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      !# * 0 -> No conservation of surface pressure (for LAM grids)
      !# * 1 -> Conservation of total air mass pressure (for global grids)
      !# * 2 -> Conservation of dry    air mass pressure (for global grids)

Cascadeing

When the resolution of the driving data is too large with respect to the model grid resolution, one or more simulations can get run with an intermediate resolution and a domain slightly larger than the next inner domain.

Spectral nudging

To constrain the large scales of a simulation spectral nudging can get used. To learn more about this and which parameters to set have a look at the following wiki page: Spectral nudging

Period

Start and end date of a simulation need to get set in the file configexp.cfg with the parameters:
    CLIMAT_startdate="YYYY MM DD hh"
    CLIMAT_enddate="YYYY MM DD hh"

Greenhouse gases / Scenario

Depending on the period (past, current, future) and for future simulation depending on the scenario simulated, a table containing the annual mean concentrations of the main 5 greenhouse gases (CO2, N2O, CH4, CFC-11, CFC-12) needs to get assigned to the parameter 'CLIMAT_ghg_list' (in file configexp.cfg). A selection of different lists can be found under: ${MODEL_DATA}/Greenhouse_gases

But one can also create their own list.

Initial conditions

At the beginning of every simulations several fields (atmospheric, surface and soil) need to get initialized. Especially for short simulations it is very important to use fields that best represent the starting state of a simulation. If such fields are not available one can also chose to spinup the simulation. Whereas atmospheric fields get into equilibrium very quickly, surface fields like snow on the ground might take up to at least a season. Soil fields, like soil temperature and soil moisture, can take several years to get into equilibrium, depending on the soil depth.

To get a list of fields that need to get initialized have a look at the following wiki: Initial conditions

Driving data (lower & lateral)

Lower boundary conditions (SST & SIC)

Since our(!!!) GEM version is not coupled to an ocean model, the sea surface temperature (SST) as well as the sea ice fraction (SIC) need to get prescribed. These two fields can get prescribed at every model timestep up to monthly fields. Most of the dataset we have are either daily or monthly. If the dataset contains monthly data, all timesteps can be inside one file. If the data are at a higher frequency, one file per month should get used, with the filename ending on *_YYYYMM. The parameter 'GEM_anclima' needs to get set to the location of the dataset to get used. A selection of already available datasets can get found under: ${MODEL_DATA}/SST_SeaIce_degK. But one can also create ones own dataset.

When only one file exists, 'GEM_anclima' needs to get set to the full name of the file.

If several monthly files exist, 'GEM_anclima' needs to get set to the full name of the file without the '_YYYYMM' at the end!!! The scripts will fill in the current year and month.

Lateral boundary conditions (LAM only)

Geophysical fields

Schemes

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