NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC I5I 



This he interprets as follows : What he calls the " polar mag- 

 netic radiation " of the sun is unequal over the sun's surface and 

 may be divided between meridians of greater and less density. 

 This " magnetic radiation " would reach the earth with varying 

 intensity according to the meridian of the sun which sends it. This 

 should be concentrated in oval regions which surround our magnetic 

 and geographical poles up to 60° magnetic polar distance. Compar- 

 ing the terrestrial magnetic variations within each solar rotation wath 

 temperature variations in the United States in the same period of 

 28.68 days he finds good agreement. Nevertheless the variation of 

 temperature is sometimes in the same direction as the variation of the 

 magnetic force, at other times inverted. He gives graphically the 

 observed temperature anomalies for each solar rotation and arranges 

 these curves into two classes, according as they go generally in the 

 same way or the opposite way to the average magnetic curves for 

 these periods, and finds about equal numbers of each sort. The two 

 mean curves of each of these groups of direct or inverted curves, and 

 also the values which obtain when one takes the values of the in- 

 verted curves from the values of the direct ones, show a marked 

 similarity with the curves of the average magnetic variations within 

 the 26.68 day period. Particularly striking is this for the curves 

 which Bigelow found in this way for five stations in Dakota for 

 the time interval 1878 to 1893 which includes about 220 solar rota- 

 tions. These three curves (for the direct, inverted, and direct 

 niinus inverted temperature variations) are almost completely con- 

 gruent wnth the magnetic curve and it appears scarcely possible 

 to deny that this indicates real dependence. This further indicates 

 that the sun sends unequal quantities of energy, during its rotation 

 period, and this short interval variation in the received quantity of 

 energy produces corresponding short period variations in the condi- 

 tion of the atmosphere, at least in the United States. The air tem- 

 perature varies in association therewith sometimes in the same 

 direction as the energy variations and sometimes the opposite. 



From Bigelow's- investigations it appears that the inverted varia- 

 tions occur on the whole during half the number of the rotation 

 periods of the sun in the course of many years, and that the distri- 

 bution of these inverted periods varies accordingly to the sun spot 

 period. At the time of sun spot maxima they fall generally in the 

 summer months or in the autumn months, but at the time of sun 

 spot minima generally in the winter months. Bigelow does not pro- 

 pose any general explanation for this relation, but according to 



