19IS.] IN AIR CIRCULATION OF THE GLOBE. 209 



surface. This would explain the clear skies which are so general over both 

 Greenland and Antarctica during snows in the higher levels. It is of course 

 true that the latent heat of fusion and vaporization of ice, abstracted as it is 

 from the air during its descent within the eye of the anticyclone, will 

 counteract to some extent the warming adiabatic effect; and it is not improb- 

 able that the long duration of Antarctic blizzards and their somewhat sudden 

 terminations accompanied by snowfall are explained in part by the trans- 

 formations of latent and sensible heat. 



" Additional evidence for the continental and glacial rather than the 

 polar nature of the Antarctic anticyclone is derived from the strong blizzards 

 observed at the British winter quarters on McMurdo Sound. Whereas the 

 lighter gales came from the southeast and indicated a control by local condi- 

 tions, a blizzard of the first magnitude was not thus influenced, and always 

 swept down from the southwest — that is, from the high plateau, and not from 

 the pole, since otherwise the earth's rotation would have given it an easterly 

 direction. When its powers begin to wane, it is once more controlled by local 

 conditions and the, wind again comes from the southeasterly quarter." 



Amundsen's Meteorological Records at Framheim. — Hardly less 

 significant were the directions of prevailing winds observed at Fram- 

 heim, the winter quarters of the Norwegian Antarctic expedition 

 of 1910-12, when the position of the station is considered in refer- 

 ence to areas of inland-ice and shelf-ice. The great dome of inland- 

 ice of King Edward Land lies to the eastward and southeastward 

 distant only about 115 miles, whereas that of South Victoria Land 

 and its extension to the southeastward, lies a number of times that 

 distance away to the southwestward and westward. Now it was 

 found that easterly winds predominated (31.9 per cent, of the time), 

 with southwesterly and southerly winds next in order (14.3 per 

 cent, and 12.3 per cent, respectively). Southeasterly winds were 

 especially rare, and as calms reigned for a fifth of the time (21.3 

 per cent.), the winds for four fifths of the period are those ac- 

 counted for. Earth rotation should deviate original southwesterly 

 winds into a southerly direction, and southeasterly to easterly.**^ 



Alternations of Calm and Gale. — The strophic characteristic of 

 the glacial blizzard thus involves frequent alternation of calms with 

 strong gales, and all systematic observations about the inland-ice 

 reveal this characteristic. As already pointed out, the strophic 

 quality is to be expected from the recurring disturbance of balance 

 and later recovery in opposing forces (ante, p. 188). Below in tabu- 



■i^a R. Amundsen, " The South Pole," Vol. 2, pp. 381-382. 



