where P Q is the density of snow. 



6. Convective Heat Loss 



For the coefficient of heat loss through convection, Frank's 

 (1929) formula is used: 



0.656 .4 



CC k = 1.75 X V X 10 

 where v is the wind velocity in m/sec. 



7. Density of Sea Water 



For purposes of evaluating the formula, sea water density is con- 

 sidered as constant and equal to 1.000 throughout the whole period. 



8. Specific Heat of Sea Water 



As it varies but little with salinity, the specific heat of sea 

 water (C2) is considered a constant and equal to 0.975. 



9. Effective Radiation of a Black Surface 



From Angstrom' s formula for the effective radiation of a black 

 body, 



_ — 12 4 C - O 69 P 1 



Re = 1376 X SO X T o jo. 255 + 0.322 X 10 ' °j, 



where T Q = air temperature and 



Po - pressure of water vapor in mb. 



Taking from Falkenberg (1928), the emissivity of the snow, a, as 0.995, it 

 follows that 



-12 4 f -0.069 P\ 



QRe =1.307 X SO X T JO. 255 + 0.322 X SO f 



Therefore the heat lost through radiation is 



CC„ - 5.23 x 10" 12 x T Q 3 . 



Devik (1931) found by means of the above formula that for air temperatures 

 between and -20°C. and for relative humidities close to saturation, 

 the magnitude of aRe does not vary much. Therefore it can be taken 



as a constant equal to 30.6 x 10~\ 



10. Effect of Cloudiness on Radiation 



This is calculated by means of the following relations 

 aRe ■ aRe x (l - c n ), 

 where c is a coefficient taking into account the diminution 



13 



