During December the North Eqtiatorial Current develops In the 

 southern part of the Bay of Bengal and is present only during the 

 period from December to April. This current rises near the north- 

 vest corner of Siunatra and receives part of its water from the 

 Malacca Strait, but is supplied chiefly by water from the Counter 

 Current, which is deflected northward off the west coast of Sumatra. 

 The North Equatorial Current flows toward the west and reaches 

 maximal development during the period January to March. At the 

 same time the axis of the Equatorial Counter Current, which lies 

 near the Equator over most of the year, is shifted southward to 

 about WS latitute. During January and February when the northeast 

 monsoon is at maximal development a large anticyclonic gyre is 

 formed in the Bay of Bengal. Also south of the axis of the North 

 Equatorial Current a southwest drift caused by the monsoon extends 

 over the Equator to the south. The northeast monsoon ends in March 

 and in April the North Equatorial Current is still present but very 

 veak. 



Two extensive regions of upv/-elling were found in the northeast 

 Indian Ocean according to Rochford""" after examination of data from 

 six cruises of the Diamantina completed since I958. One of the 

 regions lies off the northwest coast of Australia and the other is 

 in the Arafara Sea. The upwelling is especially strong during the 

 summer monsoon season. Within each of these regions the inorganic 

 phosphate content near the surface was comparatively high, reaching 

 values greater than 0.20 _^ - atoms/l., and the origin of this 



^D. J. Rochford, "Hydrology of the Indian Ocean," Australian 

 Journal of Marine and Freshwater Research , XIII, No. 3 (Dec. I962), 

 pp. 226-251. ~~~ 



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