The combined effect of various meteorological factors on the ice thick- 

 ness is shown in Figure 2. Approximate average values of tQ/d'£ for; 

 Arctic latitudes are listed in Table I. These values, in the fornF of ■ 

 heat gain and loss, are tabulated by months during which ice formation 

 occurs. 



TABLE I 



Month 



Heat Loss 



Heat Gain or Loss (^V a c) 

 for the Arctic Regions 



Heat Gain 



Nov. 



-5o2°C„ 



0.2°C. 



Dec 



-5o4°C. 



0ol6°C. 



Jan 



-5o9°C. 



0.49°G. 



Feb. 



-6.0°C 



1.85°C. 



Mar 



-6.5°Co 



5o95°C 



Apr. 



-6o6°Co 



9o60°C. 



Net Gain (4) or Loss (-) 



-5.00°C, 

 -5.24°C.' 



-4ol5°C. 

 -0.55°C- : 



+3«00 o C. 





By the proper choice of parameters and physical constants, the 

 following equation for the practical determination of ice thickness in 

 fresh water is derived: 



h, + L49 



8 



+ 



100 



1.75 XV, 







+ 5.2 3 X SO 





h 



(23) 



= i2l 



9 



1+0.0033 6 



where hi = increase in ice thickness in cm., 

 S - snow thickness in cm. , 

 P - snow density, 

 v z wind velocity in knots, 

 T z air temperature in °C», 

 h Q = initial ice thickness in cm„, and 

 = equivalent temperature in °Co 



While equation (23) looks complicated and clumsy, it can be evaluated 

 easily by substituting the given meteorological parameters into the 

 numerator and denominator and dividing. 



10 



