source: trunk/NEMO/OPA_SRC/BDY/bdytra.F90 @ 1125

MODULE bdytra
   !!======================================================================
   !!                       ***  MODULE  bdytra  ***
   !! Ocean tracers:   Flow Relaxation Scheme of tracers on each open boundary
   !!======================================================================
   !! History :  1.0  !  2005-01  (J. Chanut, A. Sellar)  Original code
   !!            3.0  !  2008-04  (NEMO team)  add in the reference version
   !!----------------------------------------------------------------------
#if defined key_bdy
   !!----------------------------------------------------------------------
   !!   'key_bdy'                     Unstructured Open Boundary Conditions
   !!----------------------------------------------------------------------
   !!   bdy_tra        : Relaxation of tracers on unstructured open boundaries
   !!----------------------------------------------------------------------
   USE oce             ! ocean dynamics and tracers variables
   USE dom_oce         ! ocean space and time domain variables 
   USE bdy_oce         ! ocean open boundary conditions
   USE lbclnk          ! ocean lateral boundary conditions (or mpp link)
   USE in_out_manager  ! I/O manager

   IMPLICIT NONE
   PRIVATE

   PUBLIC bdy_tra     ! routine called in tranxt.F90 

   !!----------------------------------------------------------------------
   !! NEMO/OPA 3.0 , LOCEAN-IPSL (2008) 
   !! $Id: $ 
   !! Software governed by the CeCILL licence (modipsl/doc/NEMO_CeCILL.txt)
   !!----------------------------------------------------------------------

CONTAINS

   SUBROUTINE bdy_tra( kt )
      !!----------------------------------------------------------------------
      !!                 ***  SUBROUTINE bdy_tra  ***
      !!                    
      !! ** Purpose : Apply the Flow Relaxation Scheme for tracers in the  
      !!              case of unstructured open boundaries.
      !! 
      !! Reference : Engedahl H., 1995, Tellus, 365-382.
      !!----------------------------------------------------------------------
      INTEGER, INTENT( in ) ::   kt
      !! 
      REAL(wp) ::   zwgt           ! boundary weight
      INTEGER  ::   ib, ik, igrd   ! dummy loop indices
      INTEGER  ::   ii, ij         ! 2D addresses
      !!----------------------------------------------------------------------
      !
      IF(ln_bdy_tra_frs) THEN ! If this is false, then this routine does nothing. 

      IF( kt == nit000 ) THEN
         IF(lwp) WRITE(numout,*)
         IF(lwp) WRITE(numout,*) 'bdy_tra : Flow Relaxation Scheme for tracers'
         IF(lwp) WRITE(numout,*) '~~~~~~~'
      ENDIF
      !
      igrd = 1                       ! Everything is at T-points here
      DO ib = 1, nblen(igrd)
         DO ik = 1, jpkm1
            ii = nbi(ib,igrd)
            ij = nbj(ib,igrd)
            zwgt = nbw(ib,igrd)
            ta(ii,ij,ik) = ( ta(ii,ij,ik) * (1.-zwgt) + tbdy(ib,ik) * zwgt ) * tmask(ii,ij,ik)         
            sa(ii,ij,ik) = ( sa(ii,ij,ik) * (1.-zwgt) + sbdy(ib,ik) * zwgt ) * tmask(ii,ij,ik)
        END DO
      END DO 
      !
      CALL lbc_lnk( ta, 'T', 1. )   ! Boundary points should be updated
      CALL lbc_lnk( sa, 'T', 1. )   !
      !
      ENDIF ! ln_bdy_tra_frs

   END SUBROUTINE bdy_tra
   
#else
   !!----------------------------------------------------------------------
   !!   Dummy module                   NO Unstruct Open Boundary Conditions
   !!----------------------------------------------------------------------
CONTAINS
   SUBROUTINE bdy_tra(kt)      ! Empty routine
      WRITE(*,*) 'bdy_tra: You should not have seen this print! error?', kt
   END SUBROUTINE bdy_tra
#endif

   !!======================================================================
END MODULE bdytra