Report of Activities on the RVIB N.B.
Palmer Cruise 02-04
The third day (10 August) of the
convoy transit by the N.B. Palmer and
the L.M. Gould from
Just after noon the Gould called
to express concern about the speed at which we were moving toward Station 77
and to raise the possibility that they take up residency to the east of our
position at that time (approximately at station 60). A review of the most recent ice images revealed
that the open ocean and ice edge had moved
considerably east relative to where it was when we left
During the night of 9/10 August,
the air temperature dropped to -10ºC, warmed during the day to around -6.4ºC,
and then dropped back down in the evening to -9.0ºC. Winds were light at about
7-8 kts out of the north (349) in the morning,
shifted to about 8 kts out of the southwest (223) by
mid-afternoon, and were stronger in the evening, 20-22 kts
out of the southwest (233). This change was reflected in the barometric pressure
that was at 979.9 mb in the morning, 977.8 mb in mid-afternoon, but 981.0 mb
and rising in the evening. The skies
were mostly cloudy during the day, but quite variable. In the morning, it was very cloudy with the
sea ice merging seamlessly with the gray sky so that the horizon was not discernable. There were some snow flurries and light freezing
rain and then it cleared and off in the distance there were patches of blue
sky. On occasion the sun was like a spotlight shining on icebergs in the distance
turning them to a brilliant white against a dark background. Beautiful!
CTD Group report (Eileen
Hofmann, Baris Salihoglu,
Bob Beardsley, Chris MacKay,
Francisco (
While stopped for predator
sampling on 9 August during the transit to the first process station, we were
able to do one CTD/CMiPS cast at a location that is
approximately between survey stations 20 and 21 (-67º 11.32′S; 70º 33.09′W). This station provided the first real test of CMiPS, which is used for microstructure sampling. The next CTD/CMiPS
cast was done on 11 August after situating the Gould at the first process site.
This station is approximately at the
location of survey station 75. (The time
between the two casts was occupied with XBT surveying as described in previous
reports.) Depths at the two stations
were about 500 m and 420 m, respectively.
Both CTD/CMiPS casts were to within 8-10 m of
the bottom.
The vertical property
distributions from the two stations were quite similar in spite of the large
spatial separation (about 180 km) between the two sites. Maximum temperature at the bottom of both
casts was 1.3ºC with a salinity of 34.6.
These values are indicative of modified Circumpolar Deep Water, which
covers the west
At both stations, the surface
waters were at the freezing point and the Winter Water layer covered the upper
80 m to 100 m of the water column. This
hydrographic structure is typical for winter conditions on the west
During the transit, the discrete
dissolved oxygen samples taken from the Niskin
bottles on the Rosette from the
Phytoplankton Ecology /
Primary Production (Kari
Sines and Frank Stewart)
Primary production in the SO
GLOBEC IV grid during NBP02-04 is being measured using two principle
methods. First, net daily production is being
estimated by carbon uptake during 24 hour “simulated in situ” (SIS) deck incubations.
Water for these experiments is being collected once per day from the CTD
rosette, at the station most prior to sunrise, at depths of zero to thirty
meters. Secondly, water column profiles
are being generated using a Fast Repetition Rate Fluorometer
(FRRF) as part of the CTD package, at all stations where the depth is less than
500 meters. Chlorophyll measurements and
particulate carbon sampling are also being completed for estimation of
phytoplankton biomass.
During the first week of SO
GLOBEC IV, the primary production group completed one SIS experiment at station
4 of the
Sea Birds (Chris Ribic and Erik Chapman)
Sea Bird and seal observations
were conducted on 10 August during almost 8 hours of survey time as the ship
traveled toward station 77, across the southern edge of the mouth of
We are also collecting data on
marine mammals observed during surveys and 42 Crabeater Seals were recorded in
today's transect. These numbers agree
with results from previous cruises that suggest Crabeater Seals are
consistently found in relatively large numbers in the Southern portion of
A summary of the birds and marine
mammals observed on 10 August (YD 222) during 7 hours, 45 minutes of survey
time as the ship traveled south toward station 77 is the following:
Species (common
name) |
Species (scientific
name) |
Number observed |
Snow Petrel |
Pagodroma nivea |
11 |
Adélie Penguin |
Pygoscelis adeliae |
7 |
Southern Giant Petrel |
Macronectes giganteus |
4 |
Emperor Penguin |
Aptenodytes forsteri |
4 |
Crabeater Seal |
Lobodon carcinophagus |
42 |
Marine Mammal report (
Effort began on 10 August at 0830
and finished at 1620. During this period there were only 2 “effort” hours, the
rest were incidental hours. Effort was mainly interrupted due to weather
conditions. The day had extremely variable weather, from partially cloudy (40%,
when it was possible to see and admire
Current Position and
Conditions
Finally we have reached the end
point of the convoy and the Gould is situated at a location near grid station
77. The Palmer has begun the survey
of the southern sector of the SO GLOBEC station grid. Our current position at 2355 on 10 August is -68º
08.672′S; -75º 25.442′W. The ice pack is variable with mostly 10/10
coverage, except along the outer continental shelf. The air temperature is -11.5ºC and the sea temperature
is -1.851ºC. The barometer (982.6 mb) is rising slowly. Winds are out of the west (269) at about 10-15
kt. The skies are cloudy.
Cheers, Peter