Statistical Distribution of Bifurcation of Earth s Inner Energetic Electron Belt at tens of keV

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Abstract
We present a survey of the bifurcation of the Earth s energetic electron belt (tens of keV) using 6-year measurements from Van Allen Probes. The inner energetic electron belt usually presents one-peak radial structure with high flux intensity at L < ∼2.5, which however can be bifurcated to exhibit a double-peak radial structure. By automatically identifying the events of bifurcation based on RBSPICE data, we find that the bifurcation is mostly observed at ∼30–100 keV with a local flux minimum at L=∼2.0–∼2.3 under relatively quiet geomagnetic conditions, typically after a significant flux enhancement due to radial diffusion or injections to L<∼2.5. The bifurcation typically lasts for a few days during quiet periods until interrupted by injections or radial diffusion. The L-shell, energy and seasonal dependences of the occurrence of bifurcated inner electron belt support the important role of electron scattering by very-low-frequency transmitter waves in the bifurcation formation.
Notes
Year of Publication
2020
Journal
Geophysical Research Letters
Volume
n/a
Number
Number of Pages
e2020GL091242
Date Published
12/2020
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL091242
DOI
https://doi.org/10.1029/2020GL091242