6.0 



5.0 



3.0- 



2.0- 



1.0- 



Year Mean, m 



* *1994 1.9 



9— -0 1980-94 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 



Daily and monthly mean surface density values, plotted in Figure 21, were 

 measured with a hydrometer. Monthly means are also given in Table 8. 

 These values are direct readings from the hydrometer. Corrections for 

 differences between ocean water temperature and jar water temperature, as 

 well as use of uncalibrated hydrometers and other factors, could produce an 

 error amounting to a couple of percent in the direct hydrometer readings. 



44 



Chapter 6 Water Characteristics 



