Modeling inward diffusion and slow decay of energetic electrons in the Earth's outer radiation belt

Authors

Q. Ma, University of California - Los Angeles
W. Li, University of California - Los Angeles
R. M. Thorne, University of California - Los AngelesFollow
B. Ni, Wuhan University of Science and TechnologyFollow
C A. Kletzing, University of IowaFollow
W. S. Kurth, University of IowaFollow
G. B. Hospodarsky, University of IowaFollow
Geoffrey Reeves, Los Alamos National LaboratoryFollow
M. G. Henderson, Los Alamos National LaboratoryFollow
Harlan E. Spence, University of New HampshireFollow
D. N. Baker, University of Colorado BoulderFollow
J. B. Blake, Aerospace CorporationFollow
J. F. Fennell, Aerospce CorporationFollow
S. Claudepierre, Aerospace Corporation
V. Angelopoulos, University of California - Los Angeles

Abstract

Abstract

A new 3-D diffusion code is used to investigate the inward intrusion and slow decay of energetic radiation belt electrons (>0.5 MeV) observed by the Van Allen Probes during a 10 day quiet period on March 2013. During the inward transport, the peak differential electron fluxes decreased by approximately an order of magnitude at various energies. Our 3-D radiation belt simulation including radial diffusion and pitch angle and energy diffusion by plasmaspheric hiss and electromagnetic ion cyclotron (EMIC) waves reproduces the essential features of the observed electron flux evolution. The decay time scales and the pitch angle distributions in our simulation are consistent with the Van Allen Probe observations over multiple energy channels. Our study suggests that the quiet time energetic electron dynamics are effectively controlled by inward radial diffusion and pitch angle scattering due to a combination of plasmaspheric hiss and EMIC waves in the Earth's radiation belts.

Department

Physics

Publication Date

2-2015

Journal Title

Geophysical Research Letters

Publisher

American Geophysical Union Publications

Digital Object Identifier (DOI)

10.1002/2014GL062977

Document Type

Article

Recommended Citation

Q. Ma, W. Li, R. M. Thorne, B. Ni, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, G. D. Reeves, M. G. Henderson, H. E. Spence, D. N. Baker, J. B. Blake, J. F. Fennell, S. G. Claudepierre, and V. Angelopoulos, ‘Modeling inward diffusion and slow decay of energetic electrons in the Earth’s outer radiation belt’, Geophysical Research Letters, vol. 42, no. 4, pp. 987–995, Feb. 2015.