Changeset 1037 for trunk/NEMO/OPA_SRC/SBC/sbcice_if.F90

Timestamp:

2008-05-30T18:21:28+02:00 (16 years ago)

Author:

ctlod

Message:

trunk: replace freeze(:,:) variable with fr_i(:,:), use the tfreez function defined in eosbn2.F90 and remove the useless ocfzpt.F90 module, see ticket: #177

File:

• trunk/NEMO/OPA_SRC/SBC/sbcice_if.F90 (modified) (6 diffs)

trunk/NEMO/OPA_SRC/SBC/sbcice_if.F90

@@ -5 +5 @@
    !!                   covered area using ice-if model
    !!======================================================================
-   !! History :  9.0   !  06-06  (G. Madec)  Original code
+   !! History :  3.0   !  2006-06  (G. Madec)  Original code
    !!----------------------------------------------------------------------
 
@@ -14 +14 @@
    USE dom_oce         ! ocean space and time domain
    USE phycst          ! physical constants
-   USE ocfzpt          ! ocean freezing point
-   USE sbc_oce         ! Surface boundary condition: ocean fields
+   USE eosbn2          ! equation of state
+   USE sbc_oce         ! surface boundary condition: ocean fields
    USE fldread         ! read input field
    USE iom             ! I/O manager library
@@ -30 +30 @@
 #  include "domzgr_substitute.h90"
    !!----------------------------------------------------------------------
-   !!   OPA 9.0 , LOCEAN-IPSL (2006) 
-   !! $ Id: $
+   !! NEMO/OPA 3.0 , LOCEAN-IPSL (2008) 
+   !! $Id:$
    !! Software governed by the CeCILL licence (modipsl/doc/NEMO_CeCILL.txt)
    !!----------------------------------------------------------------------
@@ -47 +47 @@
       !!              - blah blah blah, ...
       !!
-      !! ** Action  :   qns, qsr:  update heat flux below sea-ice
-      !!                emp, emps: update freshwater flux below sea-ice
+      !! ** Action  :   utau, vtau : remain unchanged
+      !!                qns, qsr   : update heat flux below sea-ice
+      !!                emp, emps  : update freshwater flux below sea-ice
+      !!                fr_i       : update the ice fraction
       !!---------------------------------------------------------------------
       INTEGER, INTENT(in)          ::   kt         ! ocean time step
       !
+      INTEGER  ::   ji, jj     ! dummy loop indices
+      INTEGER  ::   ierror     ! return error code
+      REAL(wp) ::   ztrp, zsice, zt_fzp, zfr_obs
+      REAL(wp) ::   zqri, zqrj, zqrp, zqi
+      !!
       CHARACTER(len=100) ::   cn_dir              ! Root directory for location of ice-if files
       TYPE(FLD_N)        ::   sn_ice              ! informations about the fields to be read
       NAMELIST/namsbc_iif/ cn_dir, sn_ice
-      !
-      INTEGER  ::   ji, jj     ! dummy loop indices
-      INTEGER  ::   ierror     ! return error code
-      REAL(wp) ::   ztrp, zsice, zt_fzp, zicover_obs, zicover_opa
-      REAL(wp) ::   zqri, zqrj, zqrp, zqi
       !!---------------------------------------------------------------------
       !                                         ! ====================== !
@@ -80 +82 @@
 
          ! store namelist information in sf_ice structure
-         WRITE(sf_ice(1)%clrootname,'(a,a)' )   TRIM( cn_dir ), TRIM( sn_ice%clname )
+         WRITE(sf_ice(1)%clrootname,'(a,a)')   TRIM( cn_dir ), TRIM( sn_ice%clname )
          sf_ice(1)%freqh   = sn_ice%freqh
          sf_ice(1)%clvar   = sn_ice%clvar
@@ -111 +113 @@
          zsice = - 0.04 / 0.8    ! ratio of isohaline compressibility over isotherme compressibility
                                  ! ( d rho / dt ) / ( d rho / ds )      ( s = 34, t = -1.8 )
-         ! Flux computation
+         
+         fr_i(:,:) = tfreez( sss_m ) * tmask(:,:,1)      ! sea surface freezing temperature [Celcius]
+
+         ! Flux and ice fraction computation
 !CDIR COLLAPSE
          DO jj = 1, jpj
             DO ji = 1, jpi
-               ! ... sea surface freezing point temperature [Celcius]
-               zt_fzp = (  ( - 0.0575 + 1.710523e-3 * SQRT( sss_m(ji,jj) )   &
-            &                         - 2.154996e-4 *       sss_m(ji,jj)   ) * sss_m(ji,jj)  ) * tmask(ji,jj,1)
-            
-               ! ... indicators : ice cover (obs, ocean model) & hemisphere (=1 north, =-1 south)
-               zicover_obs = sf_ice(1)%fnow(ji,jj)                                                ! observed 
-               zicover_opa = MAX( 0., SIGN( 1., zt_fzp - sst_m(ji,jj) )  ) * tmask(ji,jj,1)   ! model   
+               !
+               zt_fzp  = fr_i(ji,jj)                        ! freezing point temperature
+               zfr_obs = sf_ice(1)%fnow(ji,jj)              ! observed ice cover
+               !                                            ! ocean ice fraction (0/1) from the freezing point temperature
+               IF( sst_m(ji,jj) <= zt_fzp ) THEN   ;   fr_i(ji,jj) = 1.e0
+               ELSE                                ;   fr_i(ji,jj) = 0.e0
+               ENDIF
 
-               ! ... avoid over-freezing point temperature
-               tn(ji,jj,1) = MAX( tn(ji,jj,1), zt_fzp )
+               tn(ji,jj,1) = MAX( tn(ji,jj,1), zt_fzp )     ! avoid over-freezing point temperature
 
-               ! ... solar heat flux : zero below observed ice cover
-               qsr(ji,jj) = ( 1. - zicover_obs ) * qsr(ji,jj)
+               qsr(ji,jj) = ( 1. - zfr_obs ) * qsr(ji,jj)   ! solar heat flux : zero below observed ice cover
 
-               ! ... non solar heat flux : add a damping term 
-               !      - gamma*(t-(tgel-1.))  if observed ice and no opa ice   (zicover_obs=1 zicover_opa=0)
-               !      - gamma*min(0,t-tgel)  if observed ice and opa ice      (zicover_obs=1 zicover_opa=1)
-
+               !                                            ! non solar heat flux : add a damping term 
+               !      # ztrp*(t-(tgel-1.))  if observed ice and no opa ice   (zfr_obs=1 fr_i=0)
+               !      # ztrp*min(0,t-tgel)  if observed ice and opa ice      (zfr_obs=1 fr_i=1)
                zqri = ztrp * ( tb(ji,jj,1) - ( zt_fzp - 1.) )
                zqrj = ztrp * MIN( 0., tb(ji,jj,1) - zt_fzp )
+               zqrp = ( zfr_obs * ( (1. - fr_i(ji,jj) ) * zqri    &
+                 &                 +      fr_i(ji,jj)   * zqrj ) ) * tmask(ji,jj,1)
 
-               zqrp =  ( zicover_obs * ( (1. - zicover_opa ) * zqri    &
-                 &                      +      zicover_opa   * zqrj ) ) * tmask(ji,jj,1)
-
-               ! c) net downward heat flux q() = q0 + qrp()
-               ! for q0
-               ! # qns unchanged              if no climatological ice              (zicover_obs=0)
-               ! # qns = zqrp                 if climatological ice and no opa ice  (zicover_obs=1, zicover_opa=0)
-               ! # qns = zqrp -2(-4) watt/m2  if climatological ice and opa ice     (zicover_obs=1, zicover_opa=1)
-               ! (-2=arctic, -4=antarctic)   
+               !                                            ! non-solar heat flux 
+               !      # qns unchanged              if no climatological ice              (zfr_obs=0)
+               !      # qns = zqrp                 if climatological ice and no opa ice  (zfr_obs=1, fr_i=0)
+               !      # qns = zqrp -2(-4) watt/m2  if climatological ice and opa ice     (zfr_obs=1, fr_i=1)
+               !                                   (-2=arctic, -4=antarctic)   
                zqi = -3. + SIGN( 1.e0, ff(ji,jj) )
-               qns(ji,jj) = ( ( 1.- zicover_obs ) * qns(ji,jj)   &
-                  &          +      zicover_obs   * zicover_opa * zqi ) * tmask(ji,jj,1)   &
+               qns(ji,jj) = ( ( 1.- zfr_obs ) * qns(ji,jj)                             &
+                  &          +      zfr_obs   * fr_i(ji,jj) * zqi ) * tmask(ji,jj,1)   &
                   &       + zqrp
             END DO