Marine Ecosystems Research Department - jamstec japan agency ...

Japan Marine Science and Technology Center
Ocean Observation and Research Department
0
ExcessCO2 [UMOL/KG]
70
DEPTH [M]
DEPTH [M]
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20N 25N 30N 35N 40N
CFC-11 [PMOL/KG]
20N 25N 30N 35N 40N
Ocean Data View Ocean Data View
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50N
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Ocean Data View
10N
130E 150E 170E
Fig.15 Distribution of the anthropogenic CO 2 and CFC-11 along 155E in 2003.
CFC- along E line.
(b) We measured nutrients and dissolved oxygen gas
concentrations in seawater during the JARE
Antarctic voyage abroad the R/V Tangaroa in
February . Samples for measurement of some
biogenic dissolved gases in seawater were also collected.
Methane concentrations and stable carbon isotopes
collected during the JARE Antarctic voyage in
were also analyzed.
Distributions of dissolved methane, silicate and
dimethyl sulfide (DMS) concentrations along E
in are shown Fig.-, - and -, respectively.
High concentrations of methane were found on
the continental slope. This distribution is similar to
that of silicate. The water mass with high methane
concentration might be related to surface or shelf
water. The stable carbon isotope ratio of methane suggests
that the methane was not decomposed yet.
Higher DMS concentrations were found around
S in February , which were observed also in
the R/V Hakuho-Maru cruise conducted in January.
However, ratios between DMS, dissolved DMSP and
DIMSP were not same between the cruises. Changes
of the ratios are important to make clear the role of
phyto- and zooplankton for the formation of DMS in
surface seawater.
16-1
Depth [m]
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Depth [m]
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Depth [m]
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CH4 [nmol/kg]
64˚S 62˚S 60˚S 58˚S 56˚S 54˚S
Si [µmol/kg]
66˚S 64˚S 62˚S 60˚S 58˚S 56˚S 54˚S
DMS [nmol/1]
66˚S 64˚S 62˚S 60˚S 58˚S 56˚S
Fig.16 Antarctic Sea during JARE43 observation in 2002.
16-1 Distribution of Methane along 140E.
16-2 Distribution of SiO 2 along 140E.
16-3 Distribution of DMS along 140E.
Ocean Data View
Ocean Data View
Ocean Data View
4.5
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12.5
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7.5
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43