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What is the Mars Climate Database ?

The Mars Climate Database (MCD) is a database of statistics describing the climate and environment of the Martian atmosphere. It is constructed directly on the basis of output from mulitannual integrations of a Global Climate Model (GCM) developed by Laboratoire de Météorologie Dynamique du CNRS, France in collaboration with the University of Oxford, UK, the Instituto de Astrofisica de Andalucia, Spain, SA, France with support from the European Space Agency (ESA) and Centre National d'Etudes Spatiales (CNES).

The MCD can be used as a tool for mission planning and is applied to prepare for many missions in Europe and the USA. It also provides useful predictions for any scientist or mission design specialists

Previous versions of the Mars Climate Database has been available to the community since 1999. For intensive use, it can be provided on a DVD ROM along with access software in Fortran, with interface for IDL, mathlab or C. This DVD version have been used by more than 60 teams around the word to prepare most martian missions, analyse data from many instruments around Mars, or many other studies.

Why a model-based climate database ?
The Martian environment is highly variable. In spite of the new observations available from Mars Global Surveyor and now, Mars Express, it remains difficult to predict what are the climatic conditions on Mars at any time and any locations from the available observational data, especially for climate variables which are not directly observed, like the wind, the water vapor mixing ratio, atmospheric composition, etc...

The Mars GCMs have been extensively validated using available observational data and we believe that they represent the current best knowledge of the state of the Martian atmosphere given the observations and the physical laws which govern the atmospheric environment and surface conditions on the planet. In other words, Models can be used to extrapolate the observations.

Contents.
The MCD contains simulated data (temperature, wind, density, pressure, radiative fluxes, etc. See Table 1) stored on a $5.675^\circ \times 3.75^\circ$ longitude-latitude grid from the surface up to an approximate altitude of 250 km: Fields are averaged and stored 12 times a day, for 12 Martian ``seasons'' to give a comprehensive representation of the annual and diurnal cycles. Each season covers 30$^o$ in solar longitude ($L_s$), and are typically 50-70 days long. In other words, at every grid-point, the database contains 12 "typical" days, one for each season. In addition, information on the variability of the data within one season and the day to day oscillations are also stored in the database.


Table 1: Variables stored in database mean data files.
Mean variable symbol units 2-D or 3-D
Surface pressure ps Pa 2-D
Surface temperature tsurf K 2-D
Atmospheric temperature temp K 3-D
Atmospheric density rho kg m$^{-3}$ 3-D
Zonal (Eastward) wind u m s$^{-1}$ 3-D
Meridional (Northward) wind v m s$^{-1}$ 3-D
Vertical (Downward) wind w m s$^{-1}$ 3-D
Turbulent eddy kinetic energy q2 m$^2$ s$^{-2}$ 3-D
LW (thermal IR) radiative flux to surface fluxsurf_lw W m$^{-2}$ 2-D
SW (solar) radiative flux to surface fluxsurf_sw W m$^{-2}$ 2-D
LW (thermal IR) radiative flux to space fluxtop_lw W m$^{-2}$ 2-D
SW (solar) radiative flux to space fluxtop_sw W m$^{-2}$ 2-D
CO$_2$ ice cover co2ice kg m$^{-2}$ 2-D
Visible Dust optical depth dod   2-D
Water vapor column col_h2ovapor kg/m$^2$ 2-D
Water vapor mixing ratio vmr_h2ovapor mol/mol 3-D
Water ice column col_h2oice kg/m$^2$ 2-D
Water ice mixing ratio vmr_h2oice mol/mol 3-D
Ozone (O$_3$) mixing ratio vmr_o3 mol/mol 3-D
$[CO_2]$ volume ratio vmr_co2 mol/mol 3-D
$[CO]$ mixing ratio vmr_co mol/mol 3-D
$[N_2]$ mixing ratio vmr_n2 mol/mol 3-D
$[H_2]$ mixing ratio vmr_n2 mol/mol 3-D
$[O]$ volume mixing ratio vmr_o mol/mol 3-D


Vertical coordinate
The data have been interpolated to 3 kinds of vertical coordinate :


next up previous
Next: How are the atmospheric Up: info_web_v4 Previous: info_web_v4
FORGET Francois 2006-02-24