Dear Daniel
OK. If experts are unanimous in their conviction that the existing names will
never be needed for the meaning that they appear to have, I agree that they
should become aliases of the new names, which convey the correct meaning.
I'm sure this change could be made. Alison Pamment is in charge of the updates
as you know and I expect she will consider as it soon as she has time. I think
that a complete list of the new and old names would be useful - that may
already be in one of your emails, perhaps.
Best wishes and thanks
Jonathan
----- Forwarded message from Daniel Neumann <daniel.neumann at io-warnemuende.de> -----
> Date: Wed, 3 Jan 2018 17:07:45 +0100
> From: Daniel Neumann <daniel.neumann at io-warnemuende.de>
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] Clarifying standard names for
> 'mass_concentration_of_*_dry_aerosol_particles'
> User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
> Thunderbird/52.5.0
>
> Dear Jonathan,
>
> > I understand. That's tricky, [...]
>
> Yes :-) .
>
>
> > We could define apple to mean orange in
> > future, for the sake of the existing datasets,
> > but only if we are certain that no-one will
> > ever want to talk about apples.
>
> I am not aware of any situation in which someone actually meant to
> talk about apples. Markus Fiebig from the World Data Centre for
> Aerosols wrote the same
> (http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2017/059588.html).
> I talked to two former colleagues, who confirmed it as well.
> Therefore, it is quite save to assume that nobody talks about
> apples.
>
>
> > We could just define and start using the new names,
> > and be aware that the CMIP5 datasets used the
> > wrong names (because the CF process somehow
> > made a mistake), without defining aliases. Would
> > that be acceptable?
>
> With respect to my personal usage of the respective standard names I
> am fine with just defining new standard names. I also see that it is
> the simplest solution for the moment considering the work effort
> needed to additionally define aliases.
>
> But, we might run into trouble (and cause confusion), if both
> standard names - apple and orange - are used to describe oranges.
> People, who used "apple" in the past, probably keep using "apple" to
> describe oranges because they are not aware of the changes. People
> who look up standard names for their new data sets might also end up
> with "apple" for describing an orange if "apple" is not marked as
> deprecated. Also people comparing data sets following the old and
> the new conventions (e.g. CMIP5 and CMIP6) might not be aware of
> this discussion. Hence, I would prefer to define aliases.
>
> Would it be feasible with respect to the required work, to define
> aliases for all the ambiguous standard names? How could I support
> this process? There seem to be 100 to 110 standard names involved:
>
> ? - atmosphere_mass_content_of_X_dry_aerosol_particles (15)
> ? - tendency_of_atmosphere_mass_content_of_X_dry_aerosol_particles*
> (78, maybe less)
> ? - mass_concentration_of_X_dry_aerosol_particles_in_air (15)
> ? - tendency_of_mass_concentration_of_X_dry_aerosol_particles_in_air (1)
>
>
> Best,
> Daniel
>
>
>
> On 03.01.2018 14:40, Jonathan Gregory wrote:
> >Dear Daniel
> >
> >>>>Is it feasible to rename all affected standard names?
> >>>It would be feasible (using aliases) but is it necessary? It seems to me that
> >>>your question has identified that there should be a distinction between e.g.
> >>> mass_concentration_of_particulate_X_in_air
> >>>and
> >>> mass_concentration_of_X_dry_aerosol_particles_in_air
> >>>for X=ammonium etc. These are different quantities: the former refers to the
> >>>mass of ammonium only, the latter to the dry mass of the aerosol of that type.
> >>>That is, we need new names for CMIP6, not aliases.
> >>Yes, there should be a distinction between both standard names.
> >>However, the latter name has been used as synonym for the first name
> >>up till now (e.g. in CMIP5 or in a data set I published recently).
> >>Additionally, the latter name has no real application - at least I
> >>am not aware of an application (neither for model nor for
> >>measurement data). Therefore, it might be reasonable for backward
> >>compatibility to use aliases.
> >I understand. That's tricky, because we've established that the second name
> >is a valid concept but not correct. When we use aliases, it's because we've
> >decided on a clearer, more consistent or more precise formulation of the
> >name, but in this case, it seemed that we called something an apple when
> >it ought to have been called an orange. We could define apple to mean orange
> >in future, for the sake of the existing datasets, but only if we are certain
> >that no-one will ever want to talk about apples.
> >
> >We could just define and start using the new names, and be aware that the
> >CMIP5 datasets used the wrong names (because the CF process somehow made a
> >mistake), without defining aliases. Would that be acceptable?
> >
> >Best wishes
> >
> >Jonathan
> >_______________________________________________
> >CF-metadata mailing list
> >CF-metadata at cgd.ucar.edu
> >http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
----- End forwarded message -----
Received on Wed Jan 03 2018 - 10:14:34 GMT
