Oceanography of Antarctic Waters
- Joseph L. Reid
Published Online: 21 MAR 2013
Copyright © 1971 by the American Geophysical Union.
Antarctic Oceanology I
How to Cite
Gordon, A. L. (1971) Oceanography of Antarctic Waters, in Antarctic Oceanology I (ed J. L. Reid), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR015p0169
- Published Online: 21 MAR 2013
- Published Print: 1 JAN 1971
Print ISBN: 9780875901152
Online ISBN: 9781118664438
- Antarctic bottom water production;
- Deep water meridional transport;
- Ekman surface divergence;
- Oceanography and water masses;
- Oxygen saturation and paleoceanography;
- Ross sea shelf water and supercooled water;
- Time variation of water structure;
- World ocean meridional transport
The physical oceanography for the southwest Atlantic and Pacific sectors of antarctic waters is investigated with particular reference to the water structure and meridional circulation. The cyclonic gyres of the Weddell Sea and area to the north and northeast of the Ross Sea are regions of intense deep water upwelling. Water at 400 meters within these gyres occurs at depths below 2000 meters before entering the gyral circulation. The northern boundary for the Weddell gyre is the Weddell-Scotia Confluence, and that for the gyre near the Ross Sea is the secondary polar front zone.
The major region for production of Antarctic Bottom Water is the Weddell Sea, whereas minor sources are found in the Ross Sea region and perhaps in the Indian Ocean sector in the vicinity of the Amery Ice Shelf. The Ross Sea Shelf Water contains, in part, water related to a freezing process at the base of the Ross Ice Shelf. The mechanism may be of local importance in bottom water production.
The salt balance within the Antarctic Surface Water indicates approximately 60×106 m3/sec of deep water upwells into the surface layer during the summer. This value is also found from Ekman divergence calculation. In winter, only one half of this value remains with the surface water; the other half sinks in the production of bottom water. An equal part of deep water is entrained by the sinking water, making the total southward migration of deep water 108 m3/sec during the winter. On averaging over a period of a year, it is found that the deep water meridional transport is approximately 77×106 m3/sec. The ratio of zonal to meridional transport is, therefore, between 3:1 to 2:l.
The recirculation of water between the antarctic water masses and Circumpolar Deep Water is large. The volume of water introduced by the inflow of North Atlantic Deep Water is only a fraction of the recirculation transport but is essential in that its high salinity maintains the steady state salinity condition of antarctic waters.