354 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 192 8 



point out that much has yet to be done in explaining the peculiar 

 Antarctic blizzards which rank among the fiercest winds on the face 

 of the globe. G. C. Simpson has given an explanation of these in 

 the Ross Sea, but are the blizzards of Wilkes and Coats Lands, which 

 occur under different topographical conditions, amenable to the same 

 explanation, or has W. H. Hobbs found the solution in his theory 

 of strophic winds associated with glacial anticyclones, a theory which 

 he applies also to Greenland, where he is at present investigating it ? 



Recent observations in Northeast Land, Spitsbergen, confirm the 

 association of this general air circulation with a dome of ice-covered 

 land, but, as Sir Napier Shaw, L. C. W. Bonacina, and others have 

 pointed out, we require another term than anticyclone for this state 

 of affairs, since the high pressure is only a shallow surface effect 

 resulting from local conditions and not a true anticyclone developed 

 as the outcome of general atmospheric circulation independent of 

 local topography. Even the qualification of " glacial " does not re- 

 move a possible confusion of ideas. The supply of cold air from 

 polar regions toward lower latitudes appears to be independent of 

 pressure, inasmuch as the winds are katabatic winds flowing down 

 the slope of high land. It is orographical relief and not pressure 

 which supjDlies the driving force of the cold air currents of the 

 polar front. ^ 



A further important meteorological problem, with strong geo- 

 graphical bearings, is the alimentation of the ice sheet. We know 

 that it is wasting by the calving of icebergs, by surface ablation, 

 and other processes, and that it has shrunk considerably since its 

 Pleistocene maximum, but we are at a loss to explain satisfactorily 

 how the precij^itation in the heart of an anticyclone can ever have 

 been sufficient to allow such an ice sheet to grow. There is every 

 reason to believe that during the great Ice Age ice sheets did not 

 develop over the Arctic islands of Canada or over most of Siberia. 

 The temperatures were low, but moisture was insufficient. And yet 

 in the Southern Hemisphere the ice grew in the heart of a vast high- 

 pressure area. 



Still another problem is that of oscillation of climate as expressed 

 by varying amounts of sea ice and variations in the intensity of cur- 

 rents. R. C. Mossman and others have shown that there is a corre- 

 lation between certain Antarctic records and those from places in the 

 Northern Hemisphere. There seems to be every likelihood that be- 

 fore long general weather forecasts of real value will be possible for 



3 W. H. Hobbs, Tbe Glacial Anticyclones (1926). A valuable symposium on Arctic 

 meteorology is the collection of papers read at tbe first meeting of the International 

 Society for the Exploration of Arctic Regions by Airship, published in Petermann's Mlt- 

 teilungen, Ergiinzungsheft 191 (1927). A chart shows the route of the proposed expedi- 

 tion and the location of observing stations. 



