566 



H. MOHN. METEOROLOGY. 



[NORW. POL. EXP. 



The computed range of the ice-temperature at 3 metres is 7 5 (Table, p. 562). 



Computing the range of the ice-temperature at the different depths from 

 the range of the surface 29'5 and the logarithmic decrement found from the 

 phase-angles, 0'2557 or log br. am h = 1-46982 0-11105 . h, we get 



With these ranges, and the constant value of the mean annual tempera- 

 ture of the Surface, 15 >0 (p. 562), we obtain the following minima and 

 means and maxima, and their difference from the observed values. 



In all depths the observed temperatures are higher than the temperatures 

 computed from the supposition of a deep layer of ice; and the deeper the 

 sheet lies, the greater is the excess of temperature. The ice is warmed from 

 beneath, from the sea- water; and the differences of the table give a measure 

 for this warming. 



The computed annual and monthly temperatures of the ice at the depth 

 of 3 metres are shown in the Table on p. 562. Supposing the boundary 

 between the ice and the sea-water to lie at the depth of 3 metres, and the 

 temperature of the water to be 1 -0 6, we get the following differences 

 between the water and the ice (-)-, water warmer, , colder than the ice) at 

 this depth. 



