Characteristic energy range of electron scattering due to plasmaspheric hiss

TitleCharacteristic energy range of electron scattering due to plasmaspheric hiss
Publication TypeJournal Article
Year of Publication2016
AuthorsMa, Q, Li, W, Thorne, RM, Bortnik, J, Reeves, GD, Kletzing, CA, Kurth, WS, Hospodarsky, GB, Spence, HE, Baker, DN, Blake, JB, Fennell, JF, Claudepierre, SG, Angelopoulos, V
JournalJournal of Geophysical Research: Space Physics
Date Published11/2016
Keywordselectron flux decay; pitch angle scattering; Plasmaspheric Hiss; Van Allen Probes; Van Allen Probes observation
AbstractWe investigate the characteristic energy range of electron flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic electron flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed energy of significant electron decay increases with decreasing L shell and is well correlated with the energy band corresponding to the first adiabatic invariant μ = 4–200 MeV/G. The electron diffusion coefficients due to hiss scattering are calculated at L = 2–6, and the modeled energy band of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed energy range of electron decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2-D Fokker-Planck simulation of the electron phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV–1 MeV electrons with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower energies and more flattened distributions at higher energies. Our study provides reasonable estimates of the electron populations that can be most significantly affected by plasmaspheric hiss and the consequent electron decay profiles.
Short TitleJ. Geophys. Res. Space Physics

Page Last Modified: January 24, 2017