[CF-metadata] Representing statistics in CF

Jon Blower j.d.blower at reading.ac.uk
Fri Apr 28 09:09:58 MDT 2017

Dear Jonathan,

Many thanks for your reply. Looks like my case 2 (statistics over time) is pretty straightforward. But I’m afraid I don’t quite understand your suggestion for case 1 (ensemble statistics):

➢ You can do this with cell_methods in exactly the same way, "e: mean" and "e: standard_deviation" where e is the ensemble dimension. If you don't have an ensemble dimension, you could put "realization: mean" and "realization: standard_deviation", since "realization" is a standard_name for ensemble member designators.

In our case we don’t have an ensemble dimension (the individual realizations will be in different files). So I guess we are looking at your second suggestion. Could you help me understand the usage of “realization” please?

From the standard name table I can see that “realization” is intended to label a dimension. Given that each realization will be in a different file, does this mean that each file will have a “realization” dimension, whose corresponding coordinate variable contains a single value (the realization label)?

In this case, do the variables containing the ensemble mean and spread go in new files? I assume so, but then how do we associate the “realization” in the cell_methods of the statistical variables with the “realization” dimension of the individual files? (And, for that matter, is there a way of expressing that the individual realization files all belong to the same “dataset”?)

Best wishes,

More information about the CF-metadata mailing list