Difference between revisions of "Talk:Units"

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==CTextor (CT) / Martin Schultz (MX) / Sebastian Rast (RS): UDUNITS in atmospheric chemistry==
 
==CTextor (CT) / Martin Schultz (MX) / Sebastian Rast (RS): UDUNITS in atmospheric chemistry==
  
::'''CT:''' usually the concentration of chemical compound are not given in UDUNITS, see the remark of Ranjeet above for the air quality community, where aerosol mass_concentration is usually stated in ug/m3ich, or the global chemistry community where the tropospheric column of a gas is given in [molec/cm2], and the dry deposition in [g/m2/month].  
+
::'''CT:''' usually the concentration of chemical compound are not given in UDUNITS, see the remark of Ranjeet above for the air quality community, where aerosol mass_concentration is usually stated in ug/m3ich, or the global chemistry community where the tropospheric column of a gas is given in [molec/cm2], and the dry deposition in [g/m2/month]. This should be changed
this should be changed
 
 
:: cm2  -> m2
 
:: cm2  -> m2
 
:: molec -> mole
 
:: molec -> mole
 
:: g    -> kg
 
:: g    -> kg
>
+
:: We had a discussion (in german) that this would be difficult, because all papers are in the non-udunits, but at the same time it would be good to agree on one standard within GEMS and HTAP.
> Ausserdem benutzt ihr gN, gC oder gS, das sind keine udunits, es muss
+
 
> in kg sein, also zB fuer SO4_ddep
 
> dry_deposition_flux_of_sulfate_as_sulfate_aerosol_at_surface
 
> in [kg/m2/s]
 
>
 
> Ich wuerde das gern
 
  
 
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Revision as of 08:42, June 30, 2006

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UDUNITS have to be used for the standard_names according to the CF convention. This is however not always obvious for chemistry and aerosol variables, where also other units are common. This page provides a discussion on this matter. See also Unidata Supported Units || Unit Converter, UDUNITS


Agreed items of former discussions on the "Units" page can be found here.


JGregory: Don't mix units with the Compound

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:

Very good idea, I will change this. --Christiane Textor (Christiane) 17:11, 2 June 2006 (EDT)

CTextor: SI units

Try to use SI units if allowed within udunits (e.g. not hours but seconds) --Christiane Textor (Christiane) 12:11, 2 June 2006 (EDT)

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

  • RS: Table 1 mass_concentration is usually stated in ug/m3 ie micrograms per cubic metre - this is conventional and used in all air quality literature (scientific and policy)
CT: --Christiane Textor (Christiane) 13 June 2006 (EDT)


CTextor (CT) / Martin Schultz (MX) / Sebastian Rast (RS): UDUNITS in atmospheric chemistry

CT: usually the concentration of chemical compound are not given in UDUNITS, see the remark of Ranjeet above for the air quality community, where aerosol mass_concentration is usually stated in ug/m3ich, or the global chemistry community where the tropospheric column of a gas is given in [molec/cm2], and the dry deposition in [g/m2/month]. This should be changed
cm2 -> m2
molec -> mole
g -> kg
We had a discussion (in german) that this would be difficult, because all papers are in the non-udunits, but at the same time it would be good to agree on one standard within GEMS and HTAP.