Rapid loss of radiation belt relativistic electrons by EMIC waves

TitleRapid loss of radiation belt relativistic electrons by EMIC waves
Publication TypeJournal Article
Year of Publication2017
AuthorsSu, Z, Gao, Z, Zheng, H, Wang, Y, Wang, S, Spence, HE, Reeves, GD, Baker, DN, Wygant, JR
JournalJournal of Geophysical Research: Space Physics
Date Published08/2017
Keywordselectron loss; EMIC waves; pitch angle scattering; radial diffusion; Radiation belts; Van Allen Probes; wave-particle interaction
AbstractHow relativistic electrons are lost is an important question surrounding the complex dynamics of the Earth's outer radiation belt. Radial loss to the magnetopause and local loss to the atmosphere are two main competing paradigms. Here, on the basis of the analysis of a radiation belt storm event on 27 February 2014, we present new evidence for the EMIC wave-driven local precipitation loss of relativistic electrons in the heart of the outer radiation belt. During the main phase of this storm, the radial profile of relativistic electron phase space density was quasi-monotonic, qualitatively inconsistent with the prediction of radial loss theory. The local loss at low L-shells was required to prevent the development of phase space density peak resulting from the radial loss process at high L-shells. The rapid loss of relativistic electrons in the heart of outer radiation belt was observed as a dip structure of the electron flux temporal profile closely related to intense EMIC waves. Our simulations further confirm that the observed EMIC waves within a quite limited longitudinal region was able to reduce the off-equatorially mirroring relativistic electron fluxes by up to 2 orders of magnitude within about 1.5 h.
URLhttp://onlinelibrary.wiley.com/doi/10.1002/2017JA024169/full
DOI10.1002/2017JA024169
Short TitleJ. Geophys. Res. Space Physics


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