[CF-metadata] CF standard names for chemical constituents and aerosols (resulting from a GRIB2 p

From: Philip J. Cameronsmith1 <cameronsmith1>
Date: Mon, 22 Sep 2008 17:53:33 -0700 (PDT)

Hi Martina, et al.

Comments interleaved below.

Best wishes,

   Philip

On Mon, 22 Sep 2008, Martina Stockhause wrote:

> Hallo Roy,
>
> there is a slight difference between a lumped species and a total:
> Total consists of different individual species, but a lumped species is a
> synthetic species representing chemical constituents with similar chemical
> behaviour. It is used for organic chemical constituents. The advantage is a
> reduction of the number of species an the number of chemical reactions that
> have to be calculated.
>
> The term 'lumped' is fairly common: lumping techniques, lumped species.

As an atmospheric chemist I understand your distinction, which is
significant for modeling. However, I'm not sure the distinction is
important for CF, since 'lumped' and 'totaled' for the same group of
species should be comparable. I therefore suggest we stick with 'total',
since it has been used before and is more understandable to non-chemists.

This does not address the issue of which species are, and are not,
included in the lumped/total specie for hydrocarbons. This is tricky.
It has been discussed at some length for CF in the past, but as I recall,
it did not reach a conclusion (the proposal that sparked the discussion
got withdrawn). I'll mention more in reply to your previous email so that
the discussion doesn't get lost here.

> Definition suggestions - good idea!
>
> Anthropogenic refers to chemical constitutents influenced, caused or created
> by human activity.
> Biogenic refers to chemical constitutents generated by natural processes.
>
> For oxygenated means simply 'containing oxygen'.
>
> For passive ozone I am not content with:
> Passive ozone means the behaviour of ozone in the absence of chemical
> processes.
>
> 'Non-reactive' isn't any better, either. One of the chemists might have a
> better definition for that.

This is another discussion that went on at length, but was withdrawn
before it was decided (as I recall). The challenge is that a tracer like
ozone can be passive with respect to many things (including selected
reactions, radiation, and deposition), and may also be partially reactive
(eg stratospheric ozone in the troposphere). The nature of a 'passive'
tracer also typically depends on how it is initialized and handled at the
boundaries.

However, I do recall from the previous discussion that everyone agreed
that putting everything in the standard name would be unworkable.

Best wishes,

      Philip


> Best wishes,
> Martina
>
>
> On Friday 19 September 2008 17:40, you wrote:
>> Hi Martina,
>>
>> Couple of points. Would the term 'total' be better than 'lumped' - lumped
>> to me is slang. We've also used 'total' before to convey similar semantics
>> (e.g. total_reactive _nitrogen).
>>
>> Definitions of anthropogenic, biogenic, passive, oxygenated would be
>> useful.
>>
>> Cheers, Roy.
>>
>>>>> Martina Stockhause <martina.stockhause at zmaw.de> 09/17/08 2:38 PM >>>
>>
>> Dear all,
>>
>> a group of chemical modellers discussed the standardization of the chemical
>> constituents and aerosols in the GRIB2 standard. I assist them. As sources
>> we used the parameters used in different intercomparison projects: GEMS
>> (http:// gems.ecmwf.int/), CCMVal (http:// www. pa.op.dlr.de/CCMVal/), TFHTAP
>> (http:// www. htap.org).
>>
>> Martin Suttie from ECMWF / GEMS created a two tables approach for GRIB2:
>> one for the physical quantity and one for the chemical constituent or
>> aerosol. Thus, a physical-chemical quantity (= CF standard name) is a
>> combination of these two parameters. Since, we want to connect GRIB2
>> standard closely to the CF standard names, we used CF standard names in the
>> proposal for WMO and propose here the missing CF standard names used in our
>> WMO proposal.
>>
>> 1. NEW physical parameters for chemical constituent X:
>> I read the discussion about 'burden' in the mailing archive. It seems that
>> the scientists stick to 'burden' as a common term in the community and have
>> started to use it for the creation of CF-like standard names (e.g. in
>> CCMVal), because CF couldn't offer an acceptable alternative.
>> Neither 'global_integral' nor 'burden' could be agreed on in the CF mailing
>> list. Sorry, for starting that discussion again without offering a new
>> alternative. Since the CF standard names should be self-explanatory for
>> those who create and analyse data, we propose the standard
>> name 'total_yearly_average_burden_of_X_in_atmosphere' among others:
>>
>> column_integrated_mass_density_of_X_in_air : kg.m-2
>> tendency_of_atmosphere_mass_content_of_X_due_to_respiration : kg.m-2.s-1
>> tendency_of_mole_concentration_of_X_due_to_chemical_gross_production :
>> mol.m-3.s-1
>> tendency_of_mole_concentration_of_X_due_to_chemical_gross_destruction :
>> mol.m-3.s-1
>> total_yearly_average_burden_of_X_in_atmosphere : mol
>> total_yearly_averaged_atmospheric_loss_of_X : mol.s-1
>> surface_area_density_of_X : m-1
>>
>>
>> 2. NEW chemical constituents:
>> We suggest to use the keyword 'lumped' to indicate a certain group of
>> species showing similar chemical behaviour (PRISM definition). And to
>> introduce 'anthropogenic' and 'biogenic' for the origin of the organic
>> compound NMVOC.
>>
>> 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 : HOx radical (OH+HO2)
>> total_peroxy_radical : Total inorganic and organic peroxy radicals (HO2 +
>> RO2) passive_ozone
>> noy_expressed_as_nitrogen : All nitrogen oxides (NOy) expressed as nitrogen
>> clox_expressed_as_chlorine : Total inorganic chlorine except HCl, ClONO2:
>> ClOx brox_expressed_as_bromine : Total inorganic bromine except HBr,
>> BrONO2: BrOx lumped_alkanes
>> lumped_alkenes
>> lumped_aromatic_compounds
>> lumped_terpenes
>> nmvoc_expressed_as_carbon : Non-methane volatile organic compounds
>> expressed as carbon
>> anthropogenic_nmvoc_expressed_as_carbon : anthropogenic
>> nmvoc_expressed_as_carbon
>> biogenic_nmvoc_expressed_as_carbon : biogenic nmvoc_expressed_as_carbon
>> lumped_oxygenated_hydrocarbons
>>
>>
>> 3. NEW CF standard names:
>> 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.
>>
>> Thank you and best wishes,
>> Martina
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------------------------------------------------------------------------
Dr Philip Cameron-Smith Atmospheric, Earth, and Energy Division
pjc at llnl.gov Lawrence Livermore National Laboratory
+1 925 4236634 7000 East Avenue, Livermore, CA94550, USA
------------------------------------------------------------------------
Received on Mon Sep 22 2008 - 18:53:33 BST