Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Ocean Observation and Research Department
(a)
(b)
Sea ice concentration
on September 25
Climatology
Siberia
Sea ice concentration
on September 25
2002
Bering
Sea
Greenland
Alaska
Land
Coast
No Data
Weather
Ocean
16-21 %
22-28 %
29-35 %
36-42 %
43-49 %
50-56 %
57-63 %
64-70 %
71-77 %
78-84 %
85-91 %
92-98 %
99+ %
Land
Coast
No Data
Weather
Ocean
16-21 %
22-28 %
29-35 %
36-42 %
43-49 %
50-56 %
57-63 %
64-70 %
71-77 %
78-84 %
85-91 %
92-98 %
99+ %
Fig. 9 Distributions of sea ice concentration on September
25. (a) Climatology, (b) 2002
Arctic Ocean plays an important role in the Arctic climate
system. Therefore, we should understand the
mechanism of the Arctic climate system and the role
of the Arctic Ocean. In the Pacific side of the Arctic
Ocean, we initiated the Canada-Japan Joint observational
project, named JWACS (Joint Western Arctic
Climate Studies), from this year. In addition, we have
been conducting drifting buoy observations in collaboration
with NPEO (North Pole Environmental
Observatory) Project in the Atlantic side of the Arctic
Ocean. We could observe the oceanographic condition
which might affect sea ice condition not only in this
area but also in the downstream area. In this annual
report, we will present results of these two observational
activities in .
Figure shows the CTD and XCTD stations that
were conducted by the JWACS project in . The
observation was carried out by multi-ship operation
Latitude
82
80
78
76
74
72
70
68
66
JWACS 2002 Hydrographic Stations
JWACS 2002:
Louis S. St-Laurent
Sir Wilfrid Laurier (July)
Sir Wilfrid Laurier (September)
R/V Mirai
US/SBI
US/Chukchi
Borderland
-180 -170 -160 -150 -140 -130 -120
Longitude
Fig.10 CTD and XCTD station conducted in the JWACS 2002
observation
using R/V Mirai, CCGS Louis S. St-Laurent and
CCGS Sir Wilfrid Laurier. Also, this was the first
basin-wide observation in the western Arctic Ocean.
We distributed JWACS hydrographic station so
as to cover the spreading pathway of Pacific and
Atlantic water in the western Arctic Ocean.
Figure shows sea ice concentration on September
in climatology and in . The sea ice in the
Arctic Ocean reached record lows in September .
The pattern of the sea ice reduction is not uniform.
Reduction in the north of Bering Strait is the most
remarkable. One mass of temperature maximum water
that originated in the Pacific Ocean enters the western
Arctic Ocean via the Barrow Canyon. It is identified
with temperature maximum water with range of salinity
- psu. This water is termed "Pacific Summer
Water (PSW)". The geographical pattern of sea ice
extent would be associated with the distribution of
PSW. We focus on the influence of PSW on the sea
ice reduction in the western Arctic Ocean.
Figure shows the horizontal distribution of the
potential temperature on salinity . psu. The temperature
distribution clearly shows the existence of
two warm regions. One is near the Barrow Canyon.
The temperature near the Barrow Canyon was higher
than C. It is a new PSW that enters the western
Arctic Ocean in this summer. The other is found over
the Northwind Ridge. It is much colder than that near
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