NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 



99 



west longitude and finally also for the most easterly fields between 

 io° and 20° west longitude of the route Channel to New York. 

 As is easily seen there is a gradual development in these curves 

 from SSW. towards NNE., while the curves on both sides of 

 this course as well toward the northwest as toward the southeast 

 have a quite dififerent nature. The conclusion seems therefore 

 natural that from the southwest corner of the Portugal-Azores 

 region water-masses of dififerent temperature were transported in 

 the direction of NNE, and it is in consequence of this transporta- 

 tion that an uninterrupted relationship exists between these fields. 



1S91' ^9 1900 123^56780 10 



w-irw. 



hS'N. 



i30-39'\N. 

 a137-JS''/v. 



Figure 47. Curves for the anomalies of the surface temperature in Feb- 

 ruary in the fields indicated on the right. 



It also points in the same direction that, as earlier remarked, the 

 current is often more at right angles to oi5r observational region 

 than along it and the transportation in a west to east direction 

 within our fields is therefore relatively small and less noticeable in 

 our observational series and isopleth diagrams. 



According to these results it appears that the islands or bands 

 which are found in the decade isopleths (see, for example, 19 10, pi. 

 41) perhaps are produced by wandering minima or maxima, but 

 more probably depend upon particular wind relations or other local 

 circumstances which one must study on the decade charts of air pres- 

 sure and wind distribution. 



