NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC II9 



is plainly shown by our charts, plates 16 to 41. However, we find 

 also that an apparently similar distribution of air pressure in the 

 same month of different years is consistent with different effects 

 upon the air temjierature over Europe. We see, for example, that 

 in the years 1905 and 1907 the air pressure distribution in January- 

 February over the North Atlantic Ocean and the west coast of 

 Europe had the same character, while the temperature distribution 

 over west Europe in February was somewhat different. In Febru- 

 ary, 1905 (see pi. 30), southwest Europe, Spain, and Portugal had 

 negative temperature anomalies while middle and north Europe 'had 

 positive anomalies. In February, 1907 (see pi. 34), on the other 

 hand, the temperature anomalies were negative in the whole west, 

 south, and middle Europe and also on the west coast of Africa and 

 northwards to southern Scandinavia. In northern Scandinavia the 

 temperatures were considerably higher than in February, 1905. On 

 the Atlantic coast of America the temperature anomalies were 

 negative in February in both years. These negative anomalies 

 had, however, a greater extension westward in 1905 than in 1907. 

 In March, 1905 and 1907, the temperature conditions over west 

 Europe were quite similar. 



The air pressure distribution in the easterly North Atlantic and 

 west Europe are very similar to one another in January and Febru- 

 ary, 1906 and 1908 (see pis. 32 and 36), with a well-developed 

 tendency to produce cold winds, colder in 1906 than in 1908. But 

 the temperature was opposed and was even very cold in the year 

 1906 over France, Great Britain, and the Faroe Islands although 

 very warm in the year 1908. Also in Hamburg and Norway it was 

 warm. In January and February, 1907, there were, on the other 

 hand, warm winds o'ver the ocean, but in spite of this, cold tempera- 

 tures prevailed in February over western, middle, and southern 

 Europe, even colder than in February, 1906. To be sure the winds 

 in January and February on the European coast were weaker and 

 also on the whole more northerly in 1907 than in 1906, but in 1908 

 (see pi. 36) the pressure distribution was nearly the same as in 

 1907, and in spite of it the temperature over the coast lands of mid- 

 dle and south Europe was relatively high with positive anomalies. 

 One is inclined to the impression that, as for example in 1907, the 

 air temperature may be made low by special causes and one is led 

 to think of those variations in the solar radiation which were found 

 by pyrheliometric measurements and which indicated a secondary 

 minimum of radiation in 1907. In March, however, unluckily for 



