Solar energetic particle event on 28 October 2021 as observed by the neutron monitor network

Rolf Bütikofer, International Foundation “High Altitude Research Stations Jungfraujoch and Gornergrat”, and Physics Institute, University of Bern, Switzerland

Christian T. Steigies, Extraterrestrial Physics, Institute of Experimental and Applied Physics, Kiel University, Germany

The first solar energetic particle event during the current solar cycle 25 observed on ground, i.e. GLE#73, was detected on 28 October 2021 by a few neutron monitors of the worldwide network. Although GLE#73 showed only a small, gradual increase in the cosmic ray intensity near Earth, the Athens GLE Alert system issued successfully an automatic alert at 16:09 UT.

We present the outcome of our GLE analysis of this SEP event based on neutron monitor data and assess the additional radiation doses that may be acquired at different locations at a typical flight altitude. In addition, we compare our results with the findings published by Mishev et al., 2022.