i 3 6 



The Realm of Nature 



CHAP. 



only by 20 on account of the sluggish heat transactions of 

 water, are at the same temperature, 55 F., as Verkhoyansk, 

 where, however, the air has been heated no less than 116 

 since January, this being the greatest annual range known. 

 The purely continental character of Verkhoyansk is 

 modified by the fact that in summer it is not far from 

 the shore of the cold Arctic Sea, whence cool monsoon 

 winds blow. In the southern hemisphere the tempera- 

 ture of the land has fallen by radiation a little below 

 that of the sea. The prevailing winds, however, are so 

 powerful, and the oceanic influence predominates so greatly, 

 that temperatures below 70 are found north of 20 S. only 

 on the west sides of the continents which are cooled by the 

 increasing upwelling of ocean water due to the trade winds. 

 The extreme tip of South America is the only southern 

 continental land which has a winter temperature below 40 

 in July, and the isotherm of 32 encircles the globe in 55 

 S., not touching any land at all, and showing but a slight 

 range from its winter position. 



191. Land and Sea Climates. The comparatively 

 cool summers and mild winters of the extremities of the 



southern continents 



compared with those 

 of the same latitudes 

 in the northern 

 hemisphere is a 

 direct result of the 

 arrangement of land 

 and sea on the 

 globe. A land 

 is every- 

 where extreme, a 

 sea climate is al- 

 ways mild ; but an 



of Fig. 27 will show that the average 

 for the year is nearly the same in both 



FIG. 28. Curve of monthly mean temperature for a r 



typical land -climate (dark) and sea -climate Climate 

 (light). The dark horizontal line marked re- 

 presents mean annual temperature ; the figures 

 show number of degrees above and below the 

 mean. 



examination 

 temperature 



hemispheres. Fig. 28 shows the annual range of tem- 

 perature in degrees above and below the mean for the 

 year in typical continental and oceanic climates. The 



