CLIMATOLOGY 



two parties at the South Pole around the New Year 

 1911-12 experienced temperatures of —22° F. and 

 — 28° F. This record was taken at an elevation of 

 about nine thousand feet. It seems certain that the 

 annual range of temperature in the heart of a continent 

 will be much greater than that recorded on the coast at 

 Cape Evans. The annual range at the latter is about 

 45° F. Perhaps we may therefore assume that the July 

 temperature at the South Pole is about —60° F., which 

 is much the same as that of the coldest place in Siberia 

 (Verkhoyansk —59° F.). Probably the highest point 

 on the Queen Maud Range (some six thousand feet 

 higher) is the coldest place on our earth, as I indicated 

 in my discussion of this problem in 1920 (see my Aus- 

 tralian Meteorology, Figures 50 and 51). These very 

 cold temperatures are of course like those of the ''iso- 

 thermal layer" (or tropopause) which lies some six 

 miles above us in temperate lands. Above this height 

 the drop in temperature of the outer atmosphere is only 

 very gradual with increased height. 



General Southern Circulation 



In the southern hemisphere it has long been known 

 that the region is dominated essentially by two belts 

 of low pressure and an intermediate belt of high pres- 

 sure. Thus Hann records the average pressure near 

 the equator at 757.9 mm. From here it increases as 

 we move south to latitude 30° S., where it is a maxi- 

 mum (for the world) of about 763.5 mm. Proceeding 

 south again we find that by far the lowest average 

 pressures occur about the Antarctic Circle, somewhere 



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