Changeset 6219

Timestamp:

2016-01-06T16:39:17+01:00 (8 years ago)

Author:

hadcv

Message:

Quick fix to omit the iso-layer calculation when rn_iso_frac = 0.

The finite-difference part of the iso-layer calculation currently has the following bugs:

• Only the first subsequent level beneath the iso-layer is considered
• If z(ik_iso) < rn_zref, the interpolation can result in a MLD shallower than rn_zref

File:

• branches/UKMO/dev_r5107_mld_zint/NEMOGCM/NEMO/OPA_SRC/ZDF/zdfmxl.F90 (modified) (2 diffs)

branches/UKMO/dev_r5107_mld_zint/NEMOGCM/NEMO/OPA_SRC/ZDF/zdfmxl.F90

@@ -193 +193 @@
 
       ! Local variables
+      REAL(wp), PARAMETER :: zepsilon = 1.e-30          ! local small value
       INTEGER, POINTER, DIMENSION(:,:) :: ikmt          ! number of active tracer levels 
       INTEGER, POINTER, DIMENSION(:,:) :: ik_ref        ! index of reference level 
@@ -268 +269 @@
       ikmt(:,:) = mbathy(:,:) - 1 
 
-      ! Search for a uniform density/temperature region where adjacent levels          
-      ! differ by less than rn_iso_frac * deltaT.                                      
-      ! ik_iso is the index of the last level in the uniform layer  
-      ! ll_found indicates whether the mixed layer depth can be found by interpolation 
-      ik_iso(:,:)   = ik_ref(:,:) 
-      ll_found(:,:) = .false. 
-      DO jj = 1, nlcj 
-         DO ji = 1, nlci 
+      IF ( rn_iso_frac - zepsilon > 0. ) THEN
+         ! Search for a uniform density/temperature region where adjacent levels          
+         ! differ by less than rn_iso_frac * deltaT.                                      
+         ! ik_iso is the index of the last level in the uniform layer  
+         ! ll_found indicates whether the mixed layer depth can be found by interpolation 
+         ik_iso(:,:)   = ik_ref(:,:) 
+         ll_found(:,:) = .false. 
+         DO jj = 1, nlcj 
+            DO ji = 1, nlci 
 !CDIR NOVECTOR 
-            DO jk = ik_ref(ji,jj), ikmt(ji,jj)-1 
-               IF ( zmoddT(ji,jj,jk) > ( rn_iso_frac * zdelta_T(ji,jj) ) ) THEN 
-                  ik_iso(ji,jj)   = jk 
-                  ll_found(ji,jj) = ( zmoddT(ji,jj,jk) > zdelta_T(ji,jj) ) 
-                  EXIT 
+               DO jk = ik_ref(ji,jj), ikmt(ji,jj)-1 
+                  IF ( zmoddT(ji,jj,jk) > ( rn_iso_frac * zdelta_T(ji,jj) ) ) THEN 
+                     ik_iso(ji,jj)   = jk 
+                     ll_found(ji,jj) = ( zmoddT(ji,jj,jk) > zdelta_T(ji,jj) ) 
+                     EXIT 
+                  END IF 
+               END DO 
+            END DO 
+         END DO 
+
+         ! Use linear interpolation to find depth of mixed layer base where possible 
+         hmld_zint(:,:) = rn_zref 
+         DO jj = 1, jpj 
+            DO ji = 1, jpi 
+               IF (ll_found(ji,jj) .and. tmask(ji,jj,1) == 1.0) THEN 
+                  zdz =  abs( zdelta_T(ji,jj) / zdTdz(ji,jj,ik_iso(ji,jj)) ) 
+                  hmld_zint(ji,jj) = fsdept(ji,jj,ik_iso(ji,jj)) + zdz 
                END IF 
             END DO 
          END DO 
-      END DO 
-
-      ! Use linear interpolation to find depth of mixed layer base where possible 
-      hmld_zint(:,:) = rn_zref 
-      DO jj = 1, jpj 
-         DO ji = 1, jpi 
-            IF (ll_found(ji,jj) .and. tmask(ji,jj,1) == 1.0) THEN 
-               zdz =  abs( zdelta_T(ji,jj) / zdTdz(ji,jj,ik_iso(ji,jj)) ) 
-               hmld_zint(ji,jj) = fsdept(ji,jj,ik_iso(ji,jj)) + zdz 
-            END IF 
-         END DO 
-      END DO 
+      END IF
 
       ! If ll_found = .false. then calculate MLD using difference of zdelta_T