mosrs ticket 1048 - adding openmp directives to chunking of ukca full domain passing

[RobWatersMet]

moved changes over from mosrs ticket 1048, these were related to adding openmp directive around chunking of full domain passing

PR Summary

Sci/Tech Reviewer:
Code Reviewer:

See https://code.metoffice.gov.uk/trac/lfric_apps/ticket/1048 for full details.

Aim of the ticket is to add optional openmp directives around the domain chunking in the full domain passing interface - ukca file: src/science/core/chemistry/ukca_chemistry_ctl_full_mod.F90

This will involve adding to the following psyclone scripts inside lfric_apps:

• applications/lfric_atm/optimisation/azngarch-sandbox/transmute/science/ukca/src/science/core/chemistry/ukca_chemistry_ctl_full_mod.py
• applications/lfric_atm/optimisation/meto-ex1a/transmute/science/ukca/src/science/core/chemistry/ukca_chemistry_ctl_full_mod.py

Current status is have omp directives off by default but they can be turned on with the following logic:

    use_omp = get_bool_env("UKCA_FULL_CHUNK_OMP", True)
    if desired_chunk_size is None and use_omp:
        logging.WARNING(
            "Turning off omp as chunk size is set to full domain size")
        use_omp = False

The use of the UKCA_FULL_CHUNK_OMP env variable is short term solution - a follow-up ticket/PR will be to add this as a namelist option but to keep things short and simple we have opted to keep the short-term solution in for this ticket (original plan prior to github migration).

Follow-up MOSRS ticket: https://code.metoffice.gov.uk/trac/lfric_apps/ticket/1082

This will become an GH issue / PR.

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 Core rose-stem suite
• If required (e.g. API changes) I have also run the LFRic Apps test suite using this branch
• 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 - ngarch_ukca_openmp_chunking_ticket_1048/run1

Suite Information

Item	Value
Suite Name	ngarch_ukca_openmp_chunking_ticket_1048/run1
Suite User	alan.j.hewitt
Workflow Start	2026-01-20T15:48:03
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2025.12.1	True
jules	MetOffice/jules@2025.12.1	True
lfric_apps	RobWatersMet/lfric_apps@ngarch_ukca_openmp_chunking_ticket_1048	False
lfric_core	MetOffice/lfric_core@aa32824	True
moci	MetOffice/moci@2025.12.1	True
SimSys_Scripts	MetOffice/SimSys_Scripts@2025.12.1	True
socrates	MetOffice/socrates@2025.12.1	True
socrates-spectral	MetOffice/socrates-spectral@2025.12.1	True
ukca	MetOffice/ukca@2025.12.1	True

Task Information

❌ failed tasks - 1

Task	State
run_gungho_model_robert-moist-lam-BiP100x8-10x10_azspice_gnu_fast-debug-64bit	failed

✅ succeeded tasks - 1102

⌛ waiting tasks - 1

Task	State
housekeep_azspice	waiting

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

[RobWatersMet]

Failed test: run_gungho_model_robert-moist-lam-BiP100x8-10x10_azspice_gnu_fast-debug-64bit

@alanjhewitt - this always fails right and is a broken test, i.e. not an issue with this PR

[RobWatersMet]

TCD email bouncing (??) - does anyone have the correct address?

[alanjhewitt]

Failed test: run_gungho_model_robert-moist-lam-BiP100x8-10x10_azspice_gnu_fast-debug-64bit

@alanjhewitt - this always fails right and is a broken test, i.e. not an issue with this PR

It does work, but this task times out almost every time it gets run. Hopefully it will get updated to either be a shorter test or request extra resourses.

[james-bruten-mo]

TCD email bouncing (??) - does anyone have the correct address?

Sorry, looks like it's missing an "l" in tools in the template. It should be toolscollabdevteam@metoffice.gov.uk
I'll get that fixed