CHAPTER IV 

 The Heat Budget of the Oceans 



To the heat budget of the earth as a whole, only processes of radiation 

 are of importance, but the heat budget of the atmosphere is more com- 

 plicated, being controlled by processes of radiation, condensation of 

 water vapor, and exchange of sensible heat with the ocean and land sur- 

 faces. The heat budget of the oceans is primarily controlled by processes 

 of radiation, exchange of sensible heat with the atmosphere, and evapora- 

 tion from the surface or condensation of water vapor on the surface, but 

 such processes as convection of heat through the ocean bottom from the 

 interior of the earth, transformation of kinetic energy into heat, and 

 heating due to chemical processes also have to be examined. 



The processes involved can be listed as follows : 



Processes of heating of the ocean Processes of cooling of the ocean 

 water water 



1. Absorption of radiation from the 1. Back radiation from the sea 



sun and the sky, Qs surface, Qb 



2. Convection of heat through the 2. Convection of sensible heat to 



ocean bottom from the interior the atmosphere, Qh 



of the earth 



3. Transformation of kinetic energy 3. Evaporation, Qe 



to heat 



4. Heating due to chemical processes 



5. Convection of sensible heat from 



the atmosphere 



6. Condensation of water vapor. 



Over all oceans between 70° N and 70° S the average incoming radiation 

 from the sun and the sky which penetrates the sea surface is about 0.22 

 g cal/cmVmin, and amounts that are small in comparison to this can be 

 neglected. 



It has been estimated that the flow of heat through the bottom of 

 the sea amounts to between 50 and 80 g cal/cmVyear — that is, 0.095 

 X 10-3 to 0.152 X 10-3 g cal/cmVmin. This amount represents less 



49 



