Add cesm2_albedo artifact

[imreddyTeja]

See related ClimaLand PR here

Originally, ClimaLand was using esw_albedo_Amon_CESM2_historical_r1i1p1f1_gn_185001-201412_v2.nc, which is now replaced with sw_albedo_Amon_CESM2_historical_r1i1p1f1_gn_185001-201412_v2_no-nans.nc, which is exactly the same.

There was a python script we had that created a similar file from different datasets. The script calculate_sw_alb.jl is based on this. It has a some manual assignment of variable attributes to make the output file the exact same as the existing
sw_albedo_Amon_CESM2_historical_r1i1p1f1_gn_185001-201412_v2_no-nans.nc, for which we do not have a generating script. The file the script generates in nearly identical to the original, except some of the variable attributes are saved in different orders, and some of the overall file attributes are different. This is possibly because this script uses Julia's NCDatsets, while the other script uses python's xarray. This should have no impact on ClimaLand's use of the file.

We had an existing Julia script to create bareground_albedo.nc. Slight modification was required to make it run without error. In particular
ds2.attrib = ds.attrib was removed, and
sw_alb = ds["sw_alb"][:] was changed to sw_alb = Array(ds["sw_alb"])

The resulting file is still exactly the same as the original. File equivalence was checked using ncompare and with a for loop, which checks each variable's data, dimensions, and attributes for equivalence. The overall file attributes were also compared.
Checklist:

• I created a new folder $artifact_name
  • I added a README.md in that that folder that
    • describes the data and processing done to it
    • lists the sources of the raw data
    • lists the required citation, licenses
  • If applicable (e.g., for Creative Commons), I added a LICENSE file
  • I added the scripts that retrieve, process, and produce the artifact
  • I added the environment used for such scripts (typically, Project.toml
    and Manifest.toml)
  • I added the OutputArtifacts.toml file containing the information
    needed for package developers to add $artifact_name to their package
• I uploaded the artifact folder to the Caltech cluster (in
  /groups/esm/ClimaArtifacts/artifacts/$artifact_name)
• I added the relevant code to the Overides.toml on the Caltech Cluster
  (in /groups/esm/ClimaArtifacts/artifacts/Overrides.toml)
• I added a link to the main README.md to point to the new artifact

[juliasloan25]

This looks great, thank you Teja! After adding the CESM license and updating some typos/outdated text this will be good to merge

[juliasloan25]

I'm surprised we can still use this syntax - I thought it got replaced with Array(ds["lat"]), but maybe that's for variables not dimensions? No need to change it, just something I noticed

[juliasloan25]

Looks good to squash and merge! Thank you Teja :)