Changeset 12576 for NEMO/branches/UKMO/NEMO_4.0.1_icesheet_and_river_coupling/src/OCE/SBC/sbcisf.F90

Timestamp:

2020-03-20T12:39:37+01:00 (4 years ago)

Author:

dancopsey

Message:

Merge in iceberg calving stuff from dev_r5518_coupling_GSI7_GSI8_landice from the start of the branch to revision 6023.

File:

• NEMO/branches/UKMO/NEMO_4.0.1_icesheet_and_river_coupling/src/OCE/SBC/sbcisf.F90 (modified) (3 diffs)

NEMO/branches/UKMO/NEMO_4.0.1_icesheet_and_river_coupling/src/OCE/SBC/sbcisf.F90

@@ -92 +92 @@
       INTEGER ::   ji, jj, jk   ! loop index
       INTEGER ::   ikt, ikb     ! local integers
+      REAL(wp)                     ::   zgreenland_fwfisf_sum, zantarctica_fwfisf_sum 
       REAL(wp), DIMENSION(jpi,jpj) ::   zt_frz, zdep   ! freezing temperature (zt_frz) at depth (zdep) 
       REAL(wp), DIMENSION(:,:)  , ALLOCATABLE ::   zqhcisf2d
@@ -127 +128 @@
                fwfisf(:,:) = - sf_rnfisf(1)%fnow(:,:,1)         ! fresh water flux from the isf (fwfisf <0 mean melting) 
             ENDIF
+
+            IF( lk_oasis) THEN
+              ! nn_coupled_iceshelf_fluxes uninitialised unless lk_oasis=true
+              IF( nn_coupled_iceshelf_fluxes .gt. 0 ) THEN
+
+                ! Adjust total iceshelf melt rates so that sum of iceberg calving and iceshelf melting in the northern
+                ! and southern hemispheres equals rate of increase of mass of greenland and antarctic ice sheets
+                ! to preserve total freshwater conservation in coupled models without an active ice sheet model.
+
+                ! All related global sums must be done bit reproducibly
+                 zgreenland_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * greenland_icesheet_mask(:,:) )
+
+                 ! use ABS function because we need to preserve the sign of fwfisf
+                 WHERE( greenland_icesheet_mask(:,:) == 1.0 )                                                                  &
+                &    fwfisf(:,:) = fwfisf(:,:)  * ABS( greenland_icesheet_mass_rate_of_change * (1.0-rn_greenland_calving_fraction) &
+                &                           / ( zgreenland_fwfisf_sum + 1.0e-10_wp ) )
+
+                 ! check
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Greenland iceshelf melting climatology (kg/s) : ',zgreenland_fwfisf_sum
+
+                 zgreenland_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * greenland_icesheet_mask(:,:) )
+
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Greenland iceshelf melting adjusted value (kg/s) : ',zgreenland_fwfisf_sum
+
+                 zantarctica_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * antarctica_icesheet_mask(:,:) )
+
+                 ! use ABS function because we need to preserve the sign of fwfisf
+                 WHERE( antarctica_icesheet_mask(:,:) == 1.0 ) &
+                &    fwfisf(:,:) = fwfisf(:,:)  * ABS( antarctica_icesheet_mass_rate_of_change * (1.0-rn_antarctica_calving_fraction) &
+                &                           / ( zantarctica_fwfisf_sum + 1.0e-10_wp ) )
+
+                 ! check
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Antarctica iceshelf melting climatology (kg/s) : ',zantarctica_fwfisf_sum
+
+                 zantarctica_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * antarctica_icesheet_mask(:,:) )
+
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Antarctica iceshelf melting adjusted value (kg/s) : ',zantarctica_fwfisf_sum
+
+              ENDIF
+            ENDIF
+
             qisf(:,:)   = fwfisf(:,:) * rLfusisf             ! heat flux
             stbl(:,:)   = soce
@@ -137 +179 @@
                fwfisf(:,:) = -sf_fwfisf(1)%fnow(:,:,1)            ! fwf
             ENDIF
+
+            IF( lk_oasis) THEN
+              ! nn_coupled_iceshelf_fluxes uninitialised unless lk_oasis=true
+              IF( nn_coupled_iceshelf_fluxes .gt. 0 ) THEN
+
+                ! Adjust total iceshelf melt rates so that sum of iceberg calving and iceshelf melting in the northern
+                ! and southern hemispheres equals rate of increase of mass of greenland and antarctic ice sheets
+                ! to preserve total freshwater conservation in coupled models without an active ice sheet model.
+
+                ! All related global sums must be done bit reproducibly
+                 zgreenland_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * greenland_icesheet_mask(:,:) )
+
+                 ! use ABS function because we need to preserve the sign of fwfisf
+                 WHERE( greenland_icesheet_mask(:,:) == 1.0 )                                                                  &
+                &    fwfisf(:,:) = fwfisf(:,:)  * ABS( greenland_icesheet_mass_rate_of_change * (1.0-rn_greenland_calving_fraction) &
+                &                           / ( zgreenland_fwfisf_sum + 1.0e-10_wp ) )
+
+                 ! check
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Greenland iceshelf melting climatology (kg/s) : ',zgreenland_fwfisf_sum
+
+                 zgreenland_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * greenland_icesheet_mask(:,:) )
+
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Greenland iceshelf melting adjusted value (kg/s) : ',zgreenland_fwfisf_sum
+
+                 zantarctica_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * antarctica_icesheet_mask(:,:) )
+
+                 ! use ABS function because we need to preserve the sign of fwfisf
+                 WHERE( antarctica_icesheet_mask(:,:) == 1.0 ) &
+                &    fwfisf(:,:) = fwfisf(:,:)  * ABS( antarctica_icesheet_mass_rate_of_change * (1.0-rn_antarctica_calving_fraction) &
+                &                           / ( zantarctica_fwfisf_sum + 1.0e-10_wp ) )
+
+                 ! check
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Antarctica iceshelf melting climatology (kg/s) : ',zantarctica_fwfisf_sum
+
+                 zantarctica_fwfisf_sum = glob_sum( fwfisf(:,:) * e1t(:,:) * e2t(:,:) * antarctica_icesheet_mask(:,:) )
+
+                 IF(lwp .AND. ll_wrtstp) WRITE(numout, *) 'Antarctica iceshelf melting adjusted value (kg/s) : ',zantarctica_fwfisf_sum
+
+              ENDIF
+            ENDIF
+
             qisf(:,:)   = fwfisf(:,:) * rLfusisf               ! heat flux
             stbl(:,:)   = soce