they are 
considered questionable). A histogram of the salinity differences 
(CTD-WS) less than =/- 0.01 psu is given in figure 4 and appears to 
have a reasonable distribution. The mean difference is -0.0005 psu and 
the standard deviation is 0.0028 psu both again appear reasonable. The 
plot of salinity differences (CTD-WS) versus pressure, figure 5, shows 
a slightly odd behavior at and below 3000 dbars. A clustering of 
positive salt differences, mainly below 4000 dbars, is apparent. The 
down-profile CTD salinities show no corresponding systematic behavior 
indicating perhaps that the polynomial pressure correction for 
conductivity was developed for the down-profile (should be addressed 
in the data documentation) and doesn't necessarily work well for the 
up-profile salinity data. These CTD salinities in the water sample 
file should be flagged as questionable.

2-decibar CTD profiles (___.WCT)

The down-profile CTD salinities are well matched to the water sample 
salinities but this does not always carry over to the up-profile CTD 
salinities in the water sample file particularly in the deep waters 
(as mentioned already). A plot of down and up CTD and water sample 
salinities for stations 57-60 again illustrated the up salinity 
mismatch in figure 6 (circles are CTD salinity from WS file). These 
CTD salinities need to be flagged as questionable or bad (they are 
currently marked as good!!!). There are a number of salinity 
interpolations apparent in the 2 decibar data files. I found that 
stations 50, 58, 59, 64, and 74 had significant intervals in the deep 
water that appear to be interpolated (see figures 7a-d). There are 
probably others that I have missed. These need to flagged in the 
quality word (value =6) as described in the WHP Office Report 90-1 
[see page 55]

Finally the stability of all data points were checked and a plot of 
unstable levels in excess of -.001 kg/m3/dbar (x) and -0.0015 kg/m3 
per decibar (*) are indicated in figure 8. Note that in the table 
below the units of density gradient are given as kg/m3 per 2 decibars 
corresponding to the vertical pressure interval. A list of the 47 
point with negative density gradients exceeding -.002 kg/m3 per 2 
decibars are given below. The data set is remarkably free of density 
inversions as only 3 levels exceeding -0.003 kg/m3 per 2 decibar. This 
is due, in part, to the narrow range of salinity and temperature 
variations in the vertical. The station numbers in the table includes 
a decimal location within the station.


   dsg/dp > -.002 kg/m3 per 2 decibar
    
   dsg/dp           station #      Prs dbars

-4.1938465e-003  4.0111765e+001  5.9400000e+002
-3.8449577e-003  4.0140000e+001  7.3800000e+002
-2.2512519e-003  4.0143137e+001  7.5400000e+002
-2.0012428e-003  4.0152549e+001  8.0200000e+002
-2.2761947e-003  4.1328627e+001  1.6900000e+003
-2.2156429e-003  4.2094510e+001  5.0800000e+002
-2.0093994e-003  4.2159608e+001  8.4000000e+002
-2.0330352e-003  4.2175686e+001  9.2200000e+002
-2.0348226e-003  4.2204314e+001  1.0680000e+003
-2.0110160e-003  4.3222353e+001  1.1720000e+003
-2.0117508e-003  4.4061961e+001  3.5000000e+002
-2.0152598e-003  4.4666667e+001  3.4340000e+003
-2.0399616e-003  4.5290980e+001  1.5120000e+003
-2.0422801e-003  4.6274118e+001  1.4220000e+003
-2.4128358e-003  5.0011765e+001  1.0200000e+002
-3.1532004e-003  5.0012157e+001  1.0400000e+002
-2.9423388e-003  5.0014118e+001  1.1400000e+002
-2.0102297e-003  5.0050588e+001  3.0000000e+002
-2.1142905e-003  5.0091765e+001  5.1000000e+002
-2.0107781e-003  5.4066275e+001  3.7800000e+002
-2.0113735e-003  5.4103529e+001  5.6800000e+002
-2.0107581e-003  5.5083137e+001  4.6600000e+002
-2.0106812e-003  5.7069020e+001  3.9800000e+002
-2.0123969e-003  6.1210196e+001  1.1340000e+003
-2.1120462e-003  6.6076863e+001  4.5600000e+002
-2.0108038e-003  6.6121569e+001  6.8400000e+002
-2.9807854e-003  6.7989804e+001  1.4000000e+001
-2.0106718e-003  6.8101176e+001  5.8400000e+002
-2.7478252e-003  6.9962745e+001  4.9900000e+003
-2.0130675e-003  7.1242745e+001  1.3120000e+003
-2.4672703e-003  7.4006667e+001  1.1400000e+002
-2.3746039e-003  7.4009804e+001  1.3000000e+002
-2.5816618e-003  7.5010196e+001  1.3400000e+002
-2.6604134e-003  7.5014902e+001  1.5800000e+002
-2.0106403e-003  7.5127843e+001  7.3400000e+002
-2.8358944e-003  7.9002353e+001  1.1200000e+002
-2.1278849e-003  8.1022353e+001  2.2000000e+002
-2.0105649e-003  8.2118824e+001  7.1400000e+002
-2.7795357e-003  8.4012157e+001  1.7400000e+002
-2.0654205e-003  9.1005882e+001  1.5400000e+002
-2.1225245e-003  9.2053725e+001  3.9800000e+002
-2.0096993e-003  9.2153725e+001  9.0800000e+002
-2.0536578e-003  9.3014510e+001  2.0200000e+002
-2.0068535e-003  9.3068235e+001  4.7600000e+002
-2.0090439e-003  9.3144706e+001  8.6600000e+002
-2.0314412e-003  9.4152941e+001  9.1000000e+002
-2.0321519e-003  9.4164314e+001  9.6800000e+002
-2.0107911e-003  9.7218039e+001  1.2480000e+003
-3.8238614e-003  9.9976078e+001  8.0000000e+000
-2.0341040e-003  1.0017843e+002  1.0420000e+003
-2.0276837e-003  1.0111961e+002  7.5400000e+002
    
   dsg/dp > -.0015 kg/m3/dbar
    
   dsg/dp  station #  Prs dbars

-4.1938465e-003  4.0111765e+001  5.9400000e+002
-3.8449577e-003  4.0140000e+001  7.3800000e+002
-3.1532004e-003  5.0012157e+001  1.0400000e+002
-3.8238614e-003  9.9976078e+001  8.0000000e+000




13.  CCHDO DATA PROCESSING NOTES

Date        Person     Data Type     Action          Summary
----------  ---------  ------------  --------------  ----------------------------------
1999-03-15  Diggs, S.  He/Tr/Ne      Submitted       not yet merged w/ btl data
            SR04 (06AQANTIX_2): we now have unmerged Helium, Neon and Tritium data 
            for this repeat.

2001-05-30  Uribe, K.  BTL           Website Update  Exchange file online 
            Bottle has been put into exchange format. There was a station/cast 
            number 121 not included in the bottle file which was removed from the 
            sumfile in order to put the data into exchange. Bottle and sumfile 
            links on website remain the same new exchange file has been added to 
            website.

2001-12-12  Uribe, K.  CTD           Website Update  Exchange file online 
            CTD has been converted to exchange using the new code and put online.
 
2012-08-15  Barna, A.  He/Tr         Website Update  Available under 'Files as received' 
            File Ant9_2.woc containing Helium and Tritium data, submitted by Dr. 
            Birgit Klein via email on 1999-03-12, available under 'Files as 
            received', unprocessed by CCHDO.

2013-07-10  Berys, C.  HE-TRIT       Website Update  Exchange, NetCDF, WOCE files online 
            ===========================================================
            06AQANTIX_2 processing - BTL/merge - HELIUM, TRITUM, DELHE3
            ===========================================================

            2013-07-10

            C Berys

            .. contents:: :depth: 2

            Submission
            ==========

            ========== ============ ========== ========= ====
            filename   submitted by date       data type id  
            ========== ============ ========== ========= ====
            Ant9_2.woc Birgit Klein 1999-03-12 He/Tr     None
            ========== ============ ========== ========= ====
            
            Parameters
            ----------
            
            Ant9_2.woc
            ~~~~~~~~~~
            
            - CTDPRS
            - CTDTMP
            - CTDSAL [1]_
            - SALNTY [1]_
            - OXYGEN [1]_
            - SILCAT [1]_
            - NITRAT [1]_
            - NITRIT [1]_
            - PHSPHT [1]_
            - TRITUM [1]_
            - HELIUM [1]_
            - DELHE3 [1]_
            - NEON [1]_
            - NEONER
            - HELIER
            - TRITER
            - DELHER
            
            .. [1] parameter has quality flag column
            
            Process
            =======
            
            Changes
            -------
            
            Ant9_2.woc
            ~~~~~~~~~~

            - converted to WHP Exchange format 
            - TRITIUM changed to TRITUM 
            - DELHE3 and DELHER units changed from % to PERCNT
            
            Merge
            -----
            
            Ant9_2.woc
            ~~~~~~~~~~
            
            Merged Ant9_2.woc into sr04_b_hy1.csv using hydro 0.8.0-10-ge326027

            :New parameters: HELIUM, HELIUM_FLAG_W, NEON, NEON_FLAG_W, NEONER, 
            TRITER, HELIER, TRITUM, TRITUM_FLAG_W, DELHER, DELHE3, DELHE3_FLAG_W

            All comment lines from original file copied back in following merge. 
            sr04_b_hy1.csv opened in JOA with no apparent problems.

            Conversion
            ----------
            
            ================= ======================== =======================
            file              converted from           software               
            ================= ======================== =======================
            he-trit_hy1.csv   Ant9_2.woc, sr04_bsu.txt hydro 0.8.0-10-ge326027
            sr04_b_nc_hyd.zip sr04_b_hy1.csv           hydro 0.8.0-10-ge326027
            sr04_bhy.txt      sr04_b_hy1.csv           hydro 0.8.0-10-ge326027
            ================= ======================== =======================

            All converted files opened in JOA with no apparent problems.
            
            Directories
            ===========
            :working directory:
              /data/repeat/southern/sr04/sr04_b/original/2013.07.10_HE-TRIT_CBG
            :cruise directory:
              /data/repeat/southern/sr04/sr04_b
            
            Updated Files Manifest
            ======================
            - sr04_bhy.txt
            - sr04_b_nc_hyd.zip
            - sr04_b_hy1.csv

2013-07-12  Berys, C.  CTDTMP-UNITS  Website Update  Corrected Exchange, netCDF and 
                                                     WOCE files online 
            ======================
            06AQANTIX_2 processing
            ======================
            
            2013-07-12
            
            C Berys
            
            .. contents:: :depth: 2
            
            Process
            =======
            
            Changes
            -------
            
            - CTDTMP units changed from 'ITS-90' to 'IPTS-68' 
            
            Conversion
            ----------
            
            ================= ============== =======================
            file              converted from software               
            ================= ============== =======================
            sr04_b_nc_hyd.zip sr04_b_hy1.csv hydro 0.8.0-10-ge326027
            ================= ============== =======================
            
            All converted files opened in JOA with no apparent problems.
            
            Directories
            ===========
            :working directory:
              /data/repeat/southern/sr04/sr04_b/original/2013.07.12_CTDTMP-UNITS_CBG
            :cruise directory:
              /data/repeat/southern/sr04/sr04_b
            
            Updated Files Manifest
            ======================
            - sr04_bhy.txt
            - sr04_b_nc_hyd.zip
            - sr04_b_hy1.csv

2013-10-23  Kappa, J.   CrsRpt       Website Update  Updated TXT version online
            I have added a new version of the cruise report:
              sr04_bdo.txt
            to the directory
              http://cchdo.ucsd.edu/data/repeat/southern/sr04/sr04_b/
            Updates include 
            • CTD data report, 
            • CTD DQE report by Robert Millard
            • CCHDO Summary Page 
            • Data Processing Notes.
 
