240 



WEATHER AND CLIMATE 



tains is moist, since the moisture in the air is condensed in 

 rising over them. On the lee side the country is dry, as 

 the air which moves over it has already been deprived of 

 its moisture. 



The country on the lee side will also be subject to hot, 

 dry winds like the chinook winds of the eastern Rockies 

 and the foehn in Switzerland. As the moist winds pass 



POPOCATEPETL 

 A snow-covered mountain in the tropics. 



over the mountains their moisture is condensed. This 

 raises their temperature so that it is above what it would 

 normally be at the altitude reached. As these winds come 

 down on the lee side of the mountain, the air is compressed 

 and thus heated (page 125) so that on this side it is consid- 

 erably warmer at the same altitude than on the windward 

 side. Thus high mountains affect not only the rainfall, 

 but the temperature changes of the region round about. 



