phenomenon by noting that, during the northeast monsoon season, water at the 

 head of the Arabian Sea is cooled by the continental wind, producing a gradient 

 of the sea surface to the north . Water moving in response to this gradient is de- 

 flected eastward due to Coriolus effect and, consequently, is placed in a clock- 

 wise motion apparently at odds with prevailing winds. 



Surface current plots in the Gulf of Oman coincide with the dominant wind 

 direction in that area, flowing southeast in response to the northwest wind in winter, 

 and into the Gulf under the domination of the southeast divergence of the summer 

 monsoon . 



B. Temperature and Salinity 



A summary of oceanographic data collected during this cruise is given in TR-176. 

 Figure 2 shows the stations at which these observations were made during the Arabian 

 Sea phase. Surface water temperature for March is shown in Figure 3. Temperatures 

 range from 23.8®C in the Strait of Hormuz and northwestern Gulf of Oman to 26.7"C 

 south of Ra's Al Hadd and 26.8*'C along the eastern shore of the Gulf of Cambay. 

 Temperature changes are gradual . The isotherms show some relationship to current 

 patterns, for example, the tongue of warmer water protruding northward along the 

 Arabian coast and the southward deflection of the isotherms along the Indian coast. 

 The influence of colder river water runoff may be seen extending from the Gulf of 

 Cambay. 



On shelf areas, bottom temperatures range from identical to those of surface 

 waters to a few degrees cooler . An exception is the Strait of Hormuz where bottom 

 temperatures actually exceed those of the surface due to the outflow at depth of 

 worm hypersaline Persian Gulf water. In deeper waters, bottom temperatures de- 

 crease rapidly with depth to values of less than 2**C at depths greater than 2,800 

 meters . 



Surface salinity measurements for March 1961, range from 34.90%o in the Gulf 

 of Cambay to 36.63%o in the Strait of Hormuz (Fig. 4). Low salinities in the Gulf 

 of Cambay can be attributed to fresh water runoff from the Narbada and Tapti Rivers . 

 Curiously the Indus River seems to exert little effect on the observed salinity distri- 

 bution . Possibly prevailing currents during this month confine this fresh water to a 

 narrow area along the coastline. High salinities in the Strait of Hormuz and Gulf 

 of Oman con be attributed to outflow of Persian Gulf water into the area. The 

 complex surface pattern in the eastern Arabian Sea may result from incomplete es- 

 tablishment of the summer clockwise surface current gyre. Movement of lower salinity 

 Indian Ocean water northward along the Arabian coast is shown by the 36.4%o iso- 

 haline. 



According to Emery (1956) most of the outflow of high salinity woter from the 

 Persian Gulf is at depth and primarily along the southeastern side of the Hormuz Strait. 



