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Van Allen Probes observations of structured whistler mode activity and coincident electron Landau acceleration inside a remnant plasmaspheric plume
Author(s) -
Woodroffe J. R.,
Jordanova V. K.,
Funsten H. O.,
Streltsov A. V.,
Bengtson M. T.,
Kletzing C. A.,
Wygant J. R.,
Thaller S. A.,
Breneman A. W.
Publication year - 2017
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2015ja022219
Subject(s) - plasmasphere , whistler , physics , plume , electron , electron density , van allen radiation belt , computational physics , acceleration , van allen probes , geophysics , astrophysics , atomic physics , magnetosphere , plasma , meteorology , nuclear physics , classical mechanics
We present observations from the Van Allen Probes spacecraft that identify a region of intense whistler mode activity within a large density enhancement outside of the plasmasphere. We speculate that this density enhancement is part of a remnant plasmaspheric plume, with the observed wave being driven by a weakly anisotropic electron injection that drifted into the plume and became nonlinearly unstable to whistler emission. Particle measurements indicate that a significant fraction of thermal (<100 eV) electrons within the plume were subject to Landau acceleration by these waves, an effect that is naturally explained by whistler emission within a gradient and high‐density ducting inside a density enhancement.