Forgot to set 'reply all'.....
Hi Allen, As I tried to explain in my last message the way things work in CF is that the Standard Name is associated with a CANONICAL unit. This is an expression of the dimensions of the measurement and NOT the actual unit of measure, which is stored in the NetCDF. For anything in ppt, ppm, ppb etc. the Canonical unit used is 'dimensionless'. 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: Allen Jordan - NOAA Affiliate <[email protected]> Sent: 28 February 2017 22:40 To: Lowry, Roy K. Cc: Steve Emmerson; CF Metadata Mail List Subject: Re: [CF-metadata] new standard names request Hi Roy and Steve. Your modified names will work fine. I would prefer units of "ppm" and "ppb" as they match our historical naming. I'm very new to the CF Conventions, please bear with me. Here is the modified request for new fields: name: volume_mixing_ratio_of_water_vapor_in_air description: The atmospheric water vapor mixing ratio in parts per million by volume. units: ppm name: volume_mixing_ratio_of_ozone_in_air description: The atmospheric ozone mixing ratio in parts per billion by volume. units: ppb I'll be sure to include the units as attributes of each variable. Thanks. - Allen On Tue, Feb 28, 2017 at 2:40 AM, Lowry, Roy K. <[email protected]<mailto:[email protected]>> wrote: Hi Steve, I think there is a CF precedent would pacify you a little here, which is to have Standard Names of the form 'volume_mixing_ratio' with canonical units of dimensionless such as volume_mixing_ratio_of_oxygen_at_stp_in_sea_water. I would suggest following this practice in this case with: volume_mixing_ratio_of_water_vapor_in_air volume_mixing_ratio_of_ozone_in_air A note to Allen is that your actual units including scaling factor are explicity included in CF NetCDF as a parameter attribute. 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]<mailto:[email protected]>. Please also use this e-mail if your requirement is urgent. ________________________________ From: CF-metadata <[email protected]<mailto:[email protected]>> on behalf of Steve Emmerson <[email protected]<mailto:[email protected]>> Sent: 27 February 2017 22:04 To: Allen Jordan - NOAA Affiliate Cc: CF Metadata Mail List Subject: Re: [CF-metadata] new standard names request BEGIN RANT This is the kind of stuff that I don't like: putting additional (and unnecessary) semantics into the unit specification. "ppm" is bad enough (1e-6 would be better) but *volume*! The attributes of a physical quantity are attributes of the quantity itself -- *not* its unit. If a physical quantity is atmospheric mixing ratio by volume, then name it as such and leave the unit alone. The alternative is to pollute the unit namespace with "volume", "mass", "carbon", and whatever else people think up -- leading to a unending additions to the units database. Call the quantity "atmospheric water vapor mixing ratio by volume" and specify the unit as "1e-6" (or "ppm" if you must). Lest you think I'm alone in this, see sections 7.4 and 7.5 of <https://www.nist.gov/pml/nist-guide-si-chapter-7-rules-and-style-conventions-expressing-values-quantities>. [https://www.nist.gov/sites/default/files/images/pml/pubs/sp811/bannersm_1.jpg]<https://www.nist.gov/pml/nist-guide-si-chapter-7-rules-and-style-conventions-expressing-values-quantities> NIST Guide to the SI, Chapter 7: Rules and Style ...<https://www.nist.gov/pml/nist-guide-si-chapter-7-rules-and-style-conventions-expressing-values-quantities> www.nist.gov<http://www.nist.gov> 7.1 Value and numerical value of a quantity The value of a quantity is its magnitude expressed as the product of a number and a unit, and the number multiplying the ... END RANT Thanks for letting me get this off my chest. :-) Regards, Steve Emmerson On Mon, Feb 27, 2017 at 2:21 PM, Allen Jordan - NOAA Affiliate <[email protected]<mailto:[email protected]>> wrote: I would like to add two standard names for the NOAA GMD OZWV group's weather balloon data: name: water_vapor_mixing_ratio description: The atmospheric water vapor mixing ratio in parts per million by volume. units: ppmv name: ozone_mixing_ratio description: The atmospheric ozone mixing ratio in parts per billion by volume. units: ppbv _______________________________________________ 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. 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