Waves and Instabilities in High-Resolution PIC simulations of Oblique Shocks

Abstract:

It is well appreciated that a variety of instabilities can develop in the transition region of collisionless shocks. Despite significant observational as well as numerical and theoretical evidence of such instabilities, their role in controlling overall energy dissipation remains unclear. In this work, we use high-resolution fully kinetic particle-in-cell (PIC) simulations to provide a holistic view of the instabilities in oblique shocks under conditions typical of the Earth’s bow shock. Whistler-mode precursors, lower-hybrid oscillations originating from modified two-stream instability, electrostatic solitary structures, and whistler-mode “lion roars” are identified in different regions of the shock. The properties, origins, are the role of the observed instabilities is discussed and the simulations are put into context of spacecraft observations.