A Climate Database for the Martian Atmosphere

O. Talagrand, F. Forget, R. Fournier, C. Hourdin, F. Hourdin (LMD, CNRS, Paris, France), M. Collins, S. R. Lewis, P. L. Read (AOPP, Oxford, UK), J.-P. Huot (ESTEC, ESA, Noordwijk, The Netherlands)

The Laboratoire de Meteorologie Dynamique (LMD, CNRS, Paris, France) and the Sub-Department of Atmospheric, Oceanic and Planetary Physics (AOPP) of the University of Oxford (Oxford, UK) have recently developed, with support of the European Space Agency, a database for the climate of the planet Mars. The primary use of the database will be for future mission planning. But the database can also be useful to all interested scientists as a source of information on the mean state and variability of the Martian environment: thermal structure of the atmosphere, atmospheric circulation, etc...

The database is built from numerical simulations performed with a state-of-the-art General Circulation Model (GCM) developed jointly at LMD and AOPP. The GCM includes a set of physical 'parametrizations' (radiative transfer in the visible and thermal infrared ranges, turbulent mixing, condensation-sublimation of CO tex2html_wrap_inline11 , thermal conduction in the soil and representation of gravity waves), and two different codes for the representation of large scale dynamics: a grid-point code for the LMD version, and a spectral code for the AOPP version. The GCM correctly reproduces the main features of the Martian meteorology, as observed by the Mariner 9 and Viking orbiters, and by the Viking landers.

The database consists of appropriate statistics computed on the results of multiannual simulations performed with a horizontal resolution of about 230 km and a diurnally and seasonally varying insolation. The simulations were performed for various atmospheric dust contents; high dust contents as observed by Viking, and lower dust contents, as observed more recently by Phobos 2, as well as from Earth.