A theoretical analysis of the semiannual component in the heliocentric dependence of highenergy galactic cosmic rays.
Abstract
Annual and semiannual variations of the galactic cosmic rays and estimates of their radial derivatives have been used to determine the most significant terms at 1 AU in the convectiondiffusion equation. It turns out that both the changes in sign and the absolute value of the semiannual variation may be explained through the interplay of convection, diffusion across magnetic field lines, and drift. Indeed, such sign changes seem to be associated with reversals of the sign in the predominant polarity of the interplanetary magnetic field.
 Publication:

The Astrophysical Journal
 Pub Date:
 August 1976
 DOI:
 10.1086/154568
 Bibcode:
 1976ApJ...207..989P
 Keywords:

 Annual Variations;
 Cosmic Rays;
 Galactic Radiation;
 Interplanetary Medium;
 Convection;
 Diffuse Radiation;
 Fourier Analysis;
 Interplanetary Magnetic Fields;
 Radiant Flux Density;
 Solar Orbits;
 Space Radiation