Effect of Low-Harmonic Magnetosonic Waves on the Radiation Belt Electrons Inside the Plasmasphere

Author
Keywords
Abstract
In this paper, we presented two observational cases and simulations to indicate the relationship between the formation of butterfly-like electron pitch angle distributions and the emission of low-harmonic (LH) fast magnetosonic (MS) waves inside the high-density plasmasphere. In the wave emission region, the pitch angle of relativistic (>1 MeV) electrons becomes obvious butterfly-like distributions for both events (near-equatorially mirroring electrons are transported to lower pitch angles). Unlike relativistic (>1 MeV) electrons, energetic electrons (<1 MeV) change slightly, except that relatively low-energy electrons (<~150 keV) show butterfly-like distributions in the 21 August 2013 event. In theory, the LH MS waves can affect different-energy electrons through the bounce resonance, Landau resonance, and transit time scattering. By performing the Fokker-Planck diffusion simulations, we demonstrate that the bounce resonance with the LH MS waves mainly leads to the butterfly pitch angle distribution of MeV electrons, whereas the Landau resonance and transit time scattering mainly affect energetic electrons in the high-density region.
Year of Publication
2019
Journal
Journal of Geophysical Research: Space Physics
Date Published
05/2019
ISSN Number
2169-9380
URL
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026328
DOI
10.1029/2018JA026328