I9IS.] IN AIR CIRCULATION OF THE GLOBE. 201 



Sudden Warming of the Air at the End of the Glacial 

 Blizzard — Foehn Effect in Descending Currents. 



Intensive Foehn Effective in Outlets. — This familiar foehn 

 effect is so general a phenomenon about the margins of both the 

 great continental glaciers that it has long been recognized.-^ The 

 general rule holds that the temperature of the air rises as the 

 blizzard is evolved.-^ Wherever a mountain rampart exists, the 

 elevation of temperature becomes accentuated within the glacier 

 outlets, and melting in Antarctica is almost unknown except under 

 these conditions. An interesting example of this which has not 

 before been emphasized, is supplied by Armitage, who on the first 

 ascent of the Farrar outlet found a stream of water seven feet in 

 width and nine inches deep flowing beside the ice.-'' The effect of 

 similar currents of water was noted by David on his ascent to the 

 plateau from McMurdo Sound. A remarkable instance, also, with 

 long continuance of high temperature, is that above cited from 

 Captain Scott's journal, while camped on the apron below the Beard- 

 more outlet. 



The Greenland Foehn. — The characteristic Greenland foehn has 

 been subjected to a special study by Stade, the meteorologist of the 

 Berlin Geographical Society's expedition to Greenland.^" He finds 

 that the temperature changes are much more pronounced during 

 the winter season, the rise on March 5, 1893, having been 12° C. 

 and probably much more within the space of a few minutes. 

 Stade's conclusion is that these foehn winds are connected with low 

 areas moving northward in the Davis Straits, the maximum of air 

 temperature and the minimum of relative humidity corresponding 

 either exactly or approximately with the minimum of pressure at 

 the station. De Quervain's later studies would indicate that Stade's 

 moving depressions may better be regarded as pulsations within a 

 stationary low pressure area lying over Davis Straits and Baffin's 



'^'^ See " Characteristics of Existing Glaciers," pp. 149-150, 268-271. 



2^ Cf. Mawson, " The Home of the Blizzard." 



'9 A. A. Armitage, " Two Years in the Antarctic," London, 1905, p. 



^0 Dr. H. Stade, " tjber Foehnerscheinungen an der Westkiiste Nord- 

 gronlands und die Veranderung der Lufttemperatur und Feuchtigkeit mit 

 der Hohe, Nach den Beobachtungen auf der Station Karajak, Gronland Ex- 

 pedition 1891-93," Vol. 2, 1897, PP- Soi-533. 



PROC. AMER. PHIL. SOC., I.IV, 2l8 N, PRINTED AUG. 4, I915. 



