= 1 Se 
a preliminary stage. It is difficult because so far such quantities 
as mixing intensity and evaporation and heat conduction by turbulence 
have not been measured directly, auantitative information dout them 
being always derived indirectly. Hence the numerical values in what 
follows are very uncertain, although there is every reason to believe 
that the order of magnitude is correct in each case.* 
Conduction of heat between ocean and atmosphere 
If ts is the temperature of the surface water and t is the air 
temperature at deek level, the rate at which unit area of the sea 
surface loses heat to the atmosphere by conduction is 
He = he (tg - t). 
Within the limitations already stated the values of the factor of he 
for various wind forces ares 
Wind force, Beaufort 1 a 
he, cal em-? day-1 (deg F)-l 24 oe a ree- «eS OHS 
A 7 /6 A Bile 
Evanoration 
Let eg be the vanor pressure at the sea surface (determined from 
surface water temperature and salinity by use of Table 2), and e be 
the vapor pressure at deck level (determined from psychrometer read- 
ings and barometric pressure by use of Tables 1 and 3). The rate of 
evaporation, expressed in terms of the thickness of the water layer 
evaporated in unit time, is . 
E=c (eg ~e), 
where c has the values: 
SO ee ene ey meena: ae tec ee ees ee a ee Ee nN RE A RN a Yc 
eet a ete rain ee ater, 
+ The chief source is Montgomery, Papers in Physical Oceanography 
and Meteorology, Vol. VII, No. 4, 1940. 
