Proton precipitation in a hybrid-Vlasov simulation with southward interplanetary magnetic field driving: First 3D results

The precipitation of charged particles from the magnetosphere into the ionosphere is one of the crucial coupling mechanisms between these two regions of geospace. While precipitating particle fluxes have been measured by numerous spacecraft missions over the past decades, it often remains difficult to obtain global precipitation patterns with a good time resolution during a substorm. Numerical simulations can contribute to bridge this gap and help improve the understanding of mechanisms leading to particle precipitation at high latitudes through the global view they offer on the near-Earth space system. We present the first results on proton precipitation within a 3-dimensional simulation of the Vlasiator hybrid-Vlasov model. The run is driven by southward interplanetary magnetic field conditions with steady solar wind parameters. We analyse the large-scale proton precipitation pattern in both hemispheres and discuss its dynamics in relation to the processes taking place in the magnetotail.