Data assimilation for Mars: an overview of results from the Mars Global Surveyor period, proposals for future plans and requirements for open access to assimilation output

The Thermal Emission Spectrometer (TES) aboard Mars Global Surveyor (MGS) has produced an extensive atmospheric data set, both during the initial aerobraking hiatus and later from the scientific mapping phase of the mission which lasted almost three complete Martian seasonal cycles. Thermal profiles for the atmosphere below about 40 km, and total dust and water ice opacities, have been retrieved from TES spectra (Conrath et al., 2000; Smith et al., 2000). These data have been analysed by assimilation into a Mars general circulation model (MGCM), making use of a sequential procedure known as the analysis correction scheme (Lorenc et al., 1991), a form of the successive corrections method which has proved simple and robust in trial studies with artificial data under Martian conditions (Lewis et al., 1996, 1997).