TEMPERATURE (DEG C) 
JPN FEB RRR APR MAY JUN JUL AUG SEP OCT NOv OEC ANN 
TINE 
Figure 31. Mean surface water temperatures 
for 1980-1981 and 1982 
again, at least in part, due to the higher frequency (in comparison to other 
years) of onshore winds during the season. 
106. All years combined. Annual and seasonal temperature variations 
have been consistent from year to year. The addition of a third year of data 
made only a minor change to the annual distribution of surface temperatures. 
Visibility 
107. Visibility in coastal nearshore waters depends on the amount of 
salts, soluble organic material, detritus, living organisms, and inorganic 
particles in the water. These dissolved and suspended materials change the 
absorption and attenuation characteristics of the water, which thus vary daily 
and throughout the year. 
108. The surface water visibility at the seaward end of the pier varies 
in a similar manner as the temperature (Figure 32). Since the pattern of off- 
shore and onshore winds that produced major temperature differences also con- 
trols the visibility, the warm surface water is usually clear, while the 
cooler bottom water contains large concentrations of suspended matter. 
109. Present data year. Daily water visibility values, measured at the 
seaward end of the pier using a secci disc (Figure 32), show that monthly 
means were the highest during July through August 1982, as were the standard 
deviations (Table 15) reflecting the wind-dominated processes discussed 
68 
