Changeset 12484 for NEMO/branches/UKMO/NEMO_4.0.1_fix_cpl/src/ICE/icethd_dh.F90

Timestamp:

2020-02-28T11:57:10+01:00 (12 months ago)

Author:

dancopsey

Message:

• Make meltponds have a maximum size.
• Make meltponds leak into the ocean.
• Make meltpond lids melt at the same rate as the pond underneath.
• Make meltpond available area proportional to the total sea ice fraction (not category fraction).

File:

• NEMO/branches/UKMO/NEMO_4.0.1_fix_cpl/src/ICE/icethd_dh.F90 (modified) (7 diffs)

NEMO/branches/UKMO/NEMO_4.0.1_fix_cpl/src/ICE/icethd_dh.F90

@@ -24 +24 @@
    USE lib_mpp        ! MPP library
    USE lib_fortran    ! fortran utilities (glob_sum + no signed zero)
+   USE icethd_pnd, ONLY : a_pnd_avail
    
    IMPLICIT NONE
@@ -98 +99 @@
       REAL(wp), DIMENSION(jpij,nlay_i) ::   zh_i      ! ice layer thickness
       REAL(wp), DIMENSION(jpij,nlay_i) ::   zdeltah
+      REAL(wp), DIMENSION(jpij,nlay_i) ::   zdeltah_pnd  ! Change in thickness due to melting into ponds
       INTEGER , DIMENSION(jpij,nlay_i) ::   icount    ! number of layers vanished by melting 
 
@@ -112 +114 @@
          CASE( 2 )       ;   zswitch_sal = 1._wp   ! varying salinity profile
       END SELECT
+
+      ! Initialise fraction of sea ice available for melt ponding
+      DO ji = 1, npti
+         a_pnd_avail_1d(ji) = a_pnd_avail * at_i_1d(ji)
+      END DO
 
       ! initialize layer thicknesses and enthalpies
@@ -242 +249 @@
                zdeltah  (ji,jk) = MAX( zdeltah(ji,jk) , - zh_s(ji,jk) )                   ! bound melting
                zdh_s_mel(ji)    = zdh_s_mel(ji) + zdeltah(ji,jk)
+               zdeltah_pnd(ji,jk) = zdeltah  (ji,jk) * a_pnd_avail_1d(ji)
                
                hfx_snw_1d(ji)     = hfx_snw_1d(ji)     - zdeltah(ji,jk) * a_i_1d(ji) * e_s_1d (ji,jk) * r1_rdtice   ! heat used to melt snow(W.m-2, >0)
@@ -248 +256 @@
                ! updates available heat + thickness
                dh_s_mlt(ji)    = dh_s_mlt(ji) + zdeltah(ji,jk)
+               dh_s_pnd(ji)    = dh_s_pnd(ji) + zdeltah_pnd(ji,jk)                ! Cumulate surface melt on areas contributing to melt ponds
                zq_top  (ji)    = MAX( 0._wp , zq_top(ji) + zdeltah(ji,jk) * e_s_1d(ji,jk) )
                h_s_1d  (ji)    = MAX( 0._wp , h_s_1d(ji) + zdeltah(ji,jk) )
@@ -343 +352 @@
                
                zdeltah(ji,jk) = - zfmdt * r1_rhoi                     ! Melt of layer jk [m, <0]
+               zdeltah_pnd(ji,jk) = - zfmdt * r1_rhoi * a_pnd_avail_1d(ji)                          ! Melt of layer jk [m, <0] into meltponds
                
                zdeltah(ji,jk) = MIN( 0._wp , MAX( zdeltah(ji,jk) , - zh_i(ji,jk) ) )    ! Melt of layer jk cannot exceed the layer thickness [m, <0]
@@ -349 +359 @@
                
                dh_i_sum(ji)   = dh_i_sum(ji) + zdeltah(ji,jk)         ! Cumulate surface melt
+               dh_i_pnd(ji)   = dh_i_pnd(ji) + zdeltah_pnd(ji,jk)      ! Cumulate surface melt on areas contributing to melt ponds
                
                zfmdt          = - rhoi * zdeltah(ji,jk)               ! Recompute mass flux [kg/m2, >0]