Indeed, many thanks for the summary Alison! re: Jonathan's second point could we use the 'non-expert' names and have the 'expert' name as an alias?
Thanks, Kevin ----- Original Message ----- From: "j m gregory" <j.m.greg...@reading.ac.uk> To: cf-metadata@cgd.ucar.edu Sent: Friday, 21 April, 2017 10:25:30 Subject: Re: [CF-metadata] New standard names for NEMO ocean model output Dear Alison and Sebastien Thanks for your summary, Alison. I agree with Sebastien that we do not need above_SURFACE in the sea-level change names, because they are changes, so the reference level cancels out. Picking up Sebastien's other point, I agree that instead of [thermo/halo]steric, we could say due_to_change_in_sea_water_temperature/salinity/density. If I was not an "expert" in this area, indeed I might argue against using the usual words, for the sake of easy understanding by others! These quantities are pretty much always called [thermo/halo]steric, and we already use "steric" in a couple of standard names. However, it would be fine to rename these ones as well if we prefer to avoid more opaque terminology. Best wishes Jonathan ----- Forwarded message from Sebastien Villaume <sebastien.villa...@ecmwf.int> ----- > Date: Tue, 18 Apr 2017 08:20:21 +0000 > From: Sebastien Villaume <sebastien.villa...@ecmwf.int> > To: alison pamment <alison.pamm...@stfc.ac.uk> > CC: cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF50 (Linux)/8.6.0_GA_1200) > > Dear Alison, > > The new standard names you are suggesting for (3), (4) and (5) are > interesting. > > I have few comments: > > when I searched "sea_surface_height" in the latest standard name table, I > noticed standard names with "sea_surface_height_amplitude_due_to", > "sea_surface_height_bias_due_to", and "sea_surface_height_correction_due_to". > would it make sense to use "sea_surface_height_change_due_to" or "due_to" is > only reserved for certain cases (like external physical processes)? > > I am also wondering if the reference "above_X" for the height is needed: the > change in height will be the same whatever the origin chosen (sea floor, > geoid, etc.) because it is the difference between 2 heights sharing the same > reference. In that sense it feels that "steric_change_in_sea_surface_height", > "halosteric_change_in_sea_surface_height" and > "thermosteric_change_in_sea_surface_height" are enough. > > Best wishes, > /Sébastien > > ----- Original Message ----- > From: "alison pamment" <alison.pamm...@stfc.ac.uk> > To: "sebastien villaume" <sebastien.villa...@ecmwf.int>, > cf-metadata@cgd.ucar.edu > Sent: Thursday, 13 April, 2017 17:41:38 > Subject: RE: New standard names for NEMO ocean model output > > Dear Jonathan and Sebastien, > > Thank you both for your comments. I think we are now agreed on the following > names (with definitions as given in my previous email > http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2017/059392.html): > > 1. sea_water_mass_per_unit_area_expressed_as_thickness (m) > 2. > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_threshold > (m) > 2a. The existing name > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity will > become an alias of > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_deficit > (m). > 6. ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale > (K s-1) > 7. ratio_of_sea_water_practical_salinity_anomaly_to_relaxation_timescale (s-1) > 8. integral_of_sea_water_practical_salinity_wrt_depth (m) > > These names are accepted for publication in the standard name table and will > be added at the next update, scheduled for 24th April. > > I think we have also agreed to drop proposal (9) > integral_of_sea_water_practical_salinity_wrt_total_depth (m) because it is > the same quantity as (8). > > For the 'steric' names, Jonathan feels these should indicate that the term > relates to a change in local sea level, rather than simply water column > thickness, and Sebastien is keen that we adopt a common approach for all > three names. We have a number of "sea_surface_height_above_X" names where X > is variously "geoid", "reference_ellipsoid", etc. Based on this syntax I > would then suggest the following names: > > 3. steric_change_in_sea_surface_height_above_sea_floor (m) > ' "Sea surface height" is a time-varying quantity. The steric change in sea > surface height is the change in height 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_above_sea_floor and > halosteric_change_in_sea_surface_height_above_sea_floor is the total steric > change in the water column height, which has the standard name of > steric_change_in_sea_surface_height_above_sea_floor. The sum of the > quantities with standard names > sea_water_mass_per_unit_area_expressed_as_thickness and > steric_change_in_sea_surface_height_above_sea_floor is the total thickness of > the sea water column.' > > 4. halosteric_change_in_sea_surface_height_above_sea_floor (m) > ' "Sea surface height" is a time-varying quantity. The halosteric change in > sea surface height is the change in height 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_above_sea_floor and > halosteric_change_in_sea_surface_height_above_sea_floor is the total steric > change in the water column height, which has the standard name of > steric_change_in_sea_surface_height_above_sea_floor.' > > 5. thermosteric_change_in_sea_surface_height_above_sea_floor (m) > ' "Sea surface height" is a time-varying quantity. The thermosteric change in > sea surface height is the change in height 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_above_sea_floor and > halosteric_change_in_sea_surface_height_above_sea_floor is the total steric > change in the water column height, which has the standard name of > steric_change_in_sea_surface_height_above_sea_floor.' > > Are these better? > > 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: 05 April 2017 11:51 > > To: cf-metadata@cgd.ucar.edu > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > > > > > Dear Alison et al, > > > > we are happy with your suggestions/modifications. > > > > I also understand from your comments to > > integral_of_sea_water_practical_salinity_wrt_depth that my proposal to > > rename > > integral_of_sea_water_potential_temperature_wrt_depth_expressed_as_heat_ > > content for consistency is no longer required. > > > > > > Regarding Jonathan comments, I think we (Eric, Kevin, myself) are fine with > > "thickness", "thickness_change", "height" or "height_change" for the steric, > > halosteric and thermosteric contributions as long as it is consistent for > > the > > three standard names and other related names. > > > > In the future, we may want to produce the steric, halosteric and > > thermosteric > > contributions of each water cell of the column, not only for the whole water > > column. The definitions of the present standard names and the possibility to > > derive new standard names for this future situation need to be taken into > > account. > > > > one more question: what is the standard name corresponding to > > sea_water_mass_per_unit_area_expressed_as_thickness (at 0degC, 35psu) + > > ocean_steric_thickness? i.e the total thickness of the water column? it is > > not > > clear to me if it exists or if we should use > > sea_water_mass_per_unit_area_expressed_as_thickness and point to an > > auxiliary variable sea_water_density at XdegC and Ypsu... > > > > thanks, > > Sebastien > > > > ____________________________________ > > > > Dr. Sébastien Villaume > > Analyst > > ECMWF Shinfield Park, > > Reading RG2 9AX, UK > > +44 7825 521592 > > sebastien.villa...@ecmwf.int > > ____________________________________ > > > > ----- Original Message ----- > > From: "Jonathan Gregory" <j.m.greg...@reading.ac.uk> > > To: cf-metadata@cgd.ucar.edu > > Sent: Tuesday, 4 April, 2017 21:13:08 > > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > > > Dear Alison > > > > Thank you for your careful and sensible analysis, as always. I agree with > > all > > your proposals except that I'm sorry to say I'm not happy about the steric > > height yet. I don't seek to insist on what I suggested before, but I don't > > think the proposal so far matches scientific terminology as far as I'm > > aware. > > > > > 3. ocean_steric_thickness (m) > > > 4. ocean_halosteric_thickness (m) > > > 5. ocean_thermosteric_thickness (m) > > > > I understand these to mean the *change* in the thickness of the water column > > caused by change to sea water density, due to change in T and S. That's what > > your definitions indicate. If it's a change in thickness, it's confusing to > > call it a thickness, I would say. People often refer to quantities of > > "steric/ > > halosteric/thermosteric sea level change", which I think are the same as > > what > > we're talking about here. The change in thickness of the water column (the > > vertical distance from the sea floor to the sea surface) is of course the > > same > > thing as local sea level change. > > > > Best wishes > > > > Jonathan > > _______________________________________________ > > CF-metadata mailing list > > CF-metadata@cgd.ucar.edu > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > _______________________________________________ > > CF-metadata mailing list > > CF-metadata@cgd.ucar.edu > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
