[ww3_ounp] TIMESPLIT=0 support

[ukmo-ccbunney]

Pull Request Summary

Add TIMESPLIT=0 (no date string) support for ww3_ounp, as per ww3_ounf

Description

This PR adds support for a zero length datetime string (TIMESPLIT=0 in the namelist) for ww3_ounp.
This brings it in-line with ww3_ounf.

When TIMESPLIT=0, the output file will simply be ww3.spec.nc for combined files or ww3.<field>_spec.nc for split files.

Commit Message

Add TIMESPLIT=0 (no date string) support for ww3_ounp.

Check list

• [✔] Branch is up to date with the authoritative repository (NOAA-EMC) develop branch.
• [✔] Checked the checklist for a developer submitting to develop.
• [ n/a ] If a version number update is required, checked the updating version number checklist.
• [ n/a ] If a new feature was added, a regression test for testing the new feature is added.

Testing

• How were these changes tested?
  • Local testing, regression tests.
• Are the changes covered by regression tests? (If not, why? Do new tests need to be added?)
  • Yes
• Have the matrix regression tests been run (if yes, please note HPC and compiler)?
  • Yes; Cray HPC, GNU Fortran

Regression tests results

Full results: matrixComp_ounp_nodate.zip

Only the usual known non-b4b results:

**********************************************************************
********************* non-identical cases ****************************
**********************************************************************
mww3_test_03/./work_PR2_UQ_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2                     (9 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2_c                     (8 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2                     (8 files differ)
mww3_test_03/./work_PR1_MPI_e                     (1 files differ)
mww3_test_03/./work_PR1_MPI_d2                     (15 files differ)
mww3_test_03/./work_PR2_UNO_MPI_d2                     (11 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2_c                     (9 files differ)
mww3_test_03/./work_PR2_UQ_MPI_d2                     (10 files differ)
mww3_test_03/./work_PR3_UNO_MPI_e                     (1 files differ)

[aliabdolali]

The regtests ran fine except for the pre-known non-identical cases:

**********************************************************************
********************* non-identical cases ****************************
**********************************************************************
mww3_test_03/./work_PR2_UQ_MPI_d2                     (8 files differ)
mww3_test_03/./work_PR2_UNO_MPI_d2                     (6 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2_c                     (8 files differ)
mww3_test_03/./work_PR1_MPI_d2                     (12 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2_c                     (10 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2                     (8 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2                     (8 files differ)
ww3_tp2.10/./work_MPI_OMPH                     (6 files differ)
ww3_tp2.16/./work_MPI_OMPH                     (4 files differ)
ww3_ufs1.1/./work_d                     (0 files differ)
ww3_ufs1.3/./work_a                     (1 files differ)

matrixCompFull.txt
matrixCompSummary.txt
matrixDiff.txt

[aliabdolali]

@mickaelaccensi could you provide your review? Then we can merge it.