Variability of the Energetic Particle Population in Geospace and Geomagnetic Cutoff Rigidity in Response to Magnetospheric Activity

Abstract:

Understanding the geospace radiation environment is a challenging and practically important task. Exposure to energetic particles often leads to malfunctions and unexpected failures of electronics onboard spacecraft. Geomagnetic field deflects SEPs and GCRs moving through geospace. However, some of these particles propagate to LEO and have a high penetration capability, thus producing significant radiation hazards for human spaceflight.

The work presented here focuses on characterizing the variability of the energetic GCRs and SEPs protons during an active time in the Earth's magnetosphere. We also discuss the variability of the cutoff rigidity. Another focus of the presentation is the variability of the protons energy spectrum as they propagate deep in the magnetosphere.

Numerical modeling of the geospace radiation environment is a complex problem. Such, the global modeling of the Earth's magnetosphere is done using SWMF/BATSRUS code. The population of SEPs and GCRs in geospace and the geomagnetic cutoff were simulated using SWMF/AMPS.

Support from grant 80NSSC17K0681 from the NASA LWS Program is gratefully acknowledged.