model/src/solve_for_pressure.F

C $Header: /u/gcmpack/MITgcm/model/src/solve_for_pressure.F,v 1.60 2007/06/01 16:42:16 heimbach Exp $
C $Name:  $

#include "PACKAGES_CONFIG.h"
#include "CPP_OPTIONS.h"

CBOP
C     !ROUTINE: SOLVE_FOR_PRESSURE
C     !INTERFACE:
      SUBROUTINE SOLVE_FOR_PRESSURE(myTime, myIter, myThid)

C     !DESCRIPTION: \bv
C     *==========================================================*
C     | SUBROUTINE SOLVE_FOR_PRESSURE
C     | o Controls inversion of two and/or three-dimensional
C     |   elliptic problems for the pressure field.
C     *==========================================================*
C     \ev

C     !USES:
      IMPLICIT NONE
C     == Global variables
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "GRID.h"
#include "SURFACE.h"
#include "FFIELDS.h"
#include "DYNVARS.h"
#include "SOLVE_FOR_PRESSURE.h"
#ifdef ALLOW_NONHYDROSTATIC
#include "SOLVE_FOR_PRESSURE3D.h"
#include "NH_VARS.h"
#endif
#ifdef ALLOW_CD_CODE
#include "CD_CODE_VARS.h"
#endif
#ifdef ALLOW_OBCS
#include "OBCS.h"
#endif

C     === Functions ====
      LOGICAL  DIFFERENT_MULTIPLE
      EXTERNAL DIFFERENT_MULTIPLE

C     !INPUT/OUTPUT PARAMETERS:
C     == Routine arguments ==
C     myTime :: Current time in simulation
C     myIter :: Current iteration number in simulation
C     myThid :: Thread number for this instance of SOLVE_FOR_PRESSURE
      _RL myTime
      INTEGER myIter
      INTEGER myThid

C     !LOCAL VARIABLES:
C     == Local variables ==
      INTEGER i,j,k,bi,bj
      _RS uf(1-Olx:sNx+Olx,1-Oly:sNy+Oly)
      _RS vf(1-Olx:sNx+Olx,1-Oly:sNy+Oly)
      _RL firstResidual,lastResidual
      _RL tmpFac
      _RL sumEmP, tileEmP
      LOGICAL putPmEinXvector
      INTEGER numIters, ks
      CHARACTER*10 sufx
      CHARACTER*(MAX_LEN_MBUF) msgBuf
#ifdef ALLOW_NONHYDROSTATIC
      INTEGER kp1
      _RL     wFacKm, wFacKp
      LOGICAL zeroPsNH
#endif
CEOP

#ifdef ALLOW_NONHYDROSTATIC
c       zeroPsNH = .FALSE.
        zeroPsNH = exactConserv
#endif

C deepAtmosphere & useRealFreshWaterFlux: only valid if deepFac2F(ksurf)=1
C anelastic (always Z-coordinate):
C     1) assume that rhoFacF(1)=1 (and ksurf == 1);
C        (this reduces the number of lines of code to modify)
C     2) (a) 2-D continuity eq. compute div. of mass transport (<- add rhoFac)
C        (b) gradient of surf.Press in momentum eq. (<- add 1/rhoFac)
C       => 2 factors cancel in elliptic eq. for Phi_s ,
C       but 1rst factor(a) remains in RHS cg2d_b.

C--   Initialise the Vector solution with etaN + deltaT*Global_mean_PmE
C     instead of simply etaN ; This can speed-up the solver convergence in
C     the case where |Global_mean_PmE| is large.
      putPmEinXvector = .FALSE.
c     putPmEinXvector = useRealFreshWaterFlux

C--   Save previous solution & Initialise Vector solution and source term :
      sumEmP = 0.
      DO bj=myByLo(myThid),myByHi(myThid)
       DO bi=myBxLo(myThid),myBxHi(myThid)
        DO j=1-OLy,sNy+OLy
         DO i=1-OLx,sNx+OLx
#ifdef ALLOW_CD_CODE
          etaNm1(i,j,bi,bj) = etaN(i,j,bi,bj)
#endif
          cg2d_x(i,j,bi,bj) = Bo_surf(i,j,bi,bj)*etaN(i,j,bi,bj)
          cg2d_b(i,j,bi,bj) = 0.
         ENDDO
        ENDDO
        IF (useRealFreshWaterFlux) THEN
         tmpFac = freeSurfFac*convertEmP2rUnit
         IF (exactConserv)
     &        tmpFac = freeSurfFac*convertEmP2rUnit*implicDiv2DFlow
         DO j=1,sNy
          DO i=1,sNx
           cg2d_b(i,j,bi,bj) =
     &       tmpFac*_rA(i,j,bi,bj)*EmPmR(i,j,bi,bj)/deltaTMom
          ENDDO
         ENDDO
        ENDIF
        IF ( putPmEinXvector ) THEN
         tileEmP = 0.
         DO j=1,sNy
          DO i=1,sNx
            tileEmP = tileEmP + rA(i,j,bi,bj)*EmPmR(i,j,bi,bj)
     &                                       *maskH(i,j,bi,bj)
          ENDDO
         ENDDO
         sumEmP = sumEmP + tileEmP
        ENDIF
       ENDDO
      ENDDO
      IF ( putPmEinXvector ) THEN
        _GLOBAL_SUM_R8( sumEmP, myThid )
      ENDIF

      DO bj=myByLo(myThid),myByHi(myThid)
       DO bi=myBxLo(myThid),myBxHi(myThid)
        IF ( putPmEinXvector ) THEN
          tmpFac = 0.
          IF (globalArea.GT.0.) tmpFac = freeSurfFac*deltaTfreesurf
     &                          *convertEmP2rUnit*sumEmP/globalArea
          DO j=1,sNy
           DO i=1,sNx
            cg2d_x(i,j,bi,bj) = cg2d_x(i,j,bi,bj)
     &                        - tmpFac*Bo_surf(i,j,bi,bj)
           ENDDO
          ENDDO
        ENDIF
C- RHS: similar to the divergence of the vertically integrated mass transport:
C       del_i { Sum_k [ rhoFac.(dr.hFac).(dy.deepFac).(u*) ] }  / deltaT
        DO K=Nr,1,-1
         DO j=1,sNy+1
          DO i=1,sNx+1
           uf(i,j) = _dyG(i,j,bi,bj)*deepFacC(k)
     &               *drF(k)*_hFacW(i,j,k,bi,bj)*rhoFacC(k)
           vf(i,j) = _dxG(i,j,bi,bj)*deepFacC(k)
     &               *drF(k)*_hFacS(i,j,k,bi,bj)*rhoFacC(k)
          ENDDO
         ENDDO
         CALL CALC_DIV_GHAT(
     I       bi,bj,1,sNx,1,sNy,K,
     I       uf,vf,
     U       cg2d_b,
     I       myThid)
        ENDDO
       ENDDO
      ENDDO

C--   Add source term arising from w=d/dt (p_s + p_nh)
      DO bj=myByLo(myThid),myByHi(myThid)
       DO bi=myBxLo(myThid),myBxHi(myThid)
#ifdef ALLOW_NONHYDROSTATIC
        IF ( use3Dsolver .AND. zeroPsNH ) THEN
         DO j=1,sNy
          DO i=1,sNx
           ks = ksurfC(i,j,bi,bj)
           IF ( ks.LE.Nr ) THEN
            cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         * etaH(i,j,bi,bj)
            cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         * etaH(i,j,bi,bj)
           ENDIF
          ENDDO
         ENDDO
        ELSEIF ( use3Dsolver ) THEN
         DO j=1,sNy
          DO i=1,sNx
           ks = ksurfC(i,j,bi,bj)
           IF ( ks.LE.Nr ) THEN
            cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         *( etaN(i,j,bi,bj)
     &           +phi_nh(i,j,ks,bi,bj)*recip_Bo(i,j,bi,bj) )
            cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         *( etaN(i,j,bi,bj)
     &           +phi_nh(i,j,ks,bi,bj)*recip_Bo(i,j,bi,bj) )
           ENDIF
          ENDDO
         ENDDO
        ELSEIF ( exactConserv ) THEN
#else
        IF ( exactConserv ) THEN
#endif /* ALLOW_NONHYDROSTATIC */
         DO j=1,sNy
          DO i=1,sNx
           ks = ksurfC(i,j,bi,bj)
           cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         * etaH(i,j,bi,bj)
          ENDDO
         ENDDO
        ELSE
         DO j=1,sNy
          DO i=1,sNx
           ks = ksurfC(i,j,bi,bj)
           cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
     &       -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)
     &         /deltaTMom/deltaTfreesurf
     &         * etaN(i,j,bi,bj)
          ENDDO
         ENDDO
        ENDIF

#ifdef ALLOW_OBCS
        IF (useOBCS) THEN
         DO i=1,sNx
C Northern boundary
          IF (OB_Jn(I,bi,bj).NE.0) THEN
           cg2d_b(I,OB_Jn(I,bi,bj),bi,bj)=0.
           cg2d_x(I,OB_Jn(I,bi,bj),bi,bj)=0.
          ENDIF
C Southern boundary
          IF (OB_Js(I,bi,bj).NE.0) THEN
           cg2d_b(I,OB_Js(I,bi,bj),bi,bj)=0.
           cg2d_x(I,OB_Js(I,bi,bj),bi,bj)=0.
          ENDIF
         ENDDO
         DO j=1,sNy
C Eastern boundary
          IF (OB_Ie(J,bi,bj).NE.0) THEN
           cg2d_b(OB_Ie(J,bi,bj),J,bi,bj)=0.
           cg2d_x(OB_Ie(J,bi,bj),J,bi,bj)=0.
          ENDIF
C Western boundary
          IF (OB_Iw(J,bi,bj).NE.0) THEN
           cg2d_b(OB_Iw(J,bi,bj),J,bi,bj)=0.
           cg2d_x(OB_Iw(J,bi,bj),J,bi,bj)=0.
          ENDIF
         ENDDO
        ENDIF
#endif /* ALLOW_OBCS */
C-    end bi,bj loops
       ENDDO
      ENDDO

#ifdef ALLOW_DEBUG
      IF ( debugLevel .GE. debLevB ) THEN
       CALL DEBUG_STATS_RL(1,cg2d_b,'cg2d_b (SOLVE_FOR_PRESSURE)',
     &                        myThid)
      ENDIF
#endif
      IF ( DIFFERENT_MULTIPLE(diagFreq, myTime, deltaTClock) ) THEN
       WRITE(sufx,'(I10.10)') myIter
       CALL WRITE_FLD_XY_RS( 'cg2d_b.', sufx, cg2d_b, myIter, myThid )
      ENDIF

C--   Find the surface pressure using a two-dimensional conjugate
C--   gradient solver.
C     see CG2D.h for the interface to this routine.
      firstResidual=0.
      lastResidual=0.
      numIters=cg2dMaxIters
c     CALL TIMER_START('CG2D   [SOLVE_FOR_PRESSURE]',myThid)
#ifdef ALLOW_CG2D_NSA
C--   Call the not-self-adjoint version of cg2d
      CALL CG2D_NSA(
     U           cg2d_b,
     U           cg2d_x,
     O           firstResidual,
     O           lastResidual,
     U           numIters,
     I           myThid )
#else /* not ALLOW_CG2D_NSA = default */
      CALL CG2D(
     U           cg2d_b,
     U           cg2d_x,
     O           firstResidual,
     O           lastResidual,
     U           numIters,
     I           myThid )
#endif /* ALLOW_CG2D_NSA */
      _EXCH_XY_R8(cg2d_x, myThid )
c     CALL TIMER_STOP ('CG2D   [SOLVE_FOR_PRESSURE]',myThid)

#ifdef ALLOW_DEBUG
      IF ( debugLevel .GE. debLevB ) THEN
       CALL DEBUG_STATS_RL(1,cg2d_x,'cg2d_x (SOLVE_FOR_PRESSURE)',
     &                        myThid)
      ENDIF
#endif

C- dump CG2D output at monitorFreq (to reduce size of STD-OUTPUT files) :
      IF ( DIFFERENT_MULTIPLE(monitorFreq,myTime,deltaTClock)
     &   ) THEN
       IF ( debugLevel .GE. debLevA ) THEN
        _BEGIN_MASTER( myThid )
        WRITE(msgBuf,'(A34,1PE24.14)') 'cg2d_init_res =',firstResidual
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        WRITE(msgBuf,'(A34,I6)') 'cg2d_iters =',numIters
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        WRITE(msgBuf,'(A34,1PE24.14)') 'cg2d_res =',lastResidual
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        _END_MASTER( myThid )
       ENDIF
      ENDIF

C--   Transfert the 2D-solution to "etaN" :
      DO bj=myByLo(myThid),myByHi(myThid)
       DO bi=myBxLo(myThid),myBxHi(myThid)
        DO j=1-OLy,sNy+OLy
         DO i=1-OLx,sNx+OLx
          etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)*cg2d_x(i,j,bi,bj)
         ENDDO
        ENDDO
       ENDDO
      ENDDO

#ifdef ALLOW_NONHYDROSTATIC
      IF ( use3Dsolver ) THEN

C--   Solve for a three-dimensional pressure term (NH or IGW or both ).
C     see CG3D.h for the interface to this routine.
       DO bj=myByLo(myThid),myByHi(myThid)
        DO bi=myBxLo(myThid),myBxHi(myThid)
         DO j=1,sNy+1
          DO i=1,sNx+1
           uf(i,j)=-_recip_dxC(i,j,bi,bj)*
     &         (cg2d_x(i,j,bi,bj)-cg2d_x(i-1,j,bi,bj))
           vf(i,j)=-_recip_dyC(i,j,bi,bj)*
     &         (cg2d_x(i,j,bi,bj)-cg2d_x(i,j-1,bi,bj))
          ENDDO
         ENDDO

#ifdef ALLOW_OBCS
         IF (useOBCS) THEN
          DO i=1,sNx+1
C Northern boundary
          IF (OB_Jn(I,bi,bj).NE.0) THEN
           vf(I,OB_Jn(I,bi,bj))=0.
          ENDIF
C Southern boundary
          IF (OB_Js(I,bi,bj).NE.0) THEN
           vf(I,OB_Js(I,bi,bj)+1)=0.
          ENDIF
          ENDDO
          DO j=1,sNy+1
C Eastern boundary
          IF (OB_Ie(J,bi,bj).NE.0) THEN
           uf(OB_Ie(J,bi,bj),J)=0.
          ENDIF
C Western boundary
          IF (OB_Iw(J,bi,bj).NE.0) THEN
           uf(OB_Iw(J,bi,bj)+1,J)=0.
          ENDIF
          ENDDO
         ENDIF
#endif /* ALLOW_OBCS */

         IF ( usingZCoords ) THEN
C-       Z coordinate: assume surface @ level k=1
           tmpFac = freeSurfFac*deepFac2F(1)
         ELSE
C-       Other than Z coordinate: no assumption on surface level index
           tmpFac = 0.
           DO j=1,sNy
            DO i=1,sNx
              ks = ksurfC(i,j,bi,bj)
              IF ( ks.LE.Nr ) THEN
               cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
     &              +freeSurfFac*etaN(i,j,bi,bj)/deltaTfreesurf
     &                  *_rA(i,j,bi,bj)*deepFac2F(ks)/deltaTmom
              ENDIF
            ENDDO
           ENDDO
         ENDIF
         K=1
         kp1 = MIN(k+1,Nr)
         wFacKp = deepFac2F(kp1)*rhoFacF(kp1)
         IF (k.GE.Nr) wFacKp = 0.
         DO j=1,sNy
          DO i=1,sNx
            cg3d_b(i,j,k,bi,bj) = cg3d_b(i,j,k,bi,bj)
     &       +drF(K)*dyG(i+1,j,bi,bj)*_hFacW(i+1,j,k,bi,bj)*uf(i+1,j)
     &       -drF(K)*dyG( i ,j,bi,bj)*_hFacW( i ,j,k,bi,bj)*uf( i ,j)
     &       +drF(K)*dxG(i,j+1,bi,bj)*_hFacS(i,j+1,k,bi,bj)*vf(i,j+1)
     &       -drF(K)*dxG(i, j ,bi,bj)*_hFacS(i, j ,k,bi,bj)*vf(i, j )
     &       +( tmpFac*etaN(i,j,bi,bj)/deltaTfreesurf
     &         -wVel(i,j,kp1,bi,bj)*wFacKp
     &        )*_rA(i,j,bi,bj)/deltaTmom
          ENDDO
         ENDDO
         DO K=2,Nr
          kp1 = MIN(k+1,Nr)
C-       deepFac & rhoFac cancel with the ones in uf[=del_i(Phi)/dx],vf ;
C        both appear in wVel term, but at 2 different levels
          wFacKm = deepFac2F( k )*rhoFacF( k )
          wFacKp = deepFac2F(kp1)*rhoFacF(kp1)
          IF (k.GE.Nr) wFacKp = 0.
          DO j=1,sNy
           DO i=1,sNx
            cg3d_b(i,j,k,bi,bj) = cg3d_b(i,j,k,bi,bj)
     &       +drF(K)*dyG(i+1,j,bi,bj)*_hFacW(i+1,j,k,bi,bj)*uf(i+1,j)
     &       -drF(K)*dyG( i ,j,bi,bj)*_hFacW( i ,j,k,bi,bj)*uf( i ,j)
     &       +drF(K)*dxG(i,j+1,bi,bj)*_hFacS(i,j+1,k,bi,bj)*vf(i,j+1)
     &       -drF(K)*dxG(i, j ,bi,bj)*_hFacS(i, j ,k,bi,bj)*vf(i, j )
     &       +( wVel(i,j, k ,bi,bj)*wFacKm*maskC(i,j,k-1,bi,bj)
     &         -wVel(i,j,kp1,bi,bj)*wFacKp
     &        )*_rA(i,j,bi,bj)/deltaTmom

           ENDDO
          ENDDO
         ENDDO

#ifdef ALLOW_OBCS
         IF (useOBCS) THEN
          DO K=1,Nr
          DO i=1,sNx
C Northern boundary
          IF (OB_Jn(I,bi,bj).NE.0) THEN
           cg3d_b(I,OB_Jn(I,bi,bj),K,bi,bj)=0.
          ENDIF
C Southern boundary
          IF (OB_Js(I,bi,bj).NE.0) THEN
           cg3d_b(I,OB_Js(I,bi,bj),K,bi,bj)=0.
          ENDIF
          ENDDO
          DO j=1,sNy
C Eastern boundary
          IF (OB_Ie(J,bi,bj).NE.0) THEN
           cg3d_b(OB_Ie(J,bi,bj),J,K,bi,bj)=0.
          ENDIF
C Western boundary
          IF (OB_Iw(J,bi,bj).NE.0) THEN
           cg3d_b(OB_Iw(J,bi,bj),J,K,bi,bj)=0.
          ENDIF
          ENDDO
          ENDDO
         ENDIF
#endif /* ALLOW_OBCS */
C-    end bi,bj loops
        ENDDO
       ENDDO

      firstResidual=0.
      lastResidual=0.
      numIters=cg3dMaxIters
      CALL TIMER_START('CG3D   [SOLVE_FOR_PRESSURE]',myThid)
      CALL CG3D(
     U           cg3d_b,
     U           phi_nh,
     O           firstResidual,
     O           lastResidual,
     U           numIters,
     I           myThid )
      _EXCH_XYZ_R8(phi_nh, myThid )
      CALL TIMER_STOP ('CG3D   [SOLVE_FOR_PRESSURE]',myThid)

      IF ( DIFFERENT_MULTIPLE(monitorFreq,myTime,deltaTClock)
     &   ) THEN
       IF ( debugLevel .GE. debLevA ) THEN
        _BEGIN_MASTER( myThid )
        WRITE(msgBuf,'(A34,1PE24.14)') 'cg3d_init_res =',firstResidual
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        WRITE(msgBuf,'(A34,I6)') 'cg3d_iters =',numIters
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        WRITE(msgBuf,'(A34,1PE24.14)') 'cg3d_res =',lastResidual
        CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
        _END_MASTER( myThid )
       ENDIF
      ENDIF

C--   Update surface pressure (account for NH-p @ surface level) and NH pressure:
      IF ( zeroPsNH ) THEN
       DO bj=myByLo(myThid),myByHi(myThid)
        DO bi=myBxLo(myThid),myBxHi(myThid)

         IF ( usingZCoords ) THEN
C-       Z coordinate: assume surface @ level k=1
          DO k=2,Nr
           DO j=1-OLy,sNy+OLy
            DO i=1-OLx,sNx+OLx
             phi_nh(i,j,k,bi,bj) = phi_nh(i,j,k,bi,bj)
     &                           - phi_nh(i,j,1,bi,bj)
            ENDDO
           ENDDO
          ENDDO
          DO j=1-OLy,sNy+OLy
           DO i=1-OLx,sNx+OLx
             etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)
     &                       *(cg2d_x(i,j,bi,bj) + phi_nh(i,j,1,bi,bj))
             phi_nh(i,j,1,bi,bj) = 0.
           ENDDO
          ENDDO
         ELSE
C-       Other than Z coordinate: no assumption on surface level index
          DO j=1-OLy,sNy+OLy
           DO i=1-OLx,sNx+OLx
            ks = ksurfC(i,j,bi,bj)
            IF ( ks.LE.Nr ) THEN
             etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)
     &                       *(cg2d_x(i,j,bi,bj) + phi_nh(i,j,ks,bi,bj))
             DO k=Nr,1,-1
              phi_nh(i,j,k,bi,bj) = phi_nh(i,j,k,bi,bj)
     &                            - phi_nh(i,j,ks,bi,bj)
             ENDDO
            ENDIF
           ENDDO
          ENDDO
         ENDIF

        ENDDO
       ENDDO
      ENDIF

      ENDIF
#endif /* ALLOW_NONHYDROSTATIC */

#ifdef ALLOW_SHOWFLOPS
      CALL SHOWFLOPS_INSOLVE( myThid)
#endif

      RETURN
      END
1	jmc	1.61	C $Header: /u/gcmpack/MITgcm/model/src/solve_for_pressure.F,v 1.60 2007/06/01 16:42:16 heimbach Exp $
2	heimbach	1.21	C $Name: $
3	cnh	1.1
4	edhill	1.39	#include "PACKAGES_CONFIG.h"
5	adcroft	1.5	#include "CPP_OPTIONS.h"
6	cnh	1.1
7	cnh	1.27	CBOP
8			C !ROUTINE: SOLVE_FOR_PRESSURE
9			C !INTERFACE:
10	jmc	1.29	SUBROUTINE SOLVE_FOR_PRESSURE(myTime, myIter, myThid)
11	cnh	1.27
12			C !DESCRIPTION: \bv
13			C ==========================================================
14	jmc	1.58	C \| SUBROUTINE SOLVE_FOR_PRESSURE
15			C \| o Controls inversion of two and/or three-dimensional
16			C \| elliptic problems for the pressure field.
17	cnh	1.27	C ==========================================================
18			C \ev
19
20			C !USES:
21	adcroft	1.8	IMPLICIT NONE
22	cnh	1.4	C == Global variables
23			#include "SIZE.h"
24			#include "EEPARAMS.h"
25			#include "PARAMS.h"
26	adcroft	1.12	#include "GRID.h"
27	jmc	1.17	#include "SURFACE.h"
28	jmc	1.28	#include "FFIELDS.h"
29	jmc	1.48	#include "DYNVARS.h"
30			#include "SOLVE_FOR_PRESSURE.h"
31	adcroft	1.9	#ifdef ALLOW_NONHYDROSTATIC
32	adcroft	1.25	#include "SOLVE_FOR_PRESSURE3D.h"
33	jmc	1.48	#include "NH_VARS.h"
34			#endif
35			#ifdef ALLOW_CD_CODE
36			#include "CD_CODE_VARS.h"
37	adcroft	1.12	#endif
38	adcroft	1.11	#ifdef ALLOW_OBCS
39	adcroft	1.9	#include "OBCS.h"
40	adcroft	1.11	#endif
41	cnh	1.4
42	jmc	1.32	C === Functions ====
43	jmc	1.46	LOGICAL DIFFERENT_MULTIPLE
44			EXTERNAL DIFFERENT_MULTIPLE
45	jmc	1.32
46	cnh	1.27	C !INPUT/OUTPUT PARAMETERS:
47	cnh	1.1	C == Routine arguments ==
48	jmc	1.58	C myTime :: Current time in simulation
49			C myIter :: Current iteration number in simulation
50			C myThid :: Thread number for this instance of SOLVE_FOR_PRESSURE
51	jmc	1.28	_RL myTime
52			INTEGER myIter
53	jmc	1.29	INTEGER myThid
54	cnh	1.4
55	cnh	1.27	C !LOCAL VARIABLES:
56	adcroft	1.22	C == Local variables ==
57	cnh	1.6	INTEGER i,j,k,bi,bj
58	adcroft	1.9	_RS uf(1-Olx:sNx+Olx,1-Oly:sNy+Oly)
59			_RS vf(1-Olx:sNx+Olx,1-Oly:sNy+Oly)
60	adcroft	1.22	_RL firstResidual,lastResidual
61	jmc	1.36	_RL tmpFac
62	jmc	1.47	_RL sumEmP, tileEmP
63			LOGICAL putPmEinXvector
64	jmc	1.58	INTEGER numIters, ks
65	jmc	1.61	CHARACTER*10 sufx
66	adcroft	1.25	CHARACTER*(MAX_LEN_MBUF) msgBuf
67	jmc	1.49	#ifdef ALLOW_NONHYDROSTATIC
68	jmc	1.58	INTEGER kp1
69			_RL wFacKm, wFacKp
70	jmc	1.49	LOGICAL zeroPsNH
71			#endif
72	cnh	1.27	CEOP
73	jmc	1.17
74	jmc	1.49	#ifdef ALLOW_NONHYDROSTATIC
75			c zeroPsNH = .FALSE.
76			zeroPsNH = exactConserv
77			#endif
78
79	jmc	1.58	C deepAtmosphere & useRealFreshWaterFlux: only valid if deepFac2F(ksurf)=1
80			C anelastic (always Z-coordinate):
81			C 1) assume that rhoFacF(1)=1 (and ksurf == 1);
82			C (this reduces the number of lines of code to modify)
83			C 2) (a) 2-D continuity eq. compute div. of mass transport (<- add rhoFac)
84			C (b) gradient of surf.Press in momentum eq. (<- add 1/rhoFac)
85			C => 2 factors cancel in elliptic eq. for Phi_s ,
86			C but 1rst factor(a) remains in RHS cg2d_b.
87
88	jmc	1.47	C-- Initialise the Vector solution with etaN + deltaT*Global_mean_PmE
89			C instead of simply etaN ; This can speed-up the solver convergence in
90			C the case where \|Global_mean_PmE\| is large.
91			putPmEinXvector = .FALSE.
92			c putPmEinXvector = useRealFreshWaterFlux
93
94	jmc	1.17	C-- Save previous solution & Initialise Vector solution and source term :
95	jmc	1.47	sumEmP = 0.
96	jmc	1.17	DO bj=myByLo(myThid),myByHi(myThid)
97			DO bi=myBxLo(myThid),myBxHi(myThid)
98			DO j=1-OLy,sNy+OLy
99			DO i=1-OLx,sNx+OLx
100	edhill	1.40	#ifdef ALLOW_CD_CODE
101	jmc	1.17	etaNm1(i,j,bi,bj) = etaN(i,j,bi,bj)
102	jmc	1.26	#endif
103	jmc	1.18	cg2d_x(i,j,bi,bj) = Bo_surf(i,j,bi,bj)*etaN(i,j,bi,bj)
104	jmc	1.17	cg2d_b(i,j,bi,bj) = 0.
105			ENDDO
106			ENDDO
107	jmc	1.29	IF (useRealFreshWaterFlux) THEN
108	jmc	1.36	tmpFac = freeSurfFac*convertEmP2rUnit
109	jmc	1.58	IF (exactConserv)
110	jmc	1.36	& tmpFac = freeSurfFacconvertEmP2rUnitimplicDiv2DFlow
111	jmc	1.29	DO j=1,sNy
112			DO i=1,sNx
113	jmc	1.58	cg2d_b(i,j,bi,bj) =
114	jmc	1.29	& tmpFac_rA(i,j,bi,bj)EmPmR(i,j,bi,bj)/deltaTMom
115			ENDDO
116			ENDDO
117			ENDIF
118	jmc	1.47	IF ( putPmEinXvector ) THEN
119			tileEmP = 0.
120			DO j=1,sNy
121			DO i=1,sNx
122			tileEmP = tileEmP + rA(i,j,bi,bj)*EmPmR(i,j,bi,bj)
123			& *maskH(i,j,bi,bj)
124			ENDDO
125			ENDDO
126			sumEmP = sumEmP + tileEmP
127			ENDIF
128	jmc	1.17	ENDDO
129			ENDDO
130	jmc	1.47	IF ( putPmEinXvector ) THEN
131			_GLOBAL_SUM_R8( sumEmP, myThid )
132			ENDIF
133	adcroft	1.12
134			DO bj=myByLo(myThid),myByHi(myThid)
135			DO bi=myBxLo(myThid),myBxHi(myThid)
136	jmc	1.47	IF ( putPmEinXvector ) THEN
137			tmpFac = 0.
138			IF (globalArea.GT.0.) tmpFac = freeSurfFac*deltaTfreesurf
139			& convertEmP2rUnitsumEmP/globalArea
140			DO j=1,sNy
141			DO i=1,sNx
142			cg2d_x(i,j,bi,bj) = cg2d_x(i,j,bi,bj)
143			& - tmpFac*Bo_surf(i,j,bi,bj)
144			ENDDO
145			ENDDO
146			ENDIF
147	jmc	1.58	C- RHS: similar to the divergence of the vertically integrated mass transport:
148			C del_i { Sum_k [ rhoFac.(dr.hFac).(dy.deepFac).(u*) ] } / deltaT
149	adcroft	1.12	DO K=Nr,1,-1
150			DO j=1,sNy+1
151			DO i=1,sNx+1
152	jmc	1.58	uf(i,j) = _dyG(i,j,bi,bj)*deepFacC(k)
153			& drF(k)_hFacW(i,j,k,bi,bj)*rhoFacC(k)
154			vf(i,j) = _dxG(i,j,bi,bj)*deepFacC(k)
155			& drF(k)_hFacS(i,j,k,bi,bj)*rhoFacC(k)
156	adcroft	1.12	ENDDO
157			ENDDO
158			CALL CALC_DIV_GHAT(
159			I bi,bj,1,sNx,1,sNy,K,
160			I uf,vf,
161	jmc	1.17	U cg2d_b,
162	adcroft	1.12	I myThid)
163			ENDDO
164			ENDDO
165			ENDDO
166	cnh	1.4
167	adcroft	1.12	C-- Add source term arising from w=d/dt (p_s + p_nh)
168			DO bj=myByLo(myThid),myByHi(myThid)
169			DO bi=myBxLo(myThid),myBxHi(myThid)
170	adcroft	1.13	#ifdef ALLOW_NONHYDROSTATIC
171	jmc	1.53	IF ( use3Dsolver .AND. zeroPsNH ) THEN
172	jmc	1.49	DO j=1,sNy
173			DO i=1,sNx
174	jmc	1.51	ks = ksurfC(i,j,bi,bj)
175			IF ( ks.LE.Nr ) THEN
176			cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
177	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
178			& /deltaTMom/deltaTfreesurf
179	jmc	1.49	& * etaH(i,j,bi,bj)
180	jmc	1.51	cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
181	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
182			& /deltaTMom/deltaTfreesurf
183	jmc	1.49	& * etaH(i,j,bi,bj)
184	jmc	1.51	ENDIF
185	jmc	1.49	ENDDO
186			ENDDO
187	jmc	1.53	ELSEIF ( use3Dsolver ) THEN
188	jmc	1.28	DO j=1,sNy
189			DO i=1,sNx
190	jmc	1.51	ks = ksurfC(i,j,bi,bj)
191			IF ( ks.LE.Nr ) THEN
192			cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
193	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
194			& /deltaTMom/deltaTfreesurf
195	jmc	1.28	& *( etaN(i,j,bi,bj)
196	jmc	1.59	& +phi_nh(i,j,ks,bi,bj)*recip_Bo(i,j,bi,bj) )
197	jmc	1.51	cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
198	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
199			& /deltaTMom/deltaTfreesurf
200	jmc	1.28	& *( etaN(i,j,bi,bj)
201	jmc	1.59	& +phi_nh(i,j,ks,bi,bj)*recip_Bo(i,j,bi,bj) )
202	jmc	1.51	ENDIF
203	jmc	1.28	ENDDO
204	adcroft	1.12	ENDDO
205	jmc	1.28	ELSEIF ( exactConserv ) THEN
206	adcroft	1.13	#else
207	jmc	1.26	IF ( exactConserv ) THEN
208	edhill	1.39	#endif /* ALLOW_NONHYDROSTATIC */
209	jmc	1.26	DO j=1,sNy
210			DO i=1,sNx
211	jmc	1.58	ks = ksurfC(i,j,bi,bj)
212	jmc	1.26	cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
213	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
214			& /deltaTMom/deltaTfreesurf
215	jmc	1.26	& * etaH(i,j,bi,bj)
216			ENDDO
217			ENDDO
218			ELSE
219			DO j=1,sNy
220			DO i=1,sNx
221	jmc	1.58	ks = ksurfC(i,j,bi,bj)
222	jmc	1.26	cg2d_b(i,j,bi,bj) = cg2d_b(i,j,bi,bj)
223	jmc	1.58	& -freeSurfFac_rA(i,j,bi,bj)deepFac2F(ks)
224			& /deltaTMom/deltaTfreesurf
225	jmc	1.26	& * etaN(i,j,bi,bj)
226			ENDDO
227	adcroft	1.12	ENDDO
228	jmc	1.26	ENDIF
229	adcroft	1.12
230			#ifdef ALLOW_OBCS
231	adcroft	1.14	IF (useOBCS) THEN
232	adcroft	1.12	DO i=1,sNx
233			C Northern boundary
234			IF (OB_Jn(I,bi,bj).NE.0) THEN
235			cg2d_b(I,OB_Jn(I,bi,bj),bi,bj)=0.
236	jmc	1.31	cg2d_x(I,OB_Jn(I,bi,bj),bi,bj)=0.
237	adcroft	1.12	ENDIF
238			C Southern boundary
239			IF (OB_Js(I,bi,bj).NE.0) THEN
240			cg2d_b(I,OB_Js(I,bi,bj),bi,bj)=0.
241	jmc	1.31	cg2d_x(I,OB_Js(I,bi,bj),bi,bj)=0.
242	adcroft	1.12	ENDIF
243			ENDDO
244			DO j=1,sNy
245			C Eastern boundary
246			IF (OB_Ie(J,bi,bj).NE.0) THEN
247			cg2d_b(OB_Ie(J,bi,bj),J,bi,bj)=0.
248	jmc	1.31	cg2d_x(OB_Ie(J,bi,bj),J,bi,bj)=0.
249	adcroft	1.12	ENDIF
250			C Western boundary
251			IF (OB_Iw(J,bi,bj).NE.0) THEN
252			cg2d_b(OB_Iw(J,bi,bj),J,bi,bj)=0.
253	jmc	1.31	cg2d_x(OB_Iw(J,bi,bj),J,bi,bj)=0.
254	adcroft	1.12	ENDIF
255			ENDDO
256			ENDIF
257	jmc	1.49	#endif /* ALLOW_OBCS */
258			C- end bi,bj loops
259	adcroft	1.12	ENDDO
260			ENDDO
261
262	edhill	1.42	#ifdef ALLOW_DEBUG
263	heimbach	1.38	IF ( debugLevel .GE. debLevB ) THEN
264	adcroft	1.23	CALL DEBUG_STATS_RL(1,cg2d_b,'cg2d_b (SOLVE_FOR_PRESSURE)',
265			& myThid)
266	adcroft	1.24	ENDIF
267	adcroft	1.23	#endif
268	jmc	1.61	IF ( DIFFERENT_MULTIPLE(diagFreq, myTime, deltaTClock) ) THEN
269			WRITE(sufx,'(I10.10)') myIter
270			CALL WRITE_FLD_XY_RS( 'cg2d_b.', sufx, cg2d_b, myIter, myThid )
271			ENDIF
272	adcroft	1.12
273	cnh	1.1	C-- Find the surface pressure using a two-dimensional conjugate
274			C-- gradient solver.
275	adcroft	1.22	C see CG2D.h for the interface to this routine.
276			firstResidual=0.
277			lastResidual=0.
278	adcroft	1.19	numIters=cg2dMaxIters
279	jmc	1.50	c CALL TIMER_START('CG2D [SOLVE_FOR_PRESSURE]',myThid)
280	heimbach	1.56	#ifdef ALLOW_CG2D_NSA
281			C-- Call the not-self-adjoint version of cg2d
282			CALL CG2D_NSA(
283			U cg2d_b,
284			U cg2d_x,
285			O firstResidual,
286			O lastResidual,
287			U numIters,
288			I myThid )
289			#else /* not ALLOW_CG2D_NSA = default */
290	cnh	1.1	CALL CG2D(
291	adcroft	1.22	U cg2d_b,
292	cnh	1.6	U cg2d_x,
293	adcroft	1.22	O firstResidual,
294			O lastResidual,
295	adcroft	1.19	U numIters,
296	cnh	1.1	I myThid )
297	heimbach	1.56	#endif /* ALLOW_CG2D_NSA */
298	adcroft	1.19	_EXCH_XY_R8(cg2d_x, myThid )
299	jmc	1.50	c CALL TIMER_STOP ('CG2D [SOLVE_FOR_PRESSURE]',myThid)
300	adcroft	1.23
301	edhill	1.42	#ifdef ALLOW_DEBUG
302	heimbach	1.38	IF ( debugLevel .GE. debLevB ) THEN
303	adcroft	1.23	CALL DEBUG_STATS_RL(1,cg2d_x,'cg2d_x (SOLVE_FOR_PRESSURE)',
304			& myThid)
305	adcroft	1.24	ENDIF
306	adcroft	1.23	#endif
307	cnh	1.1
308	jmc	1.32	C- dump CG2D output at monitorFreq (to reduce size of STD-OUTPUT files) :
309	jmc	1.46	IF ( DIFFERENT_MULTIPLE(monitorFreq,myTime,deltaTClock)
310	jmc	1.45	& ) THEN
311	heimbach	1.38	IF ( debugLevel .GE. debLevA ) THEN
312			_BEGIN_MASTER( myThid )
313			WRITE(msgBuf,'(A34,1PE24.14)') 'cg2d_init_res =',firstResidual
314			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
315			WRITE(msgBuf,'(A34,I6)') 'cg2d_iters =',numIters
316			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
317			WRITE(msgBuf,'(A34,1PE24.14)') 'cg2d_res =',lastResidual
318			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
319	edhill	1.43	_END_MASTER( myThid )
320	heimbach	1.38	ENDIF
321	jmc	1.32	ENDIF
322	jmc	1.17
323			C-- Transfert the 2D-solution to "etaN" :
324			DO bj=myByLo(myThid),myByHi(myThid)
325			DO bi=myBxLo(myThid),myBxHi(myThid)
326			DO j=1-OLy,sNy+OLy
327			DO i=1-OLx,sNx+OLx
328	jmc	1.18	etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)*cg2d_x(i,j,bi,bj)
329	jmc	1.17	ENDDO
330			ENDDO
331			ENDDO
332			ENDDO
333	adcroft	1.10
334	adcroft	1.9	#ifdef ALLOW_NONHYDROSTATIC
335	jmc	1.53	IF ( use3Dsolver ) THEN
336	adcroft	1.9
337			C-- Solve for a three-dimensional pressure term (NH or IGW or both ).
338			C see CG3D.h for the interface to this routine.
339			DO bj=myByLo(myThid),myByHi(myThid)
340			DO bi=myBxLo(myThid),myBxHi(myThid)
341			DO j=1,sNy+1
342			DO i=1,sNx+1
343	jmc	1.18	uf(i,j)=-_recip_dxC(i,j,bi,bj)*
344	adcroft	1.9	& (cg2d_x(i,j,bi,bj)-cg2d_x(i-1,j,bi,bj))
345	jmc	1.18	vf(i,j)=-_recip_dyC(i,j,bi,bj)*
346	adcroft	1.9	& (cg2d_x(i,j,bi,bj)-cg2d_x(i,j-1,bi,bj))
347			ENDDO
348			ENDDO
349
350	adcroft	1.12	#ifdef ALLOW_OBCS
351	adcroft	1.14	IF (useOBCS) THEN
352	adcroft	1.9	DO i=1,sNx+1
353			C Northern boundary
354			IF (OB_Jn(I,bi,bj).NE.0) THEN
355			vf(I,OB_Jn(I,bi,bj))=0.
356			ENDIF
357			C Southern boundary
358			IF (OB_Js(I,bi,bj).NE.0) THEN
359			vf(I,OB_Js(I,bi,bj)+1)=0.
360			ENDIF
361			ENDDO
362			DO j=1,sNy+1
363			C Eastern boundary
364			IF (OB_Ie(J,bi,bj).NE.0) THEN
365			uf(OB_Ie(J,bi,bj),J)=0.
366			ENDIF
367			C Western boundary
368			IF (OB_Iw(J,bi,bj).NE.0) THEN
369			uf(OB_Iw(J,bi,bj)+1,J)=0.
370			ENDIF
371			ENDDO
372			ENDIF
373	jmc	1.49	#endif /* ALLOW_OBCS */
374	adcroft	1.9
375	jmc	1.58	IF ( usingZCoords ) THEN
376	jmc	1.51	C- Z coordinate: assume surface @ level k=1
377	jmc	1.58	tmpFac = freeSurfFac*deepFac2F(1)
378	jmc	1.51	ELSE
379			C- Other than Z coordinate: no assumption on surface level index
380	jmc	1.58	tmpFac = 0.
381	jmc	1.51	DO j=1,sNy
382			DO i=1,sNx
383			ks = ksurfC(i,j,bi,bj)
384			IF ( ks.LE.Nr ) THEN
385			cg3d_b(i,j,ks,bi,bj) = cg3d_b(i,j,ks,bi,bj)
386			& +freeSurfFac*etaN(i,j,bi,bj)/deltaTfreesurf
387	jmc	1.58	& _rA(i,j,bi,bj)deepFac2F(ks)/deltaTmom
388	jmc	1.51	ENDIF
389			ENDDO
390			ENDDO
391			ENDIF
392	adcroft	1.12	K=1
393	jmc	1.51	kp1 = MIN(k+1,Nr)
394	jmc	1.58	wFacKp = deepFac2F(kp1)*rhoFacF(kp1)
395			IF (k.GE.Nr) wFacKp = 0.
396	adcroft	1.12	DO j=1,sNy
397			DO i=1,sNx
398	jmc	1.51	cg3d_b(i,j,k,bi,bj) = cg3d_b(i,j,k,bi,bj)
399	heimbach	1.56	& +drF(K)dyG(i+1,j,bi,bj)_hFacW(i+1,j,k,bi,bj)*uf(i+1,j)
400			& -drF(K)dyG( i ,j,bi,bj)_hFacW( i ,j,k,bi,bj)*uf( i ,j)
401			& +drF(K)dxG(i,j+1,bi,bj)_hFacS(i,j+1,k,bi,bj)*vf(i,j+1)
402			& -drF(K)dxG(i, j ,bi,bj)_hFacS(i, j ,k,bi,bj)*vf(i, j )
403	jmc	1.51	& +( tmpFac*etaN(i,j,bi,bj)/deltaTfreesurf
404	jmc	1.58	& -wVel(i,j,kp1,bi,bj)*wFacKp
405	adcroft	1.12	& )*_rA(i,j,bi,bj)/deltaTmom
406			ENDDO
407			ENDDO
408	jmc	1.51	DO K=2,Nr
409			kp1 = MIN(k+1,Nr)
410	jmc	1.58	C- deepFac & rhoFac cancel with the ones in uf[=del_i(Phi)/dx],vf ;
411			C both appear in wVel term, but at 2 different levels
412			wFacKm = deepFac2F( k )*rhoFacF( k )
413			wFacKp = deepFac2F(kp1)*rhoFacF(kp1)
414			IF (k.GE.Nr) wFacKp = 0.
415	adcroft	1.9	DO j=1,sNy
416			DO i=1,sNx
417			cg3d_b(i,j,k,bi,bj) = cg3d_b(i,j,k,bi,bj)
418	heimbach	1.56	& +drF(K)dyG(i+1,j,bi,bj)_hFacW(i+1,j,k,bi,bj)*uf(i+1,j)
419			& -drF(K)dyG( i ,j,bi,bj)_hFacW( i ,j,k,bi,bj)*uf( i ,j)
420			& +drF(K)dxG(i,j+1,bi,bj)_hFacS(i,j+1,k,bi,bj)*vf(i,j+1)
421			& -drF(K)dxG(i, j ,bi,bj)_hFacS(i, j ,k,bi,bj)*vf(i, j )
422	jmc	1.58	& +( wVel(i,j, k ,bi,bj)wFacKmmaskC(i,j,k-1,bi,bj)
423			& -wVel(i,j,kp1,bi,bj)*wFacKp
424	adcroft	1.12	& )*_rA(i,j,bi,bj)/deltaTmom
425
426	adcroft	1.9	ENDDO
427			ENDDO
428			ENDDO
429	adcroft	1.12
430			#ifdef ALLOW_OBCS
431	adcroft	1.14	IF (useOBCS) THEN
432	adcroft	1.12	DO K=1,Nr
433			DO i=1,sNx
434			C Northern boundary
435			IF (OB_Jn(I,bi,bj).NE.0) THEN
436			cg3d_b(I,OB_Jn(I,bi,bj),K,bi,bj)=0.
437			ENDIF
438			C Southern boundary
439			IF (OB_Js(I,bi,bj).NE.0) THEN
440			cg3d_b(I,OB_Js(I,bi,bj),K,bi,bj)=0.
441			ENDIF
442			ENDDO
443			DO j=1,sNy
444			C Eastern boundary
445			IF (OB_Ie(J,bi,bj).NE.0) THEN
446			cg3d_b(OB_Ie(J,bi,bj),J,K,bi,bj)=0.
447			ENDIF
448			C Western boundary
449			IF (OB_Iw(J,bi,bj).NE.0) THEN
450			cg3d_b(OB_Iw(J,bi,bj),J,K,bi,bj)=0.
451			ENDIF
452			ENDDO
453			ENDDO
454			ENDIF
455	jmc	1.49	#endif /* ALLOW_OBCS */
456			C- end bi,bj loops
457			ENDDO
458			ENDDO
459	adcroft	1.9
460	adcroft	1.25	firstResidual=0.
461			lastResidual=0.
462	jmc	1.49	numIters=cg3dMaxIters
463	jmc	1.50	CALL TIMER_START('CG3D [SOLVE_FOR_PRESSURE]',myThid)
464	adcroft	1.25	CALL CG3D(
465			U cg3d_b,
466			U phi_nh,
467			O firstResidual,
468			O lastResidual,
469			U numIters,
470			I myThid )
471			_EXCH_XYZ_R8(phi_nh, myThid )
472	jmc	1.50	CALL TIMER_STOP ('CG3D [SOLVE_FOR_PRESSURE]',myThid)
473	adcroft	1.25
474	jmc	1.46	IF ( DIFFERENT_MULTIPLE(monitorFreq,myTime,deltaTClock)
475	jmc	1.45	& ) THEN
476	heimbach	1.38	IF ( debugLevel .GE. debLevA ) THEN
477			_BEGIN_MASTER( myThid )
478			WRITE(msgBuf,'(A34,1PE24.14)') 'cg3d_init_res =',firstResidual
479			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
480			WRITE(msgBuf,'(A34,I6)') 'cg3d_iters =',numIters
481			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
482			WRITE(msgBuf,'(A34,1PE24.14)') 'cg3d_res =',lastResidual
483			CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1)
484	edhill	1.43	_END_MASTER( myThid )
485	heimbach	1.38	ENDIF
486	mlosch	1.37	ENDIF
487	adcroft	1.9
488	jmc	1.49	C-- Update surface pressure (account for NH-p @ surface level) and NH pressure:
489			IF ( zeroPsNH ) THEN
490			DO bj=myByLo(myThid),myByHi(myThid)
491			DO bi=myBxLo(myThid),myBxHi(myThid)
492
493			IF ( usingZCoords ) THEN
494			C- Z coordinate: assume surface @ level k=1
495			DO k=2,Nr
496			DO j=1-OLy,sNy+OLy
497			DO i=1-OLx,sNx+OLx
498			phi_nh(i,j,k,bi,bj) = phi_nh(i,j,k,bi,bj)
499			& - phi_nh(i,j,1,bi,bj)
500			ENDDO
501			ENDDO
502			ENDDO
503			DO j=1-OLy,sNy+OLy
504			DO i=1-OLx,sNx+OLx
505			etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)
506			& *(cg2d_x(i,j,bi,bj) + phi_nh(i,j,1,bi,bj))
507			phi_nh(i,j,1,bi,bj) = 0.
508			ENDDO
509			ENDDO
510			ELSE
511			C- Other than Z coordinate: no assumption on surface level index
512			DO j=1-OLy,sNy+OLy
513			DO i=1-OLx,sNx+OLx
514			ks = ksurfC(i,j,bi,bj)
515			IF ( ks.LE.Nr ) THEN
516			etaN(i,j,bi,bj) = recip_Bo(i,j,bi,bj)
517			& *(cg2d_x(i,j,bi,bj) + phi_nh(i,j,ks,bi,bj))
518			DO k=Nr,1,-1
519			phi_nh(i,j,k,bi,bj) = phi_nh(i,j,k,bi,bj)
520			& - phi_nh(i,j,ks,bi,bj)
521			ENDDO
522			ENDIF
523			ENDDO
524			ENDDO
525			ENDIF
526
527			ENDDO
528			ENDDO
529	adcroft	1.9	ENDIF
530	jmc	1.49
531			ENDIF
532			#endif /* ALLOW_NONHYDROSTATIC */
533	cnh	1.1
534	heimbach	1.60	#ifdef ALLOW_SHOWFLOPS
535			CALL SHOWFLOPS_INSOLVE( myThid)
536	ce107	1.52	#endif
537	heimbach	1.60
538	cnh	1.1	RETURN
539			END