Dear list, any more comments? can we move forward and agree on these new standard names?
thanks /Sébastien ----- Original Message ----- > From: "Jonathan Gregory" <[email protected]> > To: [email protected] > Sent: Wednesday, 11 April, 2018 18:32:30 > Subject: [CF-metadata] how to use ocean_mixed_layer_thickness_defined_by_* > Dear Sebastien > > I would favour your alternative >> Alternatively, we could move the last sentence of each description to the >> respective "ocean_mixed_layer_thickness_defined_by_*" standard names to make >> that specific usage more explicit. We then keep a more general description >> for >> the new "*_difference" standard names. > for the reason you give, which appeals to me. > > Also, instead of "auxiliary coordinate" I would say "coordinate variable or > scalar coordinate variable". A scalar coord var is formally like a size-one > auxiliary coord var. However the threshold variable could in principle be > multi-valued; then you'd have a dimension for it, and it wouldn't be an aux > coord var. > > Best wishes > > Jonathan > > > ----- Forwarded message from Sebastien Villaume <[email protected]> > ----- > >> Date: Tue, 10 Apr 2018 10:36:21 +0000 (GMT-00:00) >> From: Sebastien Villaume <[email protected]> >> To: [email protected] >> Cc: "Lowry, Roy K." <[email protected]>, Jonathan Gregory >> <[email protected]> >> Subject: Re: [CF-metadata] how to use >> ocean_mixed_layer_thickness_defined_by_* >> X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF52 (Linux)/8.6.0_GA_1200) >> >> >> Dear CF list, >> >> I took a bit longer to write down the proposed definitions of these 3 >> standard >> names. >> >> >> standard name: sea_water_temperature_difference >> units: K >> description: >> Sea water temperature is the in situ temperature of the sea water. The >> standard >> name "sea_water_temperature_difference" can be used (as an auxiliary >> coordinate) together with the standard name >> "ocean_mixed_layer_thickness_defined_by_temperature" to define its >> temperature >> criterion. >> >> >> standard name: sea_water_sigma_theta_difference >> units: kg/m3 >> description: >> Sigma-theta of sea water is the potential density (i.e. the density when >> moved >> adiabatically to a reference pressure) of water having the same temperature >> and >> salinity, minus 1000 kg m-3. The standard name >> "sea_water_sigma_theta_difference" can be used (as an auxiliary coordinate) >> together with the standard name >> "ocean_mixed_layer_thickness_defined_by_sigma_theta" to define its >> sigma_theta >> criterion. >> >> standard name: sea_water_sigma_t_difference >> units: kg/m3 >> description: >> Sigma-t of sea water is the density of water at atmospheric pressure (i.e. >> the >> surface) having the same temperature and salinity, minus 1000 kg m-3. The >> standard name "sea_water_sigma_t_difference" can be used (as an auxiliary >> coordinate) together with the standard name >> "ocean_mixed_layer_thickness_defined_by_sigma_t" to define its sigma_t >> criterion. >> >> >> Alternatively, we could move the last sentence of each description to the >> respective "ocean_mixed_layer_thickness_defined_by_*" standard names to make >> that specific usage more explicit. We then keep a more general description >> for >> the new "*_difference" standard names. >> >> /Sébastien >> >> ----- Original Message ----- >> > From: "Jonathan Gregory" <[email protected]> >> > To: "Sebastien Villaume" <[email protected]> >> > Cc: [email protected], "Lowry, Roy K." <[email protected]> >> > Sent: Friday, 6 April, 2018 14:24:18 >> > Subject: Re: [CF-metadata] how to use >> > ocean_mixed_layer_thickness_defined_by_* >> >> > Dear Sebastien and Roy >> > >> > Thanks. I agree that it's a good idea to include sea_water_. >> > >> > Best wishes >> > >> > Jonathan >> > >> > On Thu, Apr 05, 2018 at 07:04:26PM +0000, Sebastien Villaume wrote: >> >> Date: Thu, 5 Apr 2018 19:04:26 +0000 (GMT-00:00) >> >> From: Sebastien Villaume <[email protected]> >> >> To: [email protected] >> >> Cc: Jonathan Gregory <[email protected]>, "Lowry, Roy K." >> >> <[email protected]> >> >> Subject: Re: [CF-metadata] how to use >> >> ocean_mixed_layer_thickness_defined_by_* >> >> X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF59 >> >> (Linux)/8.6.0_GA_1200) >> >> >> >> Dear Jonathan and Roy, >> >> >> >> thank you for your suggestions. >> >> >> >> I am happy to go with a set of general standard names if it is fine with >> >> everyone. I find it actually useful to make the standard names reusable >> >> by not >> >> hard-coding one of the reference. It is pretty clear from the mixed layer >> >> definition that it is a difference with respect to the sea surface. >> >> >> >> I am also happy to prefix sigma_theta and sigma_t with sea_water: >> >> >> >> sea_water_temperature_difference (K) >> >> sea_water_sigma_theta_difference (kg/m3) >> >> sea_water_sigma_t_difference (kg/m3) >> >> >> >> I will draft some definitions for tomorrow. >> >> >> >> thanks! >> >> >> >> /Sébastien >> >> >> >> ----- Original Message ----- >> >> > From: "Lowry, Roy K." <[email protected]> >> >> > To: [email protected], "Jonathan Gregory" >> >> > <[email protected]> >> >> > Sent: Thursday, 5 April, 2018 18:34:48 >> >> > Subject: Re: [CF-metadata] how to use >> >> > ocean_mixed_layer_thickness_defined_by_* >> >> >> >> > Dear Jonathan and Sebastien, >> >> > >> >> > >> >> > >> >> > >> >> > I was initially thinking of not including ' _defining_mixed_layer' in my >> >> > suggestion and am certainly happy with leaving it out. However, I still >> >> > think >> >> > sigma_t and sigma_theta should be prefixed with 'sea_water'. This would >> >> > give: >> >> > >> >> > >> >> > >> >> > >> >> > >> >> > sea_water_temperature_difference >> >> > sea_water_sigma_theta_difference >> >> > sea_water_sigma_t_difference >> >> > >> >> > 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 >> >> > Jonathan >> >> > Gregory <[email protected]> >> >> > Sent: 05 April 2018 18:28 >> >> > To: [email protected] >> >> > Subject: Re: [CF-metadata] how to use >> >> > ocean_mixed_layer_thickness_defined_by_* >> >> > Dear Sebastien >> >> > >> >> > It's interesting that this question hasn't been raised before. Thanks >> >> > for doing >> >> > so now. I agree that new standard names would be appropriate. There are >> >> > already >> >> > some standard names containing "difference" in various ways. I would >> >> > suggest >> >> > that for your purpose the names don't have to be so specific. You could >> >> > use >> >> > sea_water_temperature_difference >> >> > sigma_theta_difference >> >> > sigma_t_difference >> >> > because in the context of your use of them it is obvious what >> >> > difference you >> >> > mean. That would make these names perhaps useful for other purposes >> >> > too. This >> >> > is like the rather generic name >> >> > air_temperature_threshold >> >> > which doesn't indicate what the threshold can be used for. I would also >> >> > suggest >> >> > that the definitions of the three kinds of mixed layer depth should >> >> > have a >> >> > sentence added to say that the threshold should be stored in a >> >> > coordinate var, >> >> > e.g. like the sentence for >> >> > number_of_days_with_air_temperature_above_threshold. >> >> > >> >> > Best wishes >> >> > >> >> > Jonathan >> >> > >> >> > ----- Forwarded message from Sebastien Villaume >> >> > <[email protected]> >> >> > ----- >> >> > >> >> >> Date: Thu, 5 Apr 2018 13:55:50 +0000 >> >> >> From: Sebastien Villaume <[email protected]> >> >> >> To: CF Metadata <[email protected]> >> >> >> Subject: Re: [CF-metadata] how to use >> >> >> ocean_mixed_layer_thickness_defined_by_* >> >> >> X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF52 >> >> >> (Linux)/8.6.0_GA_1200) >> >> >> >> >> >> Hi all, >> >> >> >> >> >> It seems that my question did not attract much response. :( >> >> >> >> >> >> Is it because no one knows how to use these standard names and >> >> >> properly encode >> >> >> the "quantity that differs from its surface value by a certain amount"? >> >> >> >> >> >> Giving it more thoughts I feel that I need new standard names to >> >> >> describe this >> >> >> properly. >> >> >> >> >> >> Would it make sense to describe it this way: >> >> >> >> >> >> float swtd ; >> >> >> swtd:standard_name = >> >> >> "sea_water_temperature_difference_wrt_sea_surface" ; >> >> >> swtd:units = "degC" ; >> >> >> swtd:axis = "Z" ; >> >> >> swtd:positive = "down" ; >> >> >> swtd:long_name = "temperature difference wrt its surface value" >> >> >> >> >> >> float omlt(t, j, i) ; >> >> >> omlt:standard_name = >> >> >> "ocean_mixed_layer_thickness_defined_by_temperature" ; >> >> >> omlt:units = "m" ; >> >> >> omlt:coordinates = "time swtd1 latitude longitude" ; >> >> >> omlt:long_name = "ocean mixed layer defined by difference of >> >> >> temperature from >> >> >> surface" >> >> >> >> >> >> and the scalar value swtd can be 0.5 degC, 1.0 degC, etc. >> >> >> >> >> >> In this case, I need standard names working with temperature, >> >> >> sigma_theta and >> >> >> sigma_t: >> >> >> >> >> >> sea_water_temperature_difference_wrt_sea_surface >> >> >> sigma_theta_difference_wrt_sea_surface >> >> >> sigma_t_difference_wrt_sea_surface >> >> >> >> >> >> >> >> >> any quick suggestions are very welcome! >> >> >> >> >> >> thanks >> >> >> /Sébastien >> >> >> >> >> >> ----- Original Message ----- >> >> >> > From: "Sebastien Villaume" <[email protected]> >> >> >> > To: "CF Metadata" <[email protected]> >> >> >> > Sent: Wednesday, 4 April, 2018 14:04:42 >> >> >> > Subject: [CF-metadata] how to use >> >> >> > ocean_mixed_layer_thickness_defined_by_* >> >> >> >> >> >> > Dear list, >> >> >> > >> >> >> > I have a question regarding the use of the standard names of the form >> >> >> > ocean_mixed_layer_thickness_defined_by_* >> >> >> > >> >> >> > the definition from the official standard name table is: >> >> >> > >> >> >> > "The ocean mixed layer is the upper part of the ocean, regarded as >> >> >> > being >> >> >> > well-mixed. The base of the mixed layer defined by temperature, >> >> >> > sigma or >> >> >> > sigma_theta is the level at which the quantity indicated differs >> >> >> > from its >> >> >> > surface value by a certain amount." >> >> >> > >> >> >> > From what I understand, in the case of >> >> >> > ocean_mixed_layer_thickness_defined_by_temperature, I should specify >> >> >> > some >> >> >> > quantity as a scalar (Z axis), but it is actually a temperature >> >> >> > difference that >> >> >> > I need to encode, not a plain temperature : temp_surf - >> >> >> > temp_base_level = >> >> >> > temp_delta_defining_mixed_layer_thickness >> >> >> > >> >> >> > if it was simply a temperature I would maybe use: >> >> >> > >> >> >> > float swpt ; >> >> >> > swpt:standard_name = "sea_water_potential_temperature" ; >> >> >> > swpt:units = "degC" ; >> >> >> > swpt:axis = "Z" ; >> >> >> > swpt:positive = "down" ; >> >> >> > >> >> >> > but what I really want to encode is a temperature difference. How >> >> >> > can I specify >> >> >> > that? Is "sea_water_potential_temperature" the correct standard name >> >> >> > to use? >> >> >> > >> >> >> > >> >> >> > same question for >> >> >> > ocean_mixed_layer_thickness_defined_by_sigma_theta, how do I >> >> >> > encode a "difference" in sigma_theta? >> >> >> > >> >> >> > thanks, >> >> >> > >> >> >> > ____________________________________ >> >> >> > >> >> >> > Dr. Sébastien Villaume >> >> >> > >> >> >> > M.A.R.S. Analyst >> >> >> > ECMWF Data Governance facilitator >> >> >> > >> >> >> > ECMWF >> >> >> > Shinfield Park, >> >> >> > Reading RG2 9AX, UK >> >> >> > +44 (0)118 949 9301 >> >> >> > +44 (0)7825 521592 >> >> >> > [email protected] >> >> >> > ____________________________________ >> >> >> > _______________________________________________ >> >> >> > CF-metadata mailing list >> >> >> > [email protected] >> >> >> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> > >> >> > >> >> > CF-metadata Info Page - mailman.cgd.ucar.edu >> >> > mailman.cgd.ucar.edu >> >> > This is an unmoderated list for discussions about interpretation, >> >> > clarification, >> >> > and proposals for extensions or change to the CF conventions. >> >> > >> >> > >> >> >> _______________________________________________ >> >> >> CF-metadata mailing list >> >> >> [email protected] >> >> >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> > >> >> > ----- End forwarded message ----- >> >> > _______________________________________________ >> >> > CF-metadata mailing list >> >> > [email protected] >> >> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> > >> >> > This message (and any attachments) is for the recipient only. 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