vn3.1

LFRic Core vn3.1 release notes

Key Changes

• New api for namelist configuration access #175, the old method of access is deprecated. Usage is detailed in the Using the config object
• Changes to the partitioning strategy so that MPI ranks for cubed-sphere runs are no longer limited to a factor of 6, and can now run with a factor of 2 or 3. #220

Breaking Changes

These changes will affect suites upgrading to this release

• No known breaking changes at this release.

Known Issues

• No known issues at this release.

Linked Changes

This release is part of the 2026.03.1 Simulation Systems Release..

What's Changed

• Sphinx setup initial setup by Andrew Coughtrie (@andrewcoughtrie) in #1
• Some initial documentation. by Andrew Coughtrie (@andrewcoughtrie) in #2
• First draft of DistMem doc. by Mike Hobson (@mike-hobson) in #4
• Configurator documentation by Matthew Hambley (@MatthewHambley) in #10
• Import top-level LFRic documentation by Steve Mullerworth (@stevemullerworth) in #9
• Improve data model document by Steve Mullerworth (@stevemullerworth) in #15
• Addressing the most obvious flaws in the dist mem docs. by Mike Hobson (@mike-hobson) in #11
• Added XIOS file definition standards as well as some general tweaks. by Andrew Coughtrie (@andrewcoughtrie) in #17
• First draft of clock and time documentation. by Matthew Hambley (@MatthewHambley) in #19
• Add deploy docs badge by Andrew Coughtrie (@andrewcoughtrie) in #21
• Rename readme and doc deployment by Andrew Coughtrie (@andrewcoughtrie) in #22
• Update the workflow to use newer actions by Andrew Coughtrie (@andrewcoughtrie) in #20
• Doc structure by Steve Mullerworth (@stevemullerworth) in #24
• Add a glossary page with some initial definitions as a starting point… by Ricky Wong (@mo-rickywong) in #27
• Pydata restructure by Andrew Coughtrie (@andrewcoughtrie) in #31
• Update sphinx workflow by Andrew Coughtrie (@andrewcoughtrie) in #32
• Add sphinx design to pip install in workflow by Andrew Coughtrie (@andrewcoughtrie) in #33
• Added the glossary as a link in the guide to documentation by Andrew Coughtrie (@andrewcoughtrie) in #34
• Create CODEOWNERS by Andrew Coughtrie (@andrewcoughtrie) in #36
• Fix edit source link in conf.py by Andrew Coughtrie (@andrewcoughtrie) in #38
• Update module info in readme by Andrew Coughtrie (@andrewcoughtrie) in #39
• Fix link to the GitHub repo by Andrew Coughtrie (@andrewcoughtrie) in #40
• Write-up of external fields. by Matthew Hambley (@MatthewHambley) in #25
• Application schematic added to docs by Steve Mullerworth (@stevemullerworth) in #37
• 30 document prognostics and diagnostics system by Steve Mullerworth (@stevemullerworth) in #35
• Document templaterator and templates by Matthew Hambley (@MatthewHambley) in #51
• Added issue templates by Andrew Coughtrie (@andrewcoughtrie) in #42
• Update figures in the lfric datamodel docs by Andrew Coughtrie (@andrewcoughtrie) in #49
• Data structures by Steve Mullerworth (@stevemullerworth) in #45
• Document Modeldb by Mike Hobson (@mike-hobson) in #50
• Improve issue templates by Andrew Coughtrie (@andrewcoughtrie) in #56
• Correct info on mixed-precision field collection iterators. by Mike Hobson (@mike-hobson) in #61
• 18 sphinx style guide by Steve Mullerworth (@stevemullerworth) in #65
• Some small fixes to the issue templates forms by Andrew Coughtrie (@andrewcoughtrie) in #70
• Fix yaml files by Mike Hobson (@mike-hobson) in #71
• Apply style changes to all the docs by Steve Mullerworth (@stevemullerworth) in #74
• Add info on coupling to the documentation by Mike Hobson (@mike-hobson) in #77
• Fix field collection iterator example code by Mike Hobson (@mike-hobson) in #79
• Getting going documentation by Steve Mullerworth (@stevemullerworth) in #78
• Add Fortran style guide by Steve Mullerworth (@stevemullerworth) in #83
• Doxygen usage copied from SRS and updated by Matthew Hambley (@MatthewHambley) in #67
• Moved configurator documentation to developer guide by Matthew Hambley (@MatthewHambley) in #88
• Mesh generation user guide documentation - Quick Start & Restructure by Ricky Wong (@mo-rickywong) in #63
• Fix the reference numbers for figures in the dist-mem docs. by Mike Hobson (@mike-hobson) in #85
• Clean up the data model doc and move it to developer documentation by Steve Mullerworth (@stevemullerworth) in #89
• Adding unit test documentation by Mike Hobson (@mike-hobson) in #80
• Dependerator documentation by Matthew Hambley (@MatthewHambley) in #87
• 62 documentation add configuration documentation by Ricky Wong (@mo-rickywong) in #84
• Update GitHub actions to bring in line with lfric_apps by Andrew Coughtrie (@andrewcoughtrie) in #94
• Update workflow badge by Andrew Coughtrie (@andrewcoughtrie) in #95
• Update function space documentation for split element orders by mo-jdendy in #91
• Updated modeldb documentation by allynt in #101
• Fixed a missing link by Matthew Hambley (@MatthewHambley) in #102
• Placeholder documentation for components. by Matthew Hambley (@MatthewHambley) in #92
• Introduce the simple I/O system. by Matthew Hambley (@MatthewHambley) in #105
• Introduction to logging framework. by Matthew Hambley (@MatthewHambley) in #104
• Describe the use of "big PF." by Matthew Hambley (@MatthewHambley) in #109
• Update fortran_coding_standards.rst by Mike Hobson (@mike-hobson) in #111
• Make prohibition on application specifics in driver component more explicit by Matthew Hambley (@MatthewHambley) in #112
• Add PSyclone Makefile docs by Oakley Brunt (@oakleybrunt) in #110
• Add deploy target to MakeFile by Andrew Coughtrie (@andrewcoughtrie) in #114
• Add integration testing documentation by Matthew Hambley (@MatthewHambley) in #117
• Update software_dependencies.rst by Andrew Coughtrie (@andrewcoughtrie) in #120
• Update the dist mem docs to explain the alternative to inner halos by Mike Hobson (@mike-hobson) in #121
• Refine comments on kind specification by Steve Mullerworth (@stevemullerworth) in #125
• Migrate Python style guide from SRS by Matthew Hambley (@MatthewHambley) in #124
• A primer for code reviewers by Matthew Hambley (@MatthewHambley) in #122
• Started a page of testing tips by Matthew Hambley (@MatthewHambley) in #123
• Character style by Steve Mullerworth (@stevemullerworth) in #118
• Correct Gnu version and fix formatting by Steve Mullerworth (@stevemullerworth) in #126
• Renamed the main sections of the documentation. by Andrew Coughtrie (@andrewcoughtrie) in #127
• Fix copyright format by Andrew Coughtrie (@andrewcoughtrie) in #128
• Update the README.md file by Andrew Coughtrie (@andrewcoughtrie) in #129
• Document use of the lfric mpi module by Mike Hobson (@mike-hobson) in #130
• Add basic PR template by Andrew Coughtrie (@andrewcoughtrie) in #132
• Simplify the data section by referencing other sections by Steve Mullerworth (@stevemullerworth) in #136
• Extend and refactor logging information by Steve Mullerworth (@stevemullerworth) in #137
• Configuration documentation by Steve Mullerworth (@stevemullerworth) in #138
• Add in details of File_prefix which appears to have been omitted by Ricky Wong (@mo-rickywong) in #139
• Adding a FAQs page by Andrew Coughtrie (@andrewcoughtrie) in #141
• Update glossary.rst by Mike Hobson (@mike-hobson) in #143
• Updated workflow packages to be pegged at specific versions. by Andrew Coughtrie (@andrewcoughtrie) in #142
• An illustration of the testing continuum by Matthew Hambley (@MatthewHambley) in #148
  *...

vn3.0

LFRic Core vn3.0 Release Notes

Full Changelog: core2.2...vn3.0

This is the first GitHub release of LFRic Core. Please see the refreshed Working Practices for details on how to migrate branches and work with GitHub.

Key Changes

• Additional infrastructure has been added to support flexible checkpointing in LFRic Apps. This includes, a key_value_collection_iterator class, string splitting functionality, and some refactoring of the lfric_xios component to allow multiple checkpoint files to be written (ticket:4020).
• Mesh generators now have OpenMP support for generating partitioned meshes, enabling generation of meshes in a reasonable time when running at scale (for example, running a 10km global model on several thousand ranks can now be done in a few minutes on 32 cores).
• Sphinx based documentation hosted on GitHub

Linked Codebases

This release is part of the 2025.12.1 Simulation Systems Release.