Update LFRic2LFric to store unique names for it's source and destination meshes

[Ricky Wong (mo-rickywong)]

PR Summary

Sci/Tech Reviewer: cjohnson-pi
Code Reviewer: Matthew Hambley (@MatthewHambley)
Updates LFRic2Lfric code to use core changes in MetOffice/lfric_core#452 . These changes, along with those in the linked PR should allow LFRic2Lfric to use generated meshes for re-gridding, even if the meshes where identically named in the seprate mesh input files.

Linked PRs

• linked Allow meshes to be renamed on load lfric_core#452

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)

Canned test in lfric2fric shows that the source and destination meshes are prepended with src and dst by lfric2lfric. This will satisfy the requirement for unique mesh name in the mesh collections, even if the input files have meshes named the same.

Note:
A suitable test case for lfric2lfric to use where meshes of the same name are used in source and destination mesh files. The canned lfric2lfric test was modified so that it would attempt to read the same mesh for source and destination. i.e.

&lfric2lfric
source_meshfile_prefix     = 'mesh_C24_MG',
source_mesh_name           = 'dynamics',
destination_meshfile_prefix = 'mesh_C24_MG_copy',
destination_mesh_name      = 'dynamics',
/

This failed in XIOS during the context creation of the output file. This test is out of scope, but may point to further work on lfric2lfric wrt XIOS output.

trac.log

Test Suite Results - lfric_apps - Apps_lfric2lfric_in_and_out/run1

Suite Information

Item	Value
Suite Name	Apps_lfric2lfric_in_and_out/run1
Suite User	ricky.wong
Workflow Start	2026-08-26T13:31:08
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.07.1	True
jules	MetOffice/jules@2026.07.1	True
lfric_apps	mo-rickywong/lfric_apps@Apps_lfric2lfric_in_and_out	False
lfric_core	mo-rickywong/lfric_core@lfric2lfric_in_and_out	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 - 1218

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