A multi-mission climatology of gravity waves in the Martian mesosphere and thermosphere

Gravity waves in the Martian atmosphere are generated by wind flow over topography, convection or shear instabilities. They propagate upward, transporting momentum and energy from the lower atmosphere into the mesosphere and thermosphere. While the waves are relatively small, ranging in wavelength from tens to hundreds of kilometres, their impact through thermal and dynamical forcing on the climate can be quite large.The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission started operations in 2014 and was joined in orbit by the ExoMars Trace Gas Orbiter (TGO) in 2018. Together, they have been observing the Martian atmosphere contemporaneously, allowing for an unprecedented opportunity to produce a global view of gravity wave activity over several Mars years.For this work, we use temperatures derived from the Nadir Occultation for MArs Discovery (NOMAD) Solar Occultation (SO) channel (Trompet et al., 2023), the Middle IR (MIR) channel of the Atmospheric Chemistry Suite (ACS) experiment (Belyaev et al., 2022), both onboard TGO, along with temperature retrievals from stellar occultation measurements from the Imaging UltraViolet Spectrograph (IUVS) (Gupta et al., 2022) on the MAVEN spacecraft.The NOMAD/SO and ACS/MIR observations are performed using solar occultation, so they are limited in local time to the morning and evening terminators, with the majority of observations taking place around mid-latitudes (between 50-75° N/S) due to the orbit of TGO. The addition to the study of stellar occultation observations from MAVEN/IUVS fills in some of the gaps in terms of local time and latitude. Figure 1 provides a comparison of coverage by the three instruments in terms of Mars years, season, latitude and local time.In altitude, the ACS/MIR profiles range from ~20 km to 150 km. For NOMAD, we use two different wavelength regions (diffraction orders 132 and 148) to view the atmosphere from ~20 km to 100 km. The MAVEN/IUVS stellar occultations provide temperature profiles between ~100 km to 150 km. This provides some overlap between the three instruments to compare temperature profiles, their perturbations and potential gravity wave activity.We build on the work of Starichenko et al. (2021; 2024; 2025),who performed an analysis of gravity waves using ACS observations.Figure 1: Data coverage for the three instruments used in this study, number of profiles per Mars Year (top left), Solar Longitude (top right), latitude (bottom left), and local time (bottom right). ACS/MIR profiles in blue, IUVS/stellar occultation in orange, and NOMAD in green.References :Belyaev et al. (2022), JGR: Planets, 127 (10), https://doi.org/10.1029/2022JE007286Gupta et al. (2022), JGR: Planets, 127 (11), https://doi.org/10.1029/2022JE007534Trompet et al. (2023), JGR: Planets, 128 (3), https://doi. org/10.1029/2022JE007277Starichenko et al. (2021), JGR: Planets, 126 (8), https://doi.org/10.1029/2021JE006899Starichenko et al. (2024), A&A, 683, A206, https://doi.org/10.1051/0004-6361/202348685Starichenko et al. (2025), Front. Astron. Space Sci., 12:1672283, https://doi.org/10.3389/fspas.2025.1672283