[CF-metadata] what standard names are for

Jonathan Gregory j.m.gregory at reading.ac.uk
Thu Apr 10 01:37:36 MDT 2008


Dear Martin

I believe there used to be an xsd file for the standard_name xml file. Perhaps
Velimir (copied) knows where it is?

I sympathise with the need for equivalences to CF metadata and that is of
course why the PCMDI and GRIB equivalences were set up in the first place.
However, I would say there are two reasons why putting equivalences in the
standard_name xml file is not the best approach:

* There is probably not a one-to-one correspondence between your variables
and standard names. I expect some of your variables might imply other CF
metadata as well, as is the case with some of the PCMDI and GRIB codes. This
is not recorded in the standard_name xml file, but it is noted in the separate
tables for GRIB codes and PCMDI names at
http://cf-pcmdi.llnl.gov/documents/cf-standard-names/
e.g. tas means not just air_temperature, but implies a vertical coordinate.

* The equivalence between your variables and CF metadata is not really part
of the CF convention, although it facilitates the use of CF, and it seems a
arbitrary to include equivalences to a selection of other conventions.

As I mentioned, for these reasons I think we should remove the AMIP and PCMDI
equivalences from the table. In any case, they are not being maintained and
are out of date, and probably wrong for some GRIB codes.

I feel that a better approach is to have a separate xml/html table for the
equivalence between CF metadata (not just standard names, but standard name
+ other metadata, more like common concepts) and other metadata, one for each
standard (GRIB, AMIP, HTAP, aerocom, etc.). These tables could be linked to
the CF site and would not be upset by updates to the standard name table,
because we never *delete* standard names, so the equivalences would always
remain valid.  Do you think that would work? 

I am sure that others have good ideas about this, having thought about mappings
and ontologies and how they should be maintained.

Best wishes

Jonathan



More information about the CF-metadata mailing list