Gap Formation around 0.5Ωe of whistler-mode waves excited by electron temperature anisotropy
Abstract
With a PIC simulation model, we investigate the gap formation around 0.5Ωe of quasi-parallel whistler-mode waves excited by an electron temperature anisotropy. The waves with the dominant frequency slightly larger than 0.5Ωe are firstly excited, and their frequencies gradually drift toward smaller values. Then, the electron distribution is modified into a beam/plateau-like one due to the Landau resonance. Although such an electron distribution can only slightly changes the dispersion relation of whistler-mode waves, it can cause severe damping around 0.5Ωe. At last, the wave spectrum is separated into two bands with a power gap around 0.5Ωe. The condition under different electron temperature anisotropy and plasma beta is also surveyed for such kind of power gap. Our study provides a clue to reveal the well-known 0.5Ωe power gap of whistler-mode waves ubiquitously observed in the inner magnetosphere. This result can be confirmed in both 1-D and 2-D PIC simulation model.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSM013..08C
- Keywords:
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- 2716 Energetic particles: precipitating;
- MAGNETOSPHERIC PHYSICS;
- 2730 Magnetosphere: inner;
- MAGNETOSPHERIC PHYSICS;
- 2772 Plasma waves and instabilities;
- MAGNETOSPHERIC PHYSICS;
- 2774 Radiation belts;
- MAGNETOSPHERIC PHYSICS