How to access the database ?

For moderate use : the World Wide Web site.

For anyone having access to internet, This World Wide Web site has been developed at LMD. In adition to a complete documention, this interactive site offer a direct and convenient access to the data in a variety of graphical and numerical formats. However, the variability models are not available on the web-site.

For intensive or precise work : the CD-ROMs

The MCD is available for distribution on a couple of CD-ROMs that can be obtained from LMD. In its current version The data are distributed in portable binary formats, such as the Data Retrieval and Storage (DRS) library developed for the Program for (Terrestrial) Climate Model Diagnosis and Intercomparison to facilitate the transfer of data between different platforms (See the User Manual, Lewis et al., 2001a )

Bearing in mind the potentially diverse range of users of the MCD, including engineers involved in the design of spacecraft missions, scientists specializing in GCM studies who are familiar with manipulating similar data sets and scientists from other areas who may require information on environmental conditions on Mars, the data may be accessed by several methods :

• If you know FORTRAN, the best way to retrieve environmental data from the Mars climate database is to use the subroutine mode of the software supplied with the Mars Climate Database. In practice, one only has to call a main subroutine named atmemcd from within any program written in FORTRAN to get environmental data at any given locations and times. A simple example of such a program (test_emcd), which can be easily modified, is provided. This mode was developped with a particular attention to trajectory simulation application, but It should also be used for other purpose. A Programmer's guide (Forget et al. 2001a) is available.

• An interface, MCDGM, is supplied with the Mars Climate Database. The MCDGM interface performs in a very similar way to MarsGRAM version 3.5. It is intended to make the database as easy to use as possible for those with prior experience of MarsGRAM as well as providing possible access for all users to the complete database, It can be run in interactive or batch mode.

• It is possible to access the database directly from within any program, written in FORTRAN or C, by using the DRS library.

• Control files, instructions and example scripts are provided for accessing the database using GrADS. GrADS is a freely available package for access, manipulation and display of earth science data which runs on many computing platforms.