Review of Antarctic Ocean Oceanography 



The Antarctic or Southern Ocean is unique in that it encircles a 

 continent, Antarctica; it provides about 22% of the area of the world 

 oceans, and its oceanographic characteristics are extremely uniform. 

 Since the 1920s, the Southern Ocean has received the attention of 

 oceanographers from many nations, and since the International Geo- 

 physical Year (1957-1958) studies of all aspects of the Antarctic 

 Ocean have been intensified. Many detailed and specific works are 

 available on the oceanographic and dynamic features of the Southern 

 Ocean ; more comprehensive accounts, upon which the following sum- 

 mary is based, include the studies of Deacon (1933, 1937, 1937a, 1963), 

 Sverdrup et al. (1942), Kort (1962), Pickard (1963), and Brodie 

 (1965). 



Water Masses 



The Antarctic Ocean is bounded in the south geographically by the 

 Antarctic Continent, and in the north oceanographically by the Sub- 

 tropical Convergence. The Southern Ocean comprises two major 

 regions: the subantarctic region between the Antarctic and Subtropi- 

 cal Convergences and the antarctic region between the Antarctic 

 Convergence and the Continent. The convergences are distinguished 

 as regions of rapid increase in temperature of the surface waters in a 

 northward direction. 



The Subtropical Convergence is not so easily defined as the Antarctic 

 Convergence; it is much more variable in position, and it is not cir- 

 cumglobal as is the Antarctic Convergence. The position of the Sub- 

 antarctic Convergence is marked by a rapid increase in surface tem- 

 peratures in the vicinity of 40°S in all oceans except the eastern 

 Pacific. The increase is from 10° to 14° C in winter and 14° to 18° C in 

 summer. Salinity increases from 34.3%o to 34.9%o. The sharp changes 

 represent the region of convergence of north-flowing subantarctic 

 water and south-flowing subtropical water. The subantarctic region 

 is made up of five dift'erent water masses: the warm, saline Sub- 

 antarctic Surface Water, the cool, dilute Antarctic Intermediate 

 Water, the "warm" saline Upper and Lower Deep Waters, and the 

 cold, saline Bottom Water. These subantarctic water masses vary some- 

 what between oceans, but the antarctic water masses are similar 

 throughout their extent. 

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