[CF-metadata] Getting back to ensembles

From: Jonathan Gregory <j.m.gregory>
Date: Tue, 28 Nov 2006 16:02:15 +0000

Dear Paco

> What is not so clear to me is whether attributes such as "institution"
> or "source" or the one mentioned by Jamie "experiment_id" would be
> allowed as auxiliary variables, "realization" being for me the
> coordinate variable. Their inclusion in the list of accepted standard
> names would be the best for me

I think that would be fine, myself. Bryan has a reservation about calling
them standard names, and I can see that this is a bit different from many
standard-named quantities, but on the whole I feel we don't need a distinction
since they are formally similar.

> However, the use of external
> dictionaries poses certain problems, as discussed.

I would suppose that external dictionaries would be a further optional
feature. That is, you can supply that attribute to point to a list of
standardised values for the particular quantity (such as institution), but
otherwise its values are not standardised. For the sake of self-description,
the values of the quantity should be as intelligible as possible without
an external dictionary.

In your example, I think that experiment_id, source, realization and
institution should be listed in the coordinates attribute of the data
variable, since they are auxiliary coordinate variables. Also, I would
suggest that the units of leadtime are just days, not "days since ...",
because forecast period is an elapsed time, rather than an encoded time/date,
isn't it?

Best wishes

Jonathan
Received on Tue Nov 28 2006 - 09:02:15 GMT