Lfric atm coupled

[James Bruten (james-bruten-mo)]

PR Summary

Sci/Tech Reviewer: Paul Earnshaw (@pdearnshaw)
Code Reviewer: Steve Mullerworth (@stevemullerworth)

Retire the lfric_coupled application, instead running coupled testing via the lfric_atm application.
Coupled tasks are now identified by the rose-stem suite by the addition of coupled to the build section of the task name. This causes the different modules to be loaded and the ocean and rivers builds to be done.
The rose-stem suite uses a separate lfric_atm_coupled app rather than the existing lfric_atm app, as the differences are big enough that using optional configs doesn't make sense.
The kgo doesn't match between the old lfric_coupled task and the new lfric_atm one. This is due to differences in the build and optimisation settings between the 2 applications. If I copy the old build and optimisation directories from lfric_coupled into lfric_atm, the kgo passes, indicating the differences are just due to the build settings changes.

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 - lfric_atm_coupled/run10

Suite Information

Item	Value
Suite Name	lfric_atm_coupled/run10
Suite User	james.bruten
Workflow Start	2026-07-14T14:47:03
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.07.1	True
jules	MetOffice/jules@2026.07.1	True
lfric_apps	james-bruten-mo/lfric_apps@lfric_atm_coupled	False
lfric_core	MetOffice/lfric_core@2026.07.1	True
moci	MetOffice/moci@2026.07.1	True
SimSys_Scripts	james-bruten-mo/SimSys_Scripts@coupled_meta	True
socrates	MetOffice/socrates@2026.07.1	True
socrates-spectral	MetOffice/socrates-spectral@2026.07.1	True
ukca	MetOffice/ukca@2026.07.1	True

Task Information

❌ failed tasks - 2

Task	State
check_lfric_atm_coupled_nwp-gal9_C48_ex1a_cce_coupled-fast-debug-64bit	failed
kgo_groups_checker	failed

✅ succeeded tasks - 1208

⌛ waiting tasks - 1

Task	State
housekeep_ex1a	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

[iboutle]

Looks good to me.

When I update the science of the lfric_atm & lfric_coupled apps to GC6, it may be possible to merge the 2 apps together (as the differences should be much less then), although possibly there is still an argument for keeping them separate...

[Pierre Siddall (Pierre-siddall)]

Happy with the changes to CODEOWNERS, approved on behalf of SSD.

[Wolfgang Hayek (tinyendian)]

Looks good to me

[David Lee (davelee2804)]

Thanks very much for making us aware of this change James Bruten (@james-bruten-mo) - sounds like a reasonable change to me. As part of a future PR we will look to get the lfric_atm_coupled Rose stem tests ported to our system...

[Matthew Hambley (MatthewHambley)]

Code owner (Build system) review: No problem with deleting the build system of an application which is being deleted.