Trade Wind Zone by the South Equatorial Current. The Agulhas 

 Current on the eastern side is a strong deep current. 



The fact that the continental boundaries do not extend far to 

 the south allows a great exchange of vater at all depths with the 

 Pacific and Atlantic Oceans. On the Atlantic side there is a net 

 inflow of water and on the Pacific side an outflow. 



Indian Ocean Central Water is formed by sinking at the Sub- 

 tropical Convergence and spreads at subsurface depths toward the 

 Equator. It reaches its farthest northern extension on the western 

 side of the ocean where it is found at about 10°S latitude. The 

 Antarctic Intermediate Water is formed at the Antarctic Convergence 

 and also spreads northward toward the Equator where it is gradually 

 forced to the surface by the North Indian Deep Water which is formed 

 in the Equatorial region. The North Indian Deep Water is warm and 

 saline, being formed by an admixture of Arabian Sea Water. This 

 deep water finds its way to the south and surfaces in the Antarctic 

 region distributing heat from north to south. North Indian Deep 

 Water is found in practically all parts of the Indian Ocean although 

 in the southwest comer Atlantic Deep Water is also present to a 

 limited degree. Antarctic Bottom Water, which forms by sinking from 

 the surface along the continental slope of Antarctica, is called 

 Indian Ocean Bottom Water after it passes from the Antarctic Basin 

 into the Indian Ocean. This bottom water spreads along the ocean 

 floor on both sides of the Mid-Oceanic Ridge and into the Arabian 

 Sea and Bay of Bengal. Bottom water is the coldest of all water 

 masses below the surface layer. 



Deep and bottom waters are distributed evenly over the entire 



expanse of the ocean and possess great homogeneity. They undergo 



69 



