[CF-metadata] New standard names for atmospheric sea salt and for nitrogen deposition

alison.pamment at stfc.ac.uk alison.pamment at stfc.ac.uk
Mon Jun 26 05:04:32 MDT 2017

Dear Daniel,

Thank you for getting back to me. The three aliases for the nitrogen names are now accepted and will be included in today's update of the standard name table.

It would be useful to start a new thread so we can clarify the existing dry aerosol names.

Best wishes,

Alison Pamment                                                       Tel: +44 1235 778065
Centre for Environmental Data Analysis         Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory     
R25, 2.22
Harwell Campus, Didcot, OX11 0QX, U.K.

> -----Original Message-----
> From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf
> Of Daniel Neumann
> Sent: 22 June 2017 15:07
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] New standard names for atmospheric sea salt
> and for nitrogen deposition
> Dear Alison,
> Thank you for transferring the suggestions to proposal form and
> accepting most of the proposals.
>  > Please could you also check that you are happy with the amendments
>  > to your existing nitrogen names (discussed under proposal 13).
> You wrote:
>  > Okay, so I think these three names should now be as follows:
>  >
>  >
> tendency_of_atmosphere_mass_content_of_nitrogen_compounds_express
> ed_as_nitrogen_due_to_deposition
> (kg m-2 s-1)
>  > [...]
>  >
>  >
> tendency_of_atmosphere_mass_content_of_nitrogen_compounds_express
> ed_as_nitrogen_due_to_dry_deposition
> (kg m-2 s-1)
>  > [...]
>  >
>  >
> tendency_of_atmosphere_mass_content_of_nitrogen_compounds_express
> ed_as_nitrogen_due_to_wet_deposition
> (kg m-2 s-1)
>  > [...]
>  >
>  > The existing names would then become aliases of the new versions. Are
> these okay?
> OK, I am happy with the changes that you suggested. The new versions are
> not ambiguous anymore.
> Chloride::
> I wrote:
>  > > I would suggest to keep '_chloride_dry_aerosol_particles_' instead
> of changing it to '_dry_aerosol_particles_expressed_as_chloride_'. The
> formulation '_A_expressed_as_B_' seems to appropriate in situations, in
> which (a) B is a reasonable metric for A and (b) B is an element of
> which A consists:
>  > >   - '...sulfate...expressed_as_sulfur...' or
>  > >   - '...organic_matter...expressed_as_carbon...' .
>  > >
>  > > The particulate mass concentrations (and fractions) of nitrate and
> ammonium are denoted as '_nitrate/ammonium_dry_aerosol_particles_'.
> Although nitrate and ammonium are aerosols that consist of more than one
> atom, the naming convention for other ions, such as chloride, should be
> consistent.
> Alison wrote:
>  > The correct choice of syntax depends on what is intended by the
> name.  I would interpret
> mass_concentration_of_chloride_dry_aerosol_particles_in_air to mean the
> total mass of the aerosol particles that contain chloride (i.e. the mass
> of the chloride plus whatever else it is combined with). We do have
> quite a number of existing names like this, for example,
> atmosphere_mass_content_of_ammonium_dry_aerosol_particles. [...]
>  > You are correct that we do have some existing names for mass
> concentrations and fractions of nitrate|ammonium_dry_aerosol_particles
> and thank you for drawing these to my attention. I would interpret these
> in the way I explained above i.e. referring to the total mass of the
> particles containing the nitrate or ammonium. [...]
> I did not gasp that meaning of
> "mass_concentration_of_chloride|ammonium|nitrate_dry_aerosol_particle
> s_in_air"
> before. For the total mass of aerosol particles that contain chloride, I
> would have expected a standard name like
> "mass_concentration_of_dry_aerosol_particles_containing_chloride_in_air"
> .
> I also did not consider this interpretation because I see problems in
> the practical application of it. While it is useful to have a standard
> name for the dry aerosol particle mass of primary particles, i.e. dust,
> primary organic aerosol and sea salt, it is difficult to apply it to
> secondary particulate mass. Ammonium, nitrate, and partly sulfate often
> are secondary compounds - they condense as ammonium nitrate or
> ammonium
> sulfate (form after condensation of the respective gaseous acids/bases).
> Thus, I expect that we might find these compounds at nearly every
> particle in agriculturally and industrially used areas (correct me, if I
> am wrong). Therefore, I do not see an application for a standard name,
> which describes the mass of all particles that contain ammonium. As a
> results I did not expect this standard name to mean what it should mean.
> I hope I expressed it clearly/understandably.
> Alison wrote:
>  > The definitions of the existing names don't make that clear which
> actually makes them rather ambiguous. I think perhaps we should add 'The
> mass is the total mass of the particles' to those definitions, as for
> the mass content names, although this is something that probably needs
> wider consultation on the mailing list before making a decision.
> I agree. Could we consider to modify these standard names for
> clarification instead of just modifying the definitions? I could start a
> new thread at the mailing list "Clarifying standard names for
> 'mass_concentration_of_*_dry_aerosol_particles'".
> Alison wrote:
>  > In contrast, I would interpret
> mass_concentration_of_dry_aerosol_particles_expressed_as_chloride_in_ai
> r
> to mean the mass of only the chloride that is contained within the dry
> aerosol particles. I had assumed you meant the mass of only the chloride
> which is why I suggested the second option, but perhaps that is
> incorrect. Please can you clarify?
> Your assumption is correct. I would hesitate to introduce this
> formulation because I see a problem when we want to provide the mass of
> ammonium in dry aerosol particles expressed as nitrogen. We needed to
> call it
> "mass_concentration_of_dry_aerosol_particles_expressed_as_ammonium_
> expressed_as_nitrogen_in_air".
> I would be happy with another standard name. Would it be an alternative
> to write instead "mass_concentrations_of_particulate_chloride_in_air"?
> Best,
> Daniel
> --
> Daniel Neumann
> Leibniz Institute for Baltic Sea Research Warnemuende
> Physical Oceanography and Instrumentation
> Seestrasse 15
> 18119 Rostock
> Germany
> phone:  +49-381-5197-287
> fax:    +49-381-5197-114 or 440
> e-mail: daniel.neumann at io-warnemuende.de
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