Orateur
Description
This review synthesizes global hybrid Particle-in-Cell (PIC) simulations using the Menura code to investigate how solar wind turbulence dynamically reshapes the plasma environments of magnetized and unmagnetized bodies. We employ a two-step dynamical approach: decaying turbulence simulations to generate a fully developed turbulent solar wind, followed by global simulations of the time-dependent interaction between turbulent solar wind and obstacles. We focus on the time-evolving morphology of bow shocks, magnetosheaths, and ion foreshocks, including the generation of transient structures and their propagation. We also explore how the turbulent nature of the solar wind affects kinetic instabilities in the magnetosheath, as well as the formation of magnetic holes, and alter particle acceleration and energy dissipation across plasma boundaries.
We find that the turbulent nature of the solar wind amplifies quasi-perpendicular shock oscillations and disrupts both foreshock and magnetosheath coherence. Solar wind turbulence significantly modifies the onset of the mirror instability in the magnetosheath, with growth timescales comparable to magnetosheath transit times, resulting in persistent unstable plasma in a small magnetosphere such as Mercury. Magnetic holes form via nonlinear mirror mode evolution in turbulent conditions, stabilized by time-dependent ion trapping. Large-scale solar wind structures are transmitted and compressed across the bow shock. Mercury’s magnetosheath exhibits faster dynamical responses than Earth’s, leading to high fractions of unstable plasma and short relaxation timescales. For comets, turbulence alters the structure and the dynamics of induced magnetospheres, generating bursty cometary plasma escaping structures due to forced magnetic reconnection, modifying the transport of particles and fields.
These simulations provide a global, time-resolved framework for studying the dynamical interplay between a supersonic turbulent plasma flow, such as the solar wind, and obstacles, such as planets and comets, offering predictive insights for future space missions like BepiColombo and Comet Interceptor.