[CF-metadata] CF standard names for chemical constituentsandaerosols (resulting from a GRIB2 proposal)

Schultz, Martin m.schultz at fz-juelich.de
Fri Sep 26 00:49:49 MDT 2008

Hi Philip,

   thanks for this!  Very useful. I unanimously vote for the shorter and
more common names, but I support your suggestion to include the IUPAC names
in the description.  Concerning the "lumped" discussion, we should not loose
sight of what is happening on the GRIB2 front.  In the end I believe that th
harmonisation between GRIB2 and CF would weigh more than the best possible
definition. But if it is not too late to change the species codes in GRIB2
(once we will have closed this discussion) and they would be willing to
accept for example the "greater_C4" model, then this woul dbe fine with me.
Perhaps Martin Suttie, who is cc'd here can briefly state what the status of
the GRIB2 proposal is now and what flexibility for details remains?

Best regards,


-----Original Message-----
From: Philip J. Cameronsmith1 [mailto:cameronsmith1 at llnl.gov] 
Sent: Friday, September 26, 2008 1:47 AM
To: Jonathan Gregory
Cc: Martina Stockhause; Veronika Eyring; CF-metadata email list; Marco
Giorgetta; Olivier Boucher; Schultz, Martin; Sebastian Rast;
Martin.Suttie at ecmwf.int
Subject: Re: [CF-metadata] CF standard names for chemical
constituentsandaerosols (resulting from a GRIB2 proposal)

Hi Jonathan, et al.

In terms of IUPAC names, I assume you are referring to the following in
Martina's list:

formic_acid   (IUPAC = methanoic acid)
aceto_nitrile (IUPAC = ethanenitrile)
acetic_acid   (IUPAC = ethanoic acid)

However, the IUPAC names are less familiar to me (I had to look up
ethanenitrile) and, I suspect, less familiar to most chemists.  I also
understand that some of the common names (e.g. acetic acid) are actually
IUPAC-approved nonsystematic names.

Before making decisions on those, we might also consider the following
species in the Martina's list:

alpha_pinene (IUPAC = (1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene)
beta_pinene  (IUPAC = (1S,5S)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane)
limonene     (IUPAC = 1-Methyl-4-prop-1-en-2-yl-cyclohexene)
hcfc141b     (IUPAC = 1,1-Dichloro-1-fluoroethane)
hcfc142b     (IUPAC = 1-Chloro-1,1-difluoroethane)

In the future, there may also be oxidation breakdown products of all these
species for which the IUPAC name will get much longer.

Already accepted chemicals from the CF list (below) that are not IUPAC
systematic names include:

isoprene     (IUPAC = 2-Methyl-buta-1,3-diene)
various CFCs (IUPAC = ...)
formaldehyde (IUPAC = Methanal)
methyl bromide (IUPAC = Bromomethane)
xylene         (IUPAC = 1,4-dimethylbenzene)

My opinion is that CF should be somewhat pragmatic, and when common names
are significantly shorter and/or better known than the official IUPAC
systematic name, then I would suggest the common name be used (as has been
done in CF to-date).  However, I think it would be good to make sure for
species with both IUPAC and common names, that the one not used in the CF
standard name is included in the description.

Coming back to the question of which name to use for the three chemicals at
the top of my email: on balance, I would tip towards using the common names,
but would accept using the IUPAC names.

Best wishes, :-)


On Thu, 25 Sep 2008, Jonathan Gregory wrote:

> Dear Martina, Philip, et al.
> New chemical constituents: Are the names proposed the ones which are 
> used invariably or normally for these species? Are they consistent 
> with the choices that have been made for other species in existing 
> names? (I don't know enough about this to say.) We have had previous
discussions about using IUPAC names:
> they have the advantage of being a separately maintained standard, but 
> they may be too long. In any case, we should try to avoid using 
> different conventions for different species. For instance, we have 
> ethane, ethene, ethyne; ethanol is now proposed (all IUPAC, I believe) 
> - is "acetic" consistent with that? For reference, I append to this 
> email all the existing species names (in standard names containing the
word "mole" - possibly this doesn't pick up them all).
> "Lumped"/"total": At present, we have only two names with "total":
>  mole_fraction_of_total_inorganic_bromine_in_air
>  mole_fraction_of_total_reactive_nitrogen_in_air
> I understand "total" here to emphasise that we are considering the 
> total of the mole fractions of all the species which "qualify" as 
> inorganic bromine, or reactive nitrogen, species. Is that the same as what
you mean by "lumped"
> e.g. in "lumped_alkanes"? Why do we need "lumped" or "total"? Would it 
> be clear enough just to say mole_fraction_of_alkanes_in_air?
> Philip commented
>> 2) What is meant by 'expressed_as_carbon'?  Does it mean 'mass of 
>> carbon contained in species, ignoring all other chemical elements'?  
>> If so, would it be appropriate to put this into the units instead of the
standard name?
> Yes, "expressed_as" means the amount of X contained in all the 
> species, ignoring the rest. In fact, in most of the existing names 
> with expressed_as, it is moles, not mass e.g.
>  mole_concentration_of_diatoms_in_sea_water_expressed_as_nitrogen (mol 
> m-3) which means the moles of N per m3, I believe. We adopted this 
> convention after a lot of discussion. I think it is correct to include 
> it in the standard name; CF generally does not use the units for 
> indicating quantities. CF units are SI (or equivalent) and consistent with
the udunits package.
> I agree with Philip's comments about passive_ozone: passive tracers 
> are of course useful and need names, but it is likely we have to 
> consider each case carefully to find a clear name for it, because there
are many kind of "passive"
> in models. Could you describe what passive_ozone means in your
> Best wishes
> Jonathan
> existing CF species:
> alpha_hexachlorocyclohexane
> ammonium
> atomic_bromine
> atomic_chlorine
> atomic_nitrogen
> benzene
> bromine_chloride
> bromine_monoxide
> bromine_nitrate
> carbon_dioxide
> carbon_monoxide
> carbon_tetrachloride
> cfc11
> cfc113
> cfc113a
> cfc114
> cfc115
> cfc12
> chlorine dioxide
> chlorine monoxide
> chlorine_nitrate
> dichlorine peroxide
> dimethyl_sulfide
> dinitrogen_pentoxide
> ethane
> ethene
> ethyne
> formaldehyde
> gaseous_divalent_mercury
> gaseous_elemental_mercury
> halon1202
> halon1211
> halon1301
> halon2402
> hcc140a
> hcfc22
> hexachlorobiphenyl
> hydrogen_bromide
> hydrogen_chloride
> hydrogen_cyanide
> hydrogen_peroxide
> hydroperoxyl_radical
> hydroxyl_radical
> hypobromous_acid
> hypochlorous acid
> inorganic_chlorine
> isoprene
> methane
> methyl_bromide
> methyl_chloride
> methyl_hydroperoxide
> molecular_hydrogen
> nitrate
> nitrate_and_nitrite
> nitric_acid
> nitrite
> nitrogen_dioxide
> nitrogen_monoxide
> nitrous_oxide
> organic_detritus
> oxygen
> ozone
> peroxyacetyl_nitrate
> peroxynitric_acid
> phosphate
> phytoplankton
> propane
> propene
> silicate
> sulfur_dioxide
> toluene
> total_inorganic_bromine
> total_reactive_nitrogen
> xylene

Dr Philip Cameron-Smith        Atmospheric, Earth, and Energy Division
pjc at llnl.gov                   Lawrence Livermore National Laboratory
+1 925 4236634                 7000 East Avenue, Livermore, CA94550, USA
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