Here Ql^ is the total amount of Incoming solar energy reaching 

 the sea surface in g. cal. cmT^ minT^ and C Is the percentage 

 of sky covered by clouds. 



It is now necessary to apply a correction factor to eojaation 

 (2) to account for the percentage of the incoming radiation 

 that is reflected back to space. Schmidt (1950) has determined 

 this percentage to vary from 3.3 at the Equator to 8,0 at the 

 poles. Designating this percentage as r and applying it to 

 equation [2), we have a final expression for the total amount 

 of incoming radiation, namely, 



Q„.= .025E[0.29 + 0.7l(l-,-^)](l-r) (3) 



-2 -1 

 Q^ is still expressed in g. cal. cm, min. . If it is desired 



to calculate the total incoming radiation for some period of 

 time, it is only necessary to multiply Q^^^ by the period t 

 expressed in minutes. 



b. Back radiation 



Not all of the heat energy defined in equation 

 (3) is actually absorbed by the water mass. Some of this heat 

 vjill be radiated back into space. Angstrom (1920) has defined a 

 quantity, eff. Q-j-,, which depends on air temperature and humidity 

 and gives the back radiation with a clear sky. These values are 

 tabulated in Angstrom (1920) and are presented in nomogram form, 

 slightly modified for a sea surface, in The Oceans (191+2). This 

 value also must be adjusted for the amount of cloudiness present 

 and for internal reflection. When the most generally accepted 



