Hello John,
I'm getting a little confused here. Why is the dimensionality of the surface measurement different? I would have expected it to be something like mol m-3 for concentrations at any depth. Or am I misunderstanding what you wish to describe? Cheers, Roy. Please note that I partially retired on 01/11/2015. I am now only working 7.5 hours a week and can only guarantee e-mail response on Wednesdays, my day in the office. All vocabulary queries should be sent to [email protected]. Please also use this e-mail if your requirement is urgent. ________________________________ From: CF-metadata <[email protected]> on behalf of John Dunne - NOAA Federal <[email protected]> Sent: 20 October 2016 18:20 To: Jonathan Gregory Cc: [email protected] Subject: Re: [CF-metadata] New standard names for OMIP biogeochemistry and chemistry The attempt to as sea surface - SS prefixes was only to follow the convention as my understanding was that the convention could not handle two variables with the same name but different dimensions. If that is not truly a problem on your end, then perhaps it is a non issue. On Thu, Oct 20, 2016 at 12:55 PM, Jonathan Gregory <[email protected]<mailto:[email protected]>> wrote: Dear Alison I agree with you and Roy about the below. I think that it would be much better to specify the depth of measurement, unless they really have the same unavoidable vagueness of SST and SSS. In the case of those quantities, we followed the existing universally used terminology rather than defining our own, as we often do for clarity - perhaps that was a mistake! Best wishes Jonathan > d. Surface concentration names > There are a lot of these: 42 surface_mole_concentration names (units of mol > m-3), 6 surface_mass_concentration names (kg m-3) and I'm also including 2 > surface_sea_water_alkalinity (mol m-3) names and 3 surface_sea_water_ph names > in this section. > > My concern about these proposals is that the names and units are not > consistent. In CF standard names, "surface" means the lower boundary of the > atmosphere. It has no depth, so it is not meaningful to regard it as having a > mass or a volume. For this reason we can't assign units of kg m-3 or mol m-3 > to a 'surface' name. I assume that all these quantities are in fact "near > surface" values, i.e. representative of the top model layer, in which case > there are two possible ways to deal with this. > > The first solution is simply to remove 'surface' from all these names and > instead use a vertical coordinate or scalar coordinate and coordinate bounds > to indicate the location and thickness of the layer. This has the advantage > that many of the required names actually already exist, without the need to > introduce separate surface names. E.g, instead of adding a new name > surface_mole_concentration_of_dissolved_inorganic_carbon_in_sea_water, you > could use the existing name > mole_concentration_of_dissolved_inorganic_carbon_in_sea_water accompanied by > suitable coordinate information to describe your quantity. > > The second solution, if you do feel that it is necessary to have distinct > standard names for all these near-surface quantities, would be to follow the > approach used in some existing sea_surface names such as > sea_surface_temperature and sea_surface_salinity. The names would then be > 'sea_surface' names and there would be an accompanying sentence in the > definition to explain what that means, i.e. that it refers to water close to > the surface. You would still also need to include the coordinate information > and coordinate bounds to fully describe your data. With this approach the > proposed name > surface_mole_concentration_of_dissolved_inorganic_carbon_in_sea_water would > become sea_surface_mole_concentration_of_dissolved_inorganic_carbon. _______________________________________________ CF-metadata mailing list [email protected]<mailto:[email protected]> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ________________________________ This message (and any attachments) is for the recipient only. NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. ________________________________
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