Changeset 12382 for NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icealb.F90

Timestamp:

2020-02-13T16:36:44+01:00 (4 years ago)

Author:

dancopsey

Message:

Add pond lid code that does most of the science.

File:

• NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icealb.F90 (modified) (4 diffs)

NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icealb.F90

@@ -45 +45 @@
 CONTAINS
 
-   SUBROUTINE ice_alb( pt_su, ph_ice, ph_snw, ld_pnd_alb, pafrac_pnd, ph_pnd, palb_cs, palb_os )
+   SUBROUTINE ice_alb( pt_su, ph_ice, ph_snw, ld_pnd_alb, pafrac_pnd, ph_pnd, plh_pnd, palb_cs, palb_os )
       !!----------------------------------------------------------------------
       !!               ***  ROUTINE ice_alb  ***
@@ -97 +97 @@
       REAL(wp), INTENT(in   ), DIMENSION(:,:,:) ::   pafrac_pnd   !  melt pond relative fraction (per unit ice area)
       REAL(wp), INTENT(in   ), DIMENSION(:,:,:) ::   ph_pnd       !  melt pond depth
+      REAL(wp), INTENT(in   ), DIMENSION(:,:,:) ::   plh_pnd      !  melt pond lid thickness
       REAL(wp), INTENT(  out), DIMENSION(:,:,:) ::   palb_cs      !  albedo of ice under clear    sky
       REAL(wp), INTENT(  out), DIMENSION(:,:,:) ::   palb_os      !  albedo of ice under overcast sky
+      !
+      REAL(wp), PARAMETER :: pnd_lid_max = 0.015                  !  pond lid thickness above which the ponds disappear from the albedo calculation
+      REAL(wp), PARAMETER :: pnd_lid_min = 0.005                  !  pond lid thickness below which the full pond area is used in the albedo calculation
+                                                                  ! Note: these two variables are mirrored in sbccpl.F90 (maybe put them in one place...)
       !
       INTEGER  ::   ji, jj, jl                ! dummy loop indices
@@ -106 +111 @@
       REAL(wp) ::   zalb_ice, zafrac_ice      ! bare sea ice albedo & relative ice fraction
       REAL(wp) ::   zalb_snw, zafrac_snw      ! snow-covered sea ice albedo & relative snow fraction
+      REAL(wp) ::   lfrac_pnd                 ! The fraction of the meltpond exposed (not inder a frozen lid)
       !!---------------------------------------------------------------------
       !
@@ -123 +129 @@
                   zafrac_snw = 0._wp
                   IF( ld_pnd_alb ) THEN
-                     zafrac_pnd = pafrac_pnd(ji,jj,jl)
+                     IF ( plh_pnd(ji,jj,jl) > pnd_lid_max ) THEN
+                        lfrac_pnd = 0._wp
+                     ELSE
+                        IF ( plh_pnd(ji,jj,jl) < pnd_lid_min ) THEN
+                           lfrac_pnd = 1._wp
+                        ELSE
+                           lfrac_pnd = ( plh_pnd(ji,jj,jl) - pnd_lid_min ) / (pnd_lid_max - pnd_lid_min)
+                        END IF
+                     END IF
+                     zafrac_pnd = pafrac_pnd(ji,jj,jl) * lfrac_pnd
                   ELSE
                      zafrac_pnd = 0._wp