Energy Transfer Through the Magnetopause in Global Simulations

The solar wind – magnetosphere coupling drives magnetospheric dynamic phenomena by enabling energy exchange between the magnetospheric and solar wind plasmas. We study this energy exchange by examining global magnetohydrodynamic (MHD) and kinetic simulations using Space Weather Modeling Framework and the global hybrid- Vlasov code Vlasiator. We compute the energy flux, which consists of the Poynting flux and hydrodynamic energy flux components, through the Earth's magnetopause and evaluate the effect of magnetopause motion on the energy transfer processes. The results demonstrate the spatio-temporal variations of the energy flux along the magnetopause and reveal surface fluctuations contributing significantly to net energy transfer. In kinetic simulation analyzed, flux transfer events (FTEs) travel along the magnetopause and transport energy to the nightside magnetosphere supplying the planet's Dungey cycle. The traveling FTE on the dayside is associated with a leading (trailing) edge where energy is injected into (escaped out from) the magnetosphere. We identify the tail lobes as a primary entry region for solar wind energy into the magnetosphere, consistent with results from other global MHD simulations and observations. The figure shows a snapshot of the total energy flux through the magnetopause in a Vlasiator simulation.