[CF-metadata] Proposal for new standard_names for biomass burning emissions

From: Cameron-smith, Philip <cameronsmith1>
Date: Mon, 7 Jan 2013 22:03:01 +0000

See below.

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Dr Philip Cameron-Smith, pjc at llnl.gov, Lawrence Livermore National Lab.
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> -----Original Message-----
> From: Jonathan Gregory [mailto:j.m.gregory at reading.ac.uk]
> Sent: Saturday, January 05, 2013 6:16 AM
> To: Cameron-smith, Philip
> Cc: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] Proposal for new standard_names for biomass
> burning emissions
>
> Dear Philip
>
> > Jonathan: we already have std_names without a fixed ratio, although it isn't
> explicit in the descriptions (eg,
> atmosphere_mass_content_of_anthropogenic_nmvoc_expressed_as_carbon).
> Indeed, this is one of the main reasons people use the 'expressed_as' concept.
> >
> > I did note the tiniest inconsistency for the future. As proposed,
> NOx_expressed_as_NO is consistent with the current description "The phrase
> 'expressed_as' is used in the construction A_expressed_as_B, where B is a
> chemical constituent of A. It means that the quantity indicated by the standard
> name is calculated solely with respect to the B contained in A, neglecting all
> other chemical constituents of A."
> >
> > However, in the future someone may want NOx_expressed_as_NO2, and NO2
> is not entirely contained in NOx. To put it another way, the mass of the
> emission expressed as NO2 is larger than the mass of the actual NOx emission.
>
> I think your point is similar to what I was trying to say, but it might be that I don't
> understand this properly. I think nmvoc_expressed_as_carbon is fine.
> It just means we count up the C, never mind what compounds actually contain
> the C. I assume that nox_expressed_as_no means that we pretend all the N in
> the NOx is actually present as NO. Is that right? If so, I think it is well- defined,
> but it's a bit different from previous situations, where B is truly contained in A. C
> is truly contained in nmvoc.
>
> Best wishes
>
> Jonathan

Hi Jonathan,

I agree with you that both the proposed terms are well defined, logical, and won't lead to problems. I think it is straightforward and noncontroversial to think of NO being a subunit, and therefore contained, within all molecules of NOx :-).

I probably shouldn't have made my other comment about expressed_as_NO2 (note the 2) because it wasn't actually proposed, and was a fine point that probably wouldn't cause problems in practice anyway, since it would be clear to people what we really meant to say. We can also define that term more carefully if we ever need that term. Hence, this is not an issue that should delay acceptance of the proposed std_names, and I support the std_names as proposed.

Best wishes,

       Philip
Received on Mon Jan 07 2013 - 15:03:01 GMT