wiki:DevelopmentActivities/AccelerationSpinup/ExtensionMethod

Extension of the analytical spin-up

Not all the versions of ORCHIDEE are compatible with the analytical spin-up. When Forest Managament will be included in the trunk, the method should be extended because there are two more litter pools (woody pool above and below). The nitrogen is based on the same formalism.

Extension to Forest management

I present the changes needed to integrate the 2 new pools.

  • In constantes.f90, add two new index for woody pools :
       iwoody_above = 5 
       iwoody_below = 6
    
  • Still in constantes.f90, redefine nbpools, iactive_pool, islow_pool and ipassive_pool :
       INTEGER(i_std),PARAMETER :: nbpools = 9
       INTEGER(i_std),PARAMETER :: iactive_pool = 7
       INTEGER(i_std),PARAMETER :: islow_pool   = 8
       INTEGER(i_std),PARAMETER :: ipassive_pool = 9
    
  • In stomate_litter.f90, add the flux exchanges done by the 2 woody litter compartments :
    ! Flux leaving the woody above litter pool :
    MatrixA(:, m, iwoody_above, iwoody_above) = - dt /litter_tau(iwoody) * control_temp(:,iabove) * &
         control_moist(:,iabove) * exp( -3. * lignin_wood(:,m,iabove) )
    
    ! Flux leaving the woody below litter pool :
    MatrixA(:, m, iwoody_below, iwoody_below) = - dt /litter_tau(iwoody) * control_temp(:,ibelow) * &
         control_moist(:,ibelow) * exp( -3. * lignin_wood(:,m,ibelow))
    
    
    ! Flux received by the carbon active from the woody above litter pool :
    MatrixA(:, m, iactive, iwoody_above) = frac_soil(istructural, iactive, iabove) * dt /litter_tau(iwoody) * control_temp(:,iabove) * &
         control_moist(:,iabove) * exp( -3. * lignin_wood(:,m,iabove) ) * ( 1. -  lignin_wood(:,m,iabove) ) 
    
    ! Flux received by the carbon active from the woody below litter pool :
    MatrixA(:, m, iactive, iwoody_below) = frac_soil(istructural, iactive, ibelow) * dt /litter_tau(iwoody) * control_temp(:,ibelow) * &
         control_moist(:,ibelow) * exp( -3. * lignin_wood(:,m,ibelow) ) * ( 1. -  lignin_wood(:,m,ibelow) ) 
    
    ! Flux received by the carbon slow from the woody above litter pool :
    MatrixA(:, m, islow, iwoody_above) = frac_soil(istructural, islow, iactive) * dt /litter_tau(iwoody) * control_temp(:,iabove) * &
         control_moist(:,iabove) * exp( -3. * lignin_wood(:,m,iabove) ) * lignin_wood(:,m,iabove)
    
    ! Flux received by the carbon slow from the woody below litter pool :
    MatrixA(:, m, islow, iwoody_below) =  frac_soil(istructural, islow, ibelow) * dt /litter_tau(iwoody) * control_temp(:,ibelow) * &
         control_moist(:,ibelow) * exp( -3. * lignin_wood(:,m,ibelow) ) * lignin_wood(:,m,ibelow)
    
    
  • Add the input litter in stomate_litter.f90 :
    VectorB(:, m, iwoody_above) = litter_inc_PFT(:,m,iwoody,iabove)
    VectorB(:, m, iwoody_below) = litter_inc_PFT(:,m,iwoody,ibelow)
    
    

The rest of the code is the same.

  • I was able to extend the method to the woody pools in the version MERGE_FORESTRY (with the extra-dimension for carbon variables) under my personal directory on SVN.

Extension to nitrogen pools

Due to lack of time and due to O-CN code does not use the same variables as ORCHIDEE, I cannot complete this section. Moreover, the equations used in the work paper for the PASIM model is questionable.

Update (13/12/2012)

After discussing with Nicolas Viovy, there may be two problems :

  • 1. Limitation of the decomposition : The nitrogen decomposition rate depends on the stock present in the pool at the given time step.
  • 2. Supplementary fluxes : There are more fluxes like carbon leaching and carbon uptake by the plants. Maybe they could be considered pools.
  • TO DO : A meeting should be organized with PASIM people in order to know how they have solved (or not) these problems.

Warnings

  • When SPITFIRE will be included in the trunk, this method may to be modified because it considered fire fluxes from the litter.
  • Possible modifications when ORCHIDEE_HIGH_LAT and will be merged !
  • Problem with DOC (dissolved organic carbon) ?
Last modified 5 years ago Last modified on 05/21/13 11:32:21