l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IIO 



C. Attempt at a Physical Explanation of the Observed Relationship 



In the following chapter will be described an attempt at a schematic 

 description of the manner in which the influence of short- and long- 

 duration eruptions of those solar particles which leave the sun is 

 transmitted to the troposphere. We are convinced that this expla- 

 nation is incomplete and will go through important modifications in 

 the future. 



The places of formation of these eruptions of electrically charged 

 and uncharged solar particles (negatrons, protons, neutrons, alpha 

 particles, as well as Na-, Ca-, Mg-, and other atoms) which leave the 

 sun, the so-called M-regions, are situated within the "king zones" 

 (between 40° N. latitude and 40° S. latitude). Some of the best- 

 known solar phenomena that attend this kind of eruption are: (i) a 

 considerable strenghtening of certain corona lines, especially 5303 and 

 5694 A., and (2) certain kinds of prominences. The effects of these 

 particles are partly localized, both on the dark and sunlit earth 

 hemispheres. The best known of the consecutive geophysical reac- 

 tions to these particle invasions are "ionosphere storms," auroras, 

 geomagnetic storms, disturbances of the electric earth-current sys- 

 tem, and a special kind of irregular, long-duration fading of short 

 radio waves. Being absorbed, the particles deliver to the high 



mv^ 

 atmosphere their kinetic energy , which — because of their high 



cm. 

 velocity: V'-~'2Xio® ' — is not inconsiderable. The main resulting 



consequences are : A pressure effect in the direction of the shocks ; 

 ionization ; excitation of the emission of visible light-, ultraviolet-, 

 and X-ray-photons ; dissociation, especially of the molecular oxygen ; 

 production of chemical compounds in form of condensation nuclei ; 

 and heating of the absorbing layer. Moreover, an electrical polariza- 

 tion of the high atmospheric layers may be expected, because of the 

 segregation by the geomagnetic field of those portions of the particles 

 with positive and negative electric charges, and because of the dif- 

 ferent heights of the absorbent layers for the positive protons and 

 alpha particles, and the negative electrons, according to their different 

 mass and velocity. 



As to the magnitude of the shock-pressure effect that may be ex- 

 pected, no details have hitherto been known. The dissociation of the 

 oxygen molecules must be accompanied by a considerable increase 

 in pressure, provided there is available a sufficiently great amount of 

 molecular oxygen. This condition may be fulfilled much less in sum- 



