BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 25, pp. 477-590 NOVEMBER 2, 1914 



THE SOLAR HYPOTHESIS OF CLIMATIC CHANGES ^ 



BY ELLSWORTH HUNTINGTON ^ 



(Read before the Society January 1, lOlJf) 



CONTENTS 



Page 



Introduction 479 



Geological importance of studj^ of present climatic changes 479 



Hypotheses in explanation of present climatic changes 481 



The meteorological hypothesis ^ 481 



The volcanic hypothesis • 483 



The solar hypothesis 484 



General discussion 484 



Disagreement between solar and terrestrial temperature changes. 485 



Present status of the solar hypothesis 486 



Newcomb's conclusions as to temperature 486 



Relation of temperature changes during sun-spot cycle to 



glaciation 490 



Apparent contradictions between temperature changes in dif- 

 ferent parts of the world 491 



EfCect of Arctowski's pleions on the distribution of temperature. . 492 



Cyclonic storms within the tropics 493 



Continental versus marine climates in Europe during the sun-spot 



cycle 494 



Cyclonic storms in temperate latitudes 497 



Researches of Professor KuUmer 497 



Cyclonic storms during the sun-spot cycle 501 



Kullmer's law of the shift of the storm track 502 



Shifting of storms in the main storm belt 510 



A test of the shifting of storm tracks by means of correla- 

 tion coefficients with sun-spots 513 



Cyclonic storms and volcanic eruptions 515 



Shifting of the storm track in Europe 517 



The "cyclonic" versus the "caloric" form of the solar hypothesis. . 521 



The reduction of terrestrial temperature by cyclonic storms 522 



A possible magnetic or electric cause of cyclonic storms 524 



The climate of historic times 526 



General discussion 526 



1 Manuscript received by the Secretary of the Society July 10, 1914. 

 •With the cooperation of Charles J. Kullmer and E, E. Free. 



XXXV — Bull. Geol. See Am., Vol. 25, 1913 (477) 



