Agreed Items of Discussion Future Atmospheric Chemistry and Aerosol Terms

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JGregory: Content Explanation

We have used "content" in a lot of standard names to mean the amount of something per unit area i.e. a vertical integral. Do you think e.g. "atmosphere ozone content" in kg m-2 isn't clear enough terminology? --JonathanGregory 16:51, 22 May 2006 (EDT)

......RHusar: Content Explanation

'Vertical burden' is also used to describe measured column concentrations. It may take a bit of getting used to, but I have no objections to ozone_content. --Rhusar 19:19, 22 May 2006 (EDT)

......CTextor: Content Explanation

I think in the chemistry/aerosol community "content" would rather be understood as a total mass, the amount of something per unit area would rather be called 'load' or 'column'. Therefore I would now suggest to use vertical_burden which seems less ambiguous to me. --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

JGregory:in_air vs. atmosphere

The difference between atmosphere and in_air is that atmosphere is used to refer to large-scale properties, and in_air to locally measured ones. Hence the distinction between e.g. mass concentration in air, and atmosphere content. Chemical concentrations would be in_air (as you have done), and hence distinguished from in_sea_water etc. If a given quantity could appear in places other than air, it is correct to be explicit. --JonathanGregory 16:51, 22 May 2006 (EDT)

JGregory: mole or mass fractions

You may indeed prefer mole_fraction for some quantities and mass_fraction for others. That would be your own decision for your project, but of course another project might make a different choice. --JonathanGregory 16:51, 22 May 2006 (EDT)

......CTextor: mole or mass fractions

The use of either mole_ or mass_ fraction varies within the community, so I followed the suggestions of the PRISM project. But then aerosols should allways be in mass and gases in mole fraction for consistency. --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

JGregory: Units

It doesn't matter to CF what units are used, so long as they are udunits. Any dimensionally equivalent unit can be used for a given standard name.

However, kgC and kgS aren't SI units. I think the unit has to be kg. This implies that it's the standard name which must somehow indicate that it is the mass of C or mass of S which is being referred to, rather than the mass of the compound e.g. dry_deposition_flux_of_sulfur_as_sulfate_at_surface. --JonathanGregory 16:51, 22 May 2006 (EDT)

......CTextor: Units

changed for carbon, sulfate, and nitrogen species:
--Christiane Textor (Christiane) 15:53, 8 June 2006 (EDT)

JGregory: equivalent_thickness_at_stp_of_atmosphere_ozone_content

equivalent_thickness_at_stp_of_atmosphere_ozone_content means the thickness (depth) of the layer you would get by collecting all the ozone in the atmospheric column at STP. It was named like that by analogy with the equivalent thickness (depth) of amounts of precipitation. Does that make sense? --JonathanGregory 16:51, 22 May 2006 (EDT)

......RHusar: Aerosol Scale Height

I wonder if we can use the same naming for aerosol_scale_height, i.e. the height of an aerosol layer if the concentration was vertically uniform between the surface and scale height. --Rhusar 19:27, 22 May 2006 (EDT)

......CTextor: equivalent_thickness_at_stp_of_atmosphere_ozone_content

The problem for me is STP, I realize that it is 'standard temperature and pressure'. I found it on wikipedia so I guess I should know...? --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

JGregory: Variable and File Names

Names for variables and files would not be the subject of CF conventions --JonathanGregory 16:51, 22 May 2006 (EDT)

......CTextor: Variable and File Names

I agree that this is not the focus of the CF conventions, but is still needed for model intercomparisons. We might want to open another discussion on the structure and names of files elsewhere. --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

JGregory: Avoid Abbreviations

We try to avoid abbreviations like "turdry" and "seddry". Although they make the names longer, I think these should be spelled out in full. Would this be a case for using due_to e.g. dry_deposition_..._due_to_turbulence? --JonathanGregory 16:51, 22 May 2006 (EDT)

......CTextor: Avoid Abbreviations

I will change this. --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

JGregory: Distinction between Net and Total Production

It could be unclear to have a distinction between "production" and "net production". Is there a more explicit name for the former? Can you call it "gross production", for instance, like gross/net primary productivity of ecosystems? --JonathanGregory 16:51, 22 May 2006 (EDT)

......CTextor: Distinction between Net and Total Production

changed --Christiane Textor (Christiane) 17:54, 2 June 2006 (EDT)

PVelthoven (PV) / CTextor (CT): remarks to updates on June 8 from PV and answers from CT

  • PV: aerosols: It may be useful to have a way to distinguish the dry aerosol fraction from "aerosol".
CT: With aerosol I always refer to dry aerosol as it was done in AeroCom. I add dry in the explanation.
  • PV: A decision should still be made whether IUPAC names or names common in atmospheric chemistry research should be used. There are a few species in your and my original list which are not IUPAC.
CT: There is a decision: IUPAC names should be used. Jonathan already mentioned this to me. Links provided by Jonathan and added to this web site.

--Christiane Textor (Christiane) about 9 June 2006 (EDT)

JGregory(JG) / CTextor (CT): remarks to updates on June 12 from JG and answers from CT

  • JG: Thanks for your updates. I am not monitoring your wiki, so I'm depending on your emails to prompt me to look again. I think the debate is going well! If you send your email to the CF list the wiki might have a wider readership.
CT: will write an email to the CF list
  • JG: I know that "burden" and "column" are common, but if you could get used to "content" it would have the advantage of consistency with other names. I agree that it might be misunderstood to mean the content integrated over the entire world, not per unit area, but this is also true of the existing stdnames which use "content". The units should clarify it, so it's not dangerously ambiguous! We would need some other phrase for the global total. So far no-one has asked for such a quantity. In existing names X_content where X is a material means kg m-2, and by analogy you could have number_content in m-2.
CT: ok, if this is the convention to be followed. anyway: so far, no variable has been constructed for content...
  • JG: STP is a fairly standard abbreviation, but it is also listed in the CF stdname guidelines.
CT: sorry for not knowing.
  • JG: Yes, I think we have avoided articles, because we haven't needed them, not on principle. However, prepositions do appear in some names.
CT: Yes!
  • JG: Yes, if a species could appear in more than one medium, it should have in_air in_sea_water in_soil or whatever, to specify which.
CT: Yes!
  • JG: in_air and in_atmosphere wouldn't be a clear distinction, because atmosphere is used in other names to refer to large-scale properties, not to a medium. I would suggest in_air, in_clear_air (outside clouds), in_cloudy_air, and in_cloud_water (with a _).
CT: This is how I wanted to use it. I hope it is clearer from the recent updates of the tables.
  • JG: in_troposphere is a bit different. I think this quantity is actually in_air, but within the troposphere! in_troposphere is more like a vertical coordinate (like a named surface) than a medium, I would say. But we could also regard it as a large-scale designation, like atmosphere, and put it at the start, thus: troposphere_mole_fraction_of_ozone_in_air_from_stratosphere. Is that correct?
CT: With in_troposphere I mean a large scale property, but in all phases, i.e. in clouds and air. explanation added to table. But do I understand correctly that large scale properties should be at the beginning of the variable names, and locally measurable or origin information at the end of variable?
  • JG: I don't understand the construction _of_X_compartment. What does this mean?
CT: Changed in updated versions, hope it is clearer now.
  • JG: Why is "loss" preferred to "destruction", which would parallel "production" more nearly?
CT: Good point, I have changed it too "destruction"

--Christiane Textor (Christiane) 13 June 2006 (EDT)

RanjeetSokhi(RS) / CTextor (CT): remarks on version June 12 from RS and answers from CT

  • RS: Table 2 - Nitric Oxide (NO) rather than Nitrogen Oxide
CT: I followed the IUPAC conventions here and changed it to nitrogen monooxide.
  • RS: Aerosols
you are missing PM10 (particles of aerodynamic size of 10um or less), similary PM2.5 and PM1
coarse fraction = PM10-PM2.5
fine fraction = PM2.5
ultrafine fraction PM0.1
accumulation mode particles = particles of size 0.1 to 1um
Aitken mode particles = particles of size 0.1-0.01um
nucleation mode particles = particles of size less than 0.01um
CT: I agree that these are missing, I have added them in the species list, but not in the 'proposed names section'. The philosophy of CF is to define names once they are really needed. The reason why I did not include them so far is that they are not commonly simulated in global models, but if needed these names can be included in order to be as broad as possible!

--Christiane Textor (Christiane) 13 June 2006 (EDT)