Solar Activity and Cosmic Ray Variations in September 2017

Abstract

The results are presented from an analysis of data on solar activity and cosmic ray variations observed in September 2017. This period is characterized by a sharp increase in the solar flare activity in the active region AR 12673 during the late descending phase of the 24th solar activity cycle. Solar protons are recorded by the particle instruments aboard the GOES-13 satellite, in the atmosphere, and by the ground-based neutron monitor network. A moderate Forbush decrease in the cosmic ray flux during September 6–10 is also recorded by a number of neutron monitors. Several solar proton energy spectra during September 10, 2017, (GLE72 event) are evaluated using the results from satellite measurements, balloon observations, and neutron monitor records.