Preconditioning in Mars's upper atmosphere during solar flares

During a large solar flare event, a significant amount of energy can be deposited into the thermosphere by EUV and soft X-ray photons. This energy has been shown to drastically alter the thermospheric and ionospheric temperature and density on global scales (e.g. Fang et al., 2019) with perturbations that last hours after the flare peak. As it turns out, the manner in which the upper atmosphere responds to a flare event depends on the state of the atmosphere prior to the onset of the flare. Not only is this concept of "preconditioning" of the atmosphere important for understanding the current response of the Mars atmosphere to dynamic events, but it is also important for studying the evolution of the Martian climate given that the sun was thought to be much more active shortly after Mars's formation. In this presentation, we show results from the Mars Global Ionosphere-Thermosphere Model (M-GITM) where we examine the effect of preconditioning on Mars's I-T system by simulating the atmospheric response to repetitive solar flare events. During such an event, we examine changes in the atmospheric state variables and show that Mars's atmosphere is perturbed more than it would be if a single flare occurred with the same total energy as the repetitive event.