EGU21-6003, updated on 15 May 2024
https://doi.org/10.5194/egusphere-egu21-6003
EGU General Assembly 2021
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

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

Man Hua1, Binbin Ni1,2, Wen Li3, Qianli Ma3,4, Xudong Gu1, Song Fu1, Xing Cao1, Yingjie Guo1, and Yangxizi Liu1
Man Hua et al.
  • 1Wuhan University, Department of Space Physics, China
  • 2CAS Center for Excellence in Comparative Planetology, Hefei, Anhui, China.
  • 3Center for Space Physics, Boston University, Boston, Massachusetts, USA
  • 4Department of Atmospheric and Oceanic Sciences, UCLA, Los Angeles, California, USA

The Earth’s inner energetic electron belt typically exhibits one-peak radial structure with high flux intensities at radial distances < ~2.5 Earth radii. Recent studies suggested that human-made very-low-frequency (VLF) transmitters leaked into the inner magnetosphere can efficiently scatter energetic electrons, bifurcating the inner electron belt. In this study, we use 6-year electron flux data from Van Allen Probes to comprehensively analyze the statistical distributions of the bifurcated inner electron belt and their dependence on electron energy, season, and geomagnetic activity, which is crucial to understand when and where VLF transmitters can efficiently scatter electrons in addition to other naturally occurring waves. We reveal that bifurcation can be frequently observed for tens of keV electrons under relatively quiet geomagnetic conditions, typically after significant flux enhancements that elevate fluxes at L = 2.0 – ~2.5 providing the prerequisite for the bifurcation. The bifurcation typically lasts for a few days until interrupted by substorm injections or inward radial diffusion. The L-shells of bifurcation dip decrease with increasing electron energy, and the occurrence of bifurcation is higher during northern hemisphere winter than summer, supporting the important role of VLF transmitter waves in energetic electron loss in near-Earth space.

How to cite: Hua, M., Ni, B., Li, W., Ma, Q., Gu, X., Fu, S., Cao, X., Guo, Y., and Liu, Y.: Statistical Distribution of Bifurcation of Earth's Inner Energetic Electron Belt at tens of keV, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6003, https://doi.org/10.5194/egusphere-egu21-6003, 2021.

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