Hi,
It has been a while since we had all of these disucssions, and I have
forgotten many of the detailed decisions, but below is what I recall about
the level concensus we reached....
On Fri, 20 Feb 2009, Martina Stockhause wrote:
Dear Alison,
regarding the thread "CF standard names for chemical constituents and
aerosols":.
I think we agreed on the new physical quantities, for the chemical names I am
not sure.
Then the discussion shifted towards the more general topic of how to integrate
chemical CF standard names in future and afterwards to general construction
rules for all kinds of CF standard names.
My original proposal got a bit lost in these general discussions. Therefore I
would like to focus on the chemical names again.
1. Physical Quantities
In the mails from the 24.10.2008 we agreed on:
tendency_of_atmosphere_mass_content_of_X_due_to_respiration : kg.m-2.s-1
tendency_of_mole_concentration_of_X_in_air_due_to_chemical_gross_production :/
/mol.m-3.s-1
tendency_of_mole_concentration_of_X_in_air_due_to_chemical_gross_destruction
:/
/mol.m-3.s-1
density_of_surface_area_of_X, m-1, This is the surface area of aerosol per
volume of atmosphere (i.e. /m2.m-3=m-1)/
I agree that there seemed to be general agreement on physical
quantities, although I cannot remember all the final candidates.
2. Chemical Quantities
For the new chemical species I am not that sure. I recall a discussion
about 'lumped' but cannot remember an agreement. The full list of names
for chemical species can be found in the wiki:
http://
wiki.esipfed.org/index.php/CF_Standard_Names_-_Construction_of_Atmospheric_Chemistry_and_Aerosol_Terms
Regarding my proposal, I tried to keep track and the new names I found
in my files are:
atomic_oxygen
nitrate_radical
nitrous_acid
radon
methyl_peroxy_radical
methanol
formic_acid
aceto_nitrile
ethanol
acetic_acid
butane
alpha_pinene
beta_pinene
limonene
hcfc141b
hcfc142b
nitric_acid_trihydrate_aerosol
hox_expressed_as hydrogen
total_peroxy_radical
passive_ozone
noy_expressed_as_nitrogen
clox_expressed_as_chlorine
brox_expressed_as_bromine
lumped_alkanes
lumped_alkenes
lumped_aromatic_compounds
lumped_terpenes
nmvoc_expressed_as_carbon
anthropogenic_nmvoc_expressed_as_carbon
biogenic_nmvoc_expressed_as_carbon
lumped_oxygenated_hydrocarbons
A) There seemed to be acceptance for the idea that "IUPAC names were
desirable, but that common names would be acceptable if they are well
known and shorter than the IUPAC names". There was universal agreement
that in this case the full IUPAC name should go into the description.
B) There was a discussion which noted that _expressed_as_ could be
shortened to _as_. However _expressed_as_ is already in 9 standard names,
and is slightly clearer to a reader who is unfamiliar with CF. The
opinions seemed to fall on both sides of the argument, but didn't seem to
be very strong. Personally I suggest we continue with _expressed_as_, but
I don't feel strongly.
C) There was a lot of discussion about 'lumped' quantities. After much
discussion there seemed to be general acceptance that such terms were
needed. However, I don't think we ever came to a consensus as to how
exactly to name them. The four main possibilities I recall were:
1) use 'lumped_', e.g. lumped_alkanes
2) avoid 'lumped_', e.g. alkanes
3) explicitly include a simplified description of which species are
included, eg 'lumped_alkanes_carbons_3+' for alkanes with 3 or more
carbons. (This is potentially important because different groups often
include very different sets of species in their lumped groups.)
4) As 3, but without 'lumped_'
Personally I favor option 3 because otherwise it will be too likely that
different quantities will be compared by accident. However, there were
suggestions that distinctions could be made in some other attribute.
D) A similar set of issues applied to 'passive_ozone' as to the lumped_
species. I think there was general acceptance that there should a specie
(or species) separate from ozone, but the question of how to distinguish
the different types of passive_ozone was never resolved. The options for
'passive_' species were similar to the options for 'lumped_' species, but
got mired in more complexity.
Since the meaning of such variables are likely to be fairly specific to
each intercomparison, would it make sense to deliberately NOT define a
standard name at all, in which case each intercomparison can save such
variables into their files without a standard name? It'll still mean
something to the participants of the intercomparison.
3. Construction of "chemical CF names"
The discussion about a naming convention and construction guideline for
chemicals and aerosols is summed up by Christiane in the wiki:
http:// wiki.esipfed.org/index.php/Modfication_of_existing_CF_standard_names.
The status there is:
<physical quantity>_of_<chemical quantity>_due_to_<process>
e.g.
tendency_of_atmosphere_mass_content_of_nox_expressed_as_nitrogen_due_to_emission
The position of <medium> is not absolutely clear, I would think:
<physical quantity>_of_<chemical quantity>_in_<medium>_due_to_<process>
If it is not a medium like "air" but a part of the earth system like
"atmosphere" it is not agreed (as far as I know), whether it should be
placed like the medium or in front.
Actually, the chemical names in the CF construction guideline
http:// cf-pcmdi.llnl.gov/documents/cf-standard-names/guidelines are a
bit out-dated and needs to be revised or replaced by a link to the above
mentioned wiki page of the chemists.
What is still open to me (or I missed the agreement), is the question of
whether the CF standards names with each individual chemical species are
part of the CF convention or only the physical quantities and processes
with a place-holder for the chemical quantity.
Heinke proposed a possibility how we could deal with the place-holder
(she called "constituent") in netCDF-headers, about which I could not
find a real discussion,
http:// mailman.cgd.ucar.edu/pipermail/cf-metadata/2008/002421.html:
dimensions:
lat=72;
lon=124;
maxlen=30;
float quantity(lat,lon,height,time) ;
quantity:standard_name = "mass_fraction_of_constituent_in_air" ;
quantity:units = "1" ;
quantity:coordinates = "constituent" ;
char constituent(maxlen);
constituent:standard_name='IUPAC_system';
data:
constituent='ozone';
I recall that there was a lively discussion about several different
alternatives which finally fizzled out with a final conclusion. I think
fatigue with the chemistry terms set in.
I recall that main options were:
1) keep the 1D (or flat) list of standard names, with the <quantity>_of_X
type constructs used for easy generation and approval of each individual
quantity.
2) have a limited 2D standard name structure, in which standard names
would be approved with an 'X' as a wild-card that could be replaced with
any specie from a separate list of species. In this case, adding a specie
to the list would automatically imply acceptance of all the standard names
with X replaced by that species.
3) A dynamic scheme in which the 'X' is NOT replaced by the specie names
in the standard names, but rather the X is specified in another attribute
or variable, such as the example above from Heinke.
4) Karl Taylor made a proposal that appeared to be more far reaching, but
I confess I don't recall the details.
As a separate issue, there was also a suggestion that instead of a single
list of species, there would be additional lists for gas phase, aerosol,
and possibly other groupings, so in addition to X there would be G, A, and
other wild cards. This would avoid some non-useful possibilities, eg
'surface area of CO2', but in practice the person producing a dataset
would never use it, so I personally don't see that the complication is
worth the effort.
Best wishes,
Philip
I hope to revive the discussion to reach an agreement of this rather old
thread as well, at least on the first and second parts (1. and 2.).
Best wishes,
Martina
Pamment, JA (Alison) wrote:
Dear All,
Over recent weeks there has been a large number of proposals for new
standard names. To help keep track of them all I have prepared a brief
summary of the currently open standard names discussion threads. The
proposals are listed in date order (oldest first). If any set of
proposals has been missed from this list please let me know and it will
be added.
The next update of the standard name table will take place on 10 March.
This will definitely go ahead as there are agreed names waiting for
inclusion. A complete list of the new names and other planned
modifications to the table will be published in advance of the update.
I have recently been concentrating on the various sets of ocean related
proposals, the majority of which are now agreed. The oldest, and by far
the largest, of the remaining threads is that relating to the set of
chemical names originally proposed by Martina Stockhause. I would like
to take the same approach with the chemistry names as I have with the
ocean names, i.e. review several threads in tandem, as this helps to
keep track of any issues affecting more than one set of names. Most
recently, various sets of names have been proposed relating to the CMIP5
work and these need to be addressed on a relatively short timescale.
Therefore, over the next few weeks I will be dividing my time mainly
between the chemistry names and the various CMIP5 threads.
As there is currently much activity in the area of standard names I will
publish another summary status report in two weeks time to give an
update on the situation.
Best wishes,
Alison
Thread(s): CF standard names for chemical constituents andaerosols
(resulting from a GRIB2 proposal); CF: new names for atmospheric
chemistry and aerosols; CF standard names for chemical constituents
andaerosols; standard names for chemistry - MCM
Proposer: Martina Stockhause
Date proposed: 18 Sep 2008
Number of names (approx.): 2 800
Project(s): GRIB2
Status: Open, currently being reviewed
Thread(s): Standard name(s) needed for satellite-based icedrift products
Proposer: Thomas Lavergne
Date proposed: 24 Oct 2008
Number of names (approx.): 6
Project(s):
Status: Open, mostly agreed, definitions still under discussion
Thread(s): new named fields for ocean
Proposer: Stephen Griffies
Date proposed: 6 Nov 2008
Number of names (approx.): 60
Project(s): CMIP5
Status: Open, most names agreed
Thread(s): CF standard names for echam5-hammoz
Proposer: Heinke Hoeck
Date proposed: 7 Nov 2008
Number of names (approx.): 90
Project(s): echam5-hammoz model (aerosol-chemistry-climate)
Status: Open, currently being reviewed
Thread(s): new names for AeroCom - optcial properties; new names for
AeroCom - cloud properties; new names for AeroCom - mass / mole /
number; new names for AeroCom - tendencies; new names for AeroCom -
remaining; new names for AeroCom
Proposer: Christiane Textor
Date proposed: 23 Nov 2008
Number of names (approx.): 50 (total for all threads)
Project(s): AeroCom; HTAP; AC&C
Status: Open, currently being reviewed
Thread: Proposed CF standard names for the NEMO oceanmodel
Proposer: Ian Culverwell
Date proposed: 26 Nov 2008
Number of names (approx.): 3
Project(s): NEMO
Status: Open, all names now accepted
Thread: Proposal for new CF standard_names, ocean biochemistry
Proposer: Bruce Hackett
Date proposed: 28 Nov 2008
Number of names (approx.): 13
Project(s):
Status: Open
Thread: Mixing Ratio
Proposer: Heinke Hoeck
Date proposed: Nov 2008 (arising from earlier thread 'new standard names
for ECHAM5/CLM/ERA')
Number of names (approx.): 1
Project(s):
Status: Open
Thread: new standard names for atmospheric dynamics
Proposer: Martin Schultz
Date proposed: 14 Jan 2009
Number of names (approx.): 8
Project(s): ECHAM
Status: Open
Thread: Some new standard names for ocean model fields
Proposer: Adam Blaker
Date proposed: 20 Jan 2009
Number of names (approx.): 14
Project(s):
Status: Open, all names now accepted
Thread: New Cryospheric variables
Proposer: Siobhan O' Farrell
Date proposed: 22 Jan 2009
Number of names (approx.): 130 (of which some appear to be quantities
already in the standard name table)
Project(s): CMIP5
Status: Open, currently being reviewed
Thread: Some new standard names for cloud feedback study
Proposer: Tomoo Ogura
Date proposed: 26 Jan 2009
Number of names (approx.): 33
Project(s): CMIP5
Status: Open, currently being reviewed
Thread: Emissivity not found in the current standard name table
Proposer: Won, Young-In
Date proposed: 29 Jan 2009
Number of names (approx.): 3
Project(s): AIRS (Atmospheric Infrared Sounders)
Status: Open, currently being reviewed
Thread: Proposal for new standard names (this thread relates to cloud
radiative properties)
Proposer: Alejandro Bodas-Salcedo
Date proposed: 11 Feb 2009
Number of names (approx.): 38
Project(s): CFMIP-2/CMIP5
Status: Open, currently being reviewed
Thread: new variables (this thread contains heat flux and friction
names)
Proposer: Christof Luepkes
Date proposed: 11 Feb 2009
Number of names (approx.): 5
Project(s):
Status: Open
------
J Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 446314
Rutherford Appleton Laboratory Email: [email protected]
Chilton, Didcot, OX11 0QX, U.K.
--
--- CliSAP - Integrated Climate Data Center ---
Martina Stockhause
University of Hamburg
CliSAP
Grindelberg 5
D-20144 Hamburg
Germany
phone: +49-40-42838-7582
FAX: +49-40-42838-7711
e-mail: [email protected]
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[email protected] Lawrence Livermore National Laboratory
+1 925 4236634 7000 East Avenue, Livermore, CA94550, USA
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