How to deal with models that have data in both nc and nc4 formats

[scotthosking]

..

[scotthosking]

I now check to see if a directory has multiple file types (e.g., nc and nc4). If so then we will receive an error and then can decide how to treat them (at least initially) on a case by case basis.

[scotthosking]

we should check that the nc and nc4 files cover the same period, and include the same values. If so, then just take one set (e.g. *.nc4).

[scotthosking]

CMIP5 EC-Earth is a good example where we have multiple files - incl. Var=psl, Model='EC-Earth', Experiment='historical'