Utilizing atmospheric temperature observed from Mars Years 33 to 36 by the Imaging Ultraviolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile Evolution (MAVEN) and Mars Climate Sounder (MCS) onboard Mars Reconnaissance Orbiter (MRO), we derive the diurnal and semidiurnal thermal tides from 30 to 160 km. Vertical phase velocities of the migrating tides indicate their upward propagation above 100 km during the dust season (solar longitude, Ls 240° to 300°). During the non-dust season (Ls 30° to 150°), the diurnal eastward wavenumber 2 (DE2) and wavenumber 3 (DE3) tides can propagate upward from the lower atmosphere to ~140 km. The seasonal variation of DE2 and DE3 amplitudes in the thermosphere corresponds well to their counterparts in the lower atmosphere, primarily controlled by their Hough (1,1) modes. The upward propagation of these tides could potentially impact the vertical coupling between the Martian lower and upper atmosphere.

During the northern spring (approximately Ls≈33°) in Martian Year 35, Mars experienced an unusual dust storm characterized by significantly increased dust in the northern troposphere. As observed by the Mars Climate Sounder (MCS), temperature significantly increases in the mid-latitude troposphere of both hemispheres and decreases in the northern mesosphere during the event. The temperature response simulated by the Martian General Circulation Model (GCM) agrees with the MCS observations. The radiative heating from dust is responsible for the increased temperature in the northern troposphere. In contrast, the dynamic heating/cooling contributes to the temperature variations in the southern troposphere and northern mesosphere. The increased dissipation of planetary waves enhances the residual meridional circulation and causes the temperature warming in the Southern Hemisphere. In addition, the enhanced meridional circulation related to this event leads to ~36% increase in water vapor transport from the Northern to the Southern Hemisphere as compared to the net interhemispheric transport over an entire Martian Year.

A regional dust storm was observed in the northern spring of Martian Year 35, a period characterized by a relatively cold and clear atmosphere. Both satellite observations and general circulation model simulations reveal that the atmospheric temperature response characteristics of this early regional dust storm closely resemble the equatorial mirror of the C-type regional dust storm responses in the Northern Hemisphere winter. Atmospheric heating in the dust-lifting region was primarily driven by shortwave radiative heating of dust particles. Anomalous cooling in the northern mesosphere and heating responses in the southern troposphere were associated with dust-modulated gravity waves and planetary waves, respectively. The anomalous atmospheric waves during the dust storm significantly enhanced the meridional circulation. Inhomogeneous heating due to dust distribution enhanced southward meridional circulation in the lower tropical troposphere, where the water vapor mixing ratio increased. As a result, the meridional water transport significantly increased from the Northern to the Southern Hemisphere during the dust event. Furthermore, the water transport during the E Event showed significant longitudinal asymmetry, highlighting the importance of the stationary eddy transport term.

High-frequency gravity waves (HFGWs) observed by the Zhurong/Tianwen-1 and Perseverance/Mars 2020 rovers between 09:00 and 11:00 local time, from Ls 140° to 165° in Mars Year 36 was investigated. By analyzing the eccentricity of hodographs for monochromatic wind perturbations obtained from harmonic fittings, HFGWs were identified via their predominantly linear characteristics. The background atmosphere stability was estimated using the Richardson number from the Dynamic Meteorology Laboratory general circulation model simulation. We find that the frequency of HFGWs doubled following the onset of a regional dust storm (RDS) in the Utopia Planitia region, where the Zhurong rover landed. The propagation directions of the HFGWs were determined using their polarization relationships. The HFGWs observed by Zhurong predominantly propagated north-south direction before the RDS and then east-west after. The propagation direction changes were likely due to the atmospheric instability changes in the region before and after the storm.