Study of gravity waves distribution and propagation in the thermosphere of Mars based on MGS, ODY, MRO and MAVEN density measurements

Abstract

By measuring the regular oscillations of the density of CO${}_2$ in the upper atmosphere (between 120 and 190~km), the mass spectrometer MAVEN/NGIMS (Atmosphere and Volatile EvolutioN/Neutral Gas Ion Mass Spectrometer) reveals the local impact of gravity waves (GWs). This yields precious information on the activity of GWs and the atmospheric conditions in which they propagate and break. The intensity of GWs measured by MAVEN in the upper atmosphere has been shown to be dictated by saturation processes in isothermal conditions. As a result, GWs activity is correlated to the evolution of the inverse of the background temperature. Previous data gathered at lower altitudes ($\sim$95 to $\sim$150~km) during aerobraking by the accelerometers on board MGS (Mars Global Surveyor), ODY (Mars Odyssey) and MRO (Mars Reconnaissance Orbiter) are analyzed in the light of those recent findings with MAVEN. The anti-correlation between GW-induced density perturbations and background temperature is plausibly found in the ODY data acquired in the polar regions, but not in he MGS and MRO data. MRO data in polar regions exhibit a correlation between the density perturbations and the Brunt-Väisälä frequency, obtained from Global Climate Modeling. At lower altitude levels (between 100 and 120~km), although wave saturation might still be dominant, isothermal conditions are no longer verified. In this case, theory predicts that the intensity of GWs is no more correlated to background temperature, but to static stability. At other latitudes in the three aerobraking datasets, the GW-induced relative density perturbations are correlated with neither inverse temperature nor static stability; in this particular case, this means that the observed activity of GWs is not only controlled by saturation, but also by the effects of GWs sources and wind filtering through critical levels.

arXiv comment21 pages, 15 figures, version submitted to Planetary and Space Science on January 8th 2019 and accepted on July 31th 2019

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• Rocket dust storms and detached dust layers in the Martian atmosphere
• High-altitude gravity waves in the Martian thermosphere observed by MAVEN/NGIMS and modeled by a gravity wave scheme
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Cited by in corpus (6)

• Dust storm-enhanced gravity wave activity in the Martian thermosphere observed by MAVEN and implication for atmospheric escape
• Martian Dust Storms and Gravity Waves: Disentangling Water Transport to the Upper Atmosphere
• Disentangling the dominant drivers of gravity wave variability in the Martian thermosphere
• Diurnal and Seasonal variations of Gravity Waves in the lower atmosphere of Mars as observed by Insight
• A Stochastic Parameterization of Non-Orographic Gravity Waves Induced Mixing for Mars Planetary Climate Model
• Variations of the Martian Thermospheric Gravity Wave Activity during the Recent Solar Minimum as Observed by MAVEN