Improve HRRR-Zarr demo program

[amotl]

Dear Brian,

while working on adding a HRRR-Zarr access use-case to GH-153, I took the chance to update the example stub you've provided.

• load_dataset accounts for the projection details.
• load_combined_dataset accounts for the directory layout regarding the extra level of nesting for the main data variable.

The gist is from ¹, thanks a stack to the original author(s) ².

With kind regards,
Andreas.

Footnotes

1. https://mesowest.utah.edu/html/hrrr/zarr_documentation/html/xarray_one_day_analysis_example.html ↩ ↩²

2. I have not been able to discover the author(s) of those resources, so I co-attributed it ¹ to @taylorgowan. Is it correct, or has it actually been you, or maybe another co-author of one the papers that have been published in this space? ↩

[blaylockbk]

Good question.
@taylorgowan I'm 99% certain you authored the example notebook referenced. Is that correct? Are there other notebooks/authors that should be referenced?

@amotl I learned about xarray datatree at the AMS meeting last week. I understand it can read multi-nested zarr groups. Perhaps that can be used here?

[amotl]

I learned about xarray datatree at the AMS meeting last week. I understand it can read multi-nested zarr groups. Perhaps that can be used here?

Interesting. Thanks. My intention was to bring in a canonical example how to read HRRR-Zarr from the resources which are already there. I think it can be worth to evaluate if the same can be achieved with more modern libraries on another iteration, or by providing an alternative example.

Parts of this code will converge into GH-153 anyway, but I thought it would be a could idea to provide a standalone version on behalf of this patch, for others to pick up from the Herbie code base.

Because this is code which will probably be staged elsewhere within Herbie, I think this file will go away on a subsequent iteration.