Antarctic Oceanography

Antarctic Water Masses
2. Circumpolar Deep Water (CDW)
– 1.5° to 2.5°C near surface, 0° to 0.5°C near bottom;
salinity ~34.7 ppt
– All around continent from just below surface to 4000
m deep
– Fairly uniform T-S properties around continent
– Source is North Atlantic Deep Water (NADW)
– Also called Warm Deep Water (esp. in Weddell
Sea) and Antarctic Circumpolar Water
Antarctic Water Masses
3. Antarctic Bottom Water (AABW)
– Formed in Weddell and Ross Seas
– Mixture of shelf and CDW
– Flows down slope into south Atlantic as
bottom water below 4000 m (also into
Pacific and Indian)
– Traced to 40°N in Atlantic, 50°N in Pacific
Antarctic Water Masses
4. Antarctic Intermediate Water (AAIW)
– 2-4°C, 34.2 ppt
– Formed by AASW sinking at APF
– Flows northward across equator at 800-
1000 m deep (traced by high oxygen and
salinity minimum)
Spread of
AAIW
Blue numbers indicate
depth of layer (m)
Black numbers indicate
salinity (ppt)
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