CHAPTER II 

 THE ARABIAN SEA 



Aside from its characteristic high teraperature and high salin- 

 ity relationship, two other features are present' in the Arabian 

 Sea which distinguish it from all other parts of the Indian Ocean. 

 One is the seasonal reversal in circulation which is induced by the 

 monsoons and the other is the layer of minimum oxygen which is 

 found below the surface waters. 



Circulation. In the northern part of the Indian Ocean the surface 

 currents are initiated by the monsoon winds and vary in direction 

 with the seasons. In the Arabian Sea the northeast monsoon prevails 

 in the winter, being replaced in summer by the southwest monsoon. 

 Of the two monsoons the southwest endures over a much longer period 

 of the year, is stronger and steadier than the northeast one. The 

 surface currents induced by these winds are a source of confusion 

 for mariners who lack the experience of sailing in these waters. 

 The U. S. Hydrographlc Office has produced charts based on thou- 

 sands of observations which show the monthly and seasonal variations 

 of these currents. The accompanying charts (Figs, 1-4) which are 

 based on the Hydrographlc Office's charts illustrate the fall 

 transition from southwest to northeast monsoon circulation. 



The fall transition takes from about the first of October and 

 usually lasts to the end of November. The northeast (fine weather 

 monsoon) is in force during the months of December and January. 



^Pilot Chart of the North Pacific Ocean No. l^iOl, "Currents 

 in the Arabian Sea" on reverse side, (u. S. Hydrographlc Office, 

 Washington, D. C. , June I956). 



