Retrieval of the Vertical Profile of Atmospheric Optical Depth using Thermal Emission Spectrometer Visible and Infrared Bolometer observations

The Mars Global Surveyor (MGS) mission carried a spectrometer and bolometer as part of the Thermal Emission Spectrometer (TES) instrument package. While the spectrometer ceased operations in early Mars Year (MY) 37 due to aging of the required neon lamp, the bolometers continued to operate for nearly a full Mars year. This time-period covered the MY 27 dust storm season and most of the MY 28 aphelion cloud belt season. TES consisted of a spectrometer with two additional broadband bolometers in the visible (0.3-3.0 µm) and infrared (5-100 µm). Observations were taken with both the spectrometer and bolometer simultaneously for nearly three Mars years prior to degradation of the neon lamp. The observational cadence during the bolometer-only extended mission alternated between one orbit of nadir observations and one orbit of limb observations. We will present results for the vertical distribution of atmospheric aerosol optical depth retrieved from the TES bolometer limb observations prior to the extended mission when spectrometer data (and previous retrievals) are available to inform the results. In addition, we will provide examples of retrieved vertical distribution of aerosol optical depth for observations taken in the bolometer-only extended mission for comparison.