Salinity distribution 



Figure 27 shows the surface salinity distribution contoured at 



0. 1 /oo intervals. On the windward side the maximum salinity of 



35.27 /oo was found at station 8 and at stations 10 and 15, in a tongue 



extending from north to south toward the island of Hawaii, where the 



o o 



salinity was 35.26 /oo. The lowest salinity, 34,79 /oo, was found 



at station 5. On the leeward side the maximum salinity of 35. 11 /oo 

 was found at station 63 and the minimum of 34.82 /oo at station 58, 

 both along the southern boundary of the survey region. Also of interest 

 is the pocket of higher salinity at station 51. In general, the average 

 salinity decreased westward north of the island chain whereas it in- 

 creased in that direction south of the islcinds. 



An isolated pocket of low salinity water (34.55 /oo), lower than 

 the minima mentioned above, was found at station 26 in Kauai Channel. 

 Although this seems unreasonably low, no reason such as faulty sam- 

 pling or chemical analysis can be found to discard the observations. 



Density distribution 



The surface density distribution in units of sigma-t was contoured 

 at 0. 1 intervals on figure 28. It shows that on the windward side the ex- 

 treme sigma-t values were found at station 5, where the minimum was 

 23.21, and at station 10, where the maximum was 23.59. On the leeward 

 side the highest sigma-t value, 23.47, was found at station 51, and the 

 lowest, 22.92, at station 35 west of Hawaii and station 40 south of Oahu, 



Figures 26, 27, and 28 indicate the relative influence of tempera- 

 ture and salinity in the density distribution. For example, the surface 

 temperature and density show the feature of relatively large horizontal 

 gradients along the island chain, which is absent in the salinity distribu- 

 tion. One can also note the pockets of warm water south of Oahu and west 

 of Hawaii corresponding with lower densities in the same regions. 



On the windward side of the island chain one cam detect the 

 influence of salinity in the surface distribution of density. For example, 

 north of the island of Hawaii the tongue of saline water extending from 

 north to south is reflected in a tongue of denser water in spite of higher 

 surface temperatures. This indicates that the salinity has become the 

 dominant variable in the density distribution. At station 51, on the lee- 

 ward side, it can be seen how both low temperature and high salinity 

 contribute to the high density, which, as before, "is associated with a 

 counterclockwise vortex. 



20 



