Energy dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions.

TitleEnergy dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions.
Publication TypeJournal Article
Year of Publication2015
AuthorsReeves, GD, Friedel, RHW, Larsen, BA, Skoug, RM, Funsten, HO, Claudepierre, SG, Fennell, JF, Turner, DL, Denton, MH, Spence, HE, J. Blake, B, Baker, DN
JournalJournal of Geophysical Research: Space Physics
Date Published12/2015
KeywordsAcceleration; energetic particles; Inner zone; Outer Zone; Radiation belts; Slot region; Van Allen Probes
AbstractWe present observations of the radiation belts from the HOPE and MagEIS particle detectors on the Van Allen Probes satellites that illustrate the energy-dependence and L-shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on March 1 in more detail. The observations show: (a) At all L-shells, lower-energy electrons are enhanced more often than higher energies; (b) Events that fill the slot region are more common at lower energies; (c) Enhancements of electrons in the inner zone are more common at lower energies; and (d) Even when events do not fully fill the slot region, enhancements at lower-energies tend to extend to lower L-shells than higher energies. During enhancement events the outer zone extends to lower L-shells at lower energies while being confined to higher L-shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L-shells for lower energies. Both boundaries are nearly straight in log(energy) vs. L-shell space. At energies below a few hundred keV radiation belt electron penetration through the slot region into the inner zone is commonplace but the number and frequency of “slot filling” events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L-shell dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.
URLhttp://doi.wiley.com/10.1002/2015JA021569http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2015JA021569
DOI10.1002/2015JA021569
Short TitleJ. Geophys. Res. Space Physics


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