Analysis of the Forbush effect in May 2005 using the spectrographic global survey method

Abstract

Based on the data from ground observations of cosmic rays (CRs) obtained by the spectrographic global survey method on the worldwide network of stations, the variations in the rigidity spectrum and anisotropy of galactic cosmic rays were investigated, along with changes in the geomagnetic cutoff rigidity in May 2005. A high degree of anisotropy (∼40–60% for the first spherical harmonics and ∼5–6% for the second spherical harmonics) was observed for particles with a rigidity of 4 GV at the moments of the maximum modulation of cosmic rays.