The Characteristics of Forbush Decreases Based on the Data from AMS-02 Experiment and the Fluxes of Solar Cosmic Rays Based on GOES-15 Data

Abstract

An analysis of the dependence of the amplitudes of ten strongest Forbush decreases (preceded by halo-type CMEs) in the fluxes of protons and helium nuclei according to AMS-02 data on the magnetic rigidity of particles showed that this dependence is well approximated by a power function (as was shown in the PAMELA experiment) in the rigidity range from 1 to 10–12 GV. The exponent of this function is in the range from –0.38 ± 0.02 to –0.68 ± 0.04 for protons and from –0.41 ± 0.03 to –0.79 ± 0.04 for helium nuclei. But in a wider range of rigidity up to 20 GV, such an approximation ensures a significance level of 90–92% for protons and 90–96% for helium nuclei. Therefore, over the entire range of rigidity, exponential functions (providing a 95–99% significance level both for protons and helium nuclei) should be used. Comparison of time series for protons according to AMS-02 and GOES-15 data shows that SEP and SPE against the background of Forbush decreases are observed.