59 



some inversions and rapid surface temperature changes at 

 other times of the year, so that it was likely an area of 

 interaction between several different water units. 

 January 1956 



The temperature characteristics of the various water 

 subunits for the winter months is typified by those of 

 January 1956 (Fig. 20). Surface and subsurface water tem- 

 perature spreads were small, amounting to about 3°F. The 

 transitional subunit was weak and inshore water was nearly 

 isothermal. Diurnal heating is evidenced by small surface 

 warm layers which became mixed into the surface layer in the 

 afternoon by wind action. 



Temperature differentials between distinct isothermal 

 layers were small and the thermograms showed temperature 

 gradients rather than thermoclines . Thus, water motion was 

 more or less uniform throughout the surface unit. 

 April 1956 



The temperature relationships between the various units 

 for April 1956 bore marked resemblances to the generalized 

 picture in the fall temperature structure (Fig. 21). The 

 surface layer was beginning to develop a definite secondary 

 structure of subunits as the main mass of the Surface Unit 

 separated into surface warm subunits and a transitional zone. 

 The warm inshore subunit was well developed. The thickness 

 of the surface unit plus the transition zone averaged 100 to 

 110 feet which is the maximum depth of the surface layer for 

 the year. 



