Observations of atmospheric tides on Mars at the season and latitude of the Phoenix atmospheric entry

We report on the atmospheric structure derived from atmospheric entry of NASA's Phoenix Mars probe using Phoenix Atmospheric Structure Experiment (ASE) data complemented by Mars Climate Sounder (MCS) temperature-pressure profiles. Oscillations in temperature, caused by thermal tides, have vertical wavelengths of tens of kilometres. Their amplitudes are much larger in individual profiles than in dayside and nightside zonal mean MCS profiles which is inconsistent with sole control by the migrating diurnal tide. In the fixed local time reference frame of dayside MCS observations, temperature varies by >15 K with longitudinal wavenumber 3, which could arise from non-migrating tides produced by the interaction of surface topography with the migrating diurnal tide.