Martian Mesospheric Gravity-Wave-Related Perturbations During Dust Storms Revealed by ACS-TGO Observations

Gravity waves (GWs) are important for understanding the coupling between dust activity and atmospheric dynamics on Mars. Using temperature and water-vapor profiles from the Near-Infrared channel of the Atmospheric Chemistry Suite (ACS-NIR) onboard the ExoMars Trace Gas Orbiter (TGO), we investigate wave-related temperature perturbations during global and regional dust-storm periods. Comparisons between Mars Years (MY) 34 and 35 reveal a localized enhancement of wave-related perturbations at southern high latitudes, particularly between 60°S and 90°S and 40–90 km. This enhancement persists after controlling for differences in observational sampling. The gravity-wave-related potential-energy proxy is approximately 2–3 times larger during the MY34 global dust storm, with a weaker enhancement during the regional event. These variations coincide with substantial differences in background temperature, static stability, and zonal winds, suggesting that dust-related changes in the atmospheric environment may modify wave propagation and filtering. Water-vapor abundance is also higher in the same region, but is more likely associated with dust-driven large-scale circulation, while wave-related processes may provide additional local modulation. These results provide observational constraints on dust–wave–water coupling in the Martian middle atmosphere.