Dear All,
Following my last posting in this thread, and the emails I sent asking
for assistance with the spreadsheet, I have received several helpful
responses which have cleared up a number of the areas still under
discussion. Many thanks to all those who replied. I have realised that
the responses came to me directly, rather than via the list, so in the
following I have tried to draw together all the relevant comments. I
have also produced another version of my spreadsheet based on the
responses received from Martin and Christiane. Rather than post it as
an attachment, I have placed a copy on the CF trac wiki at
https://cf-pcmdi.llnl.gov/trac/wiki. The file is called
grib2_chem_names_2.xls and can be downloaded by anyone. I have put some
more detailed comments about the spreadsheet at the end of this message.
Please note that I will move the issue of passive_ozone to a separate
thread, as I think it may generate quite a lot of discussion.
***
Martina wrote:
> thanks for your summary and bringing this thread close to an
agreement.
> I asked Christiane and Martin as chemists to reply as well. Thank you
both!
>
> For those of you, who are interested, the GRIB-proposal is available
at:
>
http://www.wmo.int/pages/prog/www/WMOCodes/Updates/GRIB2/GRIB2preoperati
onal28102008.pdf
***
Alison wrote:
>
> 1. Regarding the physical quantities in Martina's original proposal, I
> think many of the outstanding issues have been resolved. The
following
> is a summary of the situation:
Martina wrote:
> Your suggestions are all fine. For these yearly averaged quantities we
will have to specify this in our GRIB
> table, but you are probably right that these averaging does not belong
in the CF standard name.
***
Alison wrote:
>
> > tendency_of_atmosphere_mass_content_of_X_due_to_respiration :
> kg.m-2.s-1
> Early in the discussion Jonathan asked whether 'respiration' should
> specify heterotrophic, plant or soil as in existing respiration names,
> or whether your names represent the total. I'm not sure that this
> point was answered - Martina, please can you confirm which is the
> correct definition?
Martina wrote:
> It should be the same as in the existing definition.
At present we have three respiration names in the table:
heterotrophic_respiration_carbon_flux, plant_respiration_carbon_flux and
soil_respiration_carbon_flux, all with different definitions. I think
this is what prompted Jonathan's initial question. If your names refer
simply to 'respiration' would it be safe to assume they represent the
sum of the individual processes?
***
Alison wrote:
>
> > tendency_of_mole_concentration_of_X_due_to_chemical_gross_production
> :
> mol.m-3.s-1
> This has been agreed with the addition of 'in_air' as follows:
>
tendency_of_mole_concentration_of_X_in_air_due_to_chemical_gross_produc
> t
> ion.
>
> >
tendency_of_mole_concentration_of_X_due_to_chemical_gross_destruction
> : mol.m-3.s-1
> This has been agreed with the addition of 'in_air' as follows:
>
tendency_of_mole_concentration_of_X_in_air_due_to_chemical_gross_destru
> c
> tion.
Christiane wrote:
> > tendency_of_mole_concentration_of_X_due_to_chemical_gross_production
> >
tendency_of_mole_concentration_of_X_due_to_chemical_gross_destruction
>
> I THINK WE HAVE TO ADD THE PREFIX ATMOSPHERE_ TO BE CONSISTENT WITH
OTHER NAMES
The proposed units for these names are mol m-3 s-1, so I think they are
3D fields and it is correct to add 'in_air' as previously discussed.
Martina, please can you confirm this point?
***
Alison wrote:
> > surface_area_density_of_X : m-1
> It was agreed to modify these names to read
> density_of_surface_area_of_X (m-1). The definition of the physical
> quantity is 'the surface area of aerosol per unit volume of
> atmosphere'.
Christiane wrote:
> > surface_area_density_of_X
>
> I THINK WE HAVE TO ADD THE PREFIX ATMOSPHERE_ TO BE CONSISTENT WITH
OTHER NAMES
Thanks for spotting that we have not specified the medium in these
names. As with the gross_production|destruction names I think we need
to decide if these names describe a vertically integrated quantity or a
full 3D field. We should then either prefix with atmosphere_ or add
in_air to the names, as appropriate. Martina, please can you comment?
***
Alison wrote:
> The quantities under
> discussion are X_mole_flux (in the 'Modification of some existing CF
> standard names for chemical constituents'/'CF: surface flux versus
> emissions' threads) and atmosphere_optical_thickness (in the ECHAM5-
> hammoz thread). I think we need to resolve the separate threads
before
> reaching a final decision on those particular names.
> Christiane wrote:
> IT WOULD BE GREAT IF YOU COULD PROVIDE A SUMMARY FOR THESE NAMES
INCLUDING OTHER NAMES FOR AEROSOLS AS WELL.
> YOUR SUMMARIES ARE EXTREMELY HELPFUL !
Martina wrote:
> X_mole_flux / surface_X_mole_flux / surface_upward_X_flux_in_air /
surface_upwelling_X_flux_in_air /
> tendency_of_atmosphere_moles_of_X_due_to_emission:||
> I have a surface_X_mole_flux quantity, which is derived from the
existing surface_carbon_dioxide_flux. There
> are similar constructing methods for surface fluxes in use, however I
like the "tendency"
> description because of the consistency with the tendencies for
mass_content (
> tendency_of_atmosphere_mass_content_of_X_due_to_emission ).
I have tried to summarize the situation regarding, respectively, aerosol
quantities and atmosphere optical thickness, in two postings to the
ECHAM-Hammoz thread. Please see
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2009/002817.html and
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2009/002818.html.
Jonathan has since sent me (via email) some more comments on this
subject which I will also forward to the list under the ECHAM-Hammoz
thread. I have not yet produced a summary of the mole_flux discussion
but I will try to do that soon.
***
Alison wrote:
>
> Martina's list includes names of tendencies due to the processes
> net_production and net_production_and_emission. The latter is used in
> two existing standard names while the former is not currently used in
> the table, but I see no problem in including it as a separate process.
> We have now agreed in this thread to add the processes
> chemical_gross_production and chemical_gross_destruction and this
> prompted me to look back at the (lengthy) discussion of chemical names
> we had in 2007 when Christiane proposed net_production for use with
the
> HTAP names. Originally, Christiane proposed to use
> chemical_net_production but the word 'chemical' has been dropped from
> the two names already in the table. I couldn't find any discussion of
> dropping 'chemical' and I now think this may have happened
accidentally
> when I added the names to the table. I suggest, therefore, that
> aliases should be created for the two existing names to change
> net_production_and_emission to chemical_net_production_and_emission
and
> that the word 'chemical' should be added to Martina's 'net_production'
> proposals to make them consistent with the gross
production/destruction
> names. I'd welcome any comments on this, particularly if anyone can
> recall any agreement to drop 'chemical' from the names.
>
Christiane wrote:
> THERE HAD BEEN A DISCUSSION LAUNCHED IN JULY 2007 (20/07/2007 02:12)
BY Philip CAMERON ON 'GROSS PRODUCTON' I
> AM NOT SURE IF THIS ISSUE HAS BEEN RESOLVED.
>
> I AGREE THAT 'CHEMICAL' HAS JUST BEEN FORGOTTEN, I WENT THROUGH MY OLD
EMAILS.
>
> I SUGGEST TO MODIFY
> chemical_net/gross_production_and_emission TO net/gross_chemical
production_and_emission
Martina wrote:
> due_to_chemical_net_production_and_emission (adding the "chemical") is
fine for me.
OK, thanks - we are agreed to use 'chemical' in the gross production
names and add it to the net production names. I agree that Christiane's
suggestion of re-ordering the words is an improvement. So we will now
have names of the form
tendency_of_atmosphere_mass_content_of_X_due_to_net_chemical_production
tendency_of_atmosphere_mass_content_of_X_due_to_net_chemical_production_
and_emission
tendency_of_atmosphere_mass_content_of_X_due_to_gross_chemical_productio
n
tendency_of_atmosphere_mass_content_of_X_due_to_gross_chemical_destructi
on.
Columns for all these processes now appear in the spreadsheet.
In addition, the following two aliases will be created:
tendency_of_atmosphere_mass_content_of_particulate_organic_matter_dry_ae
rosol_due_to_net_production_and_emission becomes
tendency_of_atmosphere_mass_content_of_particulate_organic_matter_dry_ae
rosol_due_to_net_chemical_production_and_emission
tendency_of_atmosphere_mass_content_of_secondary_particulate_organic_mat
ter_dry_aerosol_due_to_net_production becomes
tendency_of_atmosphere_mass_content_of_secondary_particulate_organic_mat
ter_dry_aerosol_due_to_net_chemical_production
Regarding, Philip's discussion of 'gross production', the question was
about the definition of the term, particularly in relation to ozone. I
think that Philip stated the question very clearly in his posting:
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2007/001788.html.
Philip also said in a later posting
(
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2007/001913.html):
> On the issue of ozone GROSS production and loss which I raised in
> (http://www.cgd.ucar.edu/pipermail/cf-metadata/2007/001788.html) I am
conflicted. This is a useful and commonly
> reported variable, but the
> definition is not universally agreed upon. In practice, experts
generally use definitions that are within the same
> ball-park as each other, but an outside user could be led astray, and
judicious care needs to be used when comparing > figures from different
models. Whether this is enough to stop it being accepted by CF, I don't
know.
Jonathan responded to this by saying
(
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2007/001914.html):
> I don't know the details of this case, of course, but I don't think
that's a reason not to include a name for ozone > gross production. If
it is useful to compare quantities from different datasets for certain
purposes, even though
> they may have somewhat different definitions, then it will be useful
to assign them a common name to indicate they
> are comparable. That is the main purpose of standard names. To avoid
misunderstanding, the definition could state
> what distinctions are being ignored. For more exacting applications in
which the differences of definition are
> material, alternative more precisely phrased standard names could be
devised.
Philip
(
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2007/001915.html)
agreed with Jonathan's suggestion.
This leads me to ask whether defining gross_production|destruction is
particularly problematic in relation to ozone, or whether we need to
think carefully about its definition in all cases. We have already
agreed that the definitions for 'group' species need to be carefully
written to say how precisely/loosely the individual quantities are
defined. Do we need to take a similar approach with
gross_production|destruction? Of course, the standard name definitions
would not give details of which specific chemical reactions are included
or excluded, but they would alert data producers of the need to provide
additional information (and data consumers would know to check for that
information).
***
> > 2. NEW chemical constituents:
Alison wrote:
>
> > atomic_oxygen
>
> We already have 5 names in the standard name table that refer simply
to
> 'oxygen', presumably in its molecular form. As we will now be
> introducing 'atomic_oxygen' should we create aliases for these older
> names by replacing 'oxygen' with 'molecular_oxygen'? This would then
> also be consistent with existing and proposed 'molecular_hydrogen'
> names.
Christiane wrote:
> WHAT IS ATOMIC OXYGEN : O2 ? THEN IT SHOULD BE MOLECULAR OXYGEN, IF IT
IS JUST O, IT SHOULD BE OXYGEN RADICAL.
Martina wrote:
> oxygen / molecular_oxygen:
> I like the latter because it is more precise and distinguishable from
atomic_oxygen.
Sorry, but I'm now rather confused about the oxygen species. If I
understand correctly, both Martina and Christiane would be in favour of
creating aliases for the existing oxygen names:
fractional_saturation_of_oxygen_in_sea_water
mass_concentration_of_oxygen_in_sea_water
moles_of_oxygen_per_unit_mass_in_sea_water
temperature_of_sensor_for_oxygen_in_sea_water
volume_mixing_ratio_of_oxygen_at_stp_in_sea_water
by replacing 'oxygen' with 'molecular_oxygen'.
Then there is the question of 'atomic_oxygen' in Martina's proposed
names. Martina, please can you clarify whether you are proposing O or
O2 names? Would Christiane's suggestion of oxygen_radical be a more
appropriate term for your names?
***
>
> > nitric_acid_trihydrate_aerosol
> In the discussions under the ECHAM5-Hammoz and 'Modification of some
> existing CF standard names for chemical constituents' threads it has
> been agreed that all aerosol names should specify either 'dry' or
> 'ambient' aerosol. Martina, please could you specify which is correct
> for this species? (The definitions of 'dry' and 'ambient' aerosol are
> given below for reference).
>
Martina wrote:
> nitric_acid_trihydrate_aerosol:
> This is ambient and therefore nitric_acid_trihydrate_ambient_aerosol
OK, thank you. This species is agreed. I have added it to the
spreadsheet.
***
Alison wrote:
>
> This point about the aerosol names also affects some of the existing
> chemical species that appear in Martina's proposals. In the
> 'Modification of some existing CF standard names for chemical
> constituents' thread it was agreed that all older 'aerosol' standard
> names (which existed before the dry/ambient aerosol distinction was
> introduced) should be made aliases of 'ambient_aerosol' names. Thus
> mass_fraction names for pm1_aerosol, pm10_aerosol and pm2p5_aerosol
> will be changed to refer to pm1_ambient_aerosol, etc. The names in
> Martina's proposals should also specify ambient or dry. Is it fair to
> say that these size distribution names will always be 'ambient'?
Martina wrote:
> pm..._aerosol:
> These are dry and therefore pm10_dry_aerosol, pm2p5_dry_aerosol and
pm1_dry_aerosol.
Christiane wrote:
> I just realized that I disagree with Martina on pm aerosol names:
> Martina says:
> "These are dry and therefore pm10_dry_aerosol, pm2p5_dry_aerosol and
pm1_dry_aerosol"
>
> I do not agree on this: the PMs are not dry, but ambient (in the US),
or at 50% RH (in Europe) according to
> the regulations - I think. Need to check this.
Just to clarify, the pmX species appear in only six existing standard
names:
atmosphere_optical_thickness_due_to_pm10_ambient_aerosol
atmosphere_optical_thickness_due_to_pm1_ambient_aerosol
atmosphere_optical_thickness_due_to_pm2p5_ambient_aerosol
mass_fraction_of_pm10_aerosol_in_air
mass_fraction_of_pm1_aerosol_in_air
mass_fraction_of_pm2p5_aerosol_in_air
It was agreed under the 'Modification of some existing CF standard names
for chemical constituents' thread that the three mass_fraction names
would be changed to pmX_ambient_aerosol. The definitions also clearly
refer to ambient aerosol, for example, the definition of
mass_fraction_of_pm10_(ambient)_aerosol_in_air reads:
"Mass fraction is used in the construction mass_fraction_of_X_in_Y,
where X is a material constituent of Y. It means the ratio of the mass
of X to the mass of Y (including X). "Aerosol" means the suspended
liquid or solid particles in air (except cloud droplets). "Ambient
aerosol" is aerosol that has taken up ambient water through hygroscopic
growth. The extent of hygroscopic growth depends on the relative
humidity and the composition of the aerosol. "Pm10 aerosol" is an air
pollutant with an aerodynamic diameter of less than or equal to 10
micrometers. To specify the relative humidity and temperature at which
the particle size applies, provide scalar coordinate variables with the
standard names of, respectively, "relative_humidity" and
"air_temperature".
The question now is whether pmX should be 'dry' or 'ambient' in
Martina's proposed names. I did a quick search on the web and it seems
that most health regulations regarding limits on the concentrations of
various particle sizes do refer to ambient conditions. Also, sampling
techniques for atmospheric aerosol seem to assume some water content.
However, I am not the expert here so I'd welcome further advice on this
point. I think the main question is whether the particles are generally
assumed to be dry or ambient in the models that are presumably the
source of the GRIB 2 data. If both measures are required, then we could
introduce names for both dry and ambient aerosol.
***
Alison wrote:
>
> > noy_expressed_as_nitrogen : All nitrogen oxides (NOy) expressed as
> nitrogen
> The group of species here referred to as noy is already in the
standard
> name table using the term 'reactive_nitrogen'. For example, we have
> the name mole_fraction_of_total_reactive_nitrogen_in_air defined as
> 'Mole fraction is used in the construction mole_fraction_of_X_in_Y,
> where X is a material constituent of Y. "Reactive nitrogen", sometimes
> referred to as Noy, describes a family of chemical species. The family
> usually includes atomic nitrogen (N), nitrogen monoxide (NO), nitrogen
> dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3),
> peroxynitric acid (HNO4), bromine nitrate (BrONO2) and chlorine
nitrate
> (ClONO2).'
Martin wrote:
> ** I think you forgot the organic nitrates (notably PAN = peroxyacetyl
> nitrate = CH3COO2NO2) in this definition. There is a slight
distinction as
> to how NOy is defined in the troposphere and stratosphere. We can
safely
> take an inclusive approach here: BrONO2 doesn't matter in the
troposphere
> and PAN doesn't matter in the stratosphere, so it is safe to include
both in
> the definition.
Thank you for the additional information. I will include it in the
definition.
Alison wrote:
> There is only one reactive_nitrogen name in the table. We could
choose
> either to create an alias for that one name and change it to use
'noy',
> or we could change Martina's proposals to use the term
> 'reactive_nitrogen'. I have no strong preference for either term and
> would be happy to go with the majority view.
Martin wrote:
> I would suggest to use noy: "reactive nitrogen" is more ambigious as
this
> is sometimes used to label NOx (which is NO+NO2) instead. But as long
as we
> have a comprehensive definition sentence attached, I have no strong
> preference.
OK, thank you. Based on these comments, noy_expressed_as_nitrogen is
accepted for use in the standard name table and I have added it to the
spreadsheet. I will create an alias so that
mole_fraction_of_total_reactive_nitrogen_in_air becomes
mole_fraction_of_noy_expressed_as_nitrogen_in_air.
***
>
> > hox_expressed_as_hydrogen : HOx radical (OH+HO2)
> > clox_expressed_as_chlorine : Total inorganic chlorine except HCl,
ClONO2: ClOx
> > brox_expressed_as_bromine : Total inorganic bromine except HBr,
BrONO2: BrOx
There has been no further comment on 'expressed_as', or on these
particular species. These group species names are accepted for use in
the standard name table and I have added them to the spreadsheet. The
species definitions will be those provided above.
***
Alison wrote:
> > nmvoc_expressed_as_carbon : Non-methane volatile organic
compoundsexpressed as carbon
> > anthropogenic_nmvoc_expressed_as_carbon
> > biogenic_nmvoc_expressed_as_carbon
>
> Martina provided the following definitions during the discussion:
> 'anthropogenic' refers to chemical constituents influenced, caused, or
> created by human activity; 'biogenic' refers to chemical constituents
> generated by natural processes; 'oxygenated' means 'containing
oxygen'.
Martina wrote:
> nmvoc is a group of species but well defined as non-methane volatile
organic compounds.
I think we have agreed the names of these three groups and I have added
them to the spreadsheet. Regarding the definition - does the list of
species included in nmvoc vary widely from one model to another? Are
there certain species that are always included?
Martin wrote:
> I would like to see additional "sectors" added to the list (as per
> suggestion of Angelika Heil for IPCC emissions, for example). This
would be
> a specification of some "anthropogenic" sectors, such as
> "surface_transport", "air_transport", "international_ship_transport",
> "energy_production", "industrial_processes",
> "residential_and_commercial_processes", "waste_handling_and_storage",
>. "agricultural_activities", "agricultural_waste_burning", and also
>"biomass_burning".
I am sure that we can discuss the addition of these anthropogenic
processes to standard names. Are you thinking of names of the form
tendency_of_atmosphere_mass_content_of_anthropogenic_nmvoc_expressed_as_
carbon_due_to_agricultural_processes, for example? I think the way to
add such names would be via the 'due_to_process' syntax, but we'd have
to be careful about phrases like 'surface_transport' because 'transport'
already has a physical definition in standard names.
It is likely that a number of names along the lines you are suggesting
will be proposed shortly for carbon cycle quantities within the CMIP5
project. I am expecting proposals of the form:
tendency_of_atmosphere_mass_content_of_carbon_dioxide_due_to_process,
where the list of processes will include a number of human activities
such as biomass burning and deforestation. In the meantime, if you would
like to propose some more names of this type please send them to the
list in the usual way.
***
Alison wrote:
>
> > total_peroxy_radical: Total inorganic and organic peroxy radicals
(HO2 + RO2)
> > lumped_alkanes
> > lumped_alkenes
> > lumped_aromatic_compounds
> > lumped_terpenes
> > lumped_oxygenated_hydrocarbons
>
> Philip commented that, notwithstanding the
> difference in concept between 'total' and 'lumped', standard names
> should employ only one term - 'total' - because that would be less
> ambiguous for non-experts, or alternatively we should avoid entirely
> the use of any 'grouping' term. Jonathan agreed with the latter
> suggestion.
> If we were to adopt this suggestion, aliases would need to be created
> for the two existing 'total' names. I.e. they would become
> mole_fraction_of_inorganic_bromine_in_air and
> mole_fraction_of_reactive_nitrogen|noy_in_air. Additionally,
Martina's
> 'lumped' species above would become:
> alkanes
> alkenes
> aromatic_compounds
> terpenes
> oxygenated_hydrocarbons
> and total_peroxy_radical would become simply peroxy_radical.
> I would welcome further comments regarding this suggestion. In
> particular, would the names without 'lumped' be acceptable in the
> context of GRIB2? One last point: I think that, no matter which
> terminology we choose to adopt, the definitions of all group species
> standard names should contain a statement of how precisely or vaguely
> the group is known.
Martin wrote:
> I agree - fine for me to use the "simple" terminology, but important
to
> have a good definition statement attached.
Martina wrote:
> lumped: I like the suggestion of just leaving out the "lumped", whose
definition depends on the chemical model
> used.
OK, thank you. We are agreed! The species
alkanes
alkenes
aromatic_compounds
terpenes
oxygenated_hydrocarbons
peroxy_radical
are accepted for use in the standard name table and I have added them to
the spreadsheet.
'RO2' (used in the definition of peroxy_radical) will in turn be defined
as 'all organic peroxy radicals'.
The existing name mole_fraction_of_total_inorganic_bromine_in_air will
become mole_fraction_of_inorganic_bromine_in_air.
***
Please can anyone comment on the following species:
>
> I have a couple of questions regarding the relationships between some
> new species in Martina's list and some that already exist in the
table:
>
> hexachlorocyclohexane/alpha_hexachlorocyclohexane:
>
> We already have names in the table that refer to
> alpha_hexachlorocyclohexane and Martina's proposals include more names
> for that species, plus names that refer simply to
> 'hexachlorocyclohexane' (i.e., no isomer specified). Please can you
> confirm whether that was intentional (i.e. I want to check that both
> sets of names are needed and it isn't just a by-product of generating
> the new names with a script).
>
> ammonium/ammonium_dry_aerosol:
>
> Again I just wanted to check that these are different species, i.e,
are
> there other forms of ammonium in the atmosphere besides dry_aerosol?
> Does ammonium include ammonium_dry_aerosol?
>
>
***
> > 3. NEW CF standard names:
Martina wrote:
> > The individual CF standard names, resulting from the combination of
> physical
> > quantity and chemical constituent or aerosol, are quite many (see
> attached
> > file).
> >
> > I apologize for this long list. My idea to move the name of the
> chemical
> > constituent or aerosol from the standard name into an attribute was
> dismissed
> > by the scientists. The disadvantage of a CF standard name without
the
> > constituent was larger than the advantage of a smaller number of CF
> standard
> > names to be proposed.
> >
> > Since I had to use a script for the generation of these individual
CF
> names,
> > there might be some names in the list, which doesn't make sense.
> Therefore a
> > counter-check is necessary and highly appreciated.
>
Alison wrote:
> To assist in identifying the valid combinations within this set of
> proposals I have prepared an Excel spreadsheet containing physical
> processes as column headings and species as row headings. I have
begun
> to populate the cells of this spreadsheet, for example, I have marked
> where the names proposed from the combination of process and species
> are already in the table. I have marked as 'OK' those cells where the
> combination can be accepted immediately for inclusion in the standard
> name table - these consist mostly of the various measures of abundance
> such as mass_fraction, atmosphere_mass_content, etc. I would greatly
> appreciate some help in populating the remainder of the spreadsheet
> with 'YES' or 'NO' entries indicating whether particular combinations
> are possible. In one or two instances I have written comments
> regarding specific names. Please note that at present I have not
> included in the spreadsheet any species or process names that are
still
> under discussion in this thread (i.e., the 'lumped' and grouped
> species, 'pmx_aerosol'
> and 'passive_ozone' and the net_production, respiration,
> optical_thickness and mole_flux processes).
>
Martin wrote:
> PS: I had a go at your excel sheet. Please note that I did not work on
> "re-emission" at all. For "gross_production" and "gross_destruction" I
>. entered only those terms which I think may be used. Certainly, many
other
> species will undergo chemical formation or destruction, but if we want
to
> stick with "sensible" CF names, then we should probably add others as
the
> need arises. As long as people don't invent completely new names when
they
> only want to add a new species, this should be easy.
Christiane wrote:
> Please find my comments to the Excel sheet in the attachment. I have
added the information I know for sure,
> but it is far from being complete. Empty cells therefore just mean 'no
info given'. Please highlight the
> changes (in Tools/Track Changes) to see my modifications.
>
Many, many thanks to you both for your help. I have added your changes
into my spreadsheet, now available on the CF trac wiki at
https://cf-pcmdi.llnl.gov/trac/wiki (grib2_chem_names_2.xls).
Christiane's comments appear in blue, Martin's in red and my new
additions (i.e. the newly added processes and species) appear in green.
The following questions and comments arise from the work that has been
done on the spreadsheet.
1. Christiane commented:
> sulfate should be replaced by sulfate_aerosol.
I'm sorry, I don't really understand this comment. Are you saying that
the 'sulfate' row should simply be deleted? (There is already a row for
sulfate_dry_aerosol.) Or are you saying that we should change 'sulfate'
in the spreadsheet to sulfate_ambient_aerosol?
(N.B. There are some older 'sulfate_aerosol' names currently in the
table, but in the 'Modification of some existing CF standard names for
chemical constituents' thread it was agreed that they would be aliased
to 'sulfate_ambient_aerosol' names as follows:
atmosphere_content_of_sulfate_aerosol becomes
atmosphere_mass_content_of_sulfate_ambient_aerosol
mass_concentration_of_sulfate_aerosol_in_air becomes
mass_concentration_of_sulfate_ambient_aerosol_in_air.
There is also an existing name, atmosphere_sulfate_content, which
presumably refers to sulfate in both aerosols and the gas phase).
2. Christiane commented:
> aerosols cannot expressed as molar quantities if they do not have a
defined molar mass.
This means that standard names proposals for all molar quantities for
the following species are rejected:
black_carbon_dry_aerosol
dust_dry_aerosol
particulate_organic_matter_dry_aerosol
primary_particulate_organic_matter_dry_aerosol
secondary_particulate_organic_matter_dry_aerosol
seasalt_dry_aerosol
Also, it is not clear whether molar quantities for the following species
should be included:
ammonium_dry_aerosol
mercury_dry_aerosol
nitrate_dry_aerosol
sulfate_dry_aerosol
because presumably these would cover a mixture of aerosol species.
3. As discussed above, columns for net_chemical_production and
net_chemical_production_and_emission have been added now that the
process names have been agreed and rows have been added for the recently
agreed species. These new sections of the spreadsheet contain few
entries at present and help in populating them would be very much
appreciated. Does the point that Christiane raised in (2) regarding
undefined molar masses for aerosols also apply to the combined species
such as 'alkanes'?
4. There is disagreement as to whether the following are valid names:
tendency_of_atmosphere_mass_content_of_methyl_hydroperoxide_due_to_dry_d
eposition
tendency_of_atmosphere_mass_content_of_dinitrogen_pentoxide_due_to_wet_d
eposition
5. Gross destruction/production names:
Martin commented (above) that he has marked those names that would
actually be used in the immediate future and suggested that we do not
include the remaining names for the present. Are there any objections
to taking that approach?
***
Alison wrote:
>
> The standard names Guidelines document will need to be updated in
> response to Martina's proposals. We currently have a section in that
> document called 'Transformations' which gives a number of 'template'
> phrases that can be used within standard names to describe
mathematical
> quantities, for example, change_over_time_in_X, derivative_of_X_wrt_Y.
> Jonathan suggested some time ago (not on the list) that we could
> similarly include templates for the processes associated with the
> chemical names. I will add a section called 'Chemical phrases' and
> list in there all the currently agreed phrases (such as
> tendency_of_atmosphere_mass_content_of_X_due_to_emission). There is
> already a 'Chemical Species' section, which is well out of date, and
to
> which I will now add all the currently agreed species. Both sections
> of the Guidelines will then be kept up to date as new chemical species
> and phrases are agreed.
Martin wrote:
> This is what Christiane had documented on her Wiki pages a while ago.
I
> think we should use those terms as a starting point.
Christiane wrote:
> CONCERNING THE GUIDELINES: MAYBE YOU COULD USE SOME OF THE MATERIAL
FROM
>
http://wiki.esipfed.org/index.php/CF_Standard_Names_-_Construction_of_At
mospheric_Chemistry_and_Aerosol_Terms
> OR REFER TO THIS PAGE. I STILL THINK THAT A WIKI MAKES LIFE EASIER
THAN E.G. ALL OF US RESPONDING INDIVIDUALLY > TO YOUR EMAIL.
I agree that Christiane's wiki page is an excellent resource for the
chemistry names and it has been extremely useful in identifying both the
gaps and the inconsistencies in CF standard names. I'm sure that the
chemistry names would not be in anything like as good a state as they
are now without Christiane's efforts to organise all the information. I
will certainly take note of that page when updating the Guidelines. I
think it is important for there to be a central record of the way in
which CF standard names (not only chemistry names) are constructed and
the Guidelines document is the natural place to gather all the
information. I would like to give the Guidelines document a more
prominent role in future (in fact I think it should probably be renamed
'Rules for Construction of CF Standard Names') and my intention is to
extend and restructure it where necessary so that it contains as much
helpful and relevant information as possible.
Alison wrote:
> In fact, I think it would be quite easy to maintain the lists of
> chemical phrases and chemical species as separate documents, linked to
> from the Guidelines, but which could then be viewed separately if
> needed. Would that be a useful thing to do?
Martin wrote:
> Definitively! Many thanks for volunteering this!
Christiane wrote:
> YES !!
OK - glad to be of service :). I'll get this done as soon as possible.
***
Alison wrote:
>
> Martin and Martina have put forward the suggestion of a panel drawn
> from the atmospheric chemistry community to coordinate future
proposals
> to CF for chemistry standard names. I certainly welcome the
> willingness of the atmospheric chemists to engage so fully with the CF
> process and having domain experts to call on when dealing with
> particular sets of proposals is very valuable. It seems likely that
> there would be some overlap between the function of a chemistry panel
> and the existing standard names committee so I will need to discuss
> further with Bryan Lawrence, chair of the CF standard names committee,
> on the best way to coordinate activities.
Martin wrote:
> well, practical experience shows that in the end it does fall back on
> you. As long as this is ok for you and we don't feel that it becomes
> inefficient, we should probably leave things as they are now. I think
at
> some point we had thought that things could perhaps move a little
faster,
> but in hindsight I admit that it was probably good not to rush things
too
> quickly. If we have re-iterated the present set of propositions we
will have
> achieved a great deal already, and I hope that the amount of future
> proposals from the chemistry side will decline. The addition of new
species
> will be relatively straightforward (at some point we should make sure
that
> at least all species from the GRIB table are included), and I cannot
see too
> many new quantitities (=terms) which should be needed.
Christiane wrote:
> MAYBE THIS OFF-LINE DISCUSSION OF CHEMISTS WILL NOT BE NECESSARY IN
THE FUTURE AS WE ARE LAYING A SOLID BASIS
> AND CONCEPT FOR FUTURE NAMES.
OK, thank you for your comments. I hope that we are now on the right
track with the chemistry names. From my own point of view, always the
most helpful thing is to be able to seek the advice of domain experts,
whether in chemistry or in the other areas of science covered by CF.
I'd like to say a big thank you to all the people who take the time to
participate in the standard names discussions.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 446314
Rutherford Appleton Laboratory Email: alison.pamment at stfc.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
--
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Received on Wed May 20 2009 - 08:06:26 BST
