Postproc updates for UKESM2

[marcstring]

PR Summary

Code Reviewer: Erica Neininger (@ericaneininger)

As summarised at the top of issue #31, our prototype UKESM2 model, UKESM2_proto, uses NEMO4.2, whereas UKESM1.3 uses NEMO3.6. At NEMO3.6 the bathymentry file was an input file, but at NEMO4.2 the bathymetry files needs to be generated from a domain file. Consequently for UKESM2_proto, compared to UKESM1.3,

• The bathymetry file is no longer a starting file, the domain file is instead
• UKESM2_proto has an additional domain file.

In this ticket I add the domain file and change the rose-stem setup from the UKESM1.3 setup to the UKESM2_proto setup.

Also, includes a fix in expected_content.py for running static ice (which has no restart dumps) for either UKESM1.3 or UKESM2_proto on the final cycle.

Code Quality Checklist

(Some checks are automatically carried out via the CI pipeline)

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• [ ]*1 Comments have been included that aid undertanding and enhance the
  readability of the code
• My changes generate no new warnings
  *1 No additional comments in this change except for the additional unit test, which was written by Erica Pearce, but change is only adding additional arguments to code which is already commented.

Testing

• I have tested this change locally, using the Moci rose-stem suite
• *2 If any tests fail (rose-stem or CI) the reason is understood and
  acceptable (eg. kgo changes)
• [ ]*3 I have added tests to cover new functionality as appropriate (eg. system
  tests, unit tests, etc.)
  *2 There's no failures, see output in issue UKESM2 postproc developments #31
  *3 I found an error in the code, which this change fixes, and Erica has added a unit test into this change which protects this fix.

I've also run a UKESM2_proto for several years, which archive_integrity running every year, to comfirm that the additional files are being archived and are expected by archive_integrity.

Security Considerations

• I have reviewed my changes for potential security issues
• [ ]*4 Sensitive data is properly handled (if applicable)
• [ ]*4 Authentication and authorisation are properly implemented (if applicable)
  *4 Not applicable to this change

Performance Impact

• [x]*5 Performance of the code has been considered and, if applicable, suitable
  performance measurements have been conducted
  *5 This adds additional code to both Postproc and rose-stem, but increases should not be significant.

AI Assistance and Attribution

• [ ]*6 Some of the content of this change has been produced with the assistance
  of Generative AI tool name (e.g., Met Office Github Copilot Enterprise,
  Github Copilot Personal, ChatGPT GPT-4, etc) and I have followed the
  Simulation Systems AI policy
  (including attribution labels)
  *6 No AI used here

Documentation

• [ ]*7 Where appropriate I have updated documentation related to this change and
  confirmed that it builds correctly
  *7 No additional documentation.

Test Suite Results - moci - test_ukesm2_dev/run1

Suite Information

Item	Value
Suite Name	test_ukesm2_dev/run1
Suite User	marc.stringer
Workflow Start	2026-03-30T10:26:27
Groups Run	ALL

Dependency	Reference	Main Like
moci	marcstring/moci@ukesm2_dev	False
SimSys_Scripts	MetOffice/SimSys_Scripts@main	True

Task Information

✅ succeeded tasks - 116

Code Review

• All dependencies have been resolved
• Related Issues have been properly linked and addressed
• CLA compliance has been confirmed
• Code quality standards have been met
• Tests are adequate and have passed
• Documentation is complete and accurate
• Security considerations have been addressed
• Performance impact is acceptable

[Erica Neininger (ericaneininger)]

This looks generally fine.

Can you please copy the trac.log file from your rose-stem run - the PR template need updating to request this new feature!

Just an observation - The new output files do not follow the CMIP agreed filenaming convention. The only special character permitted in the "custom" facet is a hyphen, and here we have a period: plot.CF-AIS and plot.CF-GRiS .

Since the rest of the filenames comply with the convention, are we breaking it deliberately, or because we were not aware it was there?

Just for ease of finding them in the changes here... These custom facets are defined in archive_verify/filenames.py and in unicicles/unicicles.py. Thery are then requested in the rose-stem postproc app.

[marcstring]

Hi Erica, thanks for getting to this so quickly.

A good point about the plot.CF-AIS and plot.CF-GRiS files. The were added to our UKESM1.3 CMIP7 Fast Track at the very last minute, by Robin Smith, and I'd forgotten about this issue. It's been decided that some software other than CDDS will handle the UniCiCles data, and Robin and other ice sheet guys are handling this. Hence, we don't need to meet the CMIP agreed convention here (and it's too late for UKESM1.3 now, which is frozen), but that doesn't meet we can't meet this convention for UKESM2. I'll contact Robin Smith, and Cc you, and see what he says.

Thanks, Marc

ps. I've added the trac.log to the PR summary, as requested.

[marcstring]

Re-running rose-stem

Following Erica's review and e-mails with Robin Smith (main contributor to the UniCiCles code), I've changed the branch so that *plot.CF-AIS.hdf5 and *plot.CF-GRiS.hdf5 files are now called *plot-CF-AIS.hdf5 and *plot.CF-GRiS.hdf5.

I've re-run rose-stem and the new trac.log is

Test Suite Results - moci - test_ukesm2_dev2/run1

Suite Information

Item	Value
Suite Name	test_ukesm2_dev2/run1
Suite User	marc.stringer
Workflow Start	2026-04-02T10:36:04
Groups Run	ALL

Dependency	Reference	Main Like
moci	marcstring/moci@ukesm2_dev	False
SimSys_Scripts	MetOffice/SimSys_Scripts@main	True

Task Information

✅ succeeded tasks - 116

[marcstring]

At the bottom of https://code.metoffice.gov.uk/trac/UKESM/wiki/ticket/1036/extra_plot_files I've created a job to test the new branch, https://code.metoffice.gov.uk/trac/roses-u/log/d/y/3/4/2, and this can be seen to archive the *_plot-CF-AIS.hdf5 and *_plot-CF-GrIS.hdf5 files. And the archive_integrity looks good as well. Hence, I believe this shows the change to the branch following Erica's review is good.