I forgot: Please find a detailed description of the problem -- including
an explanatory plot -- here (login required):
https://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=readme_seasalt
I forgot that the following standard name types are also affected:
-
tendency_of_atmosphere_mass_content_of_*_dry_aerosol_particles_due_to_...
- mass_fraction_of_*_dry_aerosol_particles_in_air
Daniel
On 09.11.2017 15:52, Daniel Neumann wrote:
Dear List,
I would like to bring this treat back to attention to finalize it in
the one or another way. Further below are three suggestions ((a) to
(c)) on how to proceed.
There are standard name types:
- atmospheric_mass_content_of_X_dry_aerosol
- mass_concentration_of_X_dry_aerosol_in_air
-
atmosphere_mass_content_of_sulfate_dry_aerosol_particles_expressed_as_sulfur
They are used in (a few) CMIP5, in (a few) CMIP6, in my, and,
probably, in a lot of other data files.
The current status of discussion is that they DO NOT describe the "...
mass of X ..." but the "... the mass of all particles containing X
...". These are quite different meanings. In practice, these standard
names are used with the first meaning (at least CMIP5, CMIP6, my
data). In practice, the second meaning is not applicable. I am not
aware of any data set that uses one of these standard names 'correctly'.
Thus, the current status of the discussion is that the standard names
are generally wrongly used. What shall we do? Here are three options.
~~~~
The standard names do not 100% fit (if interpreted literally) to the
variables to which they are applied.
(a) Nevertheless we keep them as they are to remain consistent and to
avoid confusion. I volunteer to update the descriptions.
(b) We rename all these standard names (maybe 100 by number, probably
more).
(c) We keep these standard names as they are (and enforce their
literal meaning!) and create correct new standard names (maybe 100,
probably more).
~~~~
I am in favor of (a). Least work. Does not interfere with current usage.
The solution (b) would me a lot of hand work (if Batch processing of
CF-Standard Name list is not possible -- is it?). The solution (c)
would be quite bad (in my opinion): A lot of data set would not be
CF-compliant anymore because 'wrong' standard names were used.
Why do I insist on finalizing this discussion: I would like to propose
two new standard names, which are affected by this discussion.
Cheers,
Daniel
On 13.07.2017 18:23, Daniel Neumann wrote:
Dear Markus, Dear List,
Thank you for your feedback.
> doesn't make much sense beyond archiving a model output field since
it doesn't
> describe any quantity that could be readily observed. Also, the mass
> concentration of particles containing chemical X is somewhat
ill-defined. You
> will find some traces of X in almost all particles of an aerosol
containing X -
> so where is the threshold for saying that a particle contains X?
I agree with you.
Thus, it might be reasonable to introduce a new standard name (I like
the one you suggested. My idea for a name was more complicated :-) )
mass_concentration_of_X_in_dry_aerosol_particles_in_air
for (partly) secondary particulate species, namely nitrate, ammonium,
mercury, chloride, particulate organic matter, secondary particulate
organic matter and sulfate. For these species (except for chloride)
there exists already a standard name like
mass_concentration_of_X_dry_aerosol_particles_in_air
I think (please correct me if I am wrong) that
mass_concentration_of_X_dry_aerosol_particles_in_air
was meant to describe the same. Maybe one could make an alias from it?
Regards,
Daniel
On 12.07.2017 14:32, Markus Fiebig wrote:
Dear Daniel,
thanks for posting this again, I missed your first posting during
vacation.
Coming from the observation community, a name like
mass_concentration_of_X_dry_aerosol_particles_in_air
doesn't make much sense beyond archiving a model output field since
it doesn't
describe any quantity that could be readily observed. Also, the mass
concentration of particles containing chemical X is somewhat
ill-defined. You
will find some traces of X in almost all particles of an aerosol
containing X -
so where is the threshold for saying that a particle contains X?
To me, it would make much more sense to have names of the type
mass_concentration_of_X_in_dry_aerosol_particles_in_air
This type of name is less ambiguous to understand, and describes a
property that
can in fact be observed.
Best regards,
Markus
Am 11.07.2017 um 21:05 schrieb Daniel Neumann:
Dear CF-Meta Mailinglist,
I would like to advertise my long question from two weeks ago.
Maybe there
were no replies because it was to long :-) . Excuse me if I should
be wrong
with that assumption. The basic questions are:
What do these two standard names mean?
(a) mass_concentration_of_ammonium_dry_aerosol_particles_in_air
(b)
mass_concentration_of_dry_aerosol_particles_expressed_as_ammonium_in_air
What should be the standard name for the mass concentration of
atmospheric
particulate chloride/ammonium/nitrate/sulfate/...? Should it be
like (a), like
(b) or something else (e.g.
mass_concentrations_of_particulate_ammonium_in_air)?
Please find details on the question here:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2017/059573.html
Regards,
Daniel
On 27.06.2017 14:43, Daniel Neumann wrote:
Dear CF-Mailinglist,
in a recent proposal (link given below*), Alison and I discussed
about the
naming conventions for the mass of specific aerosol particle
components.
There seems to be clarification necessary in the descriptions
and/or names.
[* recent proposal with discussion:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2017/059522.html,
look for
"10. mass_concentration_of_chloride_dry_aerosol_particles_in_air
(kg m-3)"]
Currently, there exist standard names like
mass_concentration_of_ammonium_dry_aerosol_particles_in_air
mass_concentration_of_dust_dry_aerosol_particles_in_air
general form: mass_concentration_of_X_dry_aerosol_particles_in_air
which describe mass concentration of aerosol particles that
contain species
X. Thus, this standard name describes not only the mass of species
X but also
the mass of other species that are associated with X on particles.
In the
past, I thought it would describe the mass of species X only. We
think that
there is a need for clarifying this in the description of these
standard names.
When we now want to quantify the mass of particulate X only (e.g.
mass of
particulate chloride, mass of particulate ammonium), we could use the
standard name
mass_concentration_of_dry_aerosol_particles_expressed_as_X_in_air
However, I see two problems with respect to this naming
convention. First, we
get a not-nice name if we want to express the mass concentrations of
particulate ammonium in terms of nitrogen. We needed a standard
name like
mass_concentration_of_dry_aerosol_particles_expressed_as_ammonium_expressed_as_nitrogen_in_air
which contains 'expressed' twice.
Second (but that is my personal feeling only), I use the
"X_expressed_as_Y"
formulation only, when there is some relation from Y to X. Or in
other words:
when Y is a reasonable measure for X.
...organic_matter_..._expressed_as_carbon...
...nox_expressed_as_nitrogen...
...phytoplankton_expressed_as_phosphorus...
Therefore,
"mass_concentration_of_dry_aerosol_particles_expressed_as_X_in_air"
is not a
good choice for a standard name describing the mass of particulate
X in my
opinion.
An alternative would be to introduce a standard name like
mass_concentrations_of_particulate_X_in_air
mass_concentrations_of_particulate_ammonium_in_air
mass_concentrations_of_particulate_chloride_in_air
What is your opinion on this topic?
Best Regards,
Daniel
--
Dr. Markus Fiebig
Senior Scientist
Dept. Atmospheric and Climate Research (ATMOS)
Norwegian Institute for Air Research (NILU)
P.O. Box 100
N-2027 Kjeller
Norway
Tel.: +47 6389-8235
Fax : +47 6389-8050
e-mail: [email protected]
skype: markus.fiebig
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--
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
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