222 HOBBS— ROLE OF GLACIAL ANTICYCLONE [April 24, 



explorations and has endeavored to show the conjugate relationship 

 of the Antarctic anticyclone area with successive zones of cyclones 

 and anticyclones which migrate in an easterly direction around it. 

 Thus it is found that between the low pressure zones lying within 

 the tropics, and the fixed high pressure area above Antarctica, there 

 are centered near the latitude of 40° S., a series of broad anti- 

 cyclones which progress eastwardly and produce the effect of a 

 zone of mean high pressure.'^* To the southward of this series of 

 anticyclones and centered near the latitude of 60° S., there are a 

 series of more vigorous cyclones of smaller diameter but progress- 

 ing eastwardly at about the same angular rate. As we now know 

 from later observations, the stationary cyclones lying over the 

 Weddell and Ross Seas, establish further connection with the anti- 

 cyclones above the Antarctic continent. 



The cold outward flowing currents from the Antarctic conti- 

 nent upon reaching the zones of progressing cyclones are believed 

 by Lockyer to ascend in them upon the west side, thus accounting 

 for the cold western half of these cyclones near the ocean level. 



The Australian Antarctic Expedition appears now to have sup- 

 plied the evidence for such a rise of the air at the southern margin 

 of the progressing cyclones near the borders of Adelie Land. As 

 Mawson puts it : 



" It appeared as if we were situated on the battlefield, so to speak, of 

 opposing forces. The pacific influence of the ' north ' would hold sway for 

 a few hours, a whole day, or even for a few days. Then the vast energies 

 of the ' south ' would rise to the bursting point and a ' through blizzard ' 

 would be the result." 



At this junction zone of the glacial anticyclone with progressing 

 cyclones, the air rises to produce rotating cumulus clouds, and it 

 seems not unlikely that the interesting " whirlies " are connected 

 with this uprise. ^° 



The air having ascended in a cyclone on its journey northward 

 toward the equator is believed next to pass downward through the 

 progressing anticyclones to the northward, and to reach the ocean's 

 surface as the warm current on the west side of these eddies. 



'^^ W. J. Humphreys, " On the Physics of the Atmosphere," Jour. Frank- 

 lin Inst., 1913, pp. 222-223. 



so Mawson, "The Home of the Blizzard," Vol. 2, pp. 157-8 (fig.). 



