2.1. The sequence

  1. PGD (routine pgd_surf_atm.f90): this program computes the physiographic data file (called PGD file below). At this step, you perform 3 main tasks:
    1. You choose the surface schemes you will use.
    2. You choose and define the grid for the surface
    3. The physiographic fields are defined on this grid.
      Therefore, the PGD file contains the spatial characteristics of the surface and all the physiographic data necessary to run the interactive surface schemes for vegetation and town.
  2. PREP (routine prep_surf_atm_n.f90): this program performs the initialization of the surface scheme prognostic variables, as temperatures profiles, water and ice soil contents, interception reservoirs, snow reservoirs.
  3. run of the schemes (routine coupling_surf_atm_n.f90): this performs the physical evolution of the surface schemes. It is necessary that this part, contrary to the 2 previous ones, is to be coupled within an atmospheric forcing (provided either in off-line mode or via a coupling with an atmospheric model).
  4. DIAG (routine diag_surf_atm_n.f90): this computes diagnostics linked to the surface (e.g. surface energy balance terms, variables at 2m of height, etc...). It can be used either during the run (adding these diagnostics in the output file(s) of the run), or independantly from the run, for a given surface state (still, an instantaneous atmospheric forcing is necessary for this evaluation).

In addition, in order to read or write the prognostic variables or the diagnostics variables, respectively, in the surface files, the following subroutines are used: init_surf_atm_n.f90, write_surf_atm_n.f90 and write_diag_surf_atm_n.f90.