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 _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
