82 - 103 io. In the lover depths of the layer the oxygen content 

 drops sharply to 1.13 - 2.39 ml/l. and a saturation value of 22 - 



6o io. 



Subsurface Water . From immediately below the surface layer the sub- 

 surface layer extends to a depth of about UOO meters in the Arabian 

 Sea. It is formed in the gulfs of Aden and Oman and in the adjacent 

 part of the Arabian Sea^ by the mix:ing of waters coming from the Red 

 Sea and the Persian Gulf with the surface water of the Arabian Sea. 

 It then sinks in the anticyclonal gyre and partially as a result of 

 winter convection. This water spreads through the entire northern 

 part of the ocean and is bounded near the Equator by a zone of up- 

 veiling South Indian Ocean intermediate water. The latter penetrates 

 through the Equator into the western part of the sea and reduces the 

 salinity of the subsurface water of the Arabian Sea. The water coming 

 from the Red Sea is identified by a high temperature and salinity of 

 39. T %c when it reaches the Gulf of Aden. Salinity in the water 

 cx)mlng from the Persian Gulf is nearly as high as that from the Red 

 Sea. However, the volume of water from the former is much smaller 

 and therefore does not exert as much influence on the waters of the 

 Arabian Sea, The temperature in the Arabian Sea subsurface water 

 varies from 10 to 19''C. The salinity ranges from 35.0 to greater 

 than 36*0 %c and decreases with distance away from the formation 

 sources near the Persian Gulf and Red Sea. The oxygen content is 

 very low amounting to 0.21 - 2.09 ml/l., and in some places a com- 

 plete absence of oxygen is reported. 



Intermediate Water. Water from the Gulf of Aden comes into the 

 Arabian Sea at depths of 400 - 6OO meters with a salinity of 36.5 %o. 



^Bezrukov, p. 9- 



14 



