Observations of atmospheric tides in the Martian middle and upper atmosphere from MRO and MAVEN

Abstract:

The contribution of atmospheric waves to the transport of energy and momentum between layers of the Martian atmosphere is well recognized. The impacts that waves have on the mean state of the present-day Martian atmosphere are especially large at high altitude. Atmospheric tides are a well-known example of large-scale waves in the Martian atmosphere, and are believed to play a key role in transporting energy from the lower atmosphere into the upper atmosphere. Previous theoretical predictions and observations suggest that tides producing Wave-2 and Wave-3 patterns are the strongest at high altitudes, but the energy they carry and where this is deposited is not well characterized. Utilizing the relative strengths of in situ and remotely sensed data from MCS, IUVS and NGIMS instruments on MRO and MAVEN permits the identification of the vertical propagation characteristics and dissipation of tides across a broad altitude range from the middle to the upper atmosphere. Here we identify the dominant wave numbers at different Ls across multiple datasets and estimate dissipation by comparing wave amplitudes at different altitudes. A comparison of tidal characteristics in the northern hemisphere and southern hemisphere at near equatorial latitudes is shown.