I meant to post the following message to the list, as well as the individual recipients.
> -----Original Message-----
> From: Pamment, Alison (STFC,RAL,RALSP)
> Sent: 20 January 2016 12:23
> To: 'Jonathan Gregory'
> Cc: mreuter at iup.physik.uni-bremen.de; Michael.Buchwitz at iup.physik.uni-
> bremen.de; Veronika.Eyring at dlr.de; Bennett, Victoria (STFC,RAL,RALSP)
> Subject: RE: [CF-metadata] New standard names for ESA GHG CCI quantities
>
> Dear Jonathan,
>
> I agree that we don't usually combine "atmosphere" and "in_air" in the
> same name. My reason for doing it in this case was because the original
> proposal specified two conditions:
> 1) dry air;
> 2) column average quantity (therefore not local).
> I needed to find some way of including both in the name. However, it may
> be that we don't need the "dry" bit at all, in which case we could just go
> with atmosphere_mole_fraction_of_methane and
> atmosphere_mole_fraction_of_carbon_dioxide, and there is no problem. If
> it really is important that we specify "dry" for these quantities, perhaps a
> better solution would be to put it at the start of the name, thus,
> dry_atmosphere_mole_fraction_of_methane and
> dry_atmosphere_mole_fraction_of_carbon_dioxide. Does that look better?
>
> Best wishes,
> Alison
>
> > -----Original Message-----
> > From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On
> Behalf
> > Of Jonathan Gregory
> > Sent: 19 January 2016 16:55
> > To: cf-metadata at cgd.ucar.edu
> > Subject: [CF-metadata] New standard names for ESA GHG CCI quantities
> >
> > Dear Alison
> >
> > In existing names we generally use "atmosphere" to indicate a property of
> > the
> > atmosphere as a whole (or a large portion of it) and "in_air" to indicate a
> > local property within the atmosphere. We don't use both phrases at once.
> > These
> > quantities can be regarded as means of local properties, I think, so just
> > in_air would be sufficient. If no vertical coordinate is specified, it should
> > apply to the entire atmosphere, but to make that clear a cell_method
> could
> > be
> > added to record that it's a vertical mean.
> >
> > Best wishes
> >
> > Jonathan
> >
> > ----- Forwarded message from alison.pamment at stfc.ac.uk -----
> >
> > > Date: Tue, 19 Jan 2016 16:39:38 +0000
> > > From: alison.pamment at stfc.ac.uk
> > > To: cf-metadata at cgd.ucar.edu
> > > CC: Veronika.Eyring at dlr.de, victoria.bennett at stfc.ac.uk,
> > > mreuter at iup.physik.uni-bremen.de,
> > > Michael.Buchwitz at iup.physik.uni-bremen.de
> > > Subject: [CF-metadata] New standard names for ESA GHG CCI quantities
> > >
> > > Dear All,
> > >
> > > I have been asked to re-propose two standard names that were
> originally
> > proposed by Maximilian Reuter in 2014 but which did not receive any
> > comments at the time: http://mailman.cgd.ucar.edu/pipermail/cf-
> > metadata/2014/057373.html.
> > >
> > > I have rephrased the original proposal to make the names more CF like
> > and have added some standard definition text, so the names are now
> > proposed as follows:
> > > atmosphere_mole_fraction_of_methane_in_dry_air (canonical units: 1)
> > > 'Mole fraction is used in the construction "mole_fraction_of_X_in_Y",
> > where X is a material constituent of Y. A chemical species denoted by X
> may
> > be described by a single term such as "nitrogen" or a phrase such as
> > "nox_expressed_as_nitrogen". The "atmosphere mole fraction" of a
> > quantity refers to the column average from the surface to the top of the
> > atmosphere. Methane is a member of the group of hydrocarbons known as
> > alkanes. There are standard names for the alkane group as well as for
> some
> > of the individual species. The chemical formula for methane is CH4.'
> > >
> > > atmosphere_mole_fraction_of_carbon_dioxide_in_dry_air (canonical
> > units: 1)
> > > 'Mole fraction is used in the construction "mole_fraction_of_X_in_Y",
> > where X is a material constituent of Y. A chemical species denoted by X
> may
> > be described by a single term such as "nitrogen" or a phrase such as
> > "nox_expressed_as_nitrogen". The "atmosphere mole fraction" of a
> > quantity refers to the column average from the surface to the top of the
> > atmosphere. The chemical formula for carbon dioxide is CO2.'
> > >
> > > These names reflect the original proposal, and generally follow the
> syntax
> > of existing names such as mole_fraction_of_carbon_dioxide_in_air. I have
> > prepended these names with the word "atmosphere" as a way of
> indicating
> > a column amount, similar to existing atmosphere_mass_content names.
> > >
> > > We don't currently have any "dry_air" names in CF. When this topic last
> > came up on the mailing list (as far back as 2008 under the thread entitled
> > "mixing ratio") it was concluded that the current "in_air" names don't tie
> the
> > definition down to either dry or ambient air. The reason for this
> (deliberate)
> > vagueness is that numerically the quantities in dry or moist air are not very
> > different except in the case of water vapour itself where we define
> > humidity_mixing_ratio to mean " ratio of the mass of water vapor to the
> > mass of dry air". The gist of the 2008 conversation was that if we ever
> > needed to be very precise about making the distinction between ambient
> > air and dry air then we would be able to introduce appropriate names at a
> > later stage, but there wasn't a pressing need at the time. An offline
> > conversation I had more recently with Jonathan Gregory and Martin
> Schultz
> > went along similar lines, basically saying that we wouldn't change any
> > existing names where the deliberate impre
> > ci
> > > sion isn't important, but reiterating that we could introduce new names
> if
> > there are cases where it does matter, specifying dry or ambient.
> > >
> > > Please could Maximilan, Veronica or another member of the CCI team
> > answer the question about whether there is a real need to specify
> "dry_air"
> > in the case of these names, or can we get away with being a bit more
> vague?
> > If vagueness is OK, then the names would simplify to
> > atmosphere_mole_fraction_of_methane_in_dry_air and
> > atmosphere_mole_fraction_of_carbon_dioxide. Also, do others agree
> with
> > my using "atmosphere" here to indicate the column average? All
> comments
> > are welcome.
> > >
> > > Best wishes,
> > > Alison
> > > _______________________________________________
> > > CF-metadata mailing list
> > > CF-metadata at cgd.ucar.edu
> > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >
> > ----- End forwarded message -----
> > _______________________________________________
> > CF-metadata mailing list
> > CF-metadata at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Received on Wed Jan 20 2016 - 05:26:25 GMT
