10 



15 



STATION NUMBER 



20 25 30 35 40 



45 



50 



I I M M I I I I I I I 



rn r 



-A- 19-22 OCT 1975 

 ESSO KAWASAKI 



•. -•- 10-13 SEPT 1976 

 ESSO GENEVA 

 -■-30 AUG -2 SEPT 1977 

 ESSO KAGOSHIMA 



10° 

 LATITUDE 



Figure 4. Sea surface dynamic height relative to 400 dbar during the southwest monsoons 1 975, 1 976, 

 and 1977 constructed from XBT stations along the tanker sea lane (Figure 1a). For each year 

 the strong signal of the prime eddy occurs from 8''N to 1 0''N with a deep trough to the north 

 (1 1 "N to 1 2''N) between it and the Socotra eddy 1 2''N to 1 4''N. Mean temperature-salinity 

 relationship determined from previous data in this region (same temperature-salinity distribution 

 used for all stations) was used with XBT temperatures to detemnine the specific volume values 

 needed to produce these curves. 



71 



