Thus the density of pure ice which has no air bubbles would be given by 



j> ^0 ,,, 



'~ 1 +0.000165/ ' ^ ' 



where 6 ^ is the density of pure ice at a temperature t , 



6q is the density of pure ice at a temperature of ° . 



The density of sea ice depends on its temperature, salinity, and porosity. 



When computing the density of sea ice as a function of its temperature and salinity, let us 

 remember that according to Section 57, 1 g of sea water contains ( -^j g of brine and (1 --=-^ ) g of 

 pure ice, where Sj^ is the salinity of sea ice, Sj is the salinity of the brine in the cells. 



Hence, the volume of 1 g of sea ice with the salinity of 5^ and temperature t, expressed in 

 cubic centimeters, or in other words, its specific volume, will equal 



_Si 1 , /,_M_L 



(2) 



where 6 _ is the density of the brine, the salinity of which is equal to S^ at temperature t. 



It is clear that, knowing the specific volume of sea ice, it is not difficult to compute the 

 density as the reciprocal of the specific volume, according to the formula 



K. =~. (3) 



Let us make the following assumption for computing this amount i5g^. 



It is known that the density of sea water is related to its temperature and salinity by a very 

 complex relationship, but for approximate computations, density vs. salinity can be expressed by 

 the following simple formula 



S,, = So, + 0.0008 5, (4) 



where 6q^ is the density of pure water at temperature r , 



637. is the density of sea water, the salinity of which is 5 and temperature t. 



Keeping in mind that the density of supercooled water is approximately equal to unity, and 

 expanding formula (4), to the low temperatures and high concentrations of brine, we can compute 

 the density of brine according to formula (5) 



6 = 1.000 + 0.008 5 . (5) 



ST T 



Table 45 shows the results of my computations according to formulas (1) and (4), and 

 table 46, the results of computations according to formula (3) and table 45. 



163 



