Consider adding domain as a global attribute generally

[matthew-mizielinski]

This would be "global" for CMIP6 data, but would be clearer when regional data is addressed

[matthew-mizielinski]

@MartinaSt @durack1 as discussed

[taylor13]

In my proposal, this would be identified as the "dataRegionalDD" (regional data descriptor). I think "domain" is determined by both the geographical region and the "area type" (e.g., land or sea only), as specified in the cell_methods "where" directive. I have suggested the "area type" be recorded in "areaLabelDD". So domain = dataRegionDD +
"areaLabelDD".

[durack1]

@taylor13 this is where the discussion went this am, regarding #10 (which admittedly is somewhat of a dupe of this issue)