Three‐dimensional multifluid modeling of atmospheric electrodynamics in Mars' dynamo region

Abstract

The interactions between Mars' unique crustal magnetic fields and upper atmospheric particles lead to the formation of currents in the ionospheric dynamo region. This work is specifically focused on the collisions between ions, electrons, and neutrals in the atmospheric column of Mars. The remanent fields embedded in the Martian crust generate a very rich magnetic topology with important variations in terms of geometry and amplitude. Here we present mesoscale, self‐consistent, three‐dimensional, multifluid simulations of Mars' ionospheric electrodynamics in the dynamo region (∼100–400 km altitude), where differential motions of ions and electrons occur. In particular, we develop and validate a new method through the study of simple, uniform magnetic geometries. Our results demonstrate the existence of a dynamo current in the Martian atmosphere, which depends on the magnitude of the applied magnetic field and the neutral wind speeds. The simulation outputs are analyzed from mathematical and physical perspectives to identify the dominant processes at work in the formation of this current. Both case studies presented in this paper are qualitatively and quantitatively consistent with theoretical estimates and confirm the validity of the model, hence laying the groundwork for future studies of Mars' atmosphere using this new approach.