Gravity wave activity in the Martian atmosphere at altitudes 20‐160 km from ACS/TGO occultation measurements

Ekaterina D. Starichenko (1, 2) , Denis A. Belyaev (1) , Alexander S. Medvedev (1) , Anna A. Fedorova (1) , Oleg I. Korablev (1) , Alexander Trokhimovskiy (1) , Erdal Yiğit (3, 4) , Juan Alday (5) , Franck Montmessin (6) , Paul Hartogh (3)

1 IKI - Space Research Institute of the Russian Academy of Sciences
2 MIPT - Moscow Institute of Physics and Technology [Moscow]
3 MPS - Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research
4 Department of Physics and Astronomy [Fairfax]
5 Department of Physics [Oxford]
6 PLANETO - LATMOS

The paper presents observations of gravity wave-induced temperature disturbances in the Martian atmosphere obtained with the mid-infrared (MIR) spectrometer, a channel of the Atmospheric Chemistry Suite instrument on board the Trace Gas Orbiter (ACS/TGO). Solar occultation measurements of a CO₂absorption band at 2.7 µm were used for retrieving density and temperature profiles between heights of 20 and 160 km with vertical resolution sufficient for deriving small-scale structures associated with gravity waves. Several techniques for distinguishing disturbances from the background temperature have been explored and compared. Instantaneous temperature profiles, amplitudes of wave packets and potential energy have been determined. Horizontal momentum fluxes and associated wave drag have been estimated. The analyzed data set of 144 profiles encompasses the measurements made over the second half of Martian Year 34, from the Solar longitude 165° through 355°. We observe enhanced gravity wave dissipation/breaking in the mesopause region of 100-130 km. Our analysis shows no direct correlation between the wave amplitude and Brunt-Väisälä frequency. It may indicate that convective instability may not be the main mechanism limiting gravity wave growth in the middle atmosphere of Mars.

Domaines: Planète et Univers [physics]

Ekaterina D. Starichenko, Denis A. Belyaev, Alexander S. Medvedev, Anna A. Fedorova, Oleg I. Korablev, et al.. Gravity wave activity in the Martian atmosphere at altitudes 20‐160 km from ACS/TGO occultation measurements. Journal of Geophysical Research. Planets, 2021, 126 (8), pp.e2021JE006899. ⟨10.1029/2021JE006899⟩. ⟨insu-03299077⟩