New reconstruction of the event-integrated spectra for GLE events

Abstract

<p>Here we report a new reconstruction of the event-integrated spectra of solar energetic particles (SEP) detected by neutron monitor (NM) network and space-borne detectors (mainly GOES data) during ground-level enhancement (GLE) events. The reconstruction of SEP fluences is based on the “bow-tie” method employing the latest advances in the NM data analysis (a time-dependent GCR background and the use of the NM yield function directly verified with the AMS-02 experiment data), usage of different space-borne detectors data and a detailed study of different uncertainties. As a result of this work, we obtained integral fluences of SEPs in the energy range from 30 MeV to a few GeV for 58 moderate and strong GLE events since 1956. The results were fitted with the modified Band-function (a double power-law function with two exponential cutoffs). An easy-to-use presentation of SEP fluences in the form of an analytical expression forms a solid basis for new studies in different fields, such as the influence of SEPs on the atmosphere and a statistical study of extreme solar activity.</p>