Size Distribution of Forbush Effects

Abstract

The distribution of Forbush effect magnitude for cosmic rays with a rigidity of 10 GV observed in 1957–2016 is studied based on a large amount of experimental data from the IZMIRAN database of Forbush effects and interplanetary disturbances. It is demonstrated that the distribution for sufficiently strong Forbush effects follows a power law with an index close those determined earlier for coronal mass ejections. The obtained distributions are evidence that almost all Forbush effects with magnitudes exceeding 1.4% were included into the database. The majority of these effects are associated with interplanetary coronal mass ejections.