Temperatures in Venus ’ Lower Thermosphere: Comparison of VTGCM and SOIR Profiles at the Terminator

The thermospheric general circulation model for Venus (VTGCM) produces temperatures, densities, and winds over ~70-200 km that can be compared to Venus Express (VEx) measurements. This study will examine the modeled temperatures and the corresponding CO2 density distributions near the terminators in comparison with observations from the Solar Occultation in the InfraRed (SOIR) instrument. Sensitivity tests with the VTGCM will be conducted to show possible sources of variability in the modeled temperature profiles. In addition, the impacts of upward propagating waves (e.g. Kelvin wave) on these temperatures will be examined. The study will help characterize Venus ’ upper atmosphere near the terminators and provide insight into the physical mechanisms responsible for the mean structure and its variability. 1