Talk:Units

Discussion Page on Units. If needed, parctice editing in the Sandbox

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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 (MS) / Sebastian Rast (RS): UDUNITS in atmospheric chemistry: concentration

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.

CTextor (CT) / Martin Schultz (MS) / Sebastian Rast (RS): UDUNITS in atmospheric chemistry: time issues

• MS: (translated from german by ct) The use of non-UDUNITS can be of advantage, if it concern a variable that is integrated over a certain period, e.g. a the dry deposition flux over a month would need to have mole/m2/month. This is not the same as a mean dry dep. which could be given in mole/m2/s.
• CT: It would still be possible to use [mole/m2/s] if the standard name included the information, e.g. dry_deposition_flux_due_to_turbulence_of_ozone_over_one_month_at_surface... but this is very long....

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