Speaker
Description
Forbush Decreases (FDs) refer to the rapid decrease and slow recovery in the observed intensity of galactic cosmic rays (GCRs). They are primarily caused by active solar events that sweep low-energy galactic cosmic rays away from Earth. Different characteristics of FDs have been observed through various experiments. The observations are collected mostly from worldwide ground-based Neutron Monitors (NMs). These monitors primarily measure secondary neutrons originating from interactions in the Earth's atmosphere. The Dark Matter Particle Explorer (DAMPE) is a satellite-based cosmic-ray experiment that has been stably opeated for over seven years. Its precise measurements of cosmic ray electrons plus positrons provide a unique perspective for the direct study of FDs. In our analysis, we investigate the properties of FDs observed by DAMPE from 2017 to 2021. These properties include the amplitude of decrease and the recovery time, both as functions of energy. Furthermore, we employ a numerical model to simulate FDs and successfully replicate their process. Our results suggest that head-on CME events lead to energy-dependent recovery times, while edge-on events result in energy-independent recovery times for FDs.
