Dust storm-enhanced gravity wave activity in the Martian thermosphere observed by MAVEN and implication for atmospheric escape

Abstract

Lower atmospheric global dust storms affect the small- and large-scale weather and variability of the whole Martian atmosphere. Analysis of the CO${}_2$ density data from the Neutral Gas and Ion Mass Spectrometer instrument (NGIMS) on board NASA's Mars Atmosphere Volatile EvolutioN (MAVEN) spacecraft show a remarkable increase of GW-induced density fluctuations in the thermosphere during the 2018 major dust storm with distinct latitude and local time variability. The mean thermospheric GW activity increases by a factor of two during the storm event. The magnitude of relative density perturbations is around 20% on average and 40% locally. One and a half months later, the GW activity gradually decreases. Enhanced temperature disturbances in the Martian thermosphere can facilitate atmospheric escape. For the first time, we estimate that, for a 20% and 40% GW-induced disturbances, the net increase of Jeans escape flux of hydrogen is a factor of 1.3 and 2, respectively.

Accepted for publication in Geophysical Research Letters, 13 pages, 4 figures

References in corpus (1)

• Seasonal Water "Pump" in the Atmosphere of Mars: Vertical Transport to the Thermosphere

Cited by in corpus (6)

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