ANTARCTIC INFLUENCES ON AUSTRALIAN CLIMATE 



291 



,N D Jan. F 



N Dec J 



+50° 



It was soon realized by mariners that the mean isobars fell in 

 value as the Antarctic Continent was approached. But as the result 

 of comparatively recent researches it has been found that this only 

 holds good down to about 60° S. Thereafter the isobaric values in- 

 crease in general towards the pole. Fricker in 1893 perhaps first 

 discussed the meaning of the prevalence of easterly winds around the 

 Antarctic Continent. Later (as Simpson states) "The Gauss expedi- 

 tion during her stay of elev- 

 en months in 66° S. latitude 

 had easterly winds, often 

 extremely strong, during 73 

 per cent of the total time." 

 The research of Hepworth,^ 

 Lockyer,^ and Meinardus^ 

 (all writing about 19 10) 

 showed that over the 

 Southern Ocean there was a 

 constant succession of true 

 cyclonic depressions pass- 

 ing from west to east. 

 These cyclones have west- 

 erly winds (the roaring 

 forties) on their northern 

 sides and easterly winds on 

 their southern sides. 



Lockyer postulates 

 some eight of these cyclones 

 more or less continuously 

 wandering round the 

 Southern Ocean, and each 

 very much like that de- 

 picted on the weather chart 

 for April 11, 1913 (Fig. 4). 

 Over the continent itself he 



placed a permanent anticyclone centered more or less over the geo- 

 graphic pole. 



Meinardus differs from Lockyer in that his Antarctic cyclones 

 are often centered over the Gaussberg (66° S.) rather than in latitude 



- M. W. C. Hepworth: Climatology of South Victoria Land and the Neighbouring Seas (National 

 Antarctic Expedition, 1901-1904, Meteolorogy, Part I, pp. 417-452), Royal Soc, London, 1908. 



' W. J. S. Lockyer: Southern Hemisphere Surface-Air Circulation: Being a Study of the Mean 

 Monthly Pressure Amplitudes, the Tracks of the Anticylcones and Cyclones, and the Meteorological 

 Records of Several Antarctic Expeditions, Solar Physics Committee, London, 1910. 



^ Wilhelm Meinardus: Meteorologische Ergebnisse der Winterstation des "Gauss" 1902-1903 

 (Deutsche Siidpolar-Expedition, 1901-1903, Vol. 3: Meteorology, Part L PP- 1-339; see especially 

 section D: Betrachtungen iiber die allgemeine Zirkulation der Atmosphare im Bereich des Sud- 

 polargebiets, pp. 323-339), Berlin, 1909-1911. 



-40° 



Fig. 6 — Mean monthly temperatures at certain Austra- 

 lian and Antarctic stations. For comparison the mean 

 monthly temperature in 78° N. is also given. (Antarctic 

 and Arctic values from Vol. i, pp. 84-85, of report by 

 G. C. Simpson cited in footnote i.) 



