Alison Pamment CF Standard Names Status, Process and Development Alison Pamment

Overview  Current status of standard names  Process for agreeing standard names  Standard names committee  Design of standard names

Some Statistics  Latest version of the table dated 15 th May 2007  Currently 824 names in table  65 aerosol/chemistry names are ‘almost agreed’  A further 76 proposed names are under discussion

Search Search Standard NamesShow All Standard Names ANDOR Also search help text View by Category Atmospheric dynamics Ocean dynamics Carbon cycle Radiation Cloud Sea Ice Hydrology Surface Standard Name Canonical Units AMIPGRIB aerosol_angstrom_exponent air_potential_temperature 1 theta K13 zenith_angledegree

Standard Name Issues  UDunits.dat – need a CF specific version that supports dB, Sverdrups and psu  We need to increase the number of categories to add, e.g. aerosols  Need help in getting the PCMDI and GRIB equivalences up to date

Standard Name Process (1)  All proposals for new standard names must be made via the CF-Metadata mailing list (  Discussion of proposals takes place on the mailing list in public  The aim is to achieve community consensus

Standard Name Process (2)  There are guidelines for the construction of standard names (  The table is updated bi-monthly (Jan, Mar, …) on the 2 nd Tuesday of the month  Update details are published on the mailing list at least 7 days in advance (allows for last minute corrections/objections)

Standard Name Process (3)  Versioning of the standard name table was introduced in October 2006  The policy is that once names have been included in the table they will not be removed  Aliases are used to show equivalence between current names and older versions

Process Issues (1)  It can be difficult to keep track of discussions on the mailing list  Use the trac system on the website  Trac tickets won’t get lost!  Easier to see progress on each set of proposals  Trial period – 3 months?

Process Issues (2)  CF processes for agreeing change can be slow  ‘Fast track’ for new names that are very similar to existing names  BUT for new classes of names there is a need to do the ‘hard thinking’

 Decision making can be slow and this can slow down the whole process of agreeing standard names  What happens if we can’t reach a consensus?  Committee will need to vote Standard Name Committee

 When has consensus been reached?  Comment on proposals – if very few people join the discussions can we be confident that any consensus is representative?  Timescale for agreeing names  Arbitrary time limits are not helpful  BUT discussions should not be allowed to slide into dormancy Standard Name Committee

 What happens when an issue sits on the borderline between standard names and the wider conventions?  Need a mechanism for passing issues between committees so that ‘ownership’ is clear

Design of standard names (1)  Standard names are closely integrated with other data attributes  To interpret a parameter correctly need to check other parts of the metadata: cell_methods, coordinate variables, cell_bounds, cell_measures, units  Names themselves are noot constructed as a hierarchy

Design of standard names (2)  Ontologies are a hot topic! They need to capture the full semantic meaning of names and relationships between them  Does current design of standard names mean that ontologies are hard to build?  Or do we need more sophisticated tools for combining/interpreting the metadata?  Standard name design should not be changed without strong reasons

Summary  There is a strong demand for standard names  Standard name process is still under development  Standard name committee has an important role to play  Design of standard names should not be changed without strong reasons