Hello Heinke,
In principle, this is a good way to go and is a step to basing Standard Names on a semantic model, which Steve Hankin has been advocating for a while. The concern from my perspective is that I want to interoperate semantically with CF files - for example automatically generating an ISO19115 record from a directory full of CF. To do this with the physical and chemical components of the Standard Name I need a mechanism to tell me where both components are. As you rightly say, the 'common concept' would do the job.
Consequently, I see 'common concepts' as a blocker to our being able to decouple Standard Names into physical and chemical components. I also see Ticket 29 - the formalisation syntax for describing a common concept - as the blocker to 'common concepts'. Taking ticket 29 forward has been on my 'todo' list for far too long and I'm currently acquiring work faster than I'm clearing it. Is there anybody else willing to take a lead on this?
Cheers, Roy.
>>> Heinke Hoeck <heinke.hoeck at zmaw.de> 10/10/2008 8:02 am >>>
Dear all,
Martina Stockhause wrote:
>
> I apologize for this long list. My idea to move the name of the chemical
> constituent or aerosol from the standard name into an attribute was dismissed
> by the scientists. The disadvantage of a CF standard name without the
> constituent was larger than the advantage of a smaller number of CF standard
> names to be proposed.
>
>
I think it was a good idea to move the constituent into an attribute. If
we allow the
combination of physical quantity with the chemical constituent or
aerosol to construct
the cf standard name we will generate a very long list of new
cf-standard names (thousents).
The splitting could be done like the area_fraction with a coordinate
variable or scalar coordinate variable.
The list of allowed chemical constituent or aerosol should be limited.
I like to give an example (I don't know the IUPAC list, if 'ozone' is
not right, please correct it):
dimensions:
lat=72;
lon=124;
maxlen=30;
float quantity(lat,lon,height,time) ;
quantity:standard_name = "mass_fraction_of_constituent_in_air" ;
quantity:units = "1" ;
quantity:coordinates = "constituent" ;
char constituent(maxlen);
constituent:standard_name='IUPAC_system';
data:
constituent='ozone';
The list of valid constituent or aerosol could be SMILES, IUPAC or CAS.
Or the CF community build up
such list.
This is the same system Martin Suttie uses with the two tables. One
table with the physical
quantity would be the CF standard name and the second table would be the
variable with the
chemical constituents and aerosols.
If the community need the combination of both in one name in the header
the common concept
could be the solution. See track #24. But this is in work.
For example:
x:common_concept_urn = "urn:cf-cc:grib123";
x:common_concept_local = "{grib2.wmo}mass_fraction_of_ozone_in_air";
As a source to construct chemical cf standard name and to build up a
list of chemical constituent or aerosol
I like to propose:
http://wiki.esipfed.org/index.php/CF_Standard_Names_-_Construction_of_Atmospheric_Chemistry_and_Aerosol_Terms
It need an update but the I like the structure.
Best regards
Heinke
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Received on Fri Oct 10 2008 - 01:34:20 BST
