Changeset 13046 for NEMO/branches/UKMO/NEMO_4.0.1_snow_frac_cpl/src/ICE/icethd_zdf_bl99.F90

Timestamp:

2020-06-04T17:27:16+02:00 (4 years ago)

Author:

dancopsey

Message:

Add snow_frac which is fraction of snow for coupling purposes.

File:

• NEMO/branches/UKMO/NEMO_4.0.1_snow_frac_cpl/src/ICE/icethd_zdf_bl99.F90 (modified) (5 diffs)

NEMO/branches/UKMO/NEMO_4.0.1_snow_frac_cpl/src/ICE/icethd_zdf_bl99.F90

@@ -102 +102 @@
       !
       REAL(wp), DIMENSION(jpij) ::   isnow        ! switch for presence (1) or absence (0) of snow
+      REAL(wp), DIMENSION(jpij) ::   snow_frac    ! fraction of sea ice that is snow covered (for coupled variables only)
       REAL(wp), DIMENSION(jpij) ::   ztsub        ! surface temperature at previous iteration
       REAL(wp), DIMENSION(jpij) ::   zh_i, z1_h_i ! ice layer thickness
@@ -124 +125 @@
       REAL(wp), DIMENSION(jpij,0:nlay_s)   ::   zkappa_s    ! Kappa factor in the snow
       REAL(wp), DIMENSION(jpij,0:nlay_s)   ::   zeta_s      ! Eta factor in the snow
+      REAL(wp), DIMENSION(jpij)            ::   zkappa_combi ! Combined snow and ice surface conductivity 
       REAL(wp), DIMENSION(jpij,nlay_i+3)   ::   zindterm    ! 'Ind'ependent term
       REAL(wp), DIMENSION(jpij,nlay_i+3)   ::   zindtbis    ! Temporary 'ind'ependent term
@@ -148 +150 @@
       DO ji = 1, npti
          isnow(ji) = 1._wp - MAX( 0._wp , SIGN(1._wp, - h_s_1d(ji) ) )  ! is there snow or not
+         IF( h_s_1d(ji) < zhs_min ) THEN 
+           snow_frac(ji) = h_s_1d(ji) / zhs_min
+         ELSE
+           snow_frac(ji) = 1.0_wp
+         END IF
          ! layer thickness
          zh_i(ji) = h_i_1d(ji) * r1_nlay_i
@@ -311 +318 @@
          DO ji = 1, npti   ! Snow-ice interface
             IF ( .NOT. l_T_converged(ji) ) &
+               ! Calculate combined surface snow and ice conductivity to pass through the coupler 
+               zkappa_combi(ji) = zkappa_s(ji,0) * snow_frac(ji) + zkappa_i(ji,0) * ( 1._wp - snow_frac(ji) )
+
                zkappa_i(ji,0) = zkappa_s(ji,nlay_s) * isnow(ji) + zkappa_i(ji,0) * ( 1._wp - isnow(ji) )
          END DO
@@ -840 +850 @@
       DO ji = 1, npti
          IF( h_i_1d(ji) > 0.1_wp ) THEN
-            cnd_ice_1d(ji) = 2._wp * zkappa_i(ji,0)
+            cnd_ice_1d(ji) = 2._wp * zkappa_combi(ji)
          ELSE
             cnd_ice_1d(ji) = 2._wp * ztcond_i(ji,0) * 10._wp
          ENDIF
-         t1_ice_1d(ji) = isnow(ji) * t_s_1d(ji,1) + ( 1._wp - isnow(ji) ) * t_i_1d(ji,1)
+         t1_ice_1d(ji) = snow_frac(ji) * t_s_1d(ji,1) + ( 1._wp - snow_frac(ji) ) * t_i_1d(ji,1)
       END DO
       !