Replace 64-bit clim_gal9 nrun-crun test with 32-bit version

[Steve Mullerworth (stevemullerworth)]

PR Summary

Sci/Tech Reviewer: iboutle
Code Reviewer:

This test strengthens testing for tickets that went in at 3.2, but could only be done once both those tickets were on main - it would be useful to get this small change on for 3.2.

The default precision for scientific evaluation of clim_gal9 is 32-bit, and till recently rose-stem tested this configuration at 32-bit.

The test was changed to 64-bit as part of #383 in order to add a test for reproducibility across nrun-crun boundaries as that PR did not fix a further issue that prevented nrun-crun reproducibility when running at 32-bit.

PR #427 (fixing checkpointing of the random seed when running with 32-bit precision) fixed this second issue, but was done in parallel with #383 meaning the nrun-crun test was not included in the branch.

Now both PRs are done, this PR can revert the clim_gal9 test to 32-bit (as advised in the prior PRs) while still also testing for nrun-v-crun reproducibility.

Change includes replacing of the 64-bit checksums with 32-bit checksums for the modified job. As there are no science changes, I ran just the developer group.

iboutle CC:d as code owner - hopefully OK to sign of science review.

Code Quality Checklist

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• Comments have been included that aid understanding and enhance the readability of the code
• My changes generate no new warnings
• All automated checks in the CI pipeline have completed successfully

Testing

• I have tested this change locally, using the LFRic Apps rose-stem suite
• If any tests fail (rose-stem or CI) the reason is understood and acceptable (e.g. kgo changes)
• I have added tests to cover new functionality as appropriate (e.g. system tests, unit tests, etc.)
• Any new tests have been assigned an appropriate amount of compute resource and have been allocated to an appropriate testing group (i.e. the developer tests are for jobs which use a small amount of compute resource and complete in a matter of minutes)

trac.log

Test Suite Results - lfric_apps - clim_gal9_r32_chkpt_forpr/run1

Suite Information

Item	Value
Suite Name	clim_gal9_r32_chkpt_forpr/run1
Suite User	steve.mullerworth
Workflow Start	2026-06-05T10:52:12
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.03.2	True
jules	MetOffice/jules@3647a42	True
lfric_apps	stevemullerworth/lfric_apps@clim_gal9_r32_chkpt	False
lfric_core	MetOffice/lfric_core@9c85548	True
moci	MetOffice/moci@2026.03.2	True
SimSys_Scripts	MetOffice/SimSys_Scripts@3e2998b	True
socrates	MetOffice/socrates@2026.03.2	True
socrates-spectral	MetOffice/socrates-spectral@2026.03.2	True
ukca	MetOffice/ukca@1cdb9c2	True

Task Information

✅ succeeded tasks - 1196

Security Considerations

• I have reviewed my changes for potential security issues
• Sensitive data is properly handled (if applicable)
• Authentication and authorisation are properly implemented (if applicable)

Performance Impact

• Performance of the code has been considered and, if applicable, suitable performance measurements have been conducted

AI Assistance and Attribution

• 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)

Documentation

• Where appropriate I have updated documentation related to this change and confirmed that it builds correctly

PSyclone Approval

• If you have edited any PSyclone-related code (e.g. PSyKAl-lite, Kernel interface, optimisation scripts, LFRic data structure code) then please contact the TCD Team

Sci/Tech Review

• I understand this area of code and the changes being added
• The proposed changes correspond to the pull request description
• Documentation is sufficient (do documentation papers need updating)
• Sufficient testing has been completed

(Please alert the code reviewer via a tag when you have approved the SR)

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

[iboutle]

Almost trivial - looks good to me!