Diverse properties of electron Forbush decreases revealed by the Dark Matter Particle Explorer

Abstract

The Forbush decrease (FD) of cosmic rays is an important probe of the interplanetary environment disturbed by solar activities. In this work, we study the properties of 8 FDs electrons (including positrons) between 2 GeV and 20 GeV from January, 2016 to March, 2024, with the Dark Matter Particle Explorer. The maximum decrease amplitudes of these events are about 30% - 15%, and the amplitudes reduce with energy. The recovery time of these events shows diverse behaviors of their energy-dependence. Some of them show strong energy-dependence, while some have a nearly constant recovery time. It has been shown that such diverse behaviors could be related with the geometry of the disturbed regions of the interplanetary space by coronal mass ejections (CME), represented by the combined effect of the CME velocity, angular spread, and ejection direction.