MODULE traadv
   !!==============================================================================
   !!                       ***  MODULE  traadv  ***
   !! Ocean active tracers:  advection trend
   !!==============================================================================
   !! History :  2.0  !  2005-11  (G. Madec)  Original code
   !!            3.3  !  2010-09  (C. Ethe, G. Madec)  merge TRC-TRA + switch from velocity to transport
   !!            3.6  !  2011-06  (G. Madec)  Addition of Mixed Layer Eddy parameterisation
   !!            3.7  !  2014-05  (G. Madec)  Add 2nd/4th order cases for CEN and FCT schemes
   !!             -   !  2014-12  (G. Madec) suppression of cross land advection option
   !!            3.6  !  2015-06  (E. Clementi) Addition of Stokes drift in case of wave coupling
   !!----------------------------------------------------------------------

   !!----------------------------------------------------------------------
   !!   tra_adv       : compute ocean tracer advection trend
   !!   tra_adv_init  : control the different options of advection scheme
   !!----------------------------------------------------------------------
   USE oce            ! ocean dynamics and active tracers
   USE dom_oce        ! ocean space and time domain
   ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
   USE domtile
   USE domvvl         ! variable vertical scale factors
   USE sbcwave        ! wave module
   USE sbc_oce        ! surface boundary condition: ocean
   USE traadv_cen     ! centered scheme            (tra_adv_cen  routine)
   USE traadv_fct     ! FCT      scheme            (tra_adv_fct  routine)
   USE traadv_mus     ! MUSCL    scheme            (tra_adv_mus  routine)
   USE traadv_ubs     ! UBS      scheme            (tra_adv_ubs  routine)
   USE traadv_qck     ! QUICKEST scheme            (tra_adv_qck  routine)
   USE tramle         ! Mixed Layer Eddy transport (tra_mle_trp  routine)
   USE ldftra         ! Eddy Induced transport     (ldf_eiv_trp  routine)
   USE ldfslp         ! Lateral diffusion: slopes of neutral surfaces
   USE trd_oce        ! trends: ocean variables
   USE trdtra         ! trends manager: tracers
   USE diaptr         ! Poleward heat transport
   !
   USE in_out_manager ! I/O manager
   USE iom            ! I/O module
   USE prtctl         ! Print control
   USE lib_mpp        ! MPP library
   USE timing         ! Timing

   IMPLICIT NONE
   PRIVATE

   PUBLIC   tra_adv        ! called by step.F90
   PUBLIC   tra_adv_init   ! called by nemogcm.F90

   !                            !!* Namelist namtra_adv *
   LOGICAL ::   ln_traadv_OFF    ! no advection on T and S
   LOGICAL ::   ln_traadv_cen    ! centered scheme flag
   INTEGER ::      nn_cen_h, nn_cen_v   ! =2/4 : horizontal and vertical choices of the order of CEN scheme
   LOGICAL ::   ln_traadv_fct    ! FCT scheme flag
   INTEGER ::      nn_fct_h, nn_fct_v   ! =2/4 : horizontal and vertical choices of the order of FCT scheme
   LOGICAL ::   ln_traadv_mus    ! MUSCL scheme flag
   LOGICAL ::      ln_mus_ups           ! use upstream scheme in vivcinity of river mouths
   LOGICAL ::   ln_traadv_ubs    ! UBS scheme flag
   INTEGER ::      nn_ubs_v             ! =2/4 : vertical choice of the order of UBS scheme
   LOGICAL ::   ln_traadv_qck    ! QUICKEST scheme flag

   INTEGER, PUBLIC ::   nadv             ! choice of the type of advection scheme
   !                             ! associated indices:
   INTEGER, PARAMETER, PUBLIC ::   np_NO_adv  = 0   ! no T-S advection
   INTEGER, PARAMETER, PUBLIC ::   np_CEN     = 1   ! 2nd/4th order centered scheme
   INTEGER, PARAMETER, PUBLIC ::   np_FCT     = 2   ! 2nd/4th order Flux Corrected Transport scheme
   INTEGER, PARAMETER, PUBLIC ::   np_MUS     = 3   ! MUSCL scheme
   INTEGER, PARAMETER, PUBLIC ::   np_UBS     = 4   ! 3rd order Upstream Biased Scheme
   INTEGER, PARAMETER, PUBLIC ::   np_QCK     = 5   ! QUICK scheme

   !! * Substitutions
#  include "do_loop_substitute.h90"
#  include "domzgr_substitute.h90"
   !!----------------------------------------------------------------------
   !! NEMO/OCE 4.0 , NEMO Consortium (2018)
   !! $Id: traadv.F90 15073 2021-07-02 14:20:14Z clem $
   !! Software governed by the CeCILL license (see ./LICENSE)
   !!----------------------------------------------------------------------
CONTAINS

   SUBROUTINE tra_adv( kt, Kbb, Kmm, pts, Krhs )
      !!----------------------------------------------------------------------
      !!                  ***  ROUTINE tra_adv  ***
      !!
      !! ** Purpose :   compute the ocean tracer advection trend.
      !!
      !! ** Method  : - Update (uu(:,:,:,Krhs),vv(:,:,:,Krhs)) with the advection term following nadv
      !!----------------------------------------------------------------------
      INTEGER                                  , INTENT(in)    :: kt             ! ocean time-step index
      INTEGER                                  , INTENT(in)    :: Kbb, Kmm, Krhs ! time level indices
      REAL(dp), DIMENSION(jpi,jpj,jpk,jpts,jpt), INTENT(inout) :: pts            ! active tracers and RHS of tracer equation
      !
      INTEGER ::   ji, jj, jk   ! dummy loop index
      ! TEMP: [tiling] This change not necessary and can be A2D(nn_hls) after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      REAL(dp), DIMENSION(:,:,:), ALLOCATABLE, SAVE :: zuu, zvv, zww   ! 3D workspace
      REAL(dp), DIMENSION(:,:,:), ALLOCATABLE :: ztrdt, ztrds
      ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      LOGICAL :: lskip
      !!----------------------------------------------------------------------
      !
      IF( ln_timing )   CALL timing_start('tra_adv')
      !
      lskip = .FALSE.

      ! TEMP: [tiling] These changes not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      IF( .NOT. l_istiled .OR. ntile == 1 )  THEN                       ! Do only on the first tile
         ALLOCATE( zuu(jpi,jpj,jpk), zvv(jpi,jpj,jpk), zww(jpi,jpj,jpk) )
      ENDIF

      ! TEMP: [tiling] These changes not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      IF( ln_tile .AND. nadv == np_FCT )  THEN
         IF( ntile == 1 ) THEN
            CALL dom_tile_stop( ldhold=.TRUE. )
         ELSE
            lskip = .TRUE.
         ENDIF
      ENDIF
      IF( .NOT. lskip ) THEN
         !                                         !==  effective transport  ==!
         IF( ln_wave .AND. ln_sdw )  THEN
            DO_3D_OVR( nn_hls, nn_hls-1, nn_hls, nn_hls-1, 1, jpkm1 )
               zuu(ji,jj,jk) = e2u  (ji,jj) * e3u(ji,jj,jk,Kmm) * ( uu(ji,jj,jk,Kmm) + usd(ji,jj,jk) )
               zvv(ji,jj,jk) = e1v  (ji,jj) * e3v(ji,jj,jk,Kmm) * ( vv(ji,jj,jk,Kmm) + vsd(ji,jj,jk) )
            END_3D
            DO_3D_OVR( nn_hls-1, nn_hls-1, nn_hls-1, nn_hls-1, 1, jpkm1 )
               zww(ji,jj,jk) = e1e2t(ji,jj)                     * ( ww(ji,jj,jk)     + wsd(ji,jj,jk) )
            END_3D
         ELSE
            DO_3D_OVR( nn_hls, nn_hls-1, nn_hls, nn_hls-1, 1, jpkm1 )
               zuu(ji,jj,jk) = e2u  (ji,jj) * e3u(ji,jj,jk,Kmm) * uu(ji,jj,jk,Kmm)               ! eulerian transport only
               zvv(ji,jj,jk) = e1v  (ji,jj) * e3v(ji,jj,jk,Kmm) * vv(ji,jj,jk,Kmm)
            END_3D
            DO_3D_OVR( nn_hls-1, nn_hls-1, nn_hls-1, nn_hls-1, 1, jpkm1 )
               zww(ji,jj,jk) = e1e2t(ji,jj)                     * ww(ji,jj,jk)
            END_3D
         ENDIF
         !
         IF( ln_vvl_ztilde .OR. ln_vvl_layer ) THEN                                ! add z-tilde and/or vvl corrections
            DO_3D_OVR( nn_hls, nn_hls-1, nn_hls, nn_hls-1, 1, jpkm1 )
               zuu(ji,jj,jk) = zuu(ji,jj,jk) + un_td(ji,jj,jk)
               zvv(ji,jj,jk) = zvv(ji,jj,jk) + vn_td(ji,jj,jk)
            END_3D
         ENDIF
         !
         DO_2D_OVR( nn_hls, nn_hls-1, nn_hls, nn_hls-1 )
            zuu(ji,jj,jpk) = 0._wp                                                      ! no transport trough the bottom
            zvv(ji,jj,jpk) = 0._wp
            zww(ji,jj,jpk) = 0._wp
         END_2D
         !
         IF( ln_ldfeiv .AND. .NOT. ln_traldf_triad )   &
            &              CALL ldf_eiv_trp( kt, nit000, zuu, zvv, zww, 'TRA', Kmm, Krhs )   ! add the eiv transport (if necessary)
         !
         IF( ln_mle    )   CALL tra_mle_trp( kt, nit000, zuu, zvv, zww, 'TRA', Kmm       )   ! add the mle transport (if necessary)
         !
         ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
         IF( .NOT. l_istiled .OR. ntile == nijtile )  THEN                ! Do only on the last tile
            CALL iom_put( "uocetr_eff", zuu )                                        ! output effective transport
            CALL iom_put( "vocetr_eff", zvv )
            CALL iom_put( "wocetr_eff", zww )
         ENDIF
         !
!!gm ???
         ! TEMP: [tiling] This copy-in not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
         CALL dia_ptr( kt, Kmm, zvv(A2D(nn_hls),:) )                                    ! diagnose the effective MSF
!!gm ???
         !

         IF( l_trdtra )   THEN                    !* Save ta and sa trends
            ALLOCATE( ztrdt(jpi,jpj,jpk), ztrds(jpi,jpj,jpk) )
            ztrdt(:,:,:) = pts(:,:,:,jp_tem,Krhs)
            ztrds(:,:,:) = pts(:,:,:,jp_sal,Krhs)
         ENDIF
         !
         SELECT CASE ( nadv )                      !==  compute advection trend and add it to general trend  ==!
         !
         CASE ( np_CEN )                                 ! Centered scheme : 2nd / 4th order
            CALL tra_adv_cen    ( kt, nit000, 'TRA',      zuu, zvv, zww, Kmm, pts, jpts, Krhs, nn_cen_h, nn_cen_v      )
         CASE ( np_FCT )                                 ! FCT scheme      : 2nd / 4th order
               CALL tra_adv_fct ( kt, nit000, 'TRA', rDt, zuu, zvv, zww, Kbb, Kmm, pts, jpts, Krhs, nn_fct_h, nn_fct_v )
         CASE ( np_MUS )                                 ! MUSCL
                CALL tra_adv_mus( kt, nit000, 'TRA', rDt, zuu, zvv, zww, Kbb, Kmm, pts, jpts, Krhs, ln_mus_ups         )
         CASE ( np_UBS )                                 ! UBS
            CALL tra_adv_ubs    ( kt, nit000, 'TRA', rDt, zuu, zvv, zww, Kbb, Kmm, pts, jpts, Krhs, nn_ubs_v           )
         CASE ( np_QCK )                                 ! QUICKEST
            CALL tra_adv_qck    ( kt, nit000, 'TRA', rDt, zuu, zvv, zww, Kbb, Kmm, pts, jpts, Krhs                     )
         !
         END SELECT
         !
         IF( l_trdtra )   THEN                      ! save the advective trends for further diagnostics
            DO jk = 1, jpkm1
               ztrdt(:,:,jk) = pts(:,:,jk,jp_tem,Krhs) - ztrdt(:,:,jk)
               ztrds(:,:,jk) = pts(:,:,jk,jp_sal,Krhs) - ztrds(:,:,jk)
            END DO
            CALL trd_tra( kt, Kmm, Krhs, 'TRA', jp_tem, jptra_totad, ztrdt )
            CALL trd_tra( kt, Kmm, Krhs, 'TRA', jp_sal, jptra_totad, ztrds )
            DEALLOCATE( ztrdt, ztrds )
         ENDIF

         ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
         IF( ln_tile .AND. .NOT. l_istiled ) CALL dom_tile_start( ldhold=.TRUE. )
      ENDIF
      !                                              ! print mean trends (used for debugging)
      !IF(sn_cfctl%l_prtctl)   CALL prt_ctl( tab3d_1=pts(:,:,:,jp_tem,Krhs), clinfo1=' adv  - Ta: ', mask1=tmask, &
      !   &                                  tab3d_2=pts(:,:,:,jp_sal,Krhs), clinfo2=       ' Sa: ', mask2=tmask, clinfo3='tra' )

      ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      IF( .NOT. l_istiled .OR. ntile == nijtile )  THEN                ! Do only for the full domain
         DEALLOCATE( zuu, zvv, zww )
      ENDIF
      !
      IF( ln_timing )   CALL timing_stop( 'tra_adv' )
      !
   END SUBROUTINE tra_adv


   SUBROUTINE tra_adv_init
      !!---------------------------------------------------------------------
      !!                  ***  ROUTINE tra_adv_init  ***
      !!
      !! ** Purpose :   Control the consistency between namelist options for
      !!              tracer advection schemes and set nadv
      !!----------------------------------------------------------------------
      INTEGER ::   ioptio, ios   ! Local integers
      !
      NAMELIST/namtra_adv/ ln_traadv_OFF,                        &   ! No advection
         &                 ln_traadv_cen , nn_cen_h, nn_cen_v,   &   ! CEN
         &                 ln_traadv_fct , nn_fct_h, nn_fct_v,   &   ! FCT
         &                 ln_traadv_mus , ln_mus_ups,           &   ! MUSCL
         &                 ln_traadv_ubs ,           nn_ubs_v,   &   ! UBS
         &                 ln_traadv_qck                             ! QCK
      !!----------------------------------------------------------------------
      !
      !                                !==  Namelist  ==!
      READ  ( numnam_ref, namtra_adv, IOSTAT = ios, ERR = 901)
901   IF( ios /= 0 )   CALL ctl_nam ( ios , 'namtra_adv in reference namelist' )
      !
      READ  ( numnam_cfg, namtra_adv, IOSTAT = ios, ERR = 902 )
902   IF( ios >  0 )   CALL ctl_nam ( ios , 'namtra_adv in configuration namelist' )
      IF(lwm) WRITE( numond, namtra_adv )
      !
      IF(lwp) THEN                           ! Namelist print
         WRITE(numout,*)
         WRITE(numout,*) 'tra_adv_init : choice/control of the tracer advection scheme'
         WRITE(numout,*) '~~~~~~~~~~~~'
         WRITE(numout,*) '   Namelist namtra_adv : chose a advection scheme for tracers'
         WRITE(numout,*) '      No advection on T & S                     ln_traadv_OFF = ', ln_traadv_OFF
         WRITE(numout,*) '      centered scheme                           ln_traadv_cen = ', ln_traadv_cen
         WRITE(numout,*) '            horizontal 2nd/4th order               nn_cen_h   = ', nn_fct_h
         WRITE(numout,*) '            vertical   2nd/4th order               nn_cen_v   = ', nn_fct_v
         WRITE(numout,*) '      Flux Corrected Transport scheme           ln_traadv_fct = ', ln_traadv_fct
         WRITE(numout,*) '            horizontal 2nd/4th order               nn_fct_h   = ', nn_fct_h
         WRITE(numout,*) '            vertical   2nd/4th order               nn_fct_v   = ', nn_fct_v
         WRITE(numout,*) '      MUSCL scheme                              ln_traadv_mus = ', ln_traadv_mus
         WRITE(numout,*) '            + upstream scheme near river mouths    ln_mus_ups = ', ln_mus_ups
         WRITE(numout,*) '      UBS scheme                                ln_traadv_ubs = ', ln_traadv_ubs
         WRITE(numout,*) '            vertical   2nd/4th order               nn_ubs_v   = ', nn_ubs_v
         WRITE(numout,*) '      QUICKEST scheme                           ln_traadv_qck = ', ln_traadv_qck
      ENDIF
      !
      !                                !==  Parameter control & set nadv ==!
      ioptio = 0
      IF( ln_traadv_OFF ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_NO_adv   ;   ENDIF
      IF( ln_traadv_cen ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_CEN      ;   ENDIF
      IF( ln_traadv_fct ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_FCT      ;   ENDIF
      IF( ln_traadv_mus ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_MUS      ;   ENDIF
      IF( ln_traadv_ubs ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_UBS      ;   ENDIF
      IF( ln_traadv_qck ) THEN   ;   ioptio = ioptio + 1   ;   nadv = np_QCK      ;   ENDIF
      !
      IF( ioptio /= 1 )   CALL ctl_stop( 'tra_adv_init: Choose ONE advection option in namelist namtra_adv' )
      !
      IF( ln_traadv_cen .AND. ( nn_cen_h /= 2 .AND. nn_cen_h /= 4 )   &          ! Centered
                        .AND. ( nn_cen_v /= 2 .AND. nn_cen_v /= 4 )   ) THEN
        CALL ctl_stop( 'tra_adv_init: CEN scheme, choose 2nd or 4th order' )
      ENDIF
      IF( ln_traadv_fct .AND. ( nn_fct_h /= 2 .AND. nn_fct_h /= 4 )   &          ! FCT
                        .AND. ( nn_fct_v /= 2 .AND. nn_fct_v /= 4 )   ) THEN
        CALL ctl_stop( 'tra_adv_init: FCT scheme, choose 2nd or 4th order' )
      ENDIF
      ! TEMP: [tiling] This change not necessary after all lbc_lnks removed in the nn_hls = 2 case in tra_adv_fct
      IF( ln_traadv_fct .AND. ln_tile ) THEN
         CALL ctl_warn( 'tra_adv_init: FCT scheme does not yet work with tiling' )
      ENDIF
      IF( ln_traadv_ubs .AND. ( nn_ubs_v /= 2 .AND. nn_ubs_v /= 4 )   ) THEN     ! UBS
        CALL ctl_stop( 'tra_adv_init: UBS scheme, choose 2nd or 4th order' )
      ENDIF
      IF( ln_traadv_ubs .AND. nn_ubs_v == 4 ) THEN
         CALL ctl_warn( 'tra_adv_init: UBS scheme, only 2nd FCT scheme available on the vertical. It will be used' )
      ENDIF
      IF( ln_isfcav ) THEN                                                       ! ice-shelf cavities
         IF(  ln_traadv_cen .AND. nn_cen_v == 4    .OR.   &                            ! NO 4th order with ISF
            & ln_traadv_fct .AND. nn_fct_v == 4   )   CALL ctl_stop( 'tra_adv_init: 4th order COMPACT scheme not allowed with ISF' )
      ENDIF
      !
      !                                !==  Print the choice  ==!
      IF(lwp) THEN
         WRITE(numout,*)
         SELECT CASE ( nadv )
         CASE( np_NO_adv  )   ;   WRITE(numout,*) '   ==>>>   NO T-S advection'
         CASE( np_CEN     )   ;   WRITE(numout,*) '   ==>>>   CEN      scheme is used. Horizontal order: ', nn_cen_h,   &
            &                                                                        ' Vertical   order: ', nn_cen_v
         CASE( np_FCT     )   ;   WRITE(numout,*) '   ==>>>   FCT      scheme is used. Horizontal order: ', nn_fct_h,   &
            &                                                                        ' Vertical   order: ', nn_fct_v
         CASE( np_MUS     )   ;   WRITE(numout,*) '   ==>>>   MUSCL    scheme is used'
         CASE( np_UBS     )   ;   WRITE(numout,*) '   ==>>>   UBS      scheme is used'
         CASE( np_QCK     )   ;   WRITE(numout,*) '   ==>>>   QUICKEST scheme is used'
         END SELECT
      ENDIF
      !
      CALL tra_mle_init            !== initialisation of the Mixed Layer Eddy parametrisation (MLE)  ==!
      !
   END SUBROUTINE tra_adv_init

  !!======================================================================
END MODULE traadv
