Temperature 
30.0 Year eg C 
x—x 1991 16.6 
@----o 1980-91 14.9 
25.0 
20.0 
15.0 
Water Temperature, deg C 
5.0 
0.0 
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 
Month 
Figure 19. Daily water temperature values 
with monthly means 
Visibility 
54. 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 that vary daily and 
yearly. 
55. Visibility was measured with a 0.3-m—diam Secchi disk, and similar 
to water temperature, variation was related to onshore and offshore winds. 
Onshore winds moved warm clear surface water toward shore, whereas offshore 
winds brought up colder bottom water with large concentrations of suspended 
matter. Figure 20 presents the daily and monthly mean surface visibility 
values for the year. Large variations were common, and visibility less than 
1 m was expected in any month. Monthly means are given in Table 8. 
47 
