M‐GITM Simulations of the Ionosphere and Thermosphere of Mars During the 10 September 2017 Solar Flare Event: Comparison With MAVEN NGIMS Observations

Abstract Time‐dependent model simulations of the atmosphere of Mars are a necessary tool for providing context to Mars' upper atmospheric conditions during a solar flare event. They extend beyond the short windows of available atmospheric observation to offer temporal context about the different time‐dependent stages of the atmosphere's flare‐driven response. Yet to interpret this context, a simulation's reproduction of observed atmospheric conditions in the presence and absence of solar flares must first be assessed. In this study, simulations from the Mars Global Ionosphere‐Thermosphere Model (M‐GITM) during the 10 September 2017 solar flare event and baseline, control conditions are assessed through comparison with observations by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft mass spectrometer. By calculating model bias for electron, ion, and neutral densities and density changes relative to baseline mean conditions, these comparisons offer unique context on the model's accuracy across thermosphere and topside ionosphere altitudes at the timing and aerographic location of observations. Results indicate that the examined M‐GITM simulations qualitatively reproduced but quantitatively underestimated observed atmospheric changes for most plasma and neutral species, with closest agreement between 155 and 190 km altitude. Despite large observational noise, compositional trends of these changes were reproduced. Model bias was identified to differ more greatly between different upper atmospheric altitudes and species for absolute densities. This context may aid interpretation of Mars' flare‐perturbed atmospheric conditions within M‐GITM simulations at timing when observations are not available.