97. All years combined. Figure 38 shows the distribution of daily 

 values for 1980 through 1983. For 121 days a year, the visibility at the FRF 

 can be expected to be less than 1 m; while for 73 days a year, the visibility 

 can be expected to be greater then 3 m. 



10 

 9- 

 B- 

 7- 



-1 sH 



I— t 

 CD 



•— • 



3- 



l- 



0-* 



RNNUFL 80-83 



0.01 0.10 1.00 



10.00 25.00 50.00 75.00 90.00 



PERCENT GREATER THAN 



99.00 98.90 99.99 



Figure 38. Distribution of surface water visibility for 

 1980 through 1983 



Density 



98. Present year. Daily density values show large daily variations 

 (Figure 39). In general, the density varies inversely with water temperature 

 such that maxima occur during the winter and minima during the summer. Ta- 

 ble 11 shows the monthly means for the year. 



99. 1983 versus prior years. The density throughout 1983 was lower 

 than for prior years (Figure 40), which is consistent with the water tem- 

 peratures being higher during the year as discussed above. 



100. All years combined. The distribution of daily surface water den- 

 sity for 1981 through 1983 is shown in Figure 41. 



Surveys 



101. Waves and currents interacting with bottom sediments produce 



64 



