Recent satellite observations reveal localized whistler wavepackets that are correlated with density and magnetic field perturbations. This can be understood in terms of nonlinear interactions between three-dimensional whistlers and the background plasma density and magnetic field. The relevant equations for such nonlinear wave couplings are presented. Simulation studies of nonlinearly coupled electron whistlers and low-frequency magnetosonic perturbations reveal interesting features of whistler pulse compression and diffraction as well as the formation of magnetosonic wedges behind a three-dimensional (3D) localized whistler pulse. The results are useful for understanding the nonlinear propagation of whistlers in space and laboratory plasmas. We suggest that new experiments should be conducted to verify the 3D nonlinear wave phenomena involving electron whistlers and magnetosonic perturbations that we have described in here.
- whistler waves
- nonlinear waves