C $Header: /u/gcmpack/MITgcm/pkg/ecco/cost_salt0.F,v 1.3 2005/03/28 23:49:49 heimbach Exp $

#include "COST_CPPOPTIONS.h"


      subroutine COST_SALT0(
     I                           myiter,
     I                           mytime,
     I                           mythid
     &                         )

c     ==================================================================
c     SUBROUTINE cost_salt0
c     ==================================================================
c
c     o Calculate the zonal wind stress contribution to the cost function.
c
c     started: Christian Eckert eckert@mit.edu 30-Jun-1999
c
c     changed: Christian Eckert eckert@mit.edu 25-Feb-2000
c
c              - Restructured the code in order to create a package
c                for the MITgcmUV.
c
c     ==================================================================
c     SUBROUTINE cost_salt0
c     ==================================================================

      implicit none

c     == global variables ==

#include "EEPARAMS.h"
#include "SIZE.h"
#include "GRID.h"

#include "ecco_cost.h"
#include "ctrl.h"
#include "ctrl_dummy.h"
#include "optim.h"

c     == routine arguments ==

      integer myiter
      _RL     mytime
      integer mythid

c     == local variables ==

      integer bi,bj
      integer i,j,k
      integer itlo,ithi
      integer jtlo,jthi
      integer jmin,jmax
      integer imin,imax
      integer nrec
      integer irec
      integer ilfld

      _RL fctile
      _RL fcthread
      _RL tmpx

      logical doglobalread
      logical ladinit

      character*(80) fnamefld

      character*(MAX_LEN_MBUF) msgbuf

c     == external functions ==

      integer  ilnblnk
      external 

c     == end of interface ==

      jtlo = mybylo(mythid)
      jthi = mybyhi(mythid)
      itlo = mybxlo(mythid)
      ithi = mybxhi(mythid)
      jmin = 1
      jmax = sny
      imin = 1
      imax = snx

c--   Read state record from global file.
      doglobalread = .false.
      ladinit      = .false.
      
      irec = 1

#ifdef ALLOW_SALT0_COST_CONTRIBUTION

      if (optimcycle .ge. 0) then
        ilfld = ilnblnk( xx_salt_file )
        write(fnamefld(1:80),'(2a,i10.10)') 
     &       xx_salt_file(1:ilfld),'.',optimcycle
      endif

      fcthread = 0. _d 0

      call ACTIVE_READ_XYZ_LOC( fnamefld, tmpfld3d, irec, doglobalread,
     &                       ladinit, optimcycle, mythid
     &        , xx_salt_dummy )

c--     Loop over this thread's tiles.
        do bj = jtlo,jthi
          do bi = itlo,ithi

c--         Determine the weights to be used.
            
            fctile = 0. _d 0
            do k = 1,nr
            do j = jmin,jmax
              do i = imin,imax
                if (_hFacC(i,j,k,bi,bj) .ne. 0.) then
                  tmpx = tmpfld3d(i,j,k,bi,bj)
                  if ( ABS(R_low(i,j,bi,bj)) .LT. 1000. )
     &              tmpx = tmpx*ABS(R_low(i,j,bi,bj))/1000.
		  fctile = fctile
     &                 + wsalt(k,bi,bj)*cosphi(i,j,bi,bj)
     &                 *tmpx*tmpx
                  if ( wsalt(k,bi,bj)*cosphi(i,j,bi,bj) .ne. 0. )
     &                 num_salt0(bi,bj) = num_salt0(bi,bj) + 1. _d 0
                endif
              enddo
            enddo
            enddo

            objf_salt0(bi,bj) = objf_salt0(bi,bj) + fctile
            fcthread          = fcthread + fctile

#ifdef ECCO_VERBOSE
c--         Print cost function for each tile in each thread.
            write(msgbuf,'(a)') ' '
            call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                          SQUEEZE_RIGHT , mythid)
            write(msgbuf,'(a,i8.8,1x,i3.3,1x,i3.3)')
     &        ' cost_salt0: irec,bi,bj          =  ',irec,bi,bj
            call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                          SQUEEZE_RIGHT , mythid)
            write(msgbuf,'(a,d22.15)')
     &        '               cost function (dS(0)) = ',
     &        fctile
            call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
#endif
          enddo
        enddo

#ifdef ECCO_VERBOSE
c--     Print cost function for all tiles.
        _GLOBAL_SUM_R8( fcthread , myThid )
        write(msgbuf,'(a)') ' '
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
        write(msgbuf,'(a,i8.8)')
     &    ' cost_zonstress:                       irec =  ',irec
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
        write(msgbuf,'(a,d22.15)')
     &    '                 global cost function value = ',
     &    fcthread
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
        write(msgbuf,'(a)') ' '
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
#endif

#else
c--   Do not enter the calculation of the salinity increment 
c--   contribution to the final cost function.

      fctile   = 0. _d 0
      fcthread = 0. _d 0

#ifdef ECCO_VERBOSE
      _BEGIN_MASTER( mythid )
        write(msgbuf,'(a)') ' '
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
        write(msgbuf,'(a,a)')
     &    ' cost_salt0 : no contribution of the I.C. in temp. ',
     &                    ' to cost function.'
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
        write(msgbuf,'(a)') ' '
        call PRINT_MESSAGE( msgbuf, standardmessageunit,
     &                      SQUEEZE_RIGHT , mythid)
      _END_MASTER( mythid )
#endif

#endif

      end