process reduces the surface temperatures along these coasts. The 

 upvelling is more intense along the African coast than along the 

 Arabian coast, and corresponding surface temperatures are 21°C in 

 the region of Cape Ras Khafan, and 23°C near the coast of Arabia. 



The greatest salinity value north of the Equator on the surface 

 of the Indian Ocean occurs in its vestem part vhich includes the 

 Arabian Sea vhere surface salinities exceed 36. 5 %o in its northern 

 part. In the surface layer of the Arabian Sea salinity varies from 

 35-8 to over 36.5^. Precipitation falls almost exclusively in the 

 western part of the sea during the winter monsoon. On the other 

 hand, during the period of the summer monsoon, precipitation falls 

 in the eastern part near the mountainous coast of Hindustan. The 

 indicated amount of precipitation over the entire surface of the 

 Arabian Sea is considerably less than the evaporation and this 

 deficit of precipitation determines the significant increase in 

 salinity of the surface water. ^ 



Great evaporation in the Arabian Sea under conditions of high 

 temperature results in an increase in salinity. This condition 

 causes an increase in density of the surface water which exceeds 

 24.0 a^ during the course of a year. Near the Arabian peninsula in 

 summer the surface density value reaches 2^.5 cr^. Sigma-t (a^ ) is 

 a shortened expression for the density of sea water and is defined 

 "by: CTt = Cgms/cm° - l) x 1000. 



The oxygen content in the surface layer down to about 50 meters 

 equals 3'94 - 4' 75 ml/l. This corresponds to a saturation value of 



^A. M. Muromtsev, Basic Outline of the Hydrology of the .Indian 

 Ocean (Leningrad: 1959), pp. 84-90. 



13 



