Changeset 9863 for NEMO/branches/2018/dev_r9838_ENHANCE04_MLF/src/OCE/DYN/sshwzv.F90

Timestamp:

2018-06-30T12:51:02+02:00 (6 years ago)

Author:

gm

Message:

#1911 (ENHANCE-04): simplified implementation of the Euler stepping at nit000

File:

• NEMO/branches/2018/dev_r9838_ENHANCE04_MLF/src/OCE/DYN/sshwzv.F90 (modified) (9 diffs)

NEMO/branches/2018/dev_r9838_ENHANCE04_MLF/src/OCE/DYN/sshwzv.F90

@@ -68 +68 @@
       INTEGER, INTENT(in) ::   kt   ! time step
       ! 
-      INTEGER  ::   jk            ! dummy loop indice
-      REAL(wp) ::   z2dt, zcoef   ! local scalars
+      INTEGER  ::   jk         ! dummy loop indice
+      REAL(wp) ::   z1_2rau0   ! local scalars
       REAL(wp), DIMENSION(jpi,jpj) ::   zhdiv   ! 2D workspace
       !!----------------------------------------------------------------------
@@ -81 +81 @@
       ENDIF
       !
-      z2dt = 2._wp * rdt                          ! set time step size (Euler/Leapfrog)
-      IF( neuler == 0 .AND. kt == nit000 )   z2dt = rdt
-      zcoef = 0.5_wp * r1_rau0
+      z1_2rau0 = 0.5_wp * r1_rau0
 
       !                                           !------------------------------!
       !                                           !   After Sea Surface Height   !
       !                                           !------------------------------!
-      IF(ln_wd_il) THEN
-         CALL wad_lmt(sshb, zcoef * (emp_b(:,:) + emp(:,:)), z2dt)
-      ENDIF
+
+      IF(ln_wd_il)   CALL wad_lmt( sshb, z1_2rau0 * (emp_b(:,:) + emp(:,:)), r2dt )
 
       CALL div_hor( kt )                               ! Horizontal divergence
@@ -102 +99 @@
       ! compute the vertical velocity which can be used to compute the non-linear terms of the momentum equations.
       ! 
-      ssha(:,:) = (  sshb(:,:) - z2dt * ( zcoef * ( emp_b(:,:) + emp(:,:) ) + zhdiv(:,:) )  ) * ssmask(:,:)
+      ssha(:,:) = (  sshb(:,:) - r2dt * ( z1_2rau0 * ( emp_b(:,:) + emp(:,:) ) + zhdiv(:,:) )  ) * ssmask(:,:)
       !
 #if defined key_agrif
@@ -143 +140 @@
       !
       INTEGER  ::   ji, jj, jk   ! dummy loop indices
-      REAL(wp) ::   z1_2dt       ! local scalars
       REAL(wp), ALLOCATABLE, DIMENSION(:,:,:) ::   zhdiv
       !!----------------------------------------------------------------------
@@ -159 +155 @@
       !                                           !     Now Vertical Velocity    !
       !                                           !------------------------------!
-      z1_2dt = 1. / ( 2. * rdt )                         ! set time step size (Euler/Leapfrog)
-      IF( neuler == 0 .AND. kt == nit000 )   z1_2dt = 1. / rdt
       !
       IF( ln_vvl_ztilde .OR. ln_vvl_layer ) THEN      ! z_tilde and layer cases
@@ -180 +174 @@
             ! computation of w
             wn(:,:,jk) = wn(:,:,jk+1) - (  e3t_n(:,:,jk) * hdivn(:,:,jk) + zhdiv(:,:,jk)    &
-               &                         + z1_2dt * ( e3t_a(:,:,jk) - e3t_b(:,:,jk) )     ) * tmask(:,:,jk)
+               &                         + r1_2dt * ( e3t_a(:,:,jk) - e3t_b(:,:,jk) )     ) * tmask(:,:,jk)
          END DO
          !          IF( ln_vvl_layer ) wn(:,:,:) = 0.e0
@@ -188 +182 @@
             ! computation of w
             wn(:,:,jk) = wn(:,:,jk+1) - (  e3t_n(:,:,jk) * hdivn(:,:,jk)                 &
-               &                         + z1_2dt * ( e3t_a(:,:,jk) - e3t_b(:,:,jk) )  ) * tmask(:,:,jk)
+               &                         + r1_2dt * ( e3t_a(:,:,jk) - e3t_b(:,:,jk) )  ) * tmask(:,:,jk)
          END DO
       ENDIF
@@ -243 +237 @@
          IF(lwp) WRITE(numout,*) '~~~~~~~ '
       ENDIF
-      !              !==  Euler time-stepping: no filter, just swap  ==!
-      IF ( neuler == 0 .AND. kt == nit000 ) THEN
-         sshn(:,:) = ssha(:,:)                              ! now    <-- after  (before already = now)
-         !
-      ELSE           !==  Leap-Frog time-stepping: Asselin filter + swap  ==!
-         !                                                  ! before <-- now filtered
+      !              
+      IF ( l_1st_euler ) THEN    !==  Euler time-stepping  ==!   no filter, just swap
+         !
+         sshn(:,:) = ssha(:,:)               ! now    <-- after  (before already = now)
+         !
+      ELSE                       !==  Leap-Frog time-stepping  ==!   Asselin filter + swap
+         !
+         !                                   ! before <-- now filtered
          sshb(:,:) = sshn(:,:) + atfp * ( sshb(:,:) - 2 * sshn(:,:) + ssha(:,:) )
-         IF( .NOT.ln_linssh ) THEN                          ! before <-- with forcing removed
+         IF( .NOT.ln_linssh ) THEN           ! before <-- with forcing removed
             zcoef = atfp * rdt * r1_rau0
             sshb(:,:) = sshb(:,:) - zcoef * (     emp_b(:,:) - emp   (:,:)   &
@@ -256 +252 @@
                &                             + fwfisf_b(:,:) - fwfisf(:,:)   ) * ssmask(:,:)
          ENDIF
-         sshn(:,:) = ssha(:,:)                              ! now <-- after
+         sshn(:,:) = ssha(:,:)               ! now <-- after
       ENDIF
       !