CO2 effect on stomatal conductance according to Franks et a. (2013) e…

…quation

GeosCore/drydep_mod.F

@@ -194,6 +194,7 @@ MODULE DRYDEP_MOD
 !  16 Mar 2017 - R. Yantosca - Remove references to obsolete vars in Input_Opt
 !  24 Aug 2017 - M. Sulprizio- Remove support for GCAP, GEOS-4, GEOS-5 and MERRA
 !  01 Dec 2018 - H.P. Lin    - Move DEPSAV to State_Chm%DryDepSav
+!  25 Jun 2019 - A. Wong     - Add CO2 effect on stomatal resistance (RIX)
 !EOP
 !------------------------------------------------------------------------------
 !BOC
@@ -1424,6 +1425,13 @@ SUBROUTINE DEPVEL( am_I_Root, Input_Opt, State_Met, State_Chm,
             ENDIF
             
             RIX = RIX*GFACT*GFACI
+            
+            ! Apply scaling factor to RIX when CO2 effect is turned on
+            ! (ayhwong, 6/25/19)
+            IF (Input_Opt%CO2_EFFECT) THEN
+               RIX = RIX*Input_Opt%RS_SCALE
+            ENDIF
+
  150        CONTINUE
 !*                                 
 !*    Compute aerodynamic resistance to lower elements in lower part           

GeosCore/input_mod.F

@@ -3378,6 +3378,8 @@ SUBROUTINE READ_DEPOSITION_MENU( am_I_Root, Input_Opt, RC )
 !  13 Sep 2017 - M. Sulprizio- Remove Input_Opt%USE_OLSON_2001. Olson 2001 is
 !                              now the default.
 !  08 Nov 2017 - R. Yantosca - Return error condition to calling program
+!  25 Jun 2017 - A. Wong     - Add the option of inclduing CO2 effect on drydep
+
 !EOP
 !------------------------------------------------------------------------------
 !BOC
@@ -3427,6 +3429,30 @@ SUBROUTINE READ_DEPOSITION_MENU( am_I_Root, Input_Opt, RC )
       ENDIF
       READ( SUBSTRS(1:N), * ) Input_OPt%LWETD
 
+      ! Turn on CO2 effect on drydep?
+      CALL SPLIT_ONE_LINE( SUBSTRS, N, 1, 'CO2_EFFECT', RC )
+      IF ( RC /= GC_SUCCESS ) THEN
+         CALL GC_Error( ErrMsg, RC, ThisLoc )
+         RETURN
+      ENDIF
+      READ( SUBSTRS(1:N), * ) Input_Opt%CO2_EFFECT
+
+      ! CO2 level at simulation
+      CALL SPLIT_ONE_LINE( SUBSTRS, N, 1, 'CO2_LEVEL', RC )
+      IF ( RC /= GC_SUCCESS ) THEN
+         CALL GC_Error( ErrMsg, RC, ThisLoc )
+         RETURN
+      ENDIF
+      READ( SUBSTRS(1:N), * ) Input_Opt%CO2_LEVEL
+
+      ! Reference CO2 level
+      CALL SPLIT_ONE_LINE( SUBSTRS, N, 1, 'CO2_REF', RC )
+      IF ( RC /= GC_SUCCESS ) THEN
+         CALL GC_Error( ErrMsg, RC, ThisLoc )
+         RETURN
+      ENDIF
+      READ( SUBSTRS(1:N), * ) Input_Opt%CO2_REF
+
       ! Separator line
       CALL SPLIT_ONE_LINE( SUBSTRS, N, 1, 'separator', RC )
       IF ( RC /= GC_SUCCESS ) THEN
@@ -3460,7 +3486,18 @@ SUBROUTINE READ_DEPOSITION_MENU( am_I_Root, Input_Opt, RC )
       ELSE
          Input_Opt%PBL_DRYDEP = .TRUE.
       ENDIF 
-
+
+      ! If CO2 effect on RS in turned on, calculate the scaling factor 
+      ! on Rs based on Franks et al. (2013) (ayhwong, 6/25/2019)
+
+      If (Input_Opt%CO2_EFFECT) THEN
+         Input_Opt%RS_SCALE = Input_Opt%CO2_LEVEL / Input_Opt%CO2_REF * 
+     &                       (Input_Opt%CO2_LEVEL + 80.0_fp) * 
+     &                       (Input_Opt%CO2_REF - 40.0_fp) /
+     &                       (Input_Opt%CO2_LEVEL - 40.0_fp) / 
+     &                       (Input_Opt%CO2_REF + 80.0_fp)
+      ENDIF
+
       !=================================================================
       ! Print to screen
       !=================================================================
@@ -3473,10 +3510,20 @@ SUBROUTINE READ_DEPOSITION_MENU( am_I_Root, Input_Opt, RC )
      &                        Input_Opt%PBL_DRYDEP
          WRITE( 6, 100     ) 'Turn on wet deposition?     : ', 
      &                        Input_Opt%LWETD
+         WRITE( 6, 100     ) 'Turn on CO2 effect?         : ', 
+     &                        Input_Opt%CO2_EFFECT
+         WRITE( 6, 110     ) 'CO2 level                   : ', 
+     &                        Input_Opt%CO2_LEVEL         
+         WRITE( 6, 110     ) 'CO2 reference level         : ', 
+     &                        Input_Opt%CO2_REF         
+         WRITE( 6, 110     ) 'RIX scaling factor          : ', 
+     &                        Input_Opt%RS_SCALE
+
       ENDIF
 
       ! FORMAT statements
  100  FORMAT( A, L5 )
+ 110  FORMAT( A, f6.2 )
 
       END SUBROUTINE READ_DEPOSITION_MENU
 !EOC

Headers/input_opt_mod.F90

@@ -233,7 +233,11 @@ MODULE Input_Opt_Mod
      LOGICAL                     :: LDRYD
      LOGICAL                     :: LWETD
      REAL(fp)                    :: WETD_CONV_SCAL
-     LOGICAL                     :: PBL_DRYDEP      
+     LOGICAL                     :: PBL_DRYDEP   
+     LOGICAL                     :: CO2_EFFECT
+     REAL(fp)                    :: CO2_LEVEL, CO2_REF
+     REAL(fp)                    :: RS_SCALE
+
 
      !----------------------------------------
      ! GAMAP MENU fields
@@ -704,6 +708,7 @@ SUBROUTINE Set_Input_Opt( am_I_Root, Input_Opt, RC )
 !  07 Nov 2017 - R. Yantosca - Remove LVARTROP; it's not needed
 !  08 Mar 2018 - R. Yantosca - Bug fix, remove reference to TINDEX here
 !  06 Nov 2018 - R. Yantosca - Add error trapping for allocation statements
+!  25 Jun 2019 - A. Wong     - Add CO2_LEVEL, CO2_REF, CO2_EFFECT
 !EOP
 !------------------------------------------------------------------------------
 !BOC
@@ -994,6 +999,10 @@ SUBROUTINE Set_Input_Opt( am_I_Root, Input_Opt, RC )
     Input_Opt%LWETD                  = .FALSE.
     Input_Opt%WETD_CONV_SCAL         = 1.0_fp 
     Input_Opt%PBL_DRYDEP             = .FALSE.
+    Input_Opt%CO2_LEVEL              = 390.0_fp
+    Input_Opt%CO2_REF                = 390.0_fp
+    Input_Opt%CO2_EFFECT             = .FALSE.
+    Input_Opt%RS_SCALE               = 1.0_fp
 
     !----------------------------------------
     ! GAMAP_MENU fields