E 

 Oo.2e 



<M 



2 o 24 



I- 



a. 

 rr 

 o 



4 

 > 



3 



ll 



iJzi 



-— A..--^ — y^ — \-/- 



-ta|w 



1 \ r— 



ULTRAVIOLET 



Figure 18. — Comparison of selected properties of 

 the environment in fiscal year 1968. Moving 

 averages of the order three were used to smooth 

 the data except for ultraviolet absorption — for 

 it, raw data were used. Transparency is the 

 depth (m.) to which 35 percent of surface light 

 penetrated. Dashed lines indicate discontinuity 

 between June 1968 and July 1967. 



JAN. FEE MAR. APR. MAY JUN. I JUL. AUG. SEP OCT. NOV. DEC. 

 1968 1967 



23 



