Index: branches/2014/dev_r4621_NOC4_BDY_VERT_INTERP/NEMOGCM/NEMO/OPA_SRC/TRA/tranxt.F90
===================================================================
--- branches/2014/dev_r4621_NOC4_BDY_VERT_INTERP/NEMOGCM/NEMO/OPA_SRC/TRA/tranxt.F90	(revision 5901)
+++ branches/2014/dev_r4621_NOC4_BDY_VERT_INTERP/NEMOGCM/NEMO/OPA_SRC/TRA/tranxt.F90	(revision 6079)
@@ -31,6 +31,4 @@
    USE zdf_oce         ! ocean vertical mixing
    USE domvvl          ! variable volume
-   USE dynspg_oce      ! surface     pressure gradient variables
-   USE dynhpg          ! hydrostatic pressure gradient 
    USE trd_oce         ! trends: ocean variables
    USE trdtra          ! trends manager: tracers 
@@ -58,5 +56,4 @@
    PUBLIC   tra_nxt_vvl   ! to be used in trcnxt
 
-   REAL(wp) ::   rbcp   ! Brown & Campana parameters for semi-implicit hpg
 
    !! * Substitutions
@@ -90,5 +87,5 @@
       !!
       !! ** Action  : - (tb,sb) and (tn,sn) ready for the next time step
-      !!              - (ta,sa) time averaged (t,s)   (ln_dynhpg_imp = T)
+      !!
       !!----------------------------------------------------------------------
       INTEGER, INTENT(in) ::   kt    ! ocean time-step index
@@ -105,10 +102,9 @@
          IF(lwp) WRITE(numout,*) 'tra_nxt : achieve the time stepping by Asselin filter and array swap'
          IF(lwp) WRITE(numout,*) '~~~~~~~'
-         !
-         rbcp = 0.25_wp * (1._wp + atfp) * (1._wp + atfp) * ( 1._wp - atfp)      ! Brown & Campana parameter for semi-implicit hpg
       ENDIF
 
       ! Update after tracer on domain lateral boundaries
       ! 
+      !
 #if defined key_agrif
       CALL Agrif_tra                     ! AGRIF zoom boundaries
@@ -181,18 +177,8 @@
       !! 
       !! ** Method  : - Apply a Asselin time filter on now fields.
-      !!              - save in (ta,sa) an average over the three time levels 
-      !!             which will be used to compute rdn and thus the semi-implicit
-      !!             hydrostatic pressure gradient (ln_dynhpg_imp = T)
       !!              - swap tracer fields to prepare the next time_step.
-      !!                This can be summurized for tempearture as:
-      !!             ztm = tn + rbcp * [ta -2 tn + tb ]       ln_dynhpg_imp = T
-      !!             ztm = 0                                   otherwise
-      !!                   with rbcp=1/4 * (1-atfp^4) / (1-atfp)
-      !!             tb  = tn + atfp*[ tb - 2 tn + ta ]
-      !!             tn  = ta  
-      !!             ta  = ztm       (NB: reset to 0 after eos_bn2 call)
       !!
       !! ** Action  : - (tb,sb) and (tn,sn) ready for the next time step
-      !!              - (ta,sa) time averaged (t,s)   (ln_dynhpg_imp = T)
+      !!              
       !!----------------------------------------------------------------------
       INTEGER         , INTENT(in   )                               ::   kt       ! ocean time-step index
@@ -205,5 +191,4 @@
       !
       INTEGER  ::   ji, jj, jk, jn   ! dummy loop indices
-      LOGICAL  ::   ll_tra_hpg       ! local logical
       REAL(wp) ::   ztn, ztd         ! local scalars
       !!----------------------------------------------------------------------
@@ -215,7 +200,4 @@
       ENDIF
       !
-      IF( cdtype == 'TRA' )  THEN   ;   ll_tra_hpg = ln_dynhpg_imp    ! active  tracers case  and  semi-implicit hpg    
-      ELSE                          ;   ll_tra_hpg = .FALSE.          ! passive tracers case or NO semi-implicit hpg
-      ENDIF
       !
       DO jn = 1, kjpt
@@ -230,5 +212,4 @@
                   ptn(ji,jj,jk,jn) = pta(ji,jj,jk,jn)                       ! ptn <-- pta
                   !
-                  IF( ll_tra_hpg )   pta(ji,jj,jk,jn) = ztn + rbcp * ztd    ! pta <-- Brown & Campana average
                END DO
            END DO
@@ -248,19 +229,9 @@
       !! 
       !! ** Method  : - Apply a thickness weighted Asselin time filter on now fields.
-      !!              - save in (ta,sa) a thickness weighted average over the three 
-      !!             time levels which will be used to compute rdn and thus the semi-
-      !!             implicit hydrostatic pressure gradient (ln_dynhpg_imp = T)
       !!              - swap tracer fields to prepare the next time_step.
       !!                This can be summurized for tempearture as:
-      !!             ztm = ( e3t_n*tn + rbcp*[ e3t_b*tb - 2 e3t_n*tn + e3t_a*ta ] )   ln_dynhpg_imp = T
-      !!                  /( e3t_n    + rbcp*[ e3t_b    - 2 e3t_n    + e3t_a    ] )   
-      !!             ztm = 0                                                       otherwise
-      !!             tb  = ( e3t_n*tn + atfp*[ e3t_b*tb - 2 e3t_n*tn + e3t_a*ta ] )
-      !!                  /( e3t_n    + atfp*[ e3t_b    - 2 e3t_n    + e3t_a    ] )
-      !!             tn  = ta 
-      !!             ta  = zt        (NB: reset to 0 after eos_bn2 call)
       !!
       !! ** Action  : - (tb,sb) and (tn,sn) ready for the next time step
-      !!              - (ta,sa) time averaged (t,s)   (ln_dynhpg_imp = T)
+      !!
       !!----------------------------------------------------------------------
       INTEGER         , INTENT(in   )                               ::  kt       ! ocean time-step index
@@ -276,5 +247,5 @@
 
       !!     
-      LOGICAL  ::   ll_tra_hpg, ll_traqsr, ll_rnf, ll_isf   ! local logical
+      LOGICAL  ::   ll_traqsr, ll_rnf, ll_isf   ! local logical
       INTEGER  ::   ji, jj, jk, jn              ! dummy loop indices
       REAL(wp) ::   zfact1, ztc_a , ztc_n , ztc_b , ztc_f , ztc_d    ! local scalar
@@ -289,5 +260,4 @@
       !
       IF( cdtype == 'TRA' )  THEN   
-         ll_tra_hpg = ln_dynhpg_imp    ! active  tracers case  and  semi-implicit hpg
          ll_traqsr  = ln_traqsr        ! active  tracers case  and  solar penetration
          ll_rnf     = ln_rnf           ! active  tracers case  and  river runoffs
@@ -298,5 +268,4 @@
          END IF
       ELSE                          
-         ll_tra_hpg = .FALSE.          ! passive tracers case or NO semi-implicit hpg
          ll_traqsr  = .FALSE.          ! active  tracers case and NO solar penetration
          ll_rnf     = .FALSE.          ! passive tracers or NO river runoffs
@@ -356,8 +325,4 @@
                   ptn(ji,jj,jk,jn) = pta(ji,jj,jk,jn)     ! ptn <-- pta
                   !
-                  IF( ll_tra_hpg ) THEN        ! semi-implicit hpg (T & S only)
-                     ze3t_d           = 1.e0   / ( ze3t_n + rbcp * ze3t_d )
-                     pta(ji,jj,jk,jn) = ze3t_d * ( ztc_n  + rbcp * ztc_d  )   ! ta <-- Brown & Campana average
-                  ENDIF
                END DO
             END DO
