I9IS.] IN AIR CIRCULATION OF THE GLOBE. 203 



is stiper-adiabatic. The typical foehn cloud layer at 1,200 meters 

 is also at such times much more marked, and up to this level the 

 wind velocity falls off with altitude. Of the greatest significance 

 were the results of ascents made at the time of easterly winds — 

 always light ; since these show that the easterly winds fade away 

 below the altitude of 1,000 meters, at which level they become 

 replaced by the westerly winds which are controlled by the anti- 

 cyclones.'^^ 



Areas of Relative Calm and of Air Highly Charged with 



Moisture Corresponding to the Central Plains 



Upon the Ice Domes. 



Few Early Data. — At the time " Existing Glaciers " was pub- 

 lished, no observational evidence bearing upon this point was avail- 

 able from either of the large continental glaciers, since neither had 

 been penetrated to the central area. Nansen's crossing of Green- 

 land within its narrowed southern portion, had revealed an area of 

 calm near the divide on his section, but it could not then be predi- 

 cated that this represented more than the margin of the central ice 

 plain. The most valuable evidence then available was derived from 

 Northeast Land (Spitzbergen), which is covered by a dome of 

 inland-ice about a hundred and eightly miles in diameter and be- 

 tween two thousand three thousand feet in altitude in the central 

 area. This area of inland-ice had in 1873 been penetrated by A. E. 

 Nordenskiold and Palander, who several times observed the simul- 

 taneous fall of irregular ice-grains enveloped in water and of small 

 snow-flakes either rounded or star-like, the ice-grains freezing im- 

 mediately on falling and becoming attached to the hair or clothes, 

 since the air temperature was — 4° to — 5°.^'^ 



Recently Acquired Evidence from Antarctica. — During his pene- 

 tration of the inland-ice area of Antarctica, Captain Amundsen en- 

 tered near the 88th parallel, what he believed to be a region of per- 

 manent calm or of light winds and of generally clear weather. 

 As evidence of this, the snow surface was smooth and with no in- 



33 A. Wegener, " Drachen- und Fesselballonauf stiege," Med. om Gronl., 

 Vol. 42, 1909, pp. 60-75. 



3-i Cf. " Existing Glaciers," p. 277. 



