Changeset 6393

Timestamp:

2019-12-16T12:11:50+01:00 (5 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

Location:

branches/ORCHIDEE_2_2/ORCHIDEE

Files:

• orchidee.default (modified) (3 diffs)
• src_parameters/constantes_var.f90 (modified) (1 diff)
• src_sechiba/diffuco.f90 (modified) (1 diff)

branches/ORCHIDEE_2_2/ORCHIDEE/orchidee.default

@@ -289 +289 @@
 VCMAX_FIX =  0., 40., 50., 30., 35., 40.,30., 40., 35., 60., 60., 70., 70. 
 
-# DOWNREG_CO2 ([-]) :  coefficient for CO2 downregulation (unitless)    {}
+# DOWNREG_CO2 ([-]) :  coefficient for CO2 downregulation (unitless)    {OK_CO2 and DOWNREGULATION_CO2}
 DOWNREG_CO2 =  0., 0.38, 0.38, 0.28, 0.28, 0.28, 0.22, 0.22, 0.22, 0.26, 0.26, 0.26, 0.26 
+
+# DOWNREG_CO2_NEW ([-]) :  coefficient for CO2 downregulation (unitless)        {OK_CO2 and DOWNREGULATION_CO2_NEW}
+DOWNREG_CO2_NEW =  0., 0.35, 0.35, 0.26, 0.26, 0.26, 0.20, 0.20, 0.20, 0.24, 0.03, 0.24, 0.03 
 
 # E_KmC ([J mol-1]) :  Energy of activation for KmC     {}
@@ -976 +979 @@
 DEW_VEG_POLY_COEFF =  0.887773, 0.205673, 0.110112, 0.014843, 0.000824, 0.000017  
 
-# DOWNREGULATION_CO2 ([FLAG]   ) :  Activation of CO2 downregulation    {OK_SECHIBA}
+# DOWNREGULATION_CO2 ([FLAG]   ) :  Activation of CO2 downregulation (used for CMIP6 version 6.1.0-6.1.10)      {OK_SECHIBA}
 DOWNREGULATION_CO2 =  y 
 
-# DOWNREGULATION_CO2_BASELEVEL ([ppm]   ) :  CO2 base level     {OK_SECHIBA }
+# DOWNREGULATION_CO2_NEW ([FLAG]   ) :  Activation of CO2 downregulation (used for CMIP6 version 6.1.11 and later)      {OK_SECHIBA}
+DOWNREGULATION_CO2_NEW =  n 
+
+# DOWNREGULATION_CO2_BASELEVEL ([ppm]   ) :  CO2 base level     {DOWNREGULATION_CO2 or DOWNREGULATION_CO2_NEW}
 DOWNREGULATION_CO2_BASELEVEL =  380. 
+
+# DOWNREGULATION_CO2_MINIMUM ([ppm]   ) :  CO2 value above which downregulation is taken into account   {DOWNREGULATION_CO2_NEW}
+DOWNREGULATION_CO2_MINIMUM =  280. 
 
 # GB_REF ([s m-1]   ) :  Leaf bulk boundary layer resistance    {}
@@ -1726 +1735 @@
 XIOS_REMAP_OUTPUT =  True 
 
+# DT_STOMATE ([seconds]) :  Time step of STOMATE and other slow processes       {OK_STOMATE}
+DT_STOMATE =  86400. 
+

branches/ORCHIDEE_2_2/ORCHIDEE/src_parameters/constantes_var.f90

@@ -629 +629 @@
   REAL(r_std), SAVE :: laimax = 12.             !! Maximal LAI used for splitting LAI into N layers (m^2.m^{-2})
 !$OMP THREADPRIVATE(laimax)
-  LOGICAL, SAVE :: downregulation_co2 = .TRUE.             !! Set to .TRUE. if you want CO2 downregulation.
+  LOGICAL, SAVE :: downregulation_co2 = .TRUE.             !! Set to .TRUE. if you want CO2 downregulation version used for CMIP6 6.1.0-6.1.10
 !$OMP THREADPRIVATE(downregulation_co2)
+  LOGICAL, SAVE :: downregulation_co2_new = .FALSE.        !! Set to .TRUE. if you want CO2 downregulation version revised for CMIP6 6.1.11
+!$OMP THREADPRIVATE(downregulation_co2_new)
   REAL(r_std), SAVE :: downregulation_co2_baselevel = 380. !! CO2 base level (ppm)
 !$OMP THREADPRIVATE(downregulation_co2_baselevel)
+  REAL(r_std), SAVE :: downregulation_co2_minimum = 280.   !! CO2 value above which downregulation is taken into account 
+!$OMP THREADPRIVATE(downregulation_co2_minimum)
 
   REAL(r_std), SAVE :: gb_ref = 1./25.                     !! Leaf bulk boundary layer resistance (s m-1)

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