Year: 2025
Type: article
Abstract: Semi‐empirical coefficients for electron transport in Alfvénic turbulence are used to drive the global evolution of energetic electron distributions through Earth's outer radiation belt. It is shown how these turbulent fields facilitate radial transport and pitch‐angle scattering that drive losses through the magnetopause, into the plasma sheet, through the plasmapause and to the atmosphere. Butterfly distributions are formed due to pitch‐angle scattering and the combined effect of the loss processes. For the observed spectrum of oscillations, it is estimated that Alfvénic turbulence drives order of magnitude depletions of outer radiation belt electron fluxes at relativistic energies over a period of a few hours. On the other hand, at lower energies, energization in transverse Alfvénic electric fields leads to enhancements of the electron spectrum to provide a source population for subsequent acceleration to higher energies and, in concert with the loss processes, provides exponential spectral form as a function of energy.
Source: Geophysical Research Letters
DOI: 10.1029/2025gl115125
Author: C. C. Chaston
Institutions: Space Sciences Laboratory, University of California, Berkeley
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
Funder: National Science Foundation
OpenAlex ID: W4409805677