Changeset 14939 for NEMO/branches

Timestamp:

2021-06-02T12:13:48+02:00 (3 years ago)

Author:

timgraham

Message:

Changes to allow use of a climatological iceberg distribution but taking the flux from the coupler.

Location:

NEMO/branches/UKMO/NEMO_4.0.4_icesheet_and_river_coupling

Files:

• cfgs/SHARED/namelist_ref (modified) (1 diff)
• src/OCE/SBC/sbcrnf.F90 (modified) (6 diffs)

NEMO/branches/UKMO/NEMO_4.0.4_icesheet_and_river_coupling/cfgs/SHARED/namelist_ref

@@ -435 +435 @@
       rn_dep_max  = 150.      !  depth over which runoffs is spread ( ln_rnf_depth_ini = .true )
       nn_rnf_depth_file = 0   !  create (=1) a runoff depth file or not (=0)
-   ln_rnf_icb  = .false.   !  read in iceberg flux from a file (fill sn_i_rnf if .true.)
+   ln_rnf_icb  = .false.    !  read in iceberg flux from a file (fill sn_i_rnf if .true.)
+   ln_icb_mass  = .false.   ! Scale iceberg flux to match mass flux from atmosphere model
 
    cn_dir      = './'      !  root directory for the runoff data location

NEMO/branches/UKMO/NEMO_4.0.4_icesheet_and_river_coupling/src/OCE/SBC/sbcrnf.F90

@@ -41 +41 @@
    REAL(wp)                   ::      rn_rnf_max        !: maximum value of the runoff climatologie (ln_rnf_depth_ini =T)
    REAL(wp)                   ::      rn_dep_max        !: depth over which runoffs is spread       (ln_rnf_depth_ini =T)
+   REAL(wp)                   ::      tot_flux           !: total iceberg flux (temporary variable)
    INTEGER                    ::      nn_rnf_depth_file !: create (=1) a runoff depth file or not (=0)
    LOGICAL                    ::   ln_rnf_icb        !: iceberg flux is specified in a file
+   LOGICAL                    ::   ln_icb_mass       !: Scale iceberg flux to match FW flux from coupled model
    LOGICAL                    ::   ln_rnf_tem        !: temperature river runoffs attribute specified in a file
    LOGICAL           , PUBLIC ::   ln_rnf_sal        !: salinity    river runoffs attribute specified in a file
@@ -108 +110 @@
       !!----------------------------------------------------------------------
       REAL(wp), DIMENSION(jpi,jpj) ::   ztfrz   ! freezing point used for temperature correction
+      REAL(wp), PARAMETER ::   rsmall = 1.e-10_wp    ! ICB flux epsilon
+
       !
       !
@@ -117 +121 @@
       IF( .NOT. l_rnfcpl )  THEN
                             CALL fld_read ( kt, nn_fsbc, sf_rnf   )    ! Read Runoffs data and provide it at kt ( runoffs + iceberg )
-         IF( ln_rnf_icb )   CALL fld_read ( kt, nn_fsbc, sf_i_rnf )    ! idem for iceberg flux if required
-      ENDIF
+      ENDIF
+      IF(   ln_rnf_icb   )   CALL fld_read ( kt, nn_fsbc, sf_i_rnf )    ! idem for iceberg flux if required
       IF(   ln_rnf_tem   )   CALL fld_read ( kt, nn_fsbc, sf_t_rnf )    ! idem for runoffs temperature if required
       IF(   ln_rnf_sal   )   CALL fld_read ( kt, nn_fsbc, sf_s_rnf )    ! idem for runoffs salinity    if required
@@ -126 +130 @@
          IF( .NOT. l_rnfcpl ) THEN
              rnf(:,:) = rn_rfact * ( sf_rnf(1)%fnow(:,:,1) ) * tmask(:,:,1)  ! updated runoff value at time step kt
-             IF( ln_rnf_icb ) THEN
-                fwficb(:,:) = rn_rfact * ( sf_i_rnf(1)%fnow(:,:,1) ) * tmask(:,:,1)  ! updated runoff value at time step kt
-                CALL iom_put( 'iceberg_cea'  , fwficb(:,:)  )         ! output iceberg flux
-                CALL iom_put( 'hflx_icb_cea' , fwficb(:,:) * rLfus )   ! output Heat Flux into Sea Water due to Iceberg Thermodynamics -->
-             ENDIF
+         ENDIF
+         IF( ln_rnf_icb ) THEN
+            fwficb(:,:) = rn_rfact * ( sf_i_rnf(1)%fnow(:,:,1) ) * tmask(:,:,1)  ! updated runoff value at time step kt
+            IF( ln_icb_mass ) THEN
+                ! Modify the Iceberg FW flux to be consistent with the change in
+                ! mass of the Antarctic/Greenland ice sheet for FW conservation in
+                ! coupled model. This isn't perfect as FW flux will go into ocean at
+                ! wrong time of year but more important to maintain FW balance
+                tot_flux = SUM(fwficb(:,:)*e1e2t(:,:)*tmask_i(:,:)*greenland_icesheet_mask(:,:)) !Need to multiply by area to convert to kg/s
+                IF( lk_mpp ) CALL mpp_sum( 'icbclv', tot_flux )
+                IF( tot_flux > rsmall ) THEN
+                    WHERE( greenland_icesheet_mask(:,:) == 1.0 )                                                                                 &
+                    &    fwficb(:,:) = fwficb(:,:) * greenland_icesheet_mass_rate_of_change * rn_greenland_calving_fraction &
+                    &                                     / tot_flux
+                ELSE IF( rn_greenland_calving_fraction < rsmall ) THEN
+                    WHERE( greenland_icesheet_mask(:,:) == 1.0 ) fwficb(:,:) = 0.0
+                ELSE
+                    CALL CTL_STOP('STOP', 'No iceberg runoff data read in for Greenland. Check input file or set rn_greenland_calving_fraction=0.0')
+                ENDIF
+                tot_flux =  MAXVAL(fwficb(:,:)*tmask_i(:,:))
+                IF( lk_mpp ) CALL mpp_max( 'icbclv', tot_flux )
+                WRITE(numout,*) 'Max fwficb: ',tot_flux
+
+                tot_flux = SUM(fwficb(:,:)*e1e2t(:,:)*tmask_i(:,:)*antarctica_icesheet_mask(:,:))
+                IF( lk_mpp ) CALL mpp_sum( 'icbclv', tot_flux )
+                IF( tot_flux > rsmall ) THEN
+                    WHERE( antarctica_icesheet_mask(:,:) == 1.0 )                                                                                &
+                    &    fwficb(:,:) = fwficb(:,:) * antarctica_icesheet_mass_rate_of_change * rn_antarctica_calving_fraction &
+                    &                                     / (tot_flux  + 1.0e-10_wp )
+                ELSE IF( rn_antarctica_calving_fraction < rsmall ) THEN
+                    WHERE( antarctica_icesheet_mask(:,:) == 1.0 ) fwficb(:,:) = 0.0
+                ELSE
+                    CALL CTL_STOP('STOP', 'No iceberg runoff data read in for Greenland. Check input file or set rn_antarctica_calving_fraction=0.0')
+                ENDIF
+                tot_flux =  MAXVAL(fwficb(:,:)*tmask_i(:,:))
+                IF( lk_mpp ) CALL mpp_max( 'icbclv', tot_flux )
+                WRITE(numout,*) 'Max fwficb: ',tot_flux, antarctica_icesheet_mass_rate_of_change
+            ENDIF
+            CALL iom_put( 'iceberg_cea'  , fwficb(:,:)  )          ! output iceberg flux
+            CALL iom_put( 'hflx_icb_cea' , fwficb(:,:) * rLfus )   ! output Heat Flux into Sea Water due to Iceberg Thermodynamics -->
+            rnf(:,:) = rnf(:,:) + fwficb(:,:)                      ! fwficb isn't used anywhere else so add it to runoff here
+            qns_tot(:,:) = qns_tot(:,:) - fwficb(:,:) * rLfus      ! TG: I think this is correct
          ENDIF
          !
@@ -252 +293 @@
       REAL(wp), DIMENSION(jpi,jpj,2) :: zrnfcl    
       !!
-      NAMELIST/namsbc_rnf/ cn_dir            , ln_rnf_depth, ln_rnf_tem, ln_rnf_sal, ln_rnf_icb,   &
+      NAMELIST/namsbc_rnf/ cn_dir            , ln_rnf_depth, ln_rnf_tem, ln_rnf_sal, ln_rnf_icb, ln_icb_mass,  &
          &                 sn_rnf, sn_cnf    , sn_i_rnf, sn_s_rnf    , sn_t_rnf  , sn_dep_rnf,   &
          &                 ln_rnf_mouth      , rn_hrnf     , rn_avt_rnf, rn_rfact,     &
@@ -310 +351 @@
          CALL fld_fill( sf_rnf, (/ sn_rnf /), cn_dir, 'sbc_rnf_init', 'read runoffs data', 'namsbc_rnf', no_print )
          !
-         IF( ln_rnf_icb ) THEN                      ! Create (if required) sf_i_rnf structure
-            IF(lwp) WRITE(numout,*)
-            IF(lwp) WRITE(numout,*) '          iceberg flux read in a file'
-            ALLOCATE( sf_i_rnf(1), STAT=ierror  )
-            IF( ierror > 0 ) THEN
-               CALL ctl_stop( 'sbc_rnf_init: unable to allocate sf_i_rnf structure' )   ;   RETURN
-            ENDIF
-            ALLOCATE( sf_i_rnf(1)%fnow(jpi,jpj,1)   )
-            IF( sn_i_rnf%ln_tint ) ALLOCATE( sf_i_rnf(1)%fdta(jpi,jpj,1,2) )
-            CALL fld_fill (sf_i_rnf, (/ sn_i_rnf /), cn_dir, 'sbc_rnf_init', 'read iceberg flux data', 'namsbc_rnf' )
-         ELSE
-            fwficb(:,:) = 0._wp
-         ENDIF
-
-      ENDIF
+      ENDIF
+      IF( ln_rnf_icb ) THEN                      ! Create (if required) sf_i_rnf structure
+         IF(lwp) WRITE(numout,*)
+         IF(lwp) WRITE(numout,*) '          iceberg flux read in a file'
+         ALLOCATE( sf_i_rnf(1), STAT=ierror  )
+         IF( ierror > 0 ) THEN
+            CALL ctl_stop( 'sbc_rnf_init: unable to allocate sf_i_rnf structure' )   ;   RETURN
+         ENDIF
+         ALLOCATE( sf_i_rnf(1)%fnow(jpi,jpj,1)   )
+         IF( sn_i_rnf%ln_tint ) ALLOCATE( sf_i_rnf(1)%fdta(jpi,jpj,1,2) )
+         CALL fld_fill (sf_i_rnf, (/ sn_i_rnf /), cn_dir, 'sbc_rnf_init', 'read iceberg flux data', 'namsbc_rnf' )
+      ELSE
+         fwficb(:,:) = 0._wp
+      ENDIF
+
       !
       IF( ln_rnf_tem ) THEN                      ! Create (if required) sf_t_rnf structure