[CF-metadata] When are the units attribute mandatory?

From: Egil Støren <egil.storen>
Date: Thu, 16 Feb 2012 16:00:40 +0100

 From the CF 1.6 Convention, chapter 3.1 Units:

"The units attribute is required for all variables that represent
dimensional quantities (except for boundary variables defined in Section
7.1, ?Cell Boundaries? and climatology variables defined in Section 7.4,
?Climatological Statistics?)."

In the same document, in appendix H.3.4. Contiguous ragged array
representation of profiles, the following example appears:

       int profile(profile) ;
           profile:cf_role = "profile_id";

This array obviously contains identification numbers. It is also a
dimensional quantity and accordinly the units attribute is mandatory
(none of the listed exceptions apply). Are there any unit acceptable by
udunits that can be used in this case? The best I have found is "count"
which I think is misleading.

Or should this and similar variables also be included in the list of
exceptions above?

Best regards,

    Egil St?ren
    met.no
Received on Thu Feb 16 2012 - 08:00:40 GMT