THE ATMOSPHERE AND THE SUN 



By H. helm CLAYTON 



CONTENTS 



PAGE 



Introduction i 



I. Solar changes i 



II. Latitude effect of solar changes on the earth's atmosphere 4 



III. Seasonal influences 14 



IV. Atmospheric waves 18 



V. Relation of the weather waves to solar changes 29 



VI. Solar cycles and weather cycles 32 



VII. The use of weather cycles in forecasting 44 



Summary 48 



INTRODUCTION 



This paper is the fifth of a series giving the results of investiga- 

 tions of the relation of solar activity to atmospheric changes. The 

 earlier ones were published as Smithsonian Miscellaneous Collec- 

 tions, Vol. 68, No. 3; Vol. 71, No. 3; Vol. 'jy. No. 6; and Vol. 78, 

 No. 4. The author has been stimulated to continue these researches 

 because he ]:)elieves in their great importance. The interest of 

 Dr. C. G. Abbot and the sympathy and aid oi Mr. John A. Roel^ling 

 have encouraged him in the task and enabled him to undertake much 

 work that otherwise would not have been possible. Miss M. I. Rob- 

 inson has aided in the calculations needed for the discussion. 



I. SOLAR CHANGES 



It has long 1)een known that spots appear on the surface of the 

 sun and that the number and size of these spots varies from day 

 to day, from month to month, and from year to year. ]\Iore recently 

 it has been discovered by Dr. C. G. Abbot and his associates that the 

 radiation coming from the sun varies ; so that, in general, it is known 

 that the sun is hotter when there are many spots on its surface than 

 when there are few or none. 



There is also evidence that the heat of the sun varies from day 

 to day and from week tO' week in short cycles of change. The most 

 convincing evidence of this fact is the comparison of measurements 



Smithsonian Miscellaneous Collections, Vol. 82, No. 7 



