Changeset 12489 for NEMO/trunk/src/OCE/TRA/traatf.F90

Timestamp:

2020-02-28T16:55:11+01:00 (4 years ago)

Author:

davestorkey

Message:

Preparation for new timestepping scheme #2390.
Main changes:

1. Initial euler timestep now handled in stp and not in TRA/DYN routines.
2. Renaming of all timestep parameters. In summary, the namelist parameter is now rn_Dt and the current timestep is rDt (and rDt_ice, rDt_trc etc).
3. Renaming of a few miscellaneous parameters, eg. atfp -> rn_atfp (namelist parameter used everywhere) and rau0 -> rho0.

This version gives bit-comparable results to the previous version of the trunk.

File:

• NEMO/trunk/src/OCE/TRA/traatf.F90 (modified) (9 diffs)

NEMO/trunk/src/OCE/TRA/traatf.F90

@@ -113 +113 @@
       IF( ln_bdy )   CALL bdy_tra( kt, Kbb, pts, Kaa )  ! BDY open boundaries
  
-      ! set time step size (Euler/Leapfrog)
-      IF( neuler == 0 .AND. kt == nit000 ) THEN   ;   r2dt =        rdt   ! at nit000             (Euler)
-      ELSEIF( kt <= nit000 + 1 )           THEN   ;   r2dt = 2._wp* rdt   ! at nit000 or nit000+1 (Leapfrog)
-      ENDIF
-
       ! trends computation initialisation
       IF( l_trdtra )   THEN                    
@@ -128 +123 @@
          ENDIF
          ! total trend for the non-time-filtered variables. 
-         zfact = 1.0 / rdt
+         zfact = 1.0 / rn_Dt
          ! G Nurser 23 Mar 2017. Recalculate trend as Delta(e3t*T)/e3tn; e3tn cancel from pts(Kmm) terms
          DO jk = 1, jpkm1
@@ -144 +139 @@
       ENDIF
 
-      IF( neuler == 0 .AND. kt == nit000 ) THEN       ! Euler time-stepping 
+      IF( l_1st_euler ) THEN       ! Euler time-stepping 
          !
          IF (l_trdtra .AND. .NOT. ln_linssh ) THEN   ! Zero Asselin filter contribution must be explicitly written out since for vvl
@@ -156 +151 @@
       ELSE                                            ! Leap-Frog + Asselin filter time stepping
          !
-         IF( ln_linssh ) THEN   ;   CALL tra_atf_fix( kt, Kbb, Kmm, Kaa, nit000,      'TRA', pts, jpts )  ! linear free surface 
-         ELSE                   ;   CALL tra_atf_vvl( kt, Kbb, Kmm, Kaa, nit000, rdt, 'TRA', pts, sbc_tsc, sbc_tsc_b, jpts )  ! non-linear free surface
+         IF( ln_linssh ) THEN   ;   CALL tra_atf_fix( kt, Kbb, Kmm, Kaa, nit000,        'TRA', pts, jpts )  ! linear free surface 
+         ELSE                   ;   CALL tra_atf_vvl( kt, Kbb, Kmm, Kaa, nit000, rn_Dt, 'TRA', pts, sbc_tsc, sbc_tsc_b, jpts )  ! non-linear free surface
          ENDIF
          !
@@ -167 +162 @@
       !
       IF( l_trdtra .AND. ln_linssh ) THEN      ! trend of the Asselin filter (tb filtered - tb)/dt     
-         zfact = 1._wp / r2dt             
+         zfact = 1._wp / rDt             
          DO jk = 1, jpkm1
             ztrdt(:,:,jk) = ( pts(:,:,jk,jp_tem,Kmm) - ztrdt(:,:,jk) ) * zfact
@@ -219 +214 @@
             ztd = pt(ji,jj,jk,jn,Kaa) - 2._wp * ztn + pt(ji,jj,jk,jn,Kbb)  ! time laplacian on tracers
             !
-            pt(ji,jj,jk,jn,Kmm) = ztn + atfp * ztd                      ! pt <-- filtered pt
+            pt(ji,jj,jk,jn,Kmm) = ztn + rn_atfp * ztd                      ! pt <-- filtered pt
          END_3D
          !
@@ -234 +229 @@
       !! 
       !! ** Method  : - Apply a thickness weighted Asselin time filter on now fields.
-      !!             pt(Kmm)  = ( e3t(Kmm)*pt(Kmm) + atfp*[ e3t(Kbb)*pt(Kbb) - 2 e3t(Kmm)*pt(Kmm) + e3t_a*pt(Kaa) ] )
-      !!                       /( e3t(Kmm)         + atfp*[ e3t(Kbb)         - 2 e3t(Kmm)         + e3t(Kaa)    ] )
+      !!             pt(Kmm)  = ( e3t(Kmm)*pt(Kmm) + rn_atfp*[ e3t(Kbb)*pt(Kbb) - 2 e3t(Kmm)*pt(Kmm) + e3t_a*pt(Kaa) ] )
+      !!                       /( e3t(Kmm)         + rn_atfp*[ e3t(Kbb)         - 2 e3t(Kmm)         + e3t(Kaa)    ] )
       !!
       !! ** Action  : - pt(Kmm) ready for the next time step
@@ -277 +272 @@
       ENDIF
       zfact = 1._wp / p2dt
-      zfact1 = atfp * p2dt
-      zfact2 = zfact1 * r1_rau0
+      zfact1 = rn_atfp * p2dt
+      zfact2 = zfact1 * r1_rho0
       DO jn = 1, kjpt      
          DO_3D_00_00( 1, jpkm1 )
@@ -292 +287 @@
             ztc_d  = ztc_a  - 2. * ztc_n  + ztc_b
             !
-            ze3t_f = ze3t_n + atfp * ze3t_d
-            ztc_f  = ztc_n  + atfp * ztc_d
+            ze3t_f = ze3t_n + rn_atfp * ze3t_d
+            ztc_f  = ztc_n  + rn_atfp * ztc_d
             !
             ! Add asselin correction on scale factors: