BATHYPELAGIC SQUID BATHYTEUTHIS 99 



the mixed, upwelled and surface water becomes colder and more 

 saline due to loss of water to ice formation. This low-temperature, 

 high-salinity water is very dense and it sinks along the continental 

 margin; with some mixing with Deep Water, it forms Antarctic 

 Bottom Water. As noted above, this process occurs chiefly in the 

 Weddell Sea, but more recent information indicates that it occurs in 

 the Ross Sea as well (Kort, 1962; Brodie, 1965; this report). Ant- 

 arctic Bottom Water spreads northward and eastward along the sea 

 floor away from the continent; it is found throughout the Antarctic 

 Ocean; it extends beyond the Equator in the Atlantic Ocean; it is 

 present in the southern portions of the Indian and Pacific Oceans. 



The Antarctic Circumpolar Current is the result of a strong wind- 

 driven current in the surface layers and a gradient current, due to vari- 

 ations in density, throughout the entire water mass (Sverdrup et al., 

 1942). More recent work confirms the existence of eastward movement 

 of the Antarctic Circumpolar Current around the entire Southern 

 Ocean. The structure of this largest current in the oceans is extremely 

 complicated and the total flow breaks up into streams of fast-moving 

 cores; in some places countercurrents exist (Kort, 1962), The maxi- 

 mmn current flow is in the zone of the Antarctic Convergence. Previous 

 mention has been made of the location of the Antarctic Convergence in 

 relation to bottom topography. The relationship is really to the current 

 system that in turn is responsive to bottom topography. The Coriolis 

 effect in the Southern Hemisphere exerts a northerly bend to the cur- 

 rent as it approaches a submarine ridge and a southerly bend as it 

 passes the ridge. In all, five distinct ridges are crossed by the Ant- 

 arctic Circumpolar Current : the South Antilles Arc, the Bouvet Island 

 Rise, the Kerguelen Ridge, the Macquarie Ridge, and the Pacific- 

 Antarctic Ridge. An additional influence contributes to the sharp 

 northward displacement of the Antarctic Circumpolar Current in the 

 Soutli Pacific sector of the Southern Ocean over the Pacific- Antarctic 

 Ridge : the strong anticy clonic circulation near the Ross Sea forces the 

 major current system northward. Land masses have an effect on the 

 Antarctic Circumpohir Current similar to that described for the Ant- 

 arctic Convergence. 



In the subantarctic region the current is directed fi'om west to east, 

 also, but only the southern portion close to the Antarctic Convergence 

 circulates around the Southern Ocean as part of the Antarctic Circum- 

 polar Current. In the Pacific Ocean, at least, the northern portion of 

 the subantarctic region belongs to the current system of that ocean. 



Transverse or meridional water movements are set up as a result of 

 the convergences and divergences. The southwesterly trend of the up- 

 welled waters mixed with surface water in the region of the Antarctic 



