Technical modifications

This page summarizes the choices and the modifications done for the externalization of the parameters.

Global Specifications

We tried to respect as soon as possible the structure of the code. Three folders over five were affected by the modifications : src_parameters, src_sechiba and src_stomate. We regroup all the files containing parameters in src_parameters. We rewrite some parts of the code in order not to have explicit references to indexes to some PFTs (like agricultural ones).
We delete all the multiple definitions of some parameters like pi or the terrestrial radius R_Earth.

Finally, we gave names to some coefficents intervening in equations and externalized them.

The main changing are detailed below :

Src_parameters

Originally, this folder was organized in 4 files called constantes.f90, constantes_co2.f90, constantes_veg.f90 and constantes_soil.f90.

The last three files were mixed up with stomate_constants.f90 to give pft_parameters.f90 and constantes_mtc.f90. These new files make the initialization and the overwriting of the pft-parameters.

All the default values for the pft-parameters are in constantes_mtc.f90.

constantes.f90 contains all the physical constants used by ORCHIDEE and (for the moment) the rest of the externalized parameters (scalar and no-pfts-sized arrays).

Src_sechiba

We add a new module called qsat_moisture.f90. This module regroups the routines for the calculation of qsat (previously in constantes_veg.f90).
intersurf.f90 reads the number of PFTs and the parameters values chosen by the user.

Src_stomate

We delete stomate_constants.f90 in order to move its parameters in src_parameters. The too-specific parameters were moved to stomate_data.f90.
During our validations on fluxnet sites, we modified the herbivory model and the formulation for the variable "black_carbon". In stomate_season.f90, we replace :

    DO j = 2,nvm
       !
       IF ( natural(j) ) THEN
          !
          WHERE ( nlflong_nat(:) .GT. zero )
             consumption(:) = hvc1 * nlflong_nat(:) ** hvc2
             herbivores(:,j) = one_year * green_age(:) * nlflong_nat(:) / consumption(:)
          ELSEWHERE
             herbivores(:,j) = 100000.
          ENDWHERE
          !
       ELSE
          !
          herbivores(:,j) = 100000.
          !
       ENDIF
       !
    ENDDO

by :

     DO j = 2,nvm
       !
       IF ( natural(j) ) THEN
          !
          WHERE ( nlflong_nat(:,j) .GT. zero )
             consumption(:) = hvc1 * nlflong_nat(:,j) ** hvc2
             herbivores(:,j) = one_year * green_age(:,j) * nlflong_nat(:,j) / consumption(:)
          ELSEWHERE
             herbivores(:,j) = 100000.
          ENDWHERE
          !
       ELSE
          !
          herbivores(:,j) = 100000.
          !
       ENDIF
       !
    ENDDO  

in order to make herbivores more pft-specific. For "black_carbon", we relaced the following line

 black_carbon(:) = &
                  black_carbon(:) + bcfrac(:) * residue(:) 

by :

 black_carbon(:) = &
                  black_carbon(:) + bcfrac(:) * residue(:) * veget_max(:,j)

In both cases, when we add a new PFT on the same surface, the consumption of herbivory and the quantity of black carbon was doubled ! That's why we change the formulations of these two sub-models.