Modulation of Galactic Cosmic Ray Intensity in the Approximation of Small Anisotropy

Abstract—

The propagation of cosmic rays in the interplanetary medium based on the transport equation is considered. The solution of the cosmic ray transport equation is obtained for the known energy distribution of high-energy charged particles at the heliospheric boundary. The spectrum of galactic cosmic rays in the local interstellar medium is taken on the basis of the data from the Voyager 1 and 2 spacecraft. The flux of galactic cosmic rays in different periods of solar activity is calculated. Cosmic ray intensity gradients are estimated, and these calculations are compared to the data from space missions. The anisotropy of the angular distribution of cosmic rays is calculated. It is shown that the flux of galactic cosmic rays in the Earth’s orbit has an azimuthal direction, and the value of the anisotropy of protons with energies from 1 MeV to 1 Gev is of the order of 0.5%.