NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 



17 



The arrows in the chart in figure 7 and in plates i and 8 give 

 the average direction and intensity of the wind (computed from 

 the isobars as we shall later explain) for the months January and 

 February, (see fig. 7 and pi. i) and for March (pi. 8). We shall 

 return to this in chapter VII. ^ 



In this place we may state the following principal features of 

 the average distribution of the air pressure and wind in the ocean 

 region investigated, as they are shown in figure 8, which is taken 

 principally from Angot's Meteorology. 



Figure 9. Average temperature of the air in February according to the 

 Atlas of the Deutsche Seewarte " Atlantischer Ozean." 



Near south Greenland there is an air pressure minimum. A maxi- 

 mum region extends from the Spanish Inlet across over the Atlan- 

 tic Ocean to the southern part of the United States. The actual 

 maximum is generally found between the Madeiras and the Azores. 

 Between these zones — that is to say, over the greater part of our 

 investigated region — the wind is blowing towards the east and 

 northeast. The northeast trade with the opposite direction is found 

 only in the southeastern part of our investigated region. The 



* The arrows do not give in fact exactly the winds, but the direction of the 

 isobars. Their lengths indicate the magnitude of the air pressure gradients 

 as computed according to the distance between the isobars. It is therefore 

 not to be supposed that these arrows represent the actual winds either in 

 direction or strength. 



