Changeset 6393 for branches/ORCHIDEE_2_2/ORCHIDEE/src_sechiba/diffuco.f90

Timestamp:

2019-12-16T12:11:50+01:00 (4 years ago)

Author:

josefine.ghattas

Message:

As done in ORCHIDEE_2_0:
Added new option for downregulation parametrization. Set DOWNREGULATION_CO2_NEW=y in run.def to activate. This option will be availble for configurations IPSLCM66.1.11 and later.

IF both DOWNREGULATION_CO2 and DOWNREGULATION_CO2_NEW are true, then DOWNREGULATION_CO2 will be set to false.

See ticket #641

File:

• branches/ORCHIDEE_2_2/ORCHIDEE/src_sechiba/diffuco.f90 (modified) (1 diff)

branches/ORCHIDEE_2_2/ORCHIDEE/src_sechiba/diffuco.f90

@@ -1575 +1575 @@
     !
 
-    IF (downregulation_co2) THEN
+    ! Choice of downregulation. Note that downregulation_co2_new excludes
+    IF (downregulation_co2_new) THEN
+       ! Option used for CMIP6 version from 6.1.11 
+       ! A minimum value is used for the CO2 concentration(Ca)
+       ! For low CO2 concentration values(under downregulation_co2_minimum) the
+       ! parametrization allows a behavior in the same way as for the preindustral period.
        DO jv= 1, nvm
-          vcmax(:,jv) = assim_param(:,jv,ivcmax)*(un-downregulation_co2_coeff(jv)*log(Ca(:)/downregulation_co2_baselevel))
+           vcmax(:,jv) = assim_param(:,jv,ivcmax)*(un-downregulation_co2_coeff_new(jv) * &
+                         (MAX(Ca(:),downregulation_co2_minimum)-downregulation_co2_baselevel) / &
+                         (MAX(Ca(:),downregulation_co2_minimum)+20.))
+       ENDDO
+    ELSE IF (downregulation_co2) THEN
+       ! Option used for CMIP6 version 6.1.0 up to 6.1.10
+       DO jv= 1, nvm
+          vcmax(:,jv) = assim_param(:,jv,ivcmax)*(un-downregulation_co2_coeff(jv) * &
+                          log(Ca(:)/downregulation_co2_baselevel))
        ENDDO
     ELSE