Excitation of Electron Acoustic Waves by electron beams in nonlinear Landau resonance with Whistler Waves
Abstract
Nonlinear solitary structures, identified as electron acoustic wave mode (EAW), are often observed in association with whistler waves in Earth's magnetosphere. We investigate the excitation mechanism of EAWs and their potential relation to whistler waves using particle-in-cell simulations with two dimensions in real space and three dimensions in velocity space. Whistler waves are first excited by electrons with a temperature anisotropy perpendicular to the background magnetic field. Electrons trapped by these whistler waves through nonlinear Landau resonance form localized beams, which subsequently excite electron acoustic waves. By comparing the growth rate of EAWs and the phase mixing rate of trapped electron beams, we obtain the critical condition for EAW excitation, which is consistent with simulation results obtained by exploring the relevant parameter space. Our results may be useful in the interpretation of whistler-related nonlinear solitary structures in the near-Earth space environment.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMSM43C..05M