Occurrence Rates of Nonlinear Electron Interaction with Intense Chorus Waves
Abstract
We conduct a comprehensive statistical analysis on 8 years of lower-band chorus wave packets measured by the Van Allen Probes and THEMIS spacecraft, to examine whether, when, and where these waves are above the theoretical threshold for nonlinear resonant wave-particle interaction. We find that ~5-30% of all chorus waves interact nonlinearly with ~30-300 keV electrons possessing equatorial pitch angles of >40° in the outer radiation belt, especially during disturbed (AE>500 nT) periods with energetic particles associated with injections from the plasma sheet. Such considerable occurrence rates of nonlinear interactions imply that the evolution of energetic electron fluxes should be dominated by nonlinear effects, rather than by quasi-linear diffusion as commonly assumed. We discuss the possible consequences of such a large amount of high-amplitude chorus waves and examine their characteristics that can influence the efficiency of nonlinear wave particle interactions.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSM31B..04Z
- Keywords:
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- 2774 Radiation belts;
- MAGNETOSPHERIC PHYSICS;
- 7803 Active perturbation experiments;
- SPACE PLASMA PHYSICS;
- 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS;
- 7868 Wave/wave interactions;
- SPACE PLASMA PHYSICS