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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