10 



A study of the vertical temperature structure in the upper 

 water column revealed that bathythermograph traces can be 

 used to locate the depth of the high-salinity layer often found 

 below the surface-water layer in tropical regions (fig. 11). 

 The deviation of the temperature trace from the general trend 

 lines was found to be associated with the high-salinity layer. 

 This association appears to hold true throughout the tropical 

 regions of all oceans where the high-salinity layer is present. 

 This simple technique using the bathythermograph may be 

 useful where traditional salinity determinations are either too 

 slow or cannot be made, e.g., when taking current measure- 

 ments or setting fishing gear in the high-salinity layer. 



Our present studies have led to hypotheses regarding the 

 processes which determine the oceanographic climate in the 

 tropical central Pacific. These hypotheses will be evaluated 

 as our studies continue and expand into the field phase. 



TEMPERATURE - 



Be 



Figure 10. --Mean sea level atmospheric pressure 

 charts, January 1963 and January 1964. 



Figure 11. — A typical bathythermograph trace show- 

 ing the hlgh-sallnity layer In Hawaiian waters. 



