meters reactions to seasonal changes were 

 much less extreme and were almost non- 

 existent. The rapid surface temperature 

 decrease in the fall and winter showed 

 its effect down to depths of 200 meters. 

 Possible effects were seen to 300 meters. 

 Averaged temperatures for the 300 

 meter to 1000 meter levels were similar 

 in their monthly variations. Between some 

 months there were differences in the 

 monthly variations of temperature at the 

 300 meter and 400 meter levels as com- 

 pared to those below 500 meters, but such 

 occurrences were the exception rather 

 than the rule. The steeper vertical tempera- 

 ture gradient of the shallower levels would 

 have caused larger tempeature differences 

 for equal changes in the depth of the 

 isotherms. 



Response to seasonal cycles over the 

 year was most pronounced in the surface 

 layer, as already mentioned. In the 300 

 meter to 1000 meter layers, temperatures 

 dropped from June 1967 to July 1967, 

 after which there was a sharp increase 

 through September. Temperatures 



dropped sharply until November, and then 

 feU more gradually until February 1968. 

 By March, temperatures had risen, 

 followed by a slight decrease above 400 

 meters and a continued rise below. By 

 June, all temperatures had fallen from 

 their earlier spring high. From June to 

 October, all temperatures showed a gradual 

 rise, except for a slight decrease between 

 August and September at certain deeper 

 levels. Temperatures decreased through 

 December. Temperatures in these levels 



4 



