ORCHIDEE - Ozone Impact

• Phd work carried out by Thomas Verbeke, LSCE (thomas.verbeke at lsce.ipsl.fr), 2011-2014, supervised by Didier Hauglustaine, Juliette Lathière, Sophie Szopa and Nicolas Viovy: Interactions between the terrestrial biosphere and the atmospheric chemical composition: Modeling the impact of pollution on the ecosystems

1. Context

To be written soon...

X. Perspective

• This work is related to the interactions between the terrestrial biosphere and the atmospheric chemical composition. The next step, in progress, will be to include these developments in the ORCHIDEE version used for the coupling between ORCHIDEE and the chemistry-transport model LMDzINCA: see the page.

Version

TAG 1.9.5.2

Scripts modified

• diffuco.f90
• intersurf.f90
• constantes_co2.f90
• constantes.f90
• sechiba.driver
• sechiba.card
• sechiba.def

Guide

When you launch a job...
Here you can activate the ozone impact:

sechiba.card:

OKCO2OZONE=y

Your choice will be held by the driver:

sechiba.driver:

SECHIBA_sed STOMATE_OK_CO2_OZONE ${sechiba_UserChoices_OKCO2OZONE}

Don't care about stomate control flag, if you ride with ozone, all will be compute with photosynthesis (sechiba) which activates stomate.

The impact of ozone occurs only in the subroutine diffuco_trans_co2 in diffuco.f90:

       IF ( control%ok_co2 ) THEN

                                  ...
       CALL diffuco_trans_co2 (kjpindex, dtradia, swdown, temp_air, pb, qair, q2m, t2m, rau, u, v, q_cdrag, humrel, &
            assim_param, ccanopy, &
            veget, veget_max, lai, qsintveg, qsintmax, vbeta3, rveget, rstruct, cimean, vbetaco2, vbeta23, &
            vcmax_opt, vjmax_opt, gstot, vcmax_oz_az,gsO3_oz_az,As_oz_az,FO3,SFO3_oz)

The impact of ozone is originally lead by the ambient concentration (in ppb) that you can modulate (for the moment) in the routine diffuco_trans_co2 in diffuco.f90: (Warning! do not use diffuco_trans_co2_origin!!)

diffuco.f90:

   if (control%ok_co2_ozone) THEN
      
       ...
       ozcanopy(:)=0.
       write(numout,*) ' ozcanopy ' , ozcanopy(:)
    endif

If you activate OKCO2OZONE, the impact will occur when and where there will be photosynthesis:

            DO inic=1,nic
                IF (control%ok_co2_ozone) THEN
                                        ...
                   write(numout,*) 'start impact ozone on CO2 assimilation'
                                        ...

Otherwise, diffuco compute photosynthesis with the former code:

                                        ...
                ELSE

                   !If you don't choose to run with ozone:
                   write(numout,*) 'Photosyntehsis as usual'
                                        ...

After the calculation of photosynthesis over LAI steps, we integrate to obtain the total variable:

             
                total assimilation and conductance
                assimtot(icinic) = assimtot(icinic) + &
                     assimi(icinic) * (laitab(jl+1)-laitab(jl))
                gstot(icinic) = gstot(icinic) + &
                     gs(icinic) * (laitab(jl+1)-laitab(jl))


                write(numout,*) 'Total CO2 assimilation', assimtot(icinic)
                write(numout,*) 'Total stomatal conductance', gstot(icinic)
                               ...
                write(numout,*) 'Stock gs and As for ozone impact'
                write(numout,*) 'assimtot_O3' ,As_oz_az(icinic)
                               ...
                !Fin Modifs T.V 2012

Outputs

Variables related to ozone impact are written in sechiba and stomate output files:

For instance, in a sechiba output file:

gsO3_oz_az

vcmax_oz_az

As_oz_az

FO3

SFO3_oz