TABLE 39. SPECIFIC HEAT OF SEA ICE IN G-CAL* AT DIFFERENT 

 TEMPERATURES AND SALINITIES 



Thus, the concepts of specific heat and heat of fusion are inseparable from each other for 

 sea ice. 



LITERATURE: 13, 52, 62, 73, 104, 158, 166. 



Section 61. Heat Expended in Melting 



Heat of fusion is understood to mean the amount of heat which must be transferred (on the 

 conditions of stable temperature) to a unit mass of matter in order to change it from a solid state 

 to a liquid. 



However, as Malmgren first pointed out, in dealing with the sea ice, in the cells of which 

 there is a constant and gradual melting of pure ice during a rise of temperature, it is possible to 

 speak not of the heat of fusion, but rather of the number of gram calories necessary to melt 1 g of 

 sea ice having an initial temperature r . 



Let 5^ be the salinity of sea ice, and Tg be the freezing temperature of sea water of 3 sa- 

 linity. The amount of heat U necessary to melt one gram of sea ice, whose initial temperature 

 is r, wUl be the sum of: 



1. The heat necessary to melt the pure ice contained in one gram of sea ice, i.e. , 



80 f 1 - |i) g-cal 



where 80 is the heat of fusion of pure ice, {i-Si/S-j) is the number of grams of pure ice contained 

 in 1 g of sea ice of 5 salinity at temperature r. 



2. The heat necessary to raise the temperature of pure ice** from r to r^ that is 



approximately 



0.5 (ts — t) g-cal 



where 0.5 is the specific heat of pure ice. 



*The heat of fusion of pure ice equals 79.67 g-cal but it is sufficient to use a round number 

 in approximate computations. 



**One may neglect the amount of heat necessary to change the temperature of the brine. 



153 



