NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 1 53 



The direct type of temperature curves he found within the tropics, 

 in South America, Australia, and South Africa, also in North Africa, 

 southwest Europe (France and Spain), in the most westerly of the 

 United States, on the coast of the Pacific Ocean, and in Honolulu 

 and west Greenland. 



The indirect type he found in Japan and China, northwest, middle 

 and southeast Russia, in middle Europe, on the Faroe Islands, on 

 Iceland, east Greenland, and the following parts of the United 

 States : the South Atlantic States, west Gulf States, and the states 

 of the Great Lakes. 



The indifferent type he found in the highest parts of India, in mid- 

 dle Siberia, southwest Russia, and in the following regions of the 

 United States : in the North Atlantic States, on the north and south 

 plateau states of the Rocky Mountains. 



It is apparent that these dififerent temperature regions have con- 

 siderable similarity with those which Hildebrandsson found, taking 

 into account the different action centers. 



In a later treatise (1908) Bigelow compares the variations in the 

 solar prominences for the years 1872 to 1905 with the yearly varia- 

 tions in the magnetic horizontal intensity in Europe, the air tempera- 

 ture, the vapor pressure, and the air pressure in different regions of 

 the United States. He finds an eleven-year period in the variations 

 of all these elements and a shorter period of about three, or more 

 accurately 2.75 years. In the eleven-year period, which is shown 

 most strongly in the United States along the Pacific Ocean, as also 

 in the tropics, and less strongly easterly of the Rocky Mountains, 

 the temperature and vapor pressure vary both in the west and in the 

 east oppositely as the prominences and the magnetic force. In the 

 short period which he found everywhere prominent, it appears that 

 in the western states on the coast of the Pacific Ocean the tempera- 

 ture and the vapor pressure varied in the same direction with the 

 prominences and the magnetic force, while on the Rocky Mountain 

 plateau and eastward to the Atlantic coast the variation was op- 

 posite to these. There is, however, some phase displacement in the 

 easterly region. 



Bigelow finds the simplest explanation of this inversion of tem- 

 perature variations through the horizontal air circulation. A rise 

 of temperature in the tropics accompanying increased solar radia- 

 tion would produce a horizontal flow of cold air from high latitudes 

 and tend to cool the temperate regions by the cold winds. 

 II 



