The Three-dimensional Temperature Distribution and its Variation in Time 89 



Table 36. 



Heat sources Heat losses 



1. Absorption of solar and sky radiation 1. Radiation from the sea surface Qb 



Qs 



2. Convection of sensible heat from atmos- 2. Convection of sensible heat from sea to 

 phere to sea atmosphere Q/, 



3. Conduction of heat through the sea bot- 3. Evaporation from the sea surface Q^. 

 tom from the interior of the earth 



4. Conversion of kinetic energy into heat 



5. Heat produced by chemical and bio- 

 logical processes 



6. Condensation of water vapour on the 

 sea surface 



7. Radioactive disintegration in the sea- 

 water 



reaches the surface of the sea. Of this, 27% is direct solar radiation and 16'^o is diffuse 

 radiation from the sky (sky light). From the other sources listed in Table 36 those with 

 a comparatively smaller effectiveness can be neglected. The sources listed under item 

 2 for heat gain and loss can be added giving one source. The same applies to item 6 

 (heat gain) and item 3 (heat loss). 



The heat obtained from the interior of the Earth is about 50-80 g cal/cm^ per year 

 or on the average about 10 x 10"^ g cal/cm^, min. The heat supplied from the in- 

 terior of the Earth has recently been measured directly for the deep-sea basins of the 

 Pacific Ocean by Revelle and Maxwell (1952) and for the Atlantic Ocean by 

 BuLLARD (1954). These measurements gave in agreement the value 6-2 x 10~' g 

 cal/cm- min which corresponds to the value for the continents. Compared with the 

 heat from solar radiation this is unimportant; it probably causes only small local 

 variations in the thermal structure of deeper, enclosed stagnating water (see Chap. III. 

 4d). 



The kinetic energy which the sea obtains by the tangential action of the wind on the 

 sea surface and by the dissipation of tidal energy by turbulent friction and which will 

 be transformed into heat gives only a very small heat contribution. The energy im- 

 parted by the winds amounts scarcely to a ten-thousandth part of the solar and sky 

 radiation energy and can therefore be neglected. Also the tidal energy dissipated by 

 turbulence is only of any appreciable influence in shallow waters. For example, Taylor 

 found the value of 1050 g cal/cm^ per year = 0-002 g cal/cm^ min for the Irish Sea 

 (see Vol, U. Chap. XV, 3). If this heat could accumulate in the Irish Sea for a whole 

 year the temperature rise would be only 0-2 °C. The item 5 in Table 36 has no significance 

 in the general budget of the sea and only requires to be taken into consideration where 

 there are local concentrations of plant life. The disintegration of radioactive material 

 in sea-water will afford barely 4 x lO'^gcal/cm^ min. Under these conditions the 

 heat budget of the ocean requires the following equation 



Qs - Qb- Qh ~ Qe = 0. 



