Martian ionospheric responses to dynamic pressure enhancements in the solar wind

摘要: As a weakly magnetized planet, Mars ionosphere/atmosphere interacts directly with the shocked solar wind plasma flow. Even though many numerical studies have been successful in reproducing numerous features of interaction process, these earlier focused mainly on under steady conditions. Recent observations suggest that escape fluxes are significantly enhanced response to dynamic pressure pulses. In this study, we focus ionosphere enhancements wind. Through modeling two idealized events using magnetohydrodynamics model, find upper responds almost instantaneously enhancements, while collision dominated lower (below ~150 km) does not noticeable changes density. We also ionospheric perturbations density, magnetic field, and velocity can last more than an hour after returns quiet The topside forms complicated transient shapes response, which may explain unexpected behaviors recent observations. do correlate simultaneous pressure. Rather, their intensities depend It takes few hours for ionospheric/atmospheric system reach new quasi-equilibrium state.