Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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Modeling the Electron Flux Enhancement and Butterfly Pitch Angle Distributions on L Shells <2.5
Author | Hua, Man; Li, Wen; Ma, Qianli; Ni, Binbin; Nishimura, Yukitoshi; Shen, Xiao-Chen; Li, Haimeng; |
Keywords | 3-D radial belt modeling; Butterfly pitch angle distribution; Electron flux enhancement; inner belt and slot region; Inward radial diffusion; local wave-particle interactions; Van Allen Probes |
Abstract | We analyze an energetic electron flux enhancement event in the inner radiation belt observed by Van Allen Probes during an intense geomagnetic storm. The energetic electron flux at L~1.5 increased by a factor of 3 with pronounced butterfly pitch angle distributions (PADs). Using a three-dimensional radiation belt model, we simulate the electron evolution under the impact of radial diffusion, local wave-particle interactions including hiss, very low frequency transmitters, and magnetosonic waves, as well as Coulomb scattering. Consistency between observation and simulation suggests that inward radial diffusion plays a dominant role in accelerating electrons up to 900 keV and transporting the butterfly PADs from higher L shells to form the butterfly PADs at L~1.5. However, local wave-particle interactions also contribute to drive butterfly PADs at L ≳ 1.9. Our study provides a feasible mechanism to explain the electron flux enhancement in the inner belt and the persistent presence of the butterfly PADs at L~1.5. |
Year of Publication | 2019 |
Journal | Geophysical Research Letters |
Volume | 46 |
Number of Pages | 10967-10976 |
Section | |
Date Published | 09/2019 |
ISBN | |
URL | https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL084822 |
DOI | 10.1029/2019GL084822 |