I9I5.] IN AIR CIRCULATION OF THE GLOBE. 193 



netic pole.'' Within a vortex of this nature the wind velocity is 

 determined by angular velocity multiplied into the radius, and hence 

 one of relatively small dimensions should exceed in vigor one that is 

 spread over a vast field and in which the steeper marginal area 

 bears a smaller ratio to the whole. Mawson has expressed the 

 belief that his base was near the center of a permanent anticyclone.*' 



The Centrifugal Flow of Surface Air Currents Above the 

 Inland-Ice Masses. 



Early Evidence from Greenland.— In 191 1 when my work on 

 glaciers was published, evidence was available upon this from both 

 the eastern and western coasts of southern Greenland in latitude 

 64° (Nansen), from west Greenland in latitude 69° (Peary and 

 later de Quervain and Stolberg^), from northwest Greenland in 

 latitude 78-83° (Peary), and from northeast Greenland in latitude 

 y"/" to 82° (Trolle). With the exception of the first and last men- 

 tioned, these data applied exclusively to the western coast where 

 the prevailing surface winds come from the easterly quadrants. 



Later Confirmation. — The later evidence for the centrifugal flow 

 of surface air is ample and throughout confirmatory. De Quervain, 

 who crossed the inland-ice in 1912 between the latitudes of 66° and 

 68°, found head winds while ascending the west slope> but winds 

 from behind during his descent to the east coast. ^ Referring to 

 the low temperatures and the wide diurnal temperature range within 

 the central area, de Quervain says : 



" It is the cold air of this middle part which even in summer streams 

 like water from off the high surface toward all margins, deviated to the 

 right in consequence of earth rotation" (p. 137). 



Measurements of snow temperature made at different depths show 



5 Sir Douglas Mawson, "Australasian Antarctic Expedition 1911-1914," 

 Geogr. Jour., Vol. 44, 1914, pp. 257-286. 



^ L. c, p. 69. 



"^ The first Swiss expedition, which penetrated some seventy miles from 

 the coast (A. de Quervain und A. Stolberg, " Durch Gronlands Eiswiiste," 

 Strassburg, 1909). 



^ A. de Quervain, " Quer durchs Gronlandeis, Schweizerische Gronland- 

 Expedition 1912-13." Reinhardt, Miinchen, 1914, 196 pp., 15 pis., 2i7 figs, and 

 map. Also personal communications. 



