Aether cube sphere interface

[johnsonbk]

Description:

This feature branch contains the code for the aether_cube_sphere interface to DART. Completion of this interface is part of the deliverables for the funded project NSF20-519 Aether: A Flexible Community-Based Upper Atmosphere Ensemble Prediction System.

Fixes issue

This feature branch implements an interface to the Aether cube_sphere, addressing Issue #665.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [X] Documentation update

Documentation changes needed?

• [X] My change requires a change to the documentation.
  • [X] I have updated the documentation accordingly.

Tests

1. The model_mod passes all 7 tests in model-mod_check.
2. A link to restart block files are included in the documentation. A complete cycle of aether_to_dart, filter, and dart_to_aether runs without issue.
3. create_geometry_file runs and creates an appropriate geometry_file.nc needed by the model_mod.

Checklist for merging

• [ ] Updated changelog entry
• [X] Documentation updated
• [ ] Update conf.py

Checklist for release

• [ ] Merge into main
• [ ] Create release from the main branch with appropriate tag
• [ ] Delete feature-branch

Testing Datasets

• [X] Dataset download instructions included in the readme.rst with a link to all of the necessary files needed to run model_mod_check, aether_to_dart, dart_to_aether, create_geometry_file and filter.