Changeset 12890 for NEMO/branches/2020/r4.0-HEAD_r12713_clem_dan_fixcpl/src/ICE/icevar.F90

Timestamp:

2020-05-07T16:11:23+02:00 (4 years ago)

Author:

clem

Message:

1) implement the optional nn_snwfra, i.e. the fraction of ice covered by sea ice. 2) change some namelists parameters names to avoid confusion. 3) correct a bug at ice initialization

File:

• NEMO/branches/2020/r4.0-HEAD_r12713_clem_dan_fixcpl/src/ICE/icevar.F90 (modified) (6 diffs)

NEMO/branches/2020/r4.0-HEAD_r12713_clem_dan_fixcpl/src/ICE/icevar.F90

@@ -52 +52 @@
    !!   ice_var_itd       : convert N-cat to M-cat
    !!   ice_var_snwfra    : fraction of ice covered by snow
+   !!   ice_var_snwblow   : distribute snow fall between ice and ocean
    !!----------------------------------------------------------------------
    USE dom_oce        ! ocean space and time domain
@@ -79 +80 @@
    PUBLIC   ice_var_itd
    PUBLIC   ice_var_snwfra
+   PUBLIC   ice_var_snwblow
 
    INTERFACE ice_var_itd
@@ -86 +88 @@
    INTERFACE ice_var_snwfra
       MODULE PROCEDURE ice_var_snwfra_1d, ice_var_snwfra_2d, ice_var_snwfra_3d
+   END INTERFACE
+
+   INTERFACE ice_var_snwblow
+      MODULE PROCEDURE ice_var_snwblow_1d, ice_var_snwblow_2d
    END INTERFACE
 
@@ -1009 +1015 @@
          pt_su(:,jl) = ptmsu(:)
          ps_i (:,jl) = psmi (:)
-         ps_i (:,jl) = psmi (:)         
       END DO
       !
@@ -1059 +1064 @@
       !!
       !!               2) Expand the filling to the cat jlmin-1 and jlmax+1
-       !!                   by removing 25% ice area from jlmin and jlmax (resp.) 
+      !!                   by removing 25% ice area from jlmin and jlmax (resp.) 
       !!              
       !!               3) Expand the filling to the empty cat between jlmin and jlmax 
@@ -1293 +1298 @@
    !!-------------------------------------------------------------------
    SUBROUTINE ice_var_snwfra_3d( ph_s, pa_s_fra )
-      !!-------------------------------------------------------------------
       REAL(wp), DIMENSION(:,:,:), INTENT(in   ) ::   ph_s        ! snow thickness
       REAL(wp), DIMENSION(:,:,:), INTENT(  out) ::   pa_s_fra    ! ice fraction covered by snow
-      !!-------------------------------------------------------------------
-      pa_s_fra(:,:,:) = 1._wp - EXP( -0.2_wp * rhos * ph_s(:,:,:) )
+      IF    ( nn_snwfra == 0 ) THEN   ! basic 0 or 1 snow cover
+         WHERE( ph_s > 0._wp ) ; pa_s_fra = 1._wp
+         ELSEWHERE             ; pa_s_fra = 0._wp
+         END WHERE
+      ELSEIF( nn_snwfra == 1 ) THEN   ! snow cover depends on hsnow (met-office style)
+         pa_s_fra = 1._wp - EXP( -0.2_wp * rhos * ph_s )
+      ELSEIF( nn_snwfra == 2 ) THEN   ! snow cover depends on hsnow (cice style)
+         pa_s_fra = ph_s / ( ph_s + 0.02_wp )
+      ENDIF
    END SUBROUTINE ice_var_snwfra_3d
 
    SUBROUTINE ice_var_snwfra_2d( ph_s, pa_s_fra )
-      !!-------------------------------------------------------------------
       REAL(wp), DIMENSION(:,:), INTENT(in   ) ::   ph_s        ! snow thickness
       REAL(wp), DIMENSION(:,:), INTENT(  out) ::   pa_s_fra    ! ice fraction covered by snow
-      !!-------------------------------------------------------------------
-      pa_s_fra(:,:) = 1._wp - EXP( -0.2_wp * rhos * ph_s(:,:) )
+      IF    ( nn_snwfra == 0 ) THEN   ! basic 0 or 1 snow cover
+         WHERE( ph_s > 0._wp ) ; pa_s_fra = 1._wp
+         ELSEWHERE             ; pa_s_fra = 0._wp
+         END WHERE
+      ELSEIF( nn_snwfra == 1 ) THEN   ! snow cover depends on hsnow (met-office style)
+         pa_s_fra = 1._wp - EXP( -0.2_wp * rhos * ph_s )
+      ELSEIF( nn_snwfra == 2 ) THEN   ! snow cover depends on hsnow (cice style)
+         pa_s_fra = ph_s / ( ph_s + 0.02_wp )
+      ENDIF
    END SUBROUTINE ice_var_snwfra_2d
 
    SUBROUTINE ice_var_snwfra_1d( ph_s, pa_s_fra )
-      !!-------------------------------------------------------------------
       REAL(wp), DIMENSION(:), INTENT(in   ) ::   ph_s        ! snow thickness
       REAL(wp), DIMENSION(:), INTENT(  out) ::   pa_s_fra    ! ice fraction covered by snow
-      !!-------------------------------------------------------------------
-      pa_s_fra(:) = 1._wp - EXP( -0.2_wp * rhos * ph_s(:) )
+      IF    ( nn_snwfra == 0 ) THEN   ! basic 0 or 1 snow cover
+         WHERE( ph_s > 0._wp ) ; pa_s_fra = 1._wp
+         ELSEWHERE             ; pa_s_fra = 0._wp
+         END WHERE
+      ELSEIF( nn_snwfra == 1 ) THEN   ! snow cover depends on hsnow (met-office style)
+         pa_s_fra = 1._wp - EXP( -0.2_wp * rhos * ph_s )
+      ELSEIF( nn_snwfra == 2 ) THEN   ! snow cover depends on hsnow (cice style)
+         pa_s_fra = ph_s / ( ph_s + 0.02_wp )
+      ENDIF
    END SUBROUTINE ice_var_snwfra_1d
    
+   !!--------------------------------------------------------------------------
+   !! INTERFACE ice_var_snwblow
+   !!
+   !! ** Purpose :   Compute distribution of precip over the ice
+   !!
+   !!                Snow accumulation in one thermodynamic time step
+   !!                snowfall is partitionned between leads and ice.
+   !!                If snow fall was uniform, a fraction (1-at_i) would fall into leads
+   !!                but because of the winds, more snow falls on leads than on sea ice
+   !!                and a greater fraction (1-at_i)^beta of the total mass of snow 
+   !!                (beta < 1) falls in leads.
+   !!                In reality, beta depends on wind speed, 
+   !!                and should decrease with increasing wind speed but here, it is 
+   !!                considered as a constant. an average value is 0.66
+   !!--------------------------------------------------------------------------
+!!gm  I think it can be usefull to set this as a FUNCTION, not a SUBROUTINE....
+   SUBROUTINE ice_var_snwblow_2d( pin, pout )
+      REAL(wp), DIMENSION(:,:), INTENT(in   ) :: pin   ! previous fraction lead ( 1. - a_i_b )
+      REAL(wp), DIMENSION(:,:), INTENT(inout) :: pout
+      pout = ( 1._wp - ( pin )**rn_snwblow )
+   END SUBROUTINE ice_var_snwblow_2d
+
+   SUBROUTINE ice_var_snwblow_1d( pin, pout )
+      REAL(wp), DIMENSION(:), INTENT(in   ) :: pin
+      REAL(wp), DIMENSION(:), INTENT(inout) :: pout
+      pout = ( 1._wp - ( pin )**rn_snwblow )
+   END SUBROUTINE ice_var_snwblow_1d
 
 #else