CLIMATOLOGY 



Tongue. There was a north wind at Cape Evans, a 

 west wind off the sound halfway, and a Httle later we 

 found a strong southeaster driving snow over the root 

 of Glacier Tongue. These were local winds which did 

 not indicate the onset of a blizzard. 



Another phenomenon to be noted is the increase in 

 temperature as a blizzard approaches from the south- 

 east. The intensely cold and stagnant air of the coastal 

 margin is soon swept away by the blizzard, and the 

 temperature usually rises. This rise in temperature is 

 of the same kind as is found in foehn winds, and is 

 due to adiabafic heating, the air generally being com- 

 pressed by descent from the plateau. We must also 

 take note of the rapidity with which a furious blizzard 

 develops from what has often been practically calm 

 weather. Accurate data on these points are given in 

 Simpson's large memoir. (See also p. 79.) 



There have been several attempts to weld these facts 

 into a harmonious whole. We may briefly consider 

 those of Meinardus, Hobbs, and Simpson. Meinardus 

 based his report of 191 1 on Drygalski's data. He was 

 chiefly struck with the fact that there must be a large 

 supply of snow in the interior of the plateau to main- 

 tain the ice cap, and the constant drain due to the bergs 

 breaking off all round the margin. He therefore be- 

 lieves that the fundamental feature on the plateau is 

 a cyclone which occupies the region above seven or 

 eight thousand feet, and which is fed by constant 

 westerly winds at that level. He states that in anti- 

 cyclones the air flows in at the center in the upper 

 layers, descends, becomes relatively dry and, as it 



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