influence upon biological activities. Here the salinity and temperature, 

 which determine the density of the water, show their greatest seasonal 

 variations. 



Besides effects due to the physical presence of the Hawaiicin 

 Islands in an ocean stream, one might expect the surface variables to 

 be influenced by heavy precipitation on the windward slopes of the island 

 mountains and subsequent runoff. The surface temperature is also ex- 

 pected to vary because of solar heating in shallow water and in wind- 

 sheltered regions. 



Temperature distribution 



Surface bucket temperatures obtained at each bathythermograph 

 position are contoured on figure 2 at intervals of 0. 5 F. Surface tem- 

 peratures averaged over the quadrants of the survey region are shown 

 in table 1 together with the extreme temperatures encountered. Greatest 

 deviations occurred on the leeward (southwest) side of the island chain. 

 The maximum temperature of 80,5 F. was found off the west shore of 



the island of Hawaii. The lowest temperatures were found in an area 



o o o 



centered at 20 N. , 157 20'W. , where the minimum was 74.8 F. (This 



type of cold temperature distribution was previously shown by McGary 

 (1955) to be associated with a counterclockwise vortex. ) On the wind- 

 ward (northeast) side of the island chain temperatures were more uni- 

 form, with two tongues of warmer water protruding north and northeast- 

 ward of Molokai and Maui, respectively. On the windward side there was 

 essentially no change in average temperature from east to west, whereas 

 on the leeward side the average increased by approximately 1 F. in that 

 direction. 



Salinity distribution 



Figure 3 shows the surface salinity distribution contoured at 



intervals of 0.05 /oo. Averaged surface salinities are shown in table 1. 



o 

 Maximum salinities (greater than 35.2 /oo) were encountered on the 



northern and eastern edges of the survey area and minimum salinities 



(less than 35 /oo) off the west shore of Hawaii and along the southern 



edge of the survey area. A region of high-salinity water on the leeward 



side of the island chain is centered at approximately 19 45'N. , 157°20'W., 



the same location as the temperature minimum. 



