Comparison of Gravity Wave Activity between THEMIS Band-10 and MCS Nadir Observations

Gravity wave activity on Mars can modulate the rate of atmospheric escape, impact high cloud formation, and contribute to dynamical warming in the polar middle atmosphere. Recently, a climatology of gravity wave activity in the 10—100 km horizontal wavelength range has been developed from the Mars Climate Sounder (MCS) dataset. However, this dataset is predominantly sensitive to gravity wave activity oriented in the meridional direction. To sample activity in the zonal direction, the analysis of other, complementary datasets is required.

The Thermal Emission Imaging System (THEMIS) Band-10 dataset should be sensitive to a similar range of wavelengths of gravity waves and sample similar altitudes (~25 km) as MCS nadir observations. Here, we analyze THEMIS Band-10 over multiple Mars years during the Ls=120—150 season, which overlaps with MCS nadir observations from Mars year 28. A special pre-processing pipeline has been developed, consisting of removal of THEMIS drift and wobble and band-correlated artifacts. The incredibly long duration of the THEMIS dataset (~8 Mars years) allows for the assessment of interannual variability and direct comparison to MCS to test the coverage and sensitivity of THEMIS to gravity wave orientation over multiple baselines. This will allow for further study of gravity wave activity across the entire THEMIS dataset.