226 Evaporation from the Surface of the Sea and the Water Budget of the Earth 



of evaporation. These mean annual evaporation amounts together with mean annual 

 values of precipitations are contained in Table 87. 



Table 87. Mean values of precipitation, evaporation and the difference between them 



(E — P)for the entire ocean {including adjacent seas) 



(According to Wust, 1954) 



t Maxima; : Minima; § Excluding polar zones 



4. Geophysical Aspects of Evaporation Problem 



Evaporation is a physical process that takes place at the boundary surface between 

 water and the air above it and depends on the conditions both in the water and in the 

 air in the immediate vicinity of the surface. The formula showing the dependence of 

 the evaporation height occurring in a certain time on the meteorological factors is 

 usually given in the form 



hn =f(p) X fiT) X f,(u) X (e, - Ca), 



where each term represents the effect of one of the meteorological elements (p the 

 pressure, T the absolute temperature, u the wind speed); e, is the maximum vapour 



