Localization and turbulence of beam-driven whistler wave with magnetosonic wave in magnetopause

This study proposes a model to explain how energetic electron beams (produced by the magnetic reconnection process) cause whistler turbulence in the magnetic reconnection area of the magnetopause, as observed by the Magnetospheric Multiscale Mission. In this scenario, the energetic electron beam source has replaced the magnetic reconnection mechanism. We develop dynamic equations of the beam-driven whistler mode so that because of the large amplitude of the beam energy, it rises from the noise level. As a result, nonlinear effects follow due to ponderomotive force, which results in whistler wave localization; eventually, the turbulent state is achieved. A theoretical model is developed using the basic two-fluid equations and Maxwell's equations to study the dynamics of high-frequency whistler waves and low-frequency magnetosonic waves (MSWs). Then, using a pseudospectral approach and a finite difference method, a set of dimensionless equations for the whistler wave and MSWs was numerically solved. The outcomes of the numerical simulation show a localized structure and a turbulent power spectrum, which follow Kolmogorov scaling laws. It has also been clarified that the current investigations are pertinent to the most recent observations.