Inner Belt Wisp Precipitation Measured by ELFIN: Regimes of Energetic Electron Scattering by VLF Transmitter Waves
Abstract
Man‐made very low frequency (VLF) transmitter waves play a critical role in energetic electron scattering and precipitation from the inner radiation belt, a type of which is called wisp precipitation. Wisps exhibit dispersive energy‐versus‐L spectra due to the evolution of electron cyclotron resonance conditions with near‐monochromatic VLF transmitter waves. Here, we report on such observations of inner belt wisp precipitation events with full pitch angle resolution in the energy range of 50 to ∼500 keV as measured by Electron Loss and Fields Investigation (ELFIN) at L −4 to 10−2 s−1. These are several orders of magnitude larger than the diffusion rates calculated from models using global statistical averages of VLF transmitter wave power. When using our estimated diffusion coefficients to deduce the associated local transmitter wave amplitudes near the equator, based on quasilinear calculations from a transmitter‐induced electron diffusion model, we find these wave amplitudes to be >1 mV/m. Although probable overestimates, such inferred wave amplitudes exceed the theoretical threshold amplitude for nonlinear interactions, strongly suggesting that it is necessary to include nonlinear effects for an accurate evaluation of energetic electron scattering by transmitter waves.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2022
- Source ID
- 10.1029/2022ja030968
Entities
People
- Anton V. Artemyev
- Colin Wilkins
- D. Mourenas
- Ethan Tsai
- J. Wu
- Qianli Ma
- Vassilis Angelopoulos
- Xiao‐jia Zhang
- Yangyang Shen
Organizations
- Air Force Office of Scientific Research
- Boston University
- National Aeronautics and Space Administration
- National Science Foundation
- Paris-Saclay University
- University of California, Los Angeles
- University of Texas at Dallas