Density and Temperature of the Upper Mesosphere and Lower Thermosphere of Mars Retrieved From the OI 557.7 nm Dayglow Measured by TGO/NOMAD

The upper mesosphere and lower thermosphere of Mars (70–150 km) is high interest because it a region affected by climatological/meteorological events in the atmosphere external solar forcing. However, only few measurements are available at this altitude range. OI 557.7 nm dayglow emission has been detected these altitudes limb observations with Nadir Occultation for Discovery (NOMAD) aboard ExoMars Trace Gas Orbiter (TGO). We develop an inversion method to retrieve density temperature from profiles. demonstrate that atmospheric around 90 140 km 80 during daytime can be retrieved TGO/NOMAD measurements. densities show large seasonal variation both reach maximum values perihelion period. This explained driven dust content Sun-Mars distance. Temperature higher than predicted general circulation models, which tentatively consistent warm layer recently discovered nighttime. retrieval relies on dependence quenching coefficient 1S oxygen CO2. Further validation range needed verification temperature.