Merge branch...

Merge branch '120-tracer-conservation-for-configurations-with-forward-euler-passive-tracer-time-stepping-2' into 'main'

Resolve "Tracer conservation for configurations with forward Euler passive-tracer time stepping and time-varying grid-cell volumes" ('main')

Closes #120

See merge request nemo/nemo!227

src/OCE/TRA/trabbl.F90

@@ -55,8 +55,6 @@ MODULE trabbl
    REAL(wp), PUBLIC ::   rn_ahtbbl   !: along slope bbl diffusive coefficient [m2/s]
    REAL(wp), PUBLIC ::   rn_gambbl   !: lateral coeff. for bottom boundary layer scheme [s]
 
-   LOGICAL , PUBLIC ::   l_bbl       !: flag to compute bbl diffu. flux coef and transport
-
    REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:), PUBLIC ::   utr_bbl  , vtr_bbl   ! u- (v-) transport in the bottom boundary layer
    REAL(wp), ALLOCATABLE, SAVE, DIMENSION(:,:), PUBLIC ::   ahu_bbl  , ahv_bbl   ! masked diffusive bbl coeff. at u & v-pts
 
@@ -117,8 +115,6 @@ CONTAINS
          ztrds(:,:,:) = pts(:,:,:,jp_sal,Krhs)
       ENDIF
 
-      IF( l_bbl )   CALL bbl( kt, nit000, 'TRA', Kbb, Kmm )   !* bbl coef. and transport (only if not already done in trcbbl)
-
       IF( nn_bbl_ldf == 1 ) THEN                    !* Diffusive bbl
          !
          CALL tra_bbl_dif( pts(:,:,:,:,Kbb), pts(:,:,:,:,Krhs), jpts, Kmm )
@@ -289,7 +285,7 @@ CONTAINS
    END SUBROUTINE tra_bbl_adv
 
 
-   SUBROUTINE bbl( kt, kit000, cdtype, Kbb, Kmm )
+   SUBROUTINE bbl( kt, kit000, Kbb, Kmm )
       !!----------------------------------------------------------------------
       !!                  ***  ROUTINE bbl  ***
       !!
@@ -317,7 +313,6 @@ CONTAINS
       !!----------------------------------------------------------------------
       INTEGER         , INTENT(in   ) ::   kt       ! ocean time-step index
       INTEGER         , INTENT(in   ) ::   kit000   ! first time step index
-      CHARACTER(len=3), INTENT(in   ) ::   cdtype   ! =TRA or TRC (tracer indicator)
       INTEGER         , INTENT(in   ) ::   Kbb, Kmm ! ocean time level index
       !
       INTEGER  ::   ji, jj                    ! dummy loop indices
@@ -333,7 +328,7 @@ CONTAINS
       IF( .NOT. l_istiled .OR. ntile == 1 )  THEN                       ! Do only on the first tile
          IF( kt == kit000 )  THEN
             IF(lwp)  WRITE(numout,*)
-            IF(lwp)  WRITE(numout,*) 'trabbl:bbl : Compute bbl velocities and diffusive coefficients in ', cdtype
+            IF(lwp)  WRITE(numout,*) 'trabbl:bbl : Compute bbl velocities and diffusive coefficients'
             IF(lwp)  WRITE(numout,*) '~~~~~~~~~~'
          ENDIF
       ENDIF
@@ -479,8 +474,6 @@ CONTAINS
 902   IF( ios >  0 )   CALL ctl_nam ( ios , 'nambbl in configuration namelist' )
       IF(lwm) WRITE ( numond, nambbl )
       !
-      l_bbl = .TRUE.                 !* flag to compute bbl coef and transport
-      !
       IF(lwp) THEN                   !* Parameter control and print
          WRITE(numout,*)
          WRITE(numout,*) 'tra_bbl_init : bottom boundary layer initialisation'

src/OCE/stpmlf.F90

@@ -204,6 +204,10 @@ CONTAINS
       IF( l_ldftra_time .OR. l_ldfeiv_time )   CALL ldf_tra( kstp, Nbb, Nnn )  !       and/or eiv coeff.
       IF( l_ldfdyn_time                    )   CALL ldf_dyn( kstp, Nbb )       ! eddy viscosity coeff.
 
+      ! BBL coefficients
+      !
+      IF( ln_trabbl )    CALL bbl( kstp, nit000, Nbb, Nnn )   ! BBL diffusion coefficients and transports
+
       !>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
       !  Ocean dynamics : hdiv, ssh, e3, u, v, w
       !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

src/OCE/stprk3_stg.F90

@@ -249,6 +249,10 @@ CONTAINS
       !                                            ! Advective velocity needed for tracers advection - already computed if ln_dynadv_vec=F
       IF( ln_dynadv_vec )   CALL wzv  ( kstp, Kbb, Kmm, Kaa, zaU, zaV, ww )
       !
+      !                                            ! BBL coefficients required for both passive- and active-tracer transport within
+      !                                            ! the BBL (stage 3 only, requires uu, vv, gdept at Kmm)
+      IF( ( kstg == 3 ) .AND. ln_trabbl ) CALL bbl( kstp, nit000, Kbb, Kmm )
+      !
 # if defined key_top
       !                       !==  Passive Tracer  ==!
       !

src/TOP/TRP/trcbbl.F90

@@ -55,11 +55,6 @@ CONTAINS
       !
       IF( ln_timing )   CALL timing_start('trc_bbl')
       !
-      IF( .NOT. l_offline ) THEN
-         CALL bbl( kt, nittrc000, 'TRC', Kbb, Kmm )  ! Online coupling with dynamics  : Computation of bbl coef and bbl transport
-         l_bbl = .FALSE.                             ! Offline coupling with dynamics : Read bbl coef and bbl transport from input files
-      ENDIF
-
       IF( l_trdtrc )  THEN
          ALLOCATE( ztrtrd(jpi,jpj,jpk,jptra) ) ! temporary save of trends
          ztrtrd(:,:,:,:)  = ptr(:,:,:,:,Krhs)

src/TOP/trcrst.F90

@@ -372,7 +372,7 @@ CONTAINS
       ENDIF
       !
       DO jk = 1, jpk
-         zvol(:,:,jk) = e1e2t(:,:) * e3t(:,:,jk,Krhs) * tmask(:,:,jk)
+         zvol(:,:,jk) = e1e2t(:,:) * e3t(:,:,jk,Kmm) * tmask(:,:,jk)
       END DO
       !
       DO jn = 1, jptra

src/TOP/trcstp.F90

@@ -60,6 +60,7 @@ CONTAINS
       INTEGER, INTENT( in ) :: Kbb, Kmm, Krhs, Kaa ! time level indices
       !
       INTEGER ::   jk, jn   ! dummy loop indices
+      INTEGER ::   ibb      ! local time-level index
       REAL(wp)::   ztrai    ! local scalar
       LOGICAL ::   ll_trcstat ! local logical
       CHARACTER (len=25) ::   charout   !
@@ -67,8 +68,10 @@ CONTAINS
       !
       IF( ln_timing )   CALL timing_start('trc_stp')
       !
+      ibb = Kbb                     ! default "before" time-level index
       IF( l_1st_euler .OR. ln_top_euler ) THEN     ! at nittrc000
          rDt_trc =  rn_Dt           ! = rn_Dt (use or restarting with Euler time stepping)
+         ibb = Kmm                  ! time-level index used to substitute the "before" with the "now" time level
       ELSEIF( kt <= nittrc000 + 1 ) THEN                                     ! at nittrc000 or nittrc000+1 
          rDt_trc = 2. * rn_Dt       ! = 2 rn_Dt (leapfrog) 
       ENDIF
@@ -98,9 +101,9 @@ CONTAINS
       CALL trc_rst_opn  ( kt )                            ! Open tracer restart file 
       IF( lrst_trc )  CALL trc_rst_cal  ( kt, 'WRITE' )   ! calendar
       CALL trc_wri      ( kt,      Kmm            )       ! output of passive tracers with iom I/O manager
-      CALL trc_sms      ( kt, Kbb, Kmm, Krhs      )       ! tracers: sinks and sources
+      CALL trc_sms      ( kt, ibb, Kmm, Krhs      )       ! tracers: sinks and sources
 #if ! defined key_sed_off
-      CALL trc_trp      ( kt, Kbb, Kmm, Krhs, Kaa )       ! transport of passive tracers
+      CALL trc_trp      ( kt, ibb, Kmm, Krhs, Kaa )       ! transport of passive tracers
 #endif
            !
            ! Note passive tracers have been time-filtered in trc_trp but the time level
@@ -123,7 +126,7 @@ CONTAINS
          tr(:,:,:,:,Kmm) = tr(:,:,:,:,Kaa)
       ENDIF
       !
-      IF( lrst_trc )            CALL trc_rst_wri  ( kt, Kbb, Kmm, Kaa  )       ! write tracer restart file
+      IF( lrst_trc )            CALL trc_rst_wri  ( kt, ibb, Kmm, Kaa  )       ! write tracer restart file
 !     IF( lrst_trc )            CALL trc_rst_wri  ( kt, Kmm, Kaa, Kbb  )       ! write tracer restart file
       !
       IF (ll_trcstat) THEN