Lynne Talley, 1997
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Reading and study questions
2. Indian Ocean subtropical circulation. Agulhas is western boundary current, Leeuwin is eastern boundary current and flows poleward, which is opposite from the equatorward flow of eastern boundary currents in the other oceans.
3. South Atlantic Ocean subtropical circulation. Brazil Current is western boundary current, Benguela is eastern boundary current. Agulhas eddies carrying water from Agulhas into South Atlantic.
4. Antarctic Circumpolar Current (ACC) and southernmost regions. Fronts of the ACC: subantarctic front (marked by low salinity intermediate water found to its north), polar front (marked by temperature minimum layer near surface to its south), continental water boundary. Malvinas or Falkland Current as a partial western boundary current in the South Atlantic - part of the subantarctic front. Subpolar circulations (cyclonic) to the south of the ACC - most pronounced in Weddell Sea and Ross Sea.
5. Water masses of the southern hemisphere. Central water (thermocline) as in northern hemisphere. Antarctic Intermediate Water (vertical salinity minimum) formed west and east of southern South America. Circumpolar Deep Water (high salinity core of the ACC, obtaining high salinity from inflow of North Atlantic Deep Water, and freshening due to input from Pacific and Indian Deep Waters). Antarctic Bottom Water or Weddell Sea Deep Water (cold near-bottom water with significant input due to ice formation on southern shelves). Global salinity and deep temperature distributions on various isopycnals.
6. Global overturning diagram from Schmitz, including both the North Atlantic and Antarctic deep water sources.
7. Global meridional heat transport estimates across subtropical latitudes (about 25 to 30 degrees latitude). Distribution of heat transport as a function of depth showing the gross aspects of the overturning cells in each ocean. Northward direction of heat transport in the South Atlantic, in contrast with poleward heat transport in all other basins, due to location of northern hemisphere overturning (North Atlantic only, not North Pacific).
The data were described in previous lectures.
along a meridional section at approximately 150W.
Data were collected in 1984 (north of Hawaii), and in 1991 between 38S and Hawaii, and in 1992 south of 38S. The 1991 and 1992 portions were collected as part of WOCE. A reference for the 1984 portion is:
Talley, L.D., T.M. Joyce and R. A. deSzoeke, 1991. Transpacific sections at 47N and 152W: distribution of properties. Deep-Sea Res., 38 (Suppl), S63-S82.
The data were collected in 1994-1995 as part of WOCE. They are proprietary and there are as yet no references.