Dear Christiane,
Thank you for your comments on the sulfate/nitrate names and the
"grouped" species.
> -----Original Message-----
> From: Christiane Textor [mailto:christiane.textor at lsce.ipsl.fr]
> Sent: 11 November 2007 16:16
> To: Pamment, JA (Alison); CF-metadata
> Subject: Re: Re. chemicals and aerosols
>
>
> MORE EXPLANATION for ionic aerosols needed, and this concerns not only
> the tendencies and opt. thickness, but also the variables for
> concentration.
>
>
tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_due_to_emissi
on
> :
> tendency_of_atmosphere_mass_content_of_ammonium_due_to_dry_deposition
>
tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_due_to_dry_de
po
> sition:
>
> tendency_of_atmosphere_mass_content_of_ammonium_due_to_wet_deposition
>
tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_due_to_wet_de
po
> sition
>
tendency_of_atmosphere_mass_content_of_sulfate_compounds_dry_aerosol_due
_t
> o_dry_deposition
>
> atmosphere_optical_thickness_due_to_nitrate_ambient_aerosol
> atmosphere_optical_thickness_due_to_sulfate_ambient_aerosol
> atmosphere_optical_thickness_due_to_ammonium_ambient_aerosol
>
As I understand it, the question is whether it makes sense to define
optical thicknesses due to nitrate, sulfate and ammonium aerosol when
these would not actually occur in the atmosphere as separate species but
rather as salts such as ammonium sulfate. There seems to be some
general confusion as to whether a term such as "sulfate" should be
interpreted as meaning only SO4 ions or SO4 in combination with other
ions such as ammonium.
>
> Suggestion for NOY:
>
tendency_of_atmosphere_mass_content_of_all_reactive_nitrogen_oxides_expr
es
> sed_as_nitrogen_due_to_dry_deposition:
>
tendency_of_atmosphere_mass_content_of_all_nitrogen_oxides_expressed_as_
ni
> trogen_due_to_wet_deposition:
I assume that the second name should also include the word "reactive"
like the first? Does "reactive" cover all those species that react,
however slowly, in air or only those that have some minimum reaction
rate?
>
> The species included can vary from model to model, sometime NOy is
used
> just as the sum of something not well known. It would possibly be good
> to modify the explanation to:
>
> NOy is the sum of all simulated oxidized reactive nitrogen species,
out
> of NO, NO2, HNO3, HNO4, HONO, NO3-aerosol, NO3(radical), N2O5, PAN,
> other organic nitrates, more detailed information should be given if
> needed. Expressed as mass of N.
>
Martin has suggested that the additional information, such as a list of
the included species, could go in the comment attribute of a CF file.
The comment attribute is not standardized in any way but I think it is
the only place to put such information at present. Would that meet your
needs?
>
> I would prefer to use "all" instead of "group" in the name as
suggested
> by Martin Schultz. "all" sound less limited than "group" which
suggestes
> a definite group and could lead to confusion.
>
I appreciate the need to be clear that we are not referring to one
defined group of species but rather a collection of species that can
vary between models. I wonder, though, if using "all" in the name gives
the impression that every model includes every possible species? Your
proposed definition
(
http://wiki.esipfed.org/index.php/CF_Standard_Names_-_
CF_Standard_Names_-_Submitted_Atmospheric_Chemistry_and_Aerosol_Terms)
says that these names are "the sum of all simulated oxidized nitrogen
species" so perhaps we don't actually need "all" or "group" in the name
itself. We could have:
tendency_of_atmosphere_mass_content_of_reactive_nitrogen_oxides_expresse
d_as_nitrogen_due_to_dry_deposition
tendency_of_atmosphere_mass_content_of_reactive_nitrogen_oxides_expresse
d_as_nitrogen_due_to_wet_deposition
and amend the definition slightly to read "the sum of all simulated or
observed oxidized nitrogen species" so that the same names could be used
for both models and observations. Do you agree?
>
> MORE EXPLANATIONS NEEDED Tendencies due to chemical reactions:
>
tendency_of_atmosphere_mole_concentration_of_ozone_due_to_chemical_gross
_p
> roduction
>
tendency_of_atmosphere_mole_concentration_of_ozone_due_to_chemical_gross
_d
> estruction
>
tendency_of_atmosphere_mole_concentration_of_methane_due_to_chemical_gro
ss
> _destruction
>
tendency_of_atmosphere_mole_concentration_of_carbon_monoxide_due_to_chem
ic
> al_gross_destruction
> see emails from Roy Lowry.
>
I've checked the mailing list archive for Roy's emails on this subject,
but I don't seem able to pinpoint the ones you are referring to. Please
could you send the links or forward the emails to me again.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 446314
Rutherford Appleton Laboratory Email: J.A.Pamment at rl.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
Received on Mon Nov 12 2007 - 17:06:00 GMT
