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!Environment Canada - Atmospheric Science and Technology License/Disclaimer, 
!                     version 3; Last Modified: May 7, 2008.
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***s/r  bacp_2_tl - TLM of bacp_2 
*
#include "model_macros_f.h"
*

      subroutine bacp_2_tl  1,1
     $                  ( F_itr  ,F_itnlh, F_st0   ,F_pipt0 ,
     $                    F_qt0  ,F_fit0 , F_fipt0 ,F_fis   ,F_tt0   ,
     $                    F_tpt0 ,F_tplt0, F_ut0   ,F_vt0   ,F_psdt0 ,
     $                    F_tdt0 ,F_qpt0 , F_wt0   ,
     $                    F_mut0 ,F_multx, F_gptx  ,F_gxtx  , 
     $                    F_ru   ,F_rv   , F_rth   ,F_r3    ,F_r3p   ,
     $                    F_rvv  ,F_rcn  , F_nu    ,F_nv    ,
     $                    F_nth  ,F_n3   , F_n3p   ,
     $                    F_ncn  ,F_wijk0, F_wijk1 ,
*
     $                                     F_st0m  ,F_pipt0m,
     $                    F_qt0m ,F_fit0m ,F_fipt0m,         F_tt0m  ,
     $                    F_tpt0m,F_tplt0m,F_ut0m  ,F_vt0m  ,F_psdt0m,
     $                    F_tdt0m,F_qpt0m ,F_wt0m  ,  
     $                    F_mut0m,F_multxm,F_gptxm ,F_gxtxm ,
     $                    F_rum  ,F_rvm   ,F_rthm  ,F_r3m   ,F_r3pm  ,
     $                    F_rvvm ,F_rcnm  ,F_num   ,F_nvm   ,
     $                    F_nthm ,F_n3m   ,F_n3pm  ,
     $                    F_ncnm ,F_wijk0m,F_wijk1m,
*
     $                                     DIST_DIM, Nk )
*
      implicit none
*
      integer  F_itr, F_itnlh, DIST_DIM, Nk 
      real     F_st0  (DIST_SHAPE)    ,
     %         F_pipt0(DIST_SHAPE,Nk) ,  F_qt0  (DIST_SHAPE,Nk) ,
     %         F_fit0 (DIST_SHAPE,Nk) ,  F_fipt0(DIST_SHAPE,Nk) ,
     %         F_fis  (DIST_SHAPE)    ,  F_tt0  (DIST_SHAPE,Nk) ,
     %         F_tpt0 (DIST_SHAPE,Nk) ,  F_tplt0(DIST_SHAPE,Nk) ,
     %         F_ut0  (DIST_SHAPE,Nk) ,  F_vt0  (DIST_SHAPE,Nk) ,
     %         F_psdt0(DIST_SHAPE,Nk) ,  F_tdt0 (DIST_SHAPE,Nk) ,
     %         F_qpt0 (DIST_SHAPE,Nk) ,  F_wt0  (DIST_SHAPE,Nk) ,
     %         F_mut0 (DIST_SHAPE,Nk) ,  F_multx(DIST_SHAPE,Nk) ,
     %         F_gptx (DIST_SHAPE,Nk) ,  F_gxtx (DIST_SHAPE,Nk) ,
     %         F_ru   (DIST_SHAPE,Nk) ,  F_rv   (DIST_SHAPE,Nk) ,
     %         F_rcn  (DIST_SHAPE,Nk) ,  F_rth  (DIST_SHAPE,Nk) ,
     %         F_rvv  (DIST_SHAPE,Nk) ,  F_nth  (DIST_SHAPE,Nk) ,
     %         F_r3   (DIST_SHAPE,Nk) ,  F_r3p  (DIST_SHAPE,Nk) ,
     %         F_nu   (DIST_SHAPE,Nk) ,  F_nv   (DIST_SHAPE,Nk) ,
     %         F_n3   (DIST_SHAPE,Nk) ,  F_n3p  (DIST_SHAPE,Nk) ,
     %         F_ncn  (DIST_SHAPE,Nk) ,
     %         F_wijk0(DIST_SHAPE,Nk) ,  F_wijk1(DIST_SHAPE,Nk)
*
      real     F_st0m  (DIST_SHAPE)   , 
     %         F_pipt0m(DIST_SHAPE,Nk),  F_qt0m  (DIST_SHAPE,Nk),
     %         F_fit0m (DIST_SHAPE,Nk),  F_fipt0m(DIST_SHAPE,Nk),
     %                                   F_tt0m  (DIST_SHAPE,Nk),
     %         F_tpt0m (DIST_SHAPE,Nk),  F_tplt0m(DIST_SHAPE,Nk),
     %         F_ut0m  (DIST_SHAPE,Nk),  F_vt0m  (DIST_SHAPE,Nk),
     %         F_psdt0m(DIST_SHAPE,Nk),  F_tdt0m (DIST_SHAPE,Nk),
     %         F_qpt0m (DIST_SHAPE,Nk),  F_wt0m  (DIST_SHAPE,Nk),
     %         F_mut0m (DIST_SHAPE,Nk),  F_multxm(DIST_SHAPE,Nk),
     %         F_gptxm (DIST_SHAPE,Nk),  F_gxtxm (DIST_SHAPE,Nk),
     %         F_rum   (DIST_SHAPE,Nk),  F_rvm   (DIST_SHAPE,Nk),
     %         F_rcnm  (DIST_SHAPE,Nk),  F_rthm  (DIST_SHAPE,Nk),
     %         F_rvvm  (DIST_SHAPE,Nk),  F_nthm  (DIST_SHAPE,Nk),
     %         F_r3m   (DIST_SHAPE,Nk),  F_r3pm  (DIST_SHAPE,Nk),
     %         F_num   (DIST_SHAPE,Nk),  F_nvm   (DIST_SHAPE,Nk),
     %         F_n3m   (DIST_SHAPE,Nk),  F_n3pm  (DIST_SHAPE,Nk),
     %         F_ncnm  (DIST_SHAPE,Nk),
     %         F_wijk0m(DIST_SHAPE,Nk),  F_wijk1m(DIST_SHAPE,Nk)
*
*author
*     M.Tanguay
*
*revision
* v2_10 - Tanguay M.        - initial MPI version
* v2_30 - Edouard S.        - remove pi' at the top (pptt0)
* v2_31 - Tanguay M.        - adapt for vertical hybrid coordinate and LAM version 
*                           - adapt for tracers in tr3d  
* v3_00 - Tanguay M.        - adapt to restructured bacp_2
* v3_03 - Tanguay M.        - Adjoint Lam and NoHyd configuration 
* v3_11 - Tanguay M.        - AIXport+Opti+OpenMP for TLM-ADJ
* v3_21 - Tanguay M.        - Revision Openmp
* v3_30 - Tanguay M.        - Enforce similarities between NL and TRAJ TL 
*
*object
*     see id section 
*     ------------------------------------------------------------------------
*     REMARK: INPUT TRAJ: F_gptxm, F_rthm, F_nthm,
*                         F_r3m, F_r3pm, F_rvvm, F_n3m, F_n3pm (NoHyd)
*     ------------------------------------------------------------------------
*
*arguments
*     see documentation of appropriate comdecks 
*
*implicits
#include "glb_ld.cdk"
*
      integer i0, j0, in, jn
*
      i0 = 1+pil_w
      in = l_ni-pil_e
      j0 = 1+pil_s
      jn = l_nj-pil_n
*
      call bacp_2_2_tl
     $                  ( F_itr  ,F_itnlh, F_st0   ,F_pipt0 ,
     $                    F_qt0  ,F_fit0 , F_fipt0 ,F_fis   ,F_tt0   ,
     $                    F_tpt0 ,F_tplt0, F_ut0   ,F_vt0   ,F_psdt0 ,
     $                    F_tdt0 ,F_qpt0 , F_wt0   ,
     $                    F_mut0 ,F_multx, F_gptx  ,F_gxtx  ,
     $                    F_ru   ,F_rv   , F_rth   ,F_r3    ,F_r3p   ,
     $                    F_rvv  ,F_rcn  , F_nu    ,F_nv    ,
     $                    F_nth  ,F_n3   , F_n3p   ,
     $                    F_ncn  ,F_wijk0, F_wijk1 ,
*
     $                                     F_st0m  ,F_pipt0m,
     $                    F_qt0m ,F_fit0m ,F_fipt0m,         F_tt0m  ,
     $                    F_tpt0m,F_tplt0m,F_ut0m  ,F_vt0m  ,F_psdt0m,
     $                    F_tdt0m,F_qpt0m ,F_wt0m  ,
     $                    F_mut0m,F_multxm,F_gptxm ,F_gxtxm ,
     $                    F_rum  ,F_rvm   ,F_rthm  ,F_r3m   ,F_r3pm  ,
     $                    F_rvvm ,F_rcnm  ,F_num   ,F_nvm   ,
     $                    F_nthm ,F_n3m   ,F_n3pm  ,
     $                    F_ncnm ,F_wijk0m,F_wijk1m,
*
     $                                     DIST_DIM, Nk, i0, j0, in, jn )
*
      return
      end
*

      subroutine bacp_2_2_tl 1
     $                  ( F_itr  ,F_itnlh, F_st0   ,F_pipt0 ,
     $                    F_qt0  ,F_fit0 , F_fipt0 ,F_fis   ,F_tt0   ,
     $                    F_tpt0 ,F_tplt0, F_ut0   ,F_vt0   ,F_psdt0 ,
     $                    F_tdt0 ,F_qpt0 , F_wt0   ,
     $                    F_mut0 ,F_multx, F_gptx  ,F_gxtx  ,
     $                    F_ru   ,F_rv   , F_rth   ,F_r3    ,F_r3p   ,
     $                    F_rvv  ,F_rcn  , F_nu    ,F_nv    ,
     $                    F_nth  ,F_n3   , F_n3p   ,
     $                    F_ncn  ,F_wijk0, F_wijk1 ,
*
     $                                     F_st0m  ,F_pipt0m,
     $                    F_qt0m ,F_fit0m ,F_fipt0m,         F_tt0m  ,
     $                    F_tpt0m,F_tplt0m,F_ut0m  ,F_vt0m  ,F_psdt0m,
     $                    F_tdt0m,F_qpt0m ,F_wt0m  ,
     $                    F_mut0m,F_multxm,F_gptxm ,F_gxtxm ,
     $                    F_rum  ,F_rvm   ,F_rthm  ,F_r3m   ,F_r3pm  ,
     $                    F_rvvm ,F_rcnm  ,F_num   ,F_nvm   ,
     $                    F_nthm ,F_n3m   ,F_n3pm  ,
     $                    F_ncnm ,F_wijk0m,F_wijk1m,
*
     $                                     DIST_DIM, Nk, i0, j0, in, jn )
*
      implicit none
*
      integer  F_itr, F_itnlh, DIST_DIM, Nk, i0, j0, in, jn
      real     F_st0  (DIST_SHAPE)    ,
     %         F_pipt0(DIST_SHAPE,Nk) ,  F_qt0  (DIST_SHAPE,Nk) ,
     %         F_fit0 (DIST_SHAPE,Nk) ,  F_fipt0(DIST_SHAPE,Nk) ,
     %         F_fis  (DIST_SHAPE)    ,  F_tt0  (DIST_SHAPE,Nk) ,
     %         F_tpt0 (DIST_SHAPE,Nk) ,  F_tplt0(DIST_SHAPE,Nk) ,
     %         F_ut0  (DIST_SHAPE,Nk) ,  F_vt0  (DIST_SHAPE,Nk) ,
     %         F_psdt0(DIST_SHAPE,Nk) ,  F_tdt0 (DIST_SHAPE,Nk) ,
     %         F_qpt0 (DIST_SHAPE,Nk) ,  F_wt0  (DIST_SHAPE,Nk) ,
     %         F_mut0 (DIST_SHAPE,Nk) ,  F_multx(DIST_SHAPE,Nk) ,
     %         F_gptx (DIST_SHAPE,Nk) ,  F_gxtx (DIST_SHAPE,Nk) ,
     %         F_ru   (DIST_SHAPE,Nk) ,  F_rv   (DIST_SHAPE,Nk) ,
     %         F_rcn  (DIST_SHAPE,Nk) ,  F_rth  (DIST_SHAPE,Nk) ,
     %         F_rvv  (DIST_SHAPE,Nk) ,  F_nth  (DIST_SHAPE,Nk) ,
     %         F_r3   (DIST_SHAPE,Nk) ,  F_r3p  (DIST_SHAPE,Nk) ,
     %         F_nu   (DIST_SHAPE,Nk) ,  F_nv   (DIST_SHAPE,Nk) ,
     %         F_n3   (DIST_SHAPE,Nk) ,  F_n3p  (DIST_SHAPE,Nk) ,
     %         F_ncn  (DIST_SHAPE,Nk) ,
     %         F_wijk0(DIST_SHAPE,Nk) ,  F_wijk1(DIST_SHAPE,Nk)
*
      real     F_st0m  (DIST_SHAPE)   ,
     %         F_pipt0m(DIST_SHAPE,Nk),  F_qt0m  (DIST_SHAPE,Nk),
     %         F_fit0m (DIST_SHAPE,Nk),  F_fipt0m(DIST_SHAPE,Nk),
     %                                   F_tt0m  (DIST_SHAPE,Nk),
     %         F_tpt0m (DIST_SHAPE,Nk),  F_tplt0m(DIST_SHAPE,Nk),
     %         F_ut0m  (DIST_SHAPE,Nk),  F_vt0m  (DIST_SHAPE,Nk),
     %         F_psdt0m(DIST_SHAPE,Nk),  F_tdt0m (DIST_SHAPE,Nk),
     %         F_qpt0m (DIST_SHAPE,Nk),  F_wt0m  (DIST_SHAPE,Nk),
     %         F_mut0m (DIST_SHAPE,Nk),  F_multxm(DIST_SHAPE,Nk),
     %         F_gptxm (DIST_SHAPE,Nk),  F_gxtxm (DIST_SHAPE,Nk),
     %         F_rum   (DIST_SHAPE,Nk),  F_rvm   (DIST_SHAPE,Nk),
     %         F_rcnm  (DIST_SHAPE,Nk),  F_rthm  (DIST_SHAPE,Nk),
     %         F_rvvm  (DIST_SHAPE,Nk),  F_nthm  (DIST_SHAPE,Nk),
     %         F_r3m   (DIST_SHAPE,Nk),  F_r3pm  (DIST_SHAPE,Nk),
     %         F_num   (DIST_SHAPE,Nk),  F_nvm   (DIST_SHAPE,Nk),
     %         F_n3m   (DIST_SHAPE,Nk),  F_n3pm  (DIST_SHAPE,Nk),
     %         F_ncnm  (DIST_SHAPE,Nk),
     %         F_wijk0m(DIST_SHAPE,Nk),  F_wijk1m(DIST_SHAPE,Nk)
*
*implicits
#include "glb_ld.cdk"
#include "cori.cdk"
#include "cstv.cdk"
#include "dcst.cdk"
#include "geomg.cdk"
#include "schm.cdk"
*
      integer i, j, k, nij 
      real*8  ZERO_8, ONE_8, TWO_8, HALF_8, QUARTER_8, gamma_8, eps_8 
      real*8  aaa_8,bbb_8,ccc_8,ddd_8,a1_8,b1_8,b2_8,xxx_8,xx1_8, 
     %        yyy_8,zzz_8,pd2_8,aaa1_8,aaa2_8,bbb1_8,bbb2_8,bbb3_8,
     %        ccc1_8,ccc2_8,ddd1_8
      real*8  xxx_m_8, xx1_m_8, yyy_m_8, zzz_m_8, pd2_m_8
      parameter( ZERO_8=0.0, ONE_8=1.0, TWO_8=2.0, HALF_8=.5,  QUARTER_8=.25 )
      real*8 tmp_8, c1_8, inv_z_8(G_nk), c2_8, c3_8
      real*8, dimension(i0:in,j0:jn):: xexpm_8, yexpm_8, xlogm_8,
     %                        ylogm_8, rpipm_8, xrecm_8, yrecm_8, qpm_8, eqpm_8
      real exp_m,rec_m
*
      nij = (in - i0 + 1)*(jn - j0 + 1)
*
*     Constants for nonhydro distortion 
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      gamma_8 = ONE_8 
      if (.not. Schm_hydro_L) then
           eps_8 =  Schm_nonhy_8 * Dcst_rgasd_8   * Cstv_tstr_8
     %         /( Dcst_cappa_8 * Dcst_grav_8**2 * Cstv_tau_8**2 )
         gamma_8 =  ONE_8/( ONE_8 + eps_8 )
      endif
*
      do k = 1, G_nk
         inv_z_8(k) = 1.0d0 / Geomg_z_8(k)
      end do
*
**********************************************************
*  1. Retrieve the nonhydro deviation q' of log pressure *
**********************************************************
      aaa_8  =  gamma_8/( Dcst_cappa_8*Cstv_tau_8*Dcst_rgasd_8*Cstv_tstr_8 )
      aaa1_8 = Dcst_rgasd_8*Cstv_tstr_8
      aaa2_8 = ONE_8/Dcst_rayt_8**2
      bbb_8  = Geomg_z_8(l_nk) / ( Dcst_rgasd_8*Cstv_tstr_8 )
      bbb1_8 = Dcst_cappa_8*Cstv_tstr_8
      bbb2_8 = ONE_8/(Dcst_grav_8*Cstv_tau_8)
      bbb3_8 = Schm_nonhy_8/((Dcst_grav_8**2)*(Cstv_tau_8**2))
      c1_8   = 1.0d0 / Dcst_cappa_8
      c2_8   = 1.0d0 / Geomg_pib(l_nk)
      c3_8   = 1.0d0 / Dcst_grav_8
      ccc_8  = Schm_nonhy_8*gamma_8/( Dcst_grav_8**2 * Cstv_tau_8**3 )
      ccc1_8 = Geomg_z_8(l_nk) * c2_8
      ccc2_8 = Dcst_rgasd_8*Cstv_tstr_8
      ddd_8  = Schm_nonhy_8 * gamma_8
     %         /( Dcst_cappa_8 * Dcst_grav_8**2 * Cstv_tau_8**3 )
      ddd1_8 = Cstv_tau_8*Cstv_tstr_8
*
!$omp parallel private (xlogm_8,ylogm_8,xrecm_8,yrecm_8,rpipm_8,
!$omp%                  qpm_8,  eqpm_8, exp_m,  rec_m,
!$omp%                  xxx_m_8,yyy_m_8,zzz_m_8,pd2_m_8,xx1_m_8,
!$omp%                  xxx_8,  yyy_8,  zzz_8,  pd2_8,  xx1_8, 
!$omp%                  b1_8,   b2_8,   a1_8,   tmp_8)
*
      if (.not. Schm_hydro_L) then
 
*     TRAJECTORY
*     ----------
      F_qpt0m(:,:,1) = ZERO_8 
*
*     TLM
*     ---
      F_qpt0(:,:,1) = ZERO_8 
*
!$omp do
      do j= j0, jn
         do k=1,l_nk-1
         xxx_8 = HALF_8*Geomg_hz_8(k)
         yyy_8 = (ccc_8*c1_8)*HALF_8*( Geomg_z_8(k) + Geomg_z_8(k+1) )
         zzz_8 = Cstv_tau_8*inv_z_8(k)
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_qpt0m(i,j,k+1) = F_qpt0m(i,j,k)
     %       + xxx_8*( gamma_8*(F_n3pm(i,j,k+1)-F_r3pm(i,j,k+1))
     %       + ccc_8*F_gptxm(i,j,k+1) + gamma_8*(F_n3pm(i,j,k)-F_r3pm(i,j,k))
     %       + ccc_8*F_gptxm(i,j,k) ) + yyy_8*(F_gptxm(i,j,k+1)-F_gptxm(i,j,k))
            F_qpt0m(i,j,k) = zzz_8*F_qpt0m(i,j,k)
*
*           TLM 
*           ---
            F_qpt0(i,j,k+1) = F_qpt0(i,j,k)
     %       + xxx_8*( gamma_8*(F_n3p (i,j,k+1)-F_r3p(i,j,k+1))
     %       +           ccc_8* F_gptx(i,j,k+1) 
     %       +         gamma_8*(F_n3p (i,j,k  )-F_r3p(i,j,k  ))
     %       +           ccc_8* F_gptx(i,j,k) 
     %               ) 
     %       + yyy_8*(F_gptx(i,j,k+1)-F_gptx(i,j,k))
            F_qpt0(i,j,k) = zzz_8*F_qpt0(i,j,k)
*
         end do
         end do
      end do
!$omp enddo

!$omp do
      do j= j0, jn
      do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_qpt0m(i,j,l_nk) = Cstv_tau_8*F_qpt0m(i,j,l_nk)*inv_z_8(l_nk)
*
*        TLM 
*        ---
         F_qpt0(i,j,l_nk) = Cstv_tau_8*F_qpt0(i,j,l_nk)*inv_z_8(l_nk)
*
      end do
      end do
!$omp enddo

      endif

******************************************
*  2. Compute s, pi'lin, pi', q and phi' *
******************************************

*     Compute s
*     ~~~~~~~~~
!$omp do
      do j= j0, jn
      do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_st0m(i,j)  = bbb_8*F_gptxm(i,j,l_nk)*c2_8
*
*        TLM 
*        ---
         F_st0(i,j) =  bbb_8*F_gptx(i,j,l_nk)*c2_8
*
      end do
      end do
!$omp enddo 
*
      if (.not. Schm_hydro_L) then
!$omp do
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_st0m(i,j) = F_st0m(i,j) - ccc1_8*F_qpt0m(i,j,l_nk)
*
*           TLM 
*           ---
            F_st0(i,j) = F_st0(i,j) - ccc1_8*F_qpt0(i,j,l_nk)
*
         end do
         end do
!$omp enddo 
      endif
*
*     Compute pi'lin (F_wijk0), pi', q and phi'
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
!$omp do
      do j= j0, jn
      do i= i0, in
         xexpm_8(i,j) = F_st0m(i,j)
      end do
      end do
!$omp enddo
*
!$omp single
      call vexp ( yexpm_8, xexpm_8, nij )
!$omp end single
*
!$omp do
      do 100 k=1,l_nk 

         if (k.eq.1) then

*        Impose the boundary conditions 
*        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
             do j= j0, jn
             do i= i0, in
*
*               TRAJECTORY
*               ----------
                F_pipt0m(i,j,1) = Geomg_pib(1) *(yexpm_8(i,j)-ONE_8)
                xlogm_8 (i,j)   = Geomg_z_8(1) + F_pipt0m(i,j,1)
*
*               TLM
*               ---
                F_pipt0(i,j,1)  = Geomg_pib(1) *(F_st0(i,j)*yexpm_8(i,j))
*
             end do
             end do
*
             call vlog ( ylogm_8, xlogm_8, nij )
             call vrec ( rpipm_8, xlogm_8, nij )
*
             do j= j0, jn
             do i= i0, in
*
*               TRAJECTORY
*               ----------
                F_qt0m  (i,j,1) = ylogm_8(i,j)
                F_fipt0m(i,j,1) = F_gptxm (i,j,1)
                F_gxtxm (i,j,1) = 0.
*
*               TLM
*               ---
                F_qt0  (i,j,1) = F_pipt0(i,j,1) * rpipm_8(i,j) 
                F_fipt0(i,j,1) = F_gptx (i,j,1)
                F_gxtx (i,j,1) = 0.
*
             end do
             end do
*
         else
             yyy_8 = Dcst_rgasd_8*Cstv_tstr_8 * inv_z_8(k)
             do j= j0, jn
             do i= i0, in
*
*               TRAJECTORY
*               ----------
                F_pipt0m(i,j,k)= Geomg_pib(k)*(yexpm_8(i,j)-ONE_8)
                xlogm_8 (i,j)  = Geomg_z_8(k) + F_pipt0m(i,j,k) 
*
*               TLM
*               ---
                F_pipt0(i,j,k)= Geomg_pib(k)*(F_st0(i,j)*yexpm_8(i,j))
*
             end do
             end do
*
             call vlog ( ylogm_8, xlogm_8, nij )
             call vrec ( rpipm_8, xlogm_8, nij )
*
             do j= j0, jn
             do i= i0, in
*
*               TRAJECTORY
*               ----------
                F_wijk0m(i,j,k)= Geomg_pib(k) * F_st0m(i,j)
                  F_qt0m(i,j,k)= ylogm_8(i,j)
                F_fipt0m(i,j,k)= F_gptxm(i,j,k) - yyy_8*F_wijk0m(i,j,k)
*
*               TLM
*               ---
                F_wijk0(i,j,k)= Geomg_pib(k) * F_st0(i,j)
                  F_qt0(i,j,k)= F_pipt0(i,j,k) * rpipm_8(i,j) 
                F_fipt0(i,j,k)= F_gptx(i,j,k) - yyy_8*F_wijk0(i,j,k)
*
             end do
             end do
*
             if (.not. Schm_hydro_L) then
                do j= j0, jn
                do i= i0, in
*
*                  TRAJECTORY
*                  ----------
                   F_qt0m  (i,j,k) =   F_qt0m(i,j,k) +        F_qpt0m(i,j,k)
                   F_fipt0m(i,j,k) = F_fipt0m(i,j,k) - ccc2_8*F_qpt0m(i,j,k)
*
*                  TLM 
*                  ---
                   F_qt0  (i,j,k) =   F_qt0(i,j,k) +        F_qpt0(i,j,k)
                   F_fipt0(i,j,k) = F_fipt0(i,j,k) - ccc2_8*F_qpt0(i,j,k)
*
                end do
                end do
             endif 
         endif
         if (k.eq.l_nk) then
*
*        TRAJECTORY
*        ----------
         F_fipt0m(:,:,l_nk) = ZERO_8 
*               
*        TLM
*        ---
         F_fipt0(:,:,l_nk)  = ZERO_8 
*
         endif

*******************************
*  3. Retrieve the variable X * 
*******************************
*
*     Compute term {1} (F_wijk1) without vertical staggering 
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_wijk1m(i,j,k) = F_nthm(i,j,k) - F_rthm(i,j,k) 
*
*           TLM 
*           ---
            F_wijk1(i,j,k)  = F_nth(i,j,k)  - F_rth(i,j,k) 
*
         end do
         end do
*
         if (.not. Schm_hydro_L) then
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_wijk1m(i,j,k) = F_wijk1m(i,j,k) + F_n3m(i,j,k) - F_r3m(i,j,k)
*
*           TLM 
*           ---
            F_wijk1(i,j,k) = F_wijk1(i,j,k) + F_n3(i,j,k) - F_r3(i,j,k)
*
         end do
         end do
         endif
*
         xxx_8 = gamma_8/Dcst_cappa_8*Geomg_z_8(k) 
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_wijk1m(i,j,k) = xxx_8*F_wijk1m(i,j,k) 
*
*           TLM 
*           ---
            F_wijk1(i,j,k)  = xxx_8*F_wijk1(i,j,k) 
*
         end do
         end do
*
*     Compute {1} - {2} (F_wijk1)
*     ~~~~~~~~~~~~~~~~~~~~~~~~~
*
         if (.not. Schm_hydro_L) then
            b1_8 = Geomg_z_8(k)/Cstv_tau_8
            b2_8 = ddd_8*Geomg_z_8(k)
            do j= j0, jn
            do i= i0, in
*
*              TRAJECTORY
*              ----------
               F_wijk1m(i,j,k)= F_wijk1m(i,j,k)-b1_8*F_qpt0m(i,j,k)
     $                                         +b2_8*F_gptxm(i,j,k)
*
*              TLM 
*              ---
               F_wijk1(i,j,k)= F_wijk1(i,j,k)-b1_8*F_qpt0(i,j,k)
     $                                       +b2_8*F_gptx(i,j,k)
*
            end do
            end do
         endif 
 100  continue
!$omp enddo
*
!$omp do
      do j= j0, jn
*
         do k=1,l_nk-1 
         a1_8=aaa_8*QUARTER_8*(Geomg_z_8(k)+Geomg_z_8(k+1))**2/Geomg_hz_8(k) 
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_wijk1m(i,j,k) = HALF_8*(  F_wijk1m(i,j,k+1) + F_wijk1m(i,j,k) )
     %                        - a1_8*(  F_gptxm (i,j,k+1) - F_gptxm (i,j,k) )
*
*           TLM
*           ---
            F_wijk1(i,j,k)  = HALF_8*(  F_wijk1(i,j,k+1)  + F_wijk1(i,j,k)  )
     %                        - a1_8*(  F_gptx (i,j,k+1)  - F_gptx (i,j,k)  )
*
         end do
         end do

*        Compute the desired variable X 
*        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         do k=1,l_nk-1 
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_gxtxm(i,j,k+1) = - F_gxtxm(i,j,k) + TWO_8*F_wijk1m(i,j,k) 
*
*           TLM
*           ---
            F_gxtx(i,j,k+1)  = - F_gxtx(i,j,k)  + TWO_8*F_wijk1(i,j,k) 
*
         end do
         end do
      end do
!$omp enddo
*
**********************************************************
*  4. Calculate vertical velocity & nonhydrostatic index * 
**********************************************************
*
!$omp do
      do j= j0, jn
      do i= i0, in
         xexpm_8(i,j) = F_st0m(i,j)
      end do
      end do
!$omp enddo
*
!$omp single 
      call vexp ( yexpm_8, xexpm_8, nij )
!$omp end single 
*
!$omp do
      do 300 k=1,l_nk 
*
         if (.not. Schm_hydro_L) then
*
            a1_8 = aaa1_8*Cstv_tau_8*inv_z_8(k)
            do j= j0, jn
            do i= i0, in
*
               exp_m = exp(F_qpt0m(i,j,k))
*
*              TRAJECTORY
*              ----------
               zzz_m_8 =  1.0 / (1.0 + Geomg_dpib(k)*(yexpm_8(i,j) -1.0))
               xxx_m_8 = F_gptxm(i,j,k)-aaa1_8*F_qpt0m(i,j,k)-a1_8*F_gxtxm(i,j,k)
               F_wt0m  (i,j,k)= - F_rvvm(i,j,k)*c3_8 + bbb2_8*xxx_m_8
               F_multxm(i,j,k)= Cstv_tau_8
     $                        *(F_n3m(i,j,k)-F_r3m(i,j,k))+bbb3_8*xxx_m_8
               yyy_m_8 = (1.+F_pipt0m(i,j,k)*inv_z_8(k))*
     $                            (F_multxm(i,j,k)-F_qpt0m(i,j,k))
               F_mut0m(i,j,k) = exp_m-1.
     $                         +exp_m*zzz_m_8*yyy_m_8
*
*              TLM 
*              ---
               zzz_8 =  - (      Geomg_dpib(k)*(yexpm_8(i,j)*F_st0(i,j))) /
     $                    (1.0 + Geomg_dpib(k)*(yexpm_8(i,j)       -1.0)) **2 
               xxx_8 = F_gptx(i,j,k)-aaa1_8*F_qpt0(i,j,k)-a1_8*F_gxtx(i,j,k)
               F_wt0  (i,j,k)= - F_rvv(i,j,k)*c3_8 + bbb2_8*xxx_8
               F_multx(i,j,k)= Cstv_tau_8
     $                       *(F_n3(i,j,k)-F_r3(i,j,k))+bbb3_8*xxx_8
               yyy_8 = (1.+F_pipt0m(i,j,k)*inv_z_8(k))*
     $                            (F_multx (i,j,k)-F_qpt0 (i,j,k)) +
     $                 (   F_pipt0 (i,j,k)*inv_z_8(k))*
     $                            (F_multxm(i,j,k)-F_qpt0m(i,j,k))
               F_mut0(i,j,k) = exp_m*F_qpt0(i,j,k)  
     $                        +exp_m*zzz_m_8*yyy_8   
     $                        +exp_m*zzz_8  *yyy_m_8 
     $                        +exp_m*F_qpt0(i,j,k)*zzz_m_8*yyy_m_8
*
            end do
            end do
*
         endif
*
**********************************************
*  5. Calculate the temperature perturbation * 
**********************************************
*     Calculate T'lin and prepare {$} (F_wijk1) 
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         a1_8 = Dcst_cappa_8*inv_z_8(k)
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY 
*           ----------
            F_tplt0m(i,j,k) = ddd1_8*(F_rthm(i,j,k) - F_nthm(i,j,k) +
     $                        a1_8*F_gxtxm(i,j,k))
*
*           TLM
*           ---
            F_tplt0(i,j,k)  = ddd1_8*(F_rth(i,j,k)  - F_nth(i,j,k)  + 
     $                        a1_8*F_gxtx(i,j,k))
*
         end do
         end do
*
         if (.not. Schm_hydro_L) then
             do j= j0, jn
             do i= i0, in
*
*               TRAJECTORY 
*               ----------
                F_tplt0m(i,j,k) = F_tplt0m(i,j,k) + bbb1_8*F_qpt0m(i,j,k)
*
*               TLM 
*               ---
                F_tplt0(i,j,k) = F_tplt0(i,j,k) + bbb1_8*F_qpt0(i,j,k)
*
             end do
             end do
         endif
*
*     Calculate T'
*     ~~~~~~~~~~~~
         do j= j0, jn
         do i= i0, in
            xrecm_8(i,j) = 1.0 + Geomg_dpib(k) * (yexpm_8(i,j) - 1.0)
         end do
         end do
         call vrec ( yrecm_8, xrecm_8, nij )
*
         if (Schm_hydro_L) then
*
         do j= j0, jn
         do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_wijk0m(i,j,k)= yrecm_8(i,j)
         F_wijk1m(i,j,k)= F_st0m(i,j) * Geomg_dpib(k)
         pd2_m_8 = Geomg_pib(k) * F_st0m(i,j) * inv_z_8(k) 
         xxx_m_8 = (1. + F_pipt0m(i,j,k)*inv_z_8(k)) * F_wijk0m(i,j,k)
         yyy_m_8 = F_tplt0m(i,j,k) - Cstv_tstr_8 * (( pd2_m_8 -
     %             F_wijk1m(i,j,k)) -1. )
         F_tpt0m(i,j,k) =  xxx_m_8*yyy_m_8 - Cstv_tstr_8
*
*        TLM
*        ---
         F_wijk0(i,j,k)=-(Geomg_dpib(k) *(F_st0(i,j)*yexpm_8(i,j)))*yrecm_8(i,j)*yrecm_8(i,j) 
         F_wijk1(i,j,k)= F_st0(i,j) * Geomg_dpib(k)
         pd2_8 = Geomg_pib(k) * F_st0(i,j) * inv_z_8(k) 
         xxx_8 = (     F_pipt0 (i,j,k)*inv_z_8(k)) * F_wijk0m(i,j,k) +
     %           (1. + F_pipt0m(i,j,k)*inv_z_8(k)) * F_wijk0 (i,j,k) 
         yyy_8 = F_tplt0(i,j,k) - Cstv_tstr_8 * (( pd2_8 -
     %           F_wijk1(i,j,k))      )
         F_tpt0(i,j,k) =  xxx_8*yyy_m_8 + xxx_m_8*yyy_8  
*
         end do
         end do
*
         else
*
            do j= j0, jn
            do i= i0, in
*
               exp_m = exp(F_qpt0m(i,j,k))
*
               rec_m = 1.0 / ( 1.0 + Geomg_dpib(k) * (exp(F_st0m(i,j))-1.) ) 
*
*              TRAJECTORY
*              ----------
               F_wijk0m(i,j,k)= rec_m
               F_wijk1m(i,j,k)= F_st0m(i,j) * Geomg_dpib(k)
               pd2_m_8 = Geomg_pib(k) * F_st0m(i,j) * inv_z_8(k) 
               xx1_m_8 = (1. + F_pipt0m(i,j,k)*inv_z_8(k)) * F_wijk0m(i,j,k)
               xxx_m_8 = xx1_m_8 * exp_m 
               yyy_m_8 = F_tplt0m(i,j,k)-Cstv_tstr_8*((pd2_m_8-F_wijk1m(i,j,k)+
     $                   F_qpt0m(i,j,k))-1.)
               F_tpt0m(i,j,k) =  xxx_m_8*yyy_m_8 - Cstv_tstr_8
*
*              TLM
*              ---
               F_wijk0(i,j,k)=
     $           - (       Geomg_dpib(k) * (exp(F_st0m(i,j))*F_st0(i,j)))*rec_m*rec_m
               F_wijk1(i,j,k)= F_st0(i,j) * Geomg_dpib(k)
               pd2_8 = Geomg_pib(k) * F_st0(i,j) * inv_z_8(k) 
               xx1_8 = (1. + F_pipt0m(i,j,k)*inv_z_8(k)) * F_wijk0 (i,j,k) +
     $                 (     F_pipt0 (i,j,k)*inv_z_8(k)) * F_wijk0m(i,j,k)
               xxx_8 = xx1_m_8 * exp_m      *F_qpt0(i,j,k) + xx1_8 * exp_m 
               yyy_8 = F_tplt0(i,j,k)-Cstv_tstr_8*(pd2_8-F_wijk1(i,j,k)+
     $                  F_qpt0(i,j,k))
               F_tpt0(i,j,k) =  xxx_m_8*yyy_8 + xxx_8*yyy_m_8 
*
            enddo
            enddo
         endif
*
 300  continue
!$omp enddo
*
      if (Cori_cornl_L) then 
*
!$omp single 
*
*     TRAJECTORY
*     ----------
      call rpn_comm_xch_halo( F_gptxm, LDIST_DIM,l_ni,l_nj,G_nk,
     $             G_halox,G_haloy,G_periodx,G_periody,l_ni,0)
*
*     TLM
*     ---
      call rpn_comm_xch_halo( F_gptx, LDIST_DIM,l_ni,l_nj,G_nk,
     $             G_halox,G_haloy,G_periodx,G_periody,l_ni,0)
*
!$omp end single 
*
!$omp do
      do 600 k=1,l_nk

*     Compute gradient of P and hence U & V 
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      do j= j0, jn
      do i= i0, l_niu-pil_e 
*
*     TRAJECTORY
*     ----------
      F_ut0m(i,j,k)= Cstv_tau_8*( F_rum(i,j,k)-F_num(i,j,k) - aaa2_8*
     $               (F_gptxm(i+1,j,k)-F_gptxm(i,j,k)) / Geomg_hx_8(i) )
*     TLM
*     ---
      F_ut0(i,j,k) = Cstv_tau_8*( F_ru(i,j,k) -F_nu(i,j,k)  - aaa2_8*
     $               (F_gptx(i+1,j,k) -F_gptx(i,j,k) ) / Geomg_hx_8(i) )
*
      end do
      end do

      do j= j0, l_njv-pil_n
      do i= i0, in
*
*     TRAJECTORY
*     ----------
      F_vt0m(i,j,k)= Cstv_tau_8*( F_rvm(i,j,k)-F_nvm(i,j,k) - aaa2_8*
     $               (F_gptxm(i,j+1,k) - F_gptxm(i,j,k))
     $               *Geomg_cyv2_8(j)*Geomg_invhsy_8(j) )
*     TLM
*     ---
      F_vt0(i,j,k) = Cstv_tau_8*( F_rv(i,j,k) -F_nv(i,j,k)  - aaa2_8*
     $               (F_gptx(i,j+1,k)  - F_gptx(i,j,k) )
     $               *Geomg_cyv2_8(j)*Geomg_invhsy_8(j) )
*
      end do
      end do
 600  continue
!$omp enddo
      endif
*************************************************************
*  $. Final back substitution after the nonlinear iteration * 
*************************************************************
*
      if ( .not. (F_itr .lt. F_itnlh) ) then
*
!$omp single
      if (.not.Cori_cornl_L) then
*
*
*     TRAJECTORY
*     ----------
      call rpn_comm_xch_halo( F_gptxm, LDIST_DIM,l_ni,l_nj,G_nk,
     $             G_halox,G_haloy,G_periodx,G_periody,l_ni,0)
*
*     TLM 
*     ---
      call rpn_comm_xch_halo( F_gptx, LDIST_DIM,l_ni,l_nj,G_nk,
     $             G_halox,G_haloy,G_periodx,G_periody,l_ni,0)
      endif
!$omp end single
*
!$omp do
      do 700 k=1,l_nk

         if (.not.Cori_cornl_L) then
*     Compute gradient of P and hence U & V 
*     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      do j= j0, jn
      do i= i0, l_niu-pil_e 
*
*        TRAJECTORY
*        ----------
         F_ut0m(i,j,k)= Cstv_tau_8*( F_rum(i,j,k)-F_num(i,j,k) - aaa2_8*
     $                  (F_gptxm(i+1,j,k)-F_gptxm(i,j,k)) / Geomg_hx_8(i) )
*
*        TLM
*        ---
         F_ut0(i,j,k) = Cstv_tau_8*( F_ru(i,j,k) -F_nu(i,j,k)  - aaa2_8*
     $                  (F_gptx(i+1,j,k) -F_gptx(i,j,k) ) / Geomg_hx_8(i) )
*
      end do
      end do
*
      do j= j0, l_njv-pil_n 
      do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_vt0m(i,j,k)= Cstv_tau_8*( F_rvm(i,j,k)-F_nvm(i,j,k) - aaa2_8*
     $                  (F_gptxm(i,j+1,k) - F_gptxm(i,j,k))
     $                  *Geomg_cyv2_8(j)*Geomg_invhsy_8(j) )
*
*        TLM
*        ---
         F_vt0(i,j,k) = Cstv_tau_8*( F_rv(i,j,k) -F_nv(i,j,k)  - aaa2_8*
     $                  (F_gptx(i,j+1,k)  - F_gptx(i,j,k) ) 
     $                   *Geomg_cyv2_8(j)*Geomg_invhsy_8(j) )
*
      end do
      end do
         endif
*     Compute pi*-dot 
*     ~~~~~~~~~~~~~~~
      if ( (k.eq.1) .or. (k.eq.l_nk) ) then
         F_psdt0m(:,:,k) = ZERO_8 
         F_psdt0 (:,:,k) = ZERO_8 
      else
         tmp_8 = Geomg_pib(k)/Cstv_tau_8
         do j= j0, jn
         do i= i0, in
*
*           TRAJECTORY
*           ----------
            F_psdt0m(i,j,k) = F_gxtxm(i,j,k) - tmp_8*F_st0m(i,j)
*
*           TLM
*           ---
            F_psdt0(i,j,k) = F_gxtx(i,j,k) - tmp_8*F_st0(i,j)
*
         end do
         end do
      endif

*     Compute total divergence 
*     ~~~~~~~~~~~~~~~~~~~~~~~~
      tmp_8 = Geomg_dpib(k)/Cstv_tau_8
      do j= j0, jn
      do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_tdt0m(i,j,k) = F_rcnm(i,j,k) - F_ncnm(i,j,k) - tmp_8*F_st0m(i,j)
*
*        TLM
*        ---
         F_tdt0(i,j,k) = F_rcn(i,j,k) - F_ncn(i,j,k) - tmp_8*F_st0(i,j)
*
      end do
      end do

*     Compute phi and T 
*     ~~~~~~~~~~~~~~~~~
      do j= j0, jn
      do i= i0, in
*
*        TRAJECTORY
*        ----------
         F_fit0m(i,j,k) = F_fipt0m(i,j,k) + Cstvr_fistr_8(k) + F_fis(i,j)
          F_tt0m(i,j,k) =  F_tpt0m(i,j,k) + Cstv_tstr_8
*
*        TLM
*        ---
         F_fit0(i,j,k)  = F_fipt0(i,j,k)
          F_tt0(i,j,k)  =  F_tpt0(i,j,k)
*
      end do
      end do
*
 700  continue
!$omp enddo
      endif
!$omp end parallel
*     __________________________________________________________________
*
      return
      end