CLIMATOLOGY 



climate. This formula is W = 9° — o.i C. Thus in 

 Siberia if the coldest month (C) has a temperature of 

 —40° C, then (by substitution) we see that the 

 warmest month (W) of the place can be (9 + 4 ) or 

 + 13° C. and yet it may be included within the polar 

 belt. In Staten Island (near Cape Horn) the cold- 

 est month is +2.5, so that the warmest should be 

 (9 —0.25) or 8.75, which is a trifle colder than the 

 hottest month at Staten Island. It is therefore just 

 outside the polar climatic area. At Cape Farewell 

 (Greenland) the coldest month is —5.7^, the hottest 

 +6.2° C. It falls within the polar climates, though 

 here birches and willows grow in ''forests" to the 

 height of over twelve feet. Some climatologists accept 

 a summer temperature of 9° C. (or 48° F.) as limit- 

 ing polar regions. This isotherm is plotted in Figure 

 26 at A and we see that all Antarctica and the sur- 

 rounding ocean fall well within it. Furthermore the 

 area with a summer temperature lower than this is 

 much larger in the South Polar regions than it is in 

 the north. (See B, Figure 26.) 



Considering the northern and southern regions, there 

 is no comparison in the general environments owing to 

 the absence of all plant life in Antarctica; there is no 

 land animal life (excluding a few insects) and there- 

 fore no human settlers if we may except a few ex- 

 plorers ! Yet the average annual temperatures are not 

 very dififerent, while northern Siberia has colder rec- 

 ords than anything experienced by explorers in a south- 

 ern winter. The whole difference lies in the summer 

 temperatures and this is best indicated in the diagrams 



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