Spherical ice-crystal and further cloud droplet optical properties added to ga9 and ga9_ref spectral files

[James Manners (mo-jmanners)]

PR Summary

Spherical ice-crystal and further cloud droplet optical properties added to ga9 and ga9_ref spectral files

Sci/Tech Reviewer: Dr Stephan Havemann (@Petzi1)
Code Reviewer: Sam Clarke-Green (@t00sa)

Updated refractive indices for ice and water are added. Scripts are added to calculate optical properties for spherical ice crystals and droplets using the updated refractive indices. The new optical properties are added to the ga9 and ga9_ref spectral files for research purposes: currently being used for journal articles in-prep at Leeds University.

Python scripts are updated for easy viewing of the optical properties and fits as well as a new script to plot comparisons of the refractive indices.

Some small code fixes are also included:

• Out-of-bounds in flexchem_input_mod
• Representation of bands > 999 in cloud_fit_90
• Expand dimension limits in dimensions_pp_ucf
• Remove obsolete unused routine read_schema_spectrum

• closes Include spherical ice-crystal optical properties in ga9 spectral files #10

Code Quality Checklist

(Some checks are automatically carried out via the CI pipeline)

• 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

Testing

• If shared files have been modified, I have run the UM and LFRic Apps rose stem suites
• If any tests fail (rose-stem or CI) the reason is understood and acceptable (eg. kgo changes)
• I have added tests to cover new functionality as appropriate (eg. system tests, unit tests, etc.)

• Socrates stand-alone quick_tests and slow_tests all pass.
• examples/ice_crystals/run_2022 has been modified to add tests for the new spherical ice-crystal calculations
• examples/droplets/run_ext has been added to calculate droplet parametrisations with the extended refractive index data

trac.log

No UM or LFRic files have been changed so UM/LFRic testing not required.

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

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