Correlation of cosmic‐ray geomagnetic effects

Abstract

In the theory of the cosmic‐ray orbits in the magnetic field of the Earth developed by Störmer and Lemaître and Vallarta the intensity of the cosmic radiation in space outside the atmosphere depends upon five parameters, all of which are subject to independent variation. Corresponding to these there are five geomagnetic cosmic‐ray effects, namely, the latitude‐effect, the zenith‐angle effect at constant azimuth, the azimuthal effect at constant zenith‐angle, the radius‐ or longitude‐effect, and the magnetic moment or storm‐effect. All of these effects have been reported from observational data and their interpretation given in terms of the theory. In most instances the theory has been used to determine the variation of the low‐energy limit of the incident radiation and the energy‐spectrum of primary cosmic radiation has appeared in the interpretation as an adjustable parameter. Since all of the effects depend upon this parameter and upon the relative intensities of positives and negatives in the primary beam, we may inquire to what extent the various effects are consistent with one another. Since atmospheric absorption is always present, it will be convenient to refer to the intensity as being proportional to the effects produced after reaching the point of observation by the particular component of primary radiation. Because of the greater wealth of observational data the effects observable in the vertical direction at sea‐level will be of principal interest.