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

From: Daniel Neumann <daniel.neumann>
Date: Thu, 22 Jun 2017 16:06:50 +0200

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_expressed_as_nitrogen_due_to_deposition
(kg m-2 s-1)
> [...]
>
>
tendency_of_atmosphere_mass_content_of_nitrogen_compounds_expressed_as_nitrogen_due_to_dry_deposition
(kg m-2 s-1)
> [...]
>
>
tendency_of_atmosphere_mass_content_of_nitrogen_compounds_expressed_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_particles_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_air
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
Received on Thu Jun 22 2017 - 08:06:50 BST

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