Nonlinear dynamics and phase space transport by chorus emission

TL;DR

This paper reviews the nonlinear dynamics of chorus emissions in planetary magnetospheres, combining theory, simulations, and observations, and draws interdisciplinary analogies to condensed matter and laser physics.

Contribution

It introduces a comprehensive theoretical framework for chorus frequency chirping, integrating linear and nonlinear plasma physics methods with applications to space physics.

Findings

Analytical and numerical results on chorus frequency chirping

Comparison with observations and particle-in-cell simulations

Analogies with condensed matter and laser physics

Abstract

Chorus emission in planetary magnetospheres is taken as working paradigm to motivate a short tutorial trip through theoretical plasma physics methods and their applications. Starting from basic linear theory, readers are first made comfortable with whistler wave packets and their propagation in slowly varying weakly nonuniform media, such as the Earth's magnetosphere, where they can be amplified by a population of supra-thermal electrons. The nonlinear dynamic description of energetic electrons in the phase space in the presence of self-consistently evolving whistler fluctuation spectrum is progressively introduced by addressing renormalization of the electron response and spectrum evolution equations. Analytical and numerical results on chorus frequency chirping are obtained and compared with existing observations and particle in cell simulations. Finally, the general theoretical framework constructed during this short trip through chorus physics is used to draw analogies with condensed matter and laser physics as well as magnetic confinement fusion research. Discussing these analogies ultimately presents plasma physics as an exciting cross-disciplinary field to study.