Opened 3 years ago

Closed 3 years ago

#767 closed upgrade (Done)

Updated CORRELATION algorithm

Reported by: arango Owned by:
Priority: major Milestone: Release ROMS/TOMS 3.7
Component: Adjoint Version: 3.7
Keywords: Cc:

Description

The CORRELATION driver that computes the 4D-Var error covariance normalization coefficients is updated:

  • The set-up in read_phypar.F was cleaned out, so only the input grid and initial conditions NetCDF are processed. The other input ROMS NetCDF files are ignored since they are not needed.
  • The input parameter NTIMES was overwritten and set to 1 since this driver does not timestep the ROMS kernel. The computer was running out of memory when ADJUST_BOUNDARY, ADJUST_STFLUX, or ADJUST_WSTRESS was activated with very large NTIMES and small NOBC and NSFF.

We have a case with:

   NTIMES =  788400
     NOBC == 10
     NSFF == 10

So the internal parameter:

    Nbrec = 1 + ntime(ng)/Nobc(ng) = 78841

resulting in the following array been allocated as:

    t_obc(0:217, 40, 4, 78841, 2, 2)

which is huge, and we several similar arrays when ADJUST_BOUNDARY is activated. Warnings for such cases were added in read_phypar.F. It makes sense to make NTIMES=1 in this driver to avoid such problem in the future.

  • Lots of warnings were added to get_state.F when the needed NetCDF variable is not founded in the input NetCDF file. For example, to process tangent linear model free-surface we have:
    !
    !  Read in tangent linear free-surface (m).
    !
            IF (get_var(idFsur)) THEN
              foundit=find_string(var_name, n_var, TRIM(Vname(1,idFsur)),   &
         &                        varid)
              IF (foundit) THEN
                gtype=var_flag(varid)*r2dvar
                status=nf_fread2d(ng, IDmod, ncname, ncINPid,               &
         &                        Vname(1,idFsur), varid,                   &
         &                        InpRec, gtype, Vsize,                     &
         &                        LBi, UBi, LBj, UBj,                       &
         &                        Fscl, Fmin, Fmax,                         &
    # ifdef MASKING
         &                        GRID(ng) % rmask,                         &
    # endif
         &                        OCEAN(ng) % tl_zeta(:,:,Tindex))
                IF (FoundError(status, nf90_noerr, __LINE__,                &
         &                     __FILE__)) THEN
                  IF (Master) THEN
                    WRITE (stdout,60) string, TRIM(Vname(1,idFsur)),        &
         &                            InpRec, TRIM(ncname)
                  END IF
                  exit_flag=2
                  ioerror=status
                  RETURN
                ELSE
                  IF (Master) THEN
                    WRITE (stdout,70) TRIM(Vname(2,idFsur)), Fmin, Fmax
                  END IF
                END IF
              ELSE
                IF (Master) THEN
                  WRITE (stdout,80) string, TRIM(Vname(1,idFsur)),          &
         &                          TRIM(ncname)
                END IF
                exit_flag=4
                IF (FoundError(exit_flag, nf90_noerr, __LINE__,             &
         &                     __FILE__)) THEN
                  RETURN
                END IF
              END IF
            END IF
    
    so the new piece of code is after the ELSE statement if the variable is not found:
           IF (get_var(idFsur)) THEN
             ...
             IF (foundit) THEN
               ...
             ELSE
               IF (Master) THEN
                 WRITE (stdout,80) string, TRIM(Vname(1,idFsur)),          &
        &                          TRIM(ncname)
               END IF
               exit_flag=4
               IF (FoundError(exit_flag, nf90_noerr, __LINE__,             &
        &                     __FILE__)) THEN
                 RETURN
               END IF
             END IF
           END IF
    

Many thanks to Andy Moore for reporting some of these issues.

Change History (1)

comment:1 Changed 3 years ago by arango

  • Resolution set to Done
  • Status changed from new to closed
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