Changeset 7709 for branches/NERC/dev_r5518_NOC_MEDUSA_Stable/NEMOGCM/NEMO/TOP_SRC/trcstp.F90

Timestamp:

2017-02-21T16:46:07+01:00 (7 years ago)

Author:

jpalmier

Message:

JPALM -- 21-02-2017 -- merge the branch with Richard optim branch, and add 2 fixes in trcnam_medusa

File:

• branches/NERC/dev_r5518_NOC_MEDUSA_Stable/NEMOGCM/NEMO/TOP_SRC/trcstp.F90 (modified) (2 diffs)

branches/NERC/dev_r5518_NOC_MEDUSA_Stable/NEMOGCM/NEMO/TOP_SRC/trcstp.F90

@@ -55 +55 @@
       !!              Update the passive tracers
       !!-------------------------------------------------------------------
+
+      USE dom_oce, ONLY: narea
+
       INTEGER, INTENT( in ) ::  kt      ! ocean time-step index
       INTEGER               ::  jk, jn  ! dummy loop indices
@@ -129 +132 @@
       ENDIF
       !
-      ztrai = 0._wp                                                   !  content of all tracers
-      DO jn = 1, jptra
-         ztrai = ztrai + glob_sum( trn(:,:,:,jn) * cvol(:,:,:)   )
-      END DO
-      IF( lwp ) WRITE(numstr,9300) kt,  ztrai / areatot
-9300  FORMAT(i10,e18.10)
+      IF (ln_ctl) THEN 
+         ! The following code is very expensive since it involves multiple 
+         ! reproducible global sums over all tracer fields and is potentially  
+         ! called on every timestep. The results it produces are purely for 
+         ! informational purposes and do not affect model evolution. 
+         ! Hence we restrict its use by protecting it with the ln_ctl RTL 
+         ! which should normally only be used under debugging conditions 
+         ! and not in operational runs. We also need to restrict output  
+         ! to the master PE since there's no point duplicating the same results 
+         ! on all processors.    
+         ztrai = 0._wp                                                   !  content of all tracers
+         DO jn = 1, jptra
+            ztrai = ztrai + glob_sum( trn(:,:,:,jn) * cvol(:,:,:)   )
+         END DO
+         IF( lwp ) WRITE(numstr,9300) kt,  ztrai / areatot
+9300     FORMAT(i10,e18.10)
+      ENDIF
       !
       IF( nn_timing == 1 )   CALL timing_stop('trc_stp')