Dear All, after discussing with the dataset owner/expert (Eric), he has confirmed to me that all the quantities involved are instantaneous and that sea_surface_height is the correct reference.
The definition given by Alison is correct: > the sum of > sea_water_mass_per_unit_area_expressed_as_thickness and > steric_change_in_sea_surface were meant to give the total water column > thickness in a given model time step. The steric change measures the > contribution of sea water density to the thickness compared with what it would > be if the same mass of water had standard temperature and salinity Regarding the choice between verbosity/clarity vs domain expert preferred naming, we are still open but it seemed through the discussion that the domain expert naming was favoured. Our main concern is that we want to use these standard names as soon as possible and want them published in the next release of the table. Best Wishes, /Sébastien ----- Original Message ----- From: "alison pamment" <alison.pamm...@stfc.ac.uk> To: "alison pamment" <alison.pamm...@stfc.ac.uk>, "Jonathan Gregory" <j.m.greg...@reading.ac.uk>, cf-metadata@cgd.ucar.edu Sent: Tuesday, 13 June, 2017 11:03:50 Subject: Re: [CF-metadata] New standard names for NEMO ocean model output Dear Jonathan and Sebastien, Following on from my last post and looking at the names again, I understand the steric names to mean the contribution of temperature and salinity to the (instantaneous) sea_surface_height. Is that right? If so, then I still don't think we should be referring to mean sea level. In the discussion we did consider the possibility of writing the names as: change_in_sea_surface_height_due_to_change_in_sea_water_density change_in_sea_surface_height_due_to_change_in_sea_water_practical_salinity change_in_sea_surface_height_due_to_change_in_sea_water_temperature but rejected them as being rather verbose. But are they in fact clearer? The main thing in the end is to avoid ambiguity and possible misinterpretation. What do you think? Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 Centre for Environmental Data Analysis Email: alison.pamm...@stfc.ac.uk STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Campus, Didcot, OX11 0QX, U.K. > -----Original Message----- > From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of > alison.pamm...@stfc.ac.uk > Sent: 13 June 2017 10:46 > To: j.m.greg...@reading.ac.uk; cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > Dear Jonathan and Sebastien, > > Thank you both for your replies. Jonathan is correct that sea_surface_height > means the instantaneous sea level and that's what I thought was meant by > these names. I thought that the sum of > sea_water_mass_per_unit_area_expressed_as_thickness and > steric_change_in_sea_surface were meant to give the total water column > thickness in a given model time step. The steric change measures the > contribution of sea water density to the thickness compared with what it would > be if the same mass of water had standard temperature and salinity doesn't it? > I hadn't understood the names to mean a comparison to mean sea level, but if > that is the intention then we should change the names as Jonathan suggests. > Sebastien, please can you clarify? > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 > 1235 778065 > Centre for Environmental Data Analysis Email: > alison.pamm...@stfc.ac.uk > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Campus, Didcot, OX11 0QX, U.K. > > > > -----Original Message----- > > From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of > > Jonathan Gregory > > Sent: 09 June 2017 14:20 > > To: cf-metadata@cgd.ucar.edu > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model > output > > > > Dear Sebastien and Alison > > > > Sorry to come back to this late, but in view of a more recent discussion, > > it's > > occurred to me that we should put mean_sea_level rather than > > sea_surface_height > > in these three names. By sea_surface_height we mean its instantaneous > level, > > but when we speak of steric SL change we're referring to mean sea level. > > Would > > you agree? > > > > Best wishes > > > > Jonathan > > > > ----- Forwarded message from Sebastien Villaume > > <sebastien.villa...@ecmwf.int> ----- > > > > > Date: Fri, 9 Jun 2017 07:43:19 +0000 > > > From: Sebastien Villaume <sebastien.villa...@ecmwf.int> > > > To: alison pamment <alison.pamm...@stfc.ac.uk> > > > CC: cf-metadata@cgd.ucar.edu, Jonathan Gregory > > <j.m.greg...@reading.ac.uk>, > > > Kevin Marsh <kevin.ma...@ecmwf.int> > > > Subject: Re: New standard names for NEMO ocean model output > > > X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF50 > > (Linux)/8.6.0_GA_1200) > > > > > > Thank you Alison! > > > > > > We (Kevin Marsh and myself) are happy with the amended definitions you > > proposed. > > > > > > only one minor tweak in the last sentence of the > > "steric_change_in_sea_surface_height" definition: I would add "_height" at > the > > end of "steric_change_in_sea_surface". I assume it was intended that way > but > > "_height" got somehow truncated. > > > > > > Best wishes, > > > Sébastien > > > > > > ----- Original Message ----- > > > From: "alison pamment" <alison.pamm...@stfc.ac.uk> > > > To: "sebastien villaume" <sebastien.villa...@ecmwf.int> > > > Cc: cf-metadata@cgd.ucar.edu, "Jonathan Gregory" > > <j.m.greg...@reading.ac.uk> > > > Sent: Thursday, 8 June, 2017 15:28:25 > > > Subject: RE: New standard names for NEMO ocean model output > > > > > > Dear Sebastien, > > > > > > Thank you for once again bringing this back to the list. I agree that the > > discussion seems to have settled on the "steric" names rather than the > > longer > > versions. We need to have definitions, so I've modified the text I suggested > > previously. > > > > > > We now have: > > > steric_change_in_sea_surface_height (m) > > > ' "Sea surface height" is a time-varying quantity. The steric change in > > > sea > > surface height is the change in height that a water column of standard > > temperature T=0°C and practical salinity S=35.0 would undergo when its > > temperature and salinity are changed to the observed values. The sum of the > > quantities with standard names thermosteric_change_in_sea_surface_height > > and halosteric_change_in_sea_surface_height is the total steric change in > the > > water column height, which has the standard name of > > steric_change_in_sea_surface_height. The sum of the quantities with > standard > > names sea_water_mass_per_unit_area_expressed_as_thickness and > > steric_change_in_sea_surface is the total thickness of the sea water > > column.' > > > > > > halosteric_change_in_sea_surface_height (m) > > > ' "Sea surface height" is a time-varying quantity. The halosteric change > > > in > sea > > surface height is the change in height that a water column of standard > practical > > salinity S=35.0 would undergo when its salinity is changed to the observed > > value. The sum of the quantities with standard names > > thermosteric_change_in_sea_surface_height and > > halosteric_change_in_sea_surface_height is the total steric change in the > > water column height, which has the standard name of > > steric_change_in_sea_surface_height.' > > > > > > thermosteric_change_in_sea_surface_height (m) > > > ' "Sea surface height" is a time-varying quantity. The thermosteric > > > change in > > sea surface height is the change in height that a water column of standard > > temperature T=0°C would undergo when its temperature is changed to the > > observed value. The sum of the quantities with standard names > > thermosteric_change_in_sea_surface_height and > > halosteric_change_in_sea_surface_height is the total steric change in the > > water column height, which has the standard name of > > steric_change_in_sea_surface_height.' > > > > > > If you are happy with these then the names can be accepted and added at > the > > next update of the standard name table on 26th June. > > > > > > Best wishes, > > > Alison > > > > > > ------ > > > Alison Pamment Tel: > > > +44 1235 778065 > > > Centre for Environmental Data Analysis Email: > > alison.pamm...@stfc.ac.uk > > > STFC Rutherford Appleton Laboratory > > > R25, 2.22 > > > Harwell Campus, Didcot, OX11 0QX, U.K. > > > > > > > > > > > > > -----Original Message----- > > > > From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On > Behalf > > Of > > > > Sebastien Villaume > > > > Sent: 08 June 2017 13:09 > > > > To: Sebastien Villaume > > > > Cc: cf-metadata@cgd.ucar.edu; Jonathan Gregory > > > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model > > output > > > > > > > > Dear all, > > > > > > > > since nobody is raising any more issues or showing strong feelings in > > > > the > > > > choice of final standard names, I propose to adopt > > > > > > > > steric_change_in_sea_surface_height > > > > halosteric_change_in_sea_surface_height > > > > thermosteric_change_in_sea_surface_height > > > > > > > > > > > > We will start producing variables with these standard names in the > coming > > > > weeks. > > > > > > > > thanks, > > > > /Sébastien > > > > > > > > ----- Original Message ----- > > > > From: "Sebastien Villaume" <sebastien.villa...@ecmwf.int> > > > > To: "Lowry, Roy K." <r...@bodc.ac.uk> > > > > Cc: cf-metadata@cgd.ucar.edu, "Jonathan Gregory" > > > > <j.m.greg...@reading.ac.uk> > > > > Sent: Tuesday, 30 May, 2017 09:42:54 > > > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model > > output > > > > > > > > Dear all, > > > > > > > > we would like to start using the remaining 3 standard names for NEMO > > output. > > > > We only need to reach a consensus on the standard names we would like > to > > > > have: > > > > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_density > > > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_practical_salinit > > > > y > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_temperature > > > > > > > > or > > > > > > > > steric_change_in_sea_surface_height > > > > halosteric_change_in_sea_surface_height > > > > thermosteric_change_in_sea_surface_height > > > > > > > > as I mentioned before, I don't have a strong preference, I only need a > > decision > > > > so that we can using them. > > > > > > > > thanks, > > > > /Sébastien > > > > > > > > ----- Original Message ----- > > > > From: "Lowry, Roy K." <r...@bodc.ac.uk> > > > > To: "Jonathan Gregory" <j.m.greg...@reading.ac.uk>, "Sebastien > Villaume" > > > > <sebastien.villa...@ecmwf.int> > > > > Cc: cf-metadata@cgd.ucar.edu > > > > Sent: Thursday, 27 April, 2017 09:48:42 > > > > Subject: Re: New standard names for NEMO ocean model output > > > > > > > > Dear All, > > > > > > > > > > > > My preference (but not insistence) would be for the more compact > versions > > > > providing steric, halosteric and thermosteric are clearly described in > > > > the > > > > definitions. This is cleaner, less confusing, consistent with past > > > > practice, > > more > > > > likely to be discovered and readily understandable by those who are > > > > likely > > to > > > > need to use the Standard Names. > > > > > > > > > > > > If this is unacceptable to anybody then I'm in total agreement with > Jonathan > > > > that we need to be consistent with existing Standard Names incorporating > > > > 'sterics', which means including both forms and aliasing them. > > > > > > > > > > > > Note that established practice over the past decade has caused 'alias' > > > > to > > come > > > > to mean 'deprecated and replaced by' rather than 'synonym'. > Consequently, > > if > > > > going for the option of adding both forms and replacing the existing > 'sterics' > > > > then the 'sterics' need to be the 'deprecates' and the 'due-tos' need > > > > to be > > the > > > > replacements in all cases. > > > > > > > > > > > > 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 > > enquir...@bodc.ac.uk. > > > > Please also use this e-mail if your requirement is urgent. > > > > > > > > > > > > ________________________________ > > > > From: CF-metadata <cf-metadata-boun...@cgd.ucar.edu> on behalf of > > > > Sebastien Villaume <sebastien.villa...@ecmwf.int> > > > > Sent: 27 April 2017 09:16 > > > > To: Jonathan Gregory > > > > Cc: cf-metadata@cgd.ucar.edu > > > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model > > output > > > > > > > > Dear all, > > > > > > > > I am not a domain expert, I can't really grasp which set of names is > > > > more > > > > suitable. As a non expert, I would favour the first set because it is > > > > more > > explicit. > > > > > > > > That said, I will follow what the domain experts and/or the standard > names > > > > experts would recommend. Please let us know so we can agree and start > > using > > > > these names. > > > > > > > > > > > > Best wishes, > > > > /Sébastien > > > > > > > > ----- Original Message ----- > > > > From: "Jonathan Gregory" <j.m.greg...@reading.ac.uk> > > > > To: cf-metadata@cgd.ucar.edu > > > > Sent: Wednesday, 26 April, 2017 22:36:14 > > > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model > > output > > > > > > > > Dear Sebastien > > > > > > > > > @Jonathan: what would be the standard names if we were using > > > > "_due_to_change_in_" ? Since it is a "change" of height due to a > > > > "change" > > of a > > > > physical property, we end up with: > > > > > > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_density > > > > > > > > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_practical_salinit > > > > y > > > > > > > change_in_sea_surface_height_due_to_change_in_sea_water_temperature > > > > > > > > Yes, I agree, that would be right. > > > > > > > > > It is fine for me but I understand it could look awkward to some > > users/experts. > > > > It is however nicely verbose to help understand what those parameters > are. > > > > > > > > > > If we were removing "_above_sea_floor" from the names proposed by > > Alison: > > > > > > > > > > steric_change_in_sea_surface_height > > > > > halosteric_change_in_sea_surface_height > > > > > thermosteric_change_in_sea_surface_height > > > > > > > > > > it is more compact and elegant but it could be a bit cryptic to non- > experts. > > > > > > > > Yes, I agree with this too. As I mentioned, thermosteric and steric do > appear > > > > in existing names (one each), so we should either rename those with > > due_to, or > > > > use the steric terms here, for consistency. > > > > > > > > > I am fine with both formulations and I agree with Kevin, we could keep > > both > > > > versions and make aliases. > > > > > > > > I am fine too with either of them, but not with aliases for this > > > > purpose. We > > > > use aliases to preserve backwards-compatibility when we change our > > minds, > > > > not > > > > to provide synonyms in the first place. > > > > > > > > Best wishes > > > > > > > > Jonathan > > > > _______________________________________________ > > > > CF-metadata mailing list > > > > CF-metadata@cgd.ucar.edu > > > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > > CF-metadata Info Page - > > > > mailman.cgd.ucar.edu<http://mailman.cgd.ucar.edu/mailman/listinfo/cf- > > > > metadata> > > > > 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 > > > > CF-metadata@cgd.ucar.edu > > > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > > CF-metadata Info Page - > > > > mailman.cgd.ucar.edu<http://mailman.cgd.ucar.edu/mailman/listinfo/cf- > > > > metadata> > > > > mailman.cgd.ucar.edu > > > > This is an unmoderated list for discussions about interpretation, > > clarification, > > > > and proposals for extensions or change to the CF conventions. > > > > > > > > > > > > > > > > ________________________________ > > > > This message (and any attachments) is for the recipient only. 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