5.0 



S 4.o 

 > 



s_ 3.0- 



i.o- 



Year Mean, m 



x *1987 2.2 



9— -©1980-87 2.1 



JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 

 Month 



Figure 20. Daily water visibility values with monthly means 



Density 



56. Daily and monthly mean surface density values, plotted in 

 Figure 21, were measured with a hydrometer. Monthly means are also given in 

 Table 8. 



46 



