Mars 1D testphys1d program

It is possible to run the Mars PCM in a "single-column" configuration: this is the so-called 1D Mars PCM whose program is testphys1d. It is quite useful for some studies and or when developing and testing parametrizations.

Compilation

The main program testphys1d is compiled using the same compilation script, makelmdz_fcm, as for the 3D Mars PCM. Nevertheless, there are few modifications:

• the -d option requires only one argument, the number of vertical levels;
• the main program to compile is testphys1d rather than gcm.

So for instance to compile a case for 54 vertical levels one would run something like:

makelmdz_fcm -arch somearch -d 54 -p mars testphys1d

Inputs

Like the gcm program, the testphys1d program needs some inputs to be able to run. The needed files are:

• z2sig.def for the definition of vertical levels;
• traceur.def for the definition of tracers that the user wants the model to run with;
• callphys.def for the definition of parametrizations that the user wants the model to run with;
• run.def for the run configuration, which is similar to the one for the 3D PCM described here The run.def Input File. It has to be be adapted to the 1D case. An example file, called run.def.1d, is available in LMDZ.MARS/deftank.

Unlike the gcm program, the testphys1d program can run without starting files, that is without startfi.nc and start.nc. This is the case by default (startfiles_1D=.false.). However, in this setting, it needs the profiles of each tracer. They consist in files called profile_sometracername containing column-wise the initial values of the considered tracer. Then, the first line corresponds to the surface tracer and the following lines correspond to the layers. When the program ends, it will produce by its own a startfi.nc file initialized with the default settings.

In the case of startfiles_1D=.true. set in the run.def, the program will look for starting files, that is a startfi.nc file and a start1D.txt file. The latter is specific to the 1D model and an example can be found in LMDZ.MARS/deftank. If the starting files are present, it will read them to initialize the run accordingly and it will create a restartfi.nc file and a restart1D.txt file at the end of the run. If these starting files are not present, it will start as in the previous (default) case but it will still create the restarting files at the end.

Outputs

The program testphys1d can output diagfi.nc and stats.nc files. Just like for the 3D PCM model, the optional diagfi.def and stats.def files can be respectively added to specify which variables need be outputted.

As described in the previous section, if startfiles_1D=.true. in the run.def, then testphys1d will create a restartfi.nc file and a restart1D.txt file at the end of the run. This option is particularly useful when one wants to make chained simulations with the 1D model.