NO. 4 TEMPERATURE VARIATIONS IN THE NORTH ATLANTIC 187 



ties of heat into the higher layers of the air does not tend to affect 

 them so much since they will pass on these quantities of heat into 

 outlying space by increased outgoing radiation. 



In this way Huntington thinks that the equatorial and subtropi- 

 cal regions may lose heat and that thereby the temperature may 

 be lowered by increased storminess at maximum of sun spots. In 

 higher latitudes and especially in polar regions no such sinking of 

 the temperature would follow. In those regions perhaps no great 

 difference occurs between maximum and minimum of sun spots, or 

 the relation may be even inverted so that an increase of tempera- 

 ture may occur at maximum of sun spots. 



As the reader may see, Huntington's view of the cause of the 

 variations in the air temperature of the earth agrees with that which 

 Bigelow had previously advanced in so far as he attributes the 

 principal cause to the air circulation. Other investigators, particu- 

 larly the two Lockyers, as we have said in our summary of earlier 

 investigations in this matter, have come to the same conclusion. We 

 see also that Huntington's conclusions have some similarity with 

 ours, although we had not in fact thought of the frequency of 

 storms, but more of the increase or diminution of the air circulation 

 in general. Furthermore, we had in mind a somewhat different 

 method of correlation between variations in the air circulation and 

 variations in the temperature of the atmosphere. 



Kullmer has called attention in his work to the possibility of a 

 correlation between the storms and the terrestrial magnetism. He 

 maintains that there are three storm centers which correspond to 

 the three magnetic poles. In the southern hemisphere there is only 

 one magnetic pole and the cyclonic storms circulate about it in the 

 vicinity of 60° south latitude, not concentrically about the geographi- 

 cal pole, but about the magnetic pole. In the northern hemisphere, 

 the most important storm track of the world extends almost exactly 

 concentric with the magnetic North Pole in northern Canada, thence 

 across North America, over the Atlantic Ocean to Scandinavia, and 

 the storm track in the Atlantic Ocean follows almost exactly the 

 lines of equal magnetic total intensity. In Siberia there is another 

 secondarv magnetic pole and corresponding to it there is a third 

 storm track which has its middle point in Japan. 



XI. THE VARIATIONS IN THE METEOROLOGICAL RELATIONS 



IN THE TROPICS AND THE NORTHERN REGIONS 



From Koppen's curves for the mean temperatures in different 



years in different regions of the earth it is apparent that in many 



instances very distinct relations occur between the sun spot periods 



