Ion escape rates from Mars: Results from hybrid simulations compared to MAVEN observations

Abstract

AbstractDaily averaged heavy ion escape rates from HALFSHEL hybrid simulations of the solar wind interaction with the Martian ionosphere are compared to the ion escape rates reported by Brain et al. (2015). The simulation rates are found to be in agreement with the rates measured by Mars Atmosphere and Volatile EvolutioN (MAVEN). When the simulation rates are adjusted for known variability in the Martian system, the ion escape rates are within 40% of the MAVEN results. The ion escape rate is found to vary linearly with the solar wind speed. Using the simulation results to scale the MAVEN ion escape rate to include ions of all kinetic energies, we predict a total heavy ion escape rate of 1.2 × 1025 ions/s. The assumptions used to derive the total ion escape by Brain et al. (2015) are tested against the simulation results and are found to be excellent.