Constraints on Dust Aerosol Vertical Profiles Using TES and Mini-TES Observations

Abstract:

The Mars Exploration Rovers, Spirit and Opportunity, collected thermal emission spectra of the surface and atmosphere for up to two Mars Years using the Miniature Thermal Emission Spectrometer (Mini-TES). For a short period of time after landing, there are Mini-TES atmospheric observations that are concurrent to those taken by the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor (MGS). Mini-TES was designed as a miniature version of TES, and so the two instruments took measurements within the same the same infrared spectral range. This range covers the CO2 absorption/emission band and contains broad influences from dust aerosols. At a wavenumber of 1075 cm-1 (9.3 micrometers), the observed radiance is highly sensitive to dust in the atmosphere of Mars. However, because the atmosphere is not opaque at this wavenumber, the TES and Mini-TES observations preferentially sample different vertical regions, with TES more sensitive to dust higher in the atmosphere and Mini-TES more sensitive to dust near the surface. Using this information and the two sets of observations, we can constrain parameters that describe a simple vertical dust profile. We will present results for selected dust vertical profiles for the first 300 sols of Spirit and Opportunity missions.