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
