problem with reading mesh_mask in OFF_SRC

[vichi]

If the user creates offline input data files with the version 3.6_alpha, then the OFFLINE does not work because variable e3t does not exist in the file, while it is looked for when reading the mesh_mask in OFF_SRC/domrea.F90.
This was not found because I believe everybody is using input files generated with previous versions of NEMO where e3t was written in the mesh_mask.
We have to be consistent with this release and it should be corrected before releasing the code. If users want to use previous files they will have to change the name of the variable in the input mesh_mask to make it consistent with 3.6

Suggested changes (including a better explanation of bottom indexing in the comments)

diff --git a/NEMOGCM/NEMO/OFF_SRC/domrea.F90 b/NEMOGCM/NEMO/OFF_SRC/domrea.F90
index ed95b59..54d3944 100644
--- a/NEMOGCM/NEMO/OFF_SRC/domrea.F90
+++ b/NEMOGCM/NEMO/OFF_SRC/domrea.F90
@@ -107,6 +107,13 @@ CONTAINS
             CALL iom_open( 'mesh_zgr', inum4 ) ! create 'mesh_zgr.nc'
             CALL iom_open( 'mask'    , inum2 ) ! create 'mask.nc'
 
+            !                                  ! ===========================
+         CASE DEFAULT                          ! return error 
+            !                                  ! mesh has to be provided
+            !                                  ! ===========================
+            CALL ctl_stop( ' OFFLINE mode requires the input mesh mask(s). ',   &
+            &                                 ' Invalid nn_msh value in the namelist (0 is not allowed)' )
+
          END SELECT
 
          !                                                         ! masks (inum2) 
@@ -172,10 +179,10 @@ CONTAINS
             CALL iom_get( inum4, jpdom_unknown, 'esigt', esigt )
             CALL iom_get( inum4, jpdom_unknown, 'esigw', esigw )
 
-            CALL iom_get( inum4, jpdom_data, 'e3t', fse3t_n(:,:,:) ) ! scale factors
-            CALL iom_get( inum4, jpdom_data, 'e3u', fse3u_n(:,:,:) )
-            CALL iom_get( inum4, jpdom_data, 'e3v', fse3v_n(:,:,:) )
-            CALL iom_get( inum4, jpdom_data, 'e3w', fse3w_n(:,:,:) )
+            CALL iom_get( inum4, jpdom_data, 'e3t_0', fse3t_n(:,:,:) ) ! scale factors
+            CALL iom_get( inum4, jpdom_data, 'e3u_0', fse3u_n(:,:,:) )
+            CALL iom_get( inum4, jpdom_data, 'e3v_0', fse3v_n(:,:,:) )
+            CALL iom_get( inum4, jpdom_data, 'e3w_0', fse3w_n(:,:,:) )
 
             CALL iom_get( inum4, jpdom_unknown, 'gdept_1d', gdept_1d ) ! depth
             CALL iom_get( inum4, jpdom_unknown, 'gdepw_1d', gdepw_1d )
@@ -189,10 +196,10 @@ CONTAINS
             CALL iom_get( inum4, jpdom_unknown, 'e3w_1d'  , e3w_1d   )
             !
             IF( nmsh <= 6 ) THEN                                        ! 3D vertical scale factors
-               CALL iom_get( inum4, jpdom_data, 'e3t', fse3t_n(:,:,:) )
-               CALL iom_get( inum4, jpdom_data, 'e3u', fse3u_n(:,:,:) )
-               CALL iom_get( inum4, jpdom_data, 'e3v', fse3v_n(:,:,:) )
-               CALL iom_get( inum4, jpdom_data, 'e3w', fse3w_n(:,:,:) )
+               CALL iom_get( inum4, jpdom_data, 'e3t_0', fse3t_n(:,:,:) )
+               CALL iom_get( inum4, jpdom_data, 'e3u_0', fse3u_n(:,:,:) )
+               CALL iom_get( inum4, jpdom_data, 'e3v_0', fse3v_n(:,:,:) )
+               CALL iom_get( inum4, jpdom_data, 'e3w_0', fse3w_n(:,:,:) )
             ELSE                                                        ! 2D bottom scale factors
                CALL iom_get( inum4, jpdom_data, 'e3t_ps', e3tp )
                CALL iom_get( inum4, jpdom_data, 'e3w_ps', e3wp )
@@ -227,9 +234,9 @@ CONTAINS
                END DO
             END IF
 
-            IF( iom_varid( inum4, 'gdept', ldstop = .FALSE. ) > 0 ) THEN   ! 3D depth of t- and w-level
-               CALL iom_get( inum4, jpdom_data, 'gdept', fsdept_n(:,:,:) )
-               CALL iom_get( inum4, jpdom_data, 'gdepw', fsdepw_n(:,:,:) )
+            IF( iom_varid( inum4, 'gdept_0', ldstop = .FALSE. ) > 0 ) THEN   ! 3D depth of t- and w-level
+               CALL iom_get( inum4, jpdom_data, 'gdept_0', fsdept_n(:,:,:) )
+               CALL iom_get( inum4, jpdom_data, 'gdepw_0', fsdepw_n(:,:,:) )
             ELSE                                                           ! 2D bottom depth
                CALL iom_get( inum4, jpdom_data, 'hdept', zprt )
                CALL iom_get( inum4, jpdom_data, 'hdepw', zprw )
@@ -346,22 +353,25 @@ CONTAINS
       !!
       !! ** Method  :   computes from mbathy with a minimum value of 1 over land
       !!
-      !! ** Action  : - update mbathy: level bathymetry (in level index)
+      !! ** Action  :   mbkt, mbku, mbkv :   vertical indices of the deeptest
+      !!                                     ocean level at t-, u- & v-points
+      !!                                     (min value = 1 over land)
       !!----------------------------------------------------------------------
       !
       INTEGER ::   ji, jj   ! dummy loop indices
       REAL(wp), POINTER, DIMENSION(:,:) :: zmbk
       !!----------------------------------------------------------------------
-
+      !
+      !
+      !
+      CALL wrk_alloc( jpi, jpj, zmbk )
       !
       IF(lwp) WRITE(numout,*)
       IF(lwp) WRITE(numout,*) '    zgr_bot_level : ocean bottom k-index of T-, U-, V- and W-levels '
       IF(lwp) WRITE(numout,*) '    ~~~~~~~~~~~~~'
       !
-      CALL wrk_alloc( jpi, jpj, zmbk )
-      !
       mbkt(:,:) = MAX( mbathy(:,:) , 1 )    ! bottom k-index of T-level (=1 over land)
-      !
+      !                                     ! bottom k-index of W-level = mbkt+1
       DO jj = 1, jpjm1                      ! bottom k-index of u- (v-) level
          DO ji = 1, jpim1
             mbku(ji,jj) = MIN(  mbkt(ji+1,jj  ) , mbkt(ji,jj)  )

[vichi]

Solved in commit [4569]

[vichi]

Solved in commit [4569]