transmute aerosol_ukca_kernel_mod

[Benjamin Went (MetBenjaminWent)]

PR Summary

#607 has run into issues compiling aerosol_ukca_kernel_mod and conv_comorph_kernel_mod after they have been Transmuted with CCE.

This PR gets aerosol_ukca_kernel_mod working, but sadly not conv_comorph_kernel_mod (which runs into a compiler bug for CCE when adding OMP).

After discussing possible causes with STFC, we think the best course is to:

• Confirm GCC is not affected: It is not
• Reduce optimisation with CCE for these files: -hipa0
• Explore a bespoke script which greatly reduce the number of potential parallel sections, whilst also maintaining the existing flow of the file

Sci/Tech Reviewer:
Code Reviewer:

Issue: #657
Umbrella: #424

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 - aero_ukca_conv_como_explore/run26

Suite Information

Item	Value
Suite Name	aero_ukca_conv_como_explore/run26
Suite User	benjamin.went
Workflow Start	2026-08-06T14:00:58
Groups Run	ex1a_omp_developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.07.1	True
jules	MetOffice/jules@2026.07.1	True
lfric_apps	MetBenjaminWent/lfric_apps@aero_ukca_conv_como_explore	False
lfric_core	MetOffice/lfric_core@2026.07.1	True
moci	MetOffice/moci@2026.07.1	True
SimSys_Scripts	MetOffice/SimSys_Scripts@77a5166	True
socrates	MetOffice/socrates@2026.07.1	True
socrates-spectral	MetOffice/socrates-spectral@2026.07.1	True
ukca	MetOffice/ukca@9fc2b6d	True

Task Information

✅ succeeded tasks - 51

Test Suite Results - lfric_apps - aero_ukca_conv_como_explore/run25

Suite Information

Item	Value
Suite Name	aero_ukca_conv_como_explore/run25
Suite User	benjamin.went
Workflow Start	2026-08-06T10:57:54
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.07.1	True
jules	MetOffice/jules@2026.07.1	True
lfric_apps	MetBenjaminWent/lfric_apps@aero_ukca_conv_como_explore	False
lfric_core	MetOffice/lfric_core@2026.07.1	True
moci	MetOffice/moci@2026.07.1	True
SimSys_Scripts	MetOffice/SimSys_Scripts@77a5166	True
socrates	MetOffice/socrates@2026.07.1	True
socrates-spectral	MetOffice/socrates-spectral@2026.07.1	True
ukca	MetOffice/ukca@9fc2b6d	True

Task Information

✅ succeeded tasks - 1216

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