Martian Atmospheric Tides Revealed From MAVEN/IUVS and MRO/MCS Observations

Abstract

Abstract Utilizing atmospheric temperature observed from Mars Years 33–36 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°–300°). During the non‐dust season (Ls 30°–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.

Keywords

• atmospheric tide
• vertical propagation
• nonmigrating tide
• mesosphere and thermosphere
• seasonal variation