Hi Christiane,
I think you are misunderstanding what I am saying. It is not whether the species title is included in the Standard Name, but more about the how it gets there and the nature of the Standard Name itself. At the moment we manage Standard Names as simple text strings but it is possible to consider them as an ontology class built from other classes by rules. For example we could have a 'chemical concentration Standard Name' subclass built by concatenation from 'concentration type' and 'chemical species' subclasses. You still get a bit of text in the CF file Standard Name field looking like they do now but they have been built with much less effort and in a much more robust manner.
This is a significant change to what we do now and needs significant thought plus a proposal document. I raised the issue now because I think it can be addressed by the same technology as Frank/Michael's need to have CF understand terms like '2m wind' that combine information from multiple CF attributes and so maybe we can solve both problems at once.
Cheers, Roy.
>>> Christiane Textor <christiane.textor at lsce.ipsl.fr> 07/19/07 11:42 AM >>>
Hello,
I think the huge number of possible species and the different names
possible to describe them have lead to confusion in the past.
Therefore, the fact of having many species is a PRO, not a CONTRA to
include these names in CF (as long as it is feasible). This will avoid
confusion in the future.
Cheers,
Christiane
Roy Lowry a ?crit :
> Hello Jonathan,
>
> This opens up the issue of basing Standard Names on some sort of semantic model. It's not just number of names - which is greater than Philip imagines because we are supporting multiple concentration parameters (v/v, moles/v etc.) - but issues like spelling errors creeping in (I have always found organic nomenclature to be much more error prone than other text) and the need to link to chemistry domain standards as recently raised by Christiane.
>
> One possibility would be to link consideration of this issue to the CF controlled vocabulary proposal that Frank recently put forward leading to the development of ontological support for CF. If people think this is a good way to go then I'll try and find some time to take it forward with Frank (get a Trac proposal going) when we're both around in early August.
>
> Cheers, Roy.
>
>>>> Jonathan Gregory <j.m.gregory at reading.ac.uk> 07/16/07 11:07 PM >>>
> Dear Philip
>
>> First, the list of CF standard names will ultimately become very long
>> (with concentrations, tendencies, emissions, depositions, and many other
>> quantities for each species)
>
> I agree that if we carry on as we are presently working, we could add hundreds
> of names to the standard name table for chemistry. I don't think that is in
> itself a problem, though, so long as it is easy to search the table, and it's
> available in machine-readable form for programs.
>
>> Second, unless proposers are very diligent, or there is some mechanism to
>> avoid it, there will end up being a lot of 'holes' in the convention.
>> For example, long lists of wet_deposition_of_X, and emission_of_Y, could
>> be added, but with X and Y being different sets which only partially
>> overlap.
>
> Yes, but that also doesn't necessarily matter, does it? We already have plenty
> of holes like that in other areas, because we have not added names until some-
> one has needed them. One way in which holes may be a problem is that when you
> find one you need to be filled, you have to request a new name. But if it is
> an obvious interpolation, there should be no problem with including it.
>
>> Would it make more sense to represent chemical quantities under CF by
>> splitting the standard name into two pieces, e.g. 'Quantity_of_X' and
>> 'X_is_species_name' ?
>
> We could do something like that. For consistency with other similar cases,
> we would make one of them a coordinate variable with string values. I expect
> that in some chemistry models there are data variables which have a dimension
> in chemical species, and this approach would represent that kind of
> organisation. We have started to do this with land-surface types. However,
> I do not actually think we need to do it for chemical species, because they
> are generally well-defined and discrete, even though numerous. Land-surface
> types are rather more model-dependent and so far we have not standardised them;
> it is convenient to put the non-standardised part of the quantity in a
> coordinate variable.
>
> Best wishes
>
> Jonathan
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>
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Christiane Textor
Laboratoire des Sciences du Climat et de l'Environnement
Unite Mixte de Recherche CEA-CNRS-UVSQ
LSCE, CEA Saclay
L'Orme des Merisiers, Bat. 701 Piece 3b
mailto: christiane.textor at lsce.ipsl.fr
Tel ++33 1 69 08 34 07
F-91191 Gif-sur-Yvette Cedex
FRANCE
GEOMON scientific project manager http://www.geomon.eu
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Received on Thu Jul 19 2007 - 09:12:00 BST
