Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Jonathan and Sebastien, Thank you both again. The NEMO names are now agreed and they are accepted for publication in the standard name table. The next update is planned for 26th June. N.B. I will also amend the definition of sea_water_mass_per_unit_area_expressed_as_thickness because it cross-references with steric_change_in_sea_surface_height. I have some comments about Jonathan's proposal for steric mean sea level changes. I'll put those in a separate thread. 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: Jonathan Gregory [mailto:j.m.greg...@reading.ac.uk] > Sent: 13 June 2017 15:00 > To: Sebastien Villaume > Cc: Pamment, Alison (STFC,RAL,RALSP); cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > Dear Alison and Sebastien > > I am happy too, with the clarification that it's SSH which is wanted in this > case. Thanks for the discussion. > > Although I haven't an immediate use-case, I would say it's very likely that > the > corresponding stdnames for mean sea level change will be wanted sometime. > They > are quantities which I have often calculated and plotted, for example, but not > yet archived in CF-netCDF files! If we add those quantities to the standard > name table now as well, it might avoid people using the SSH names when really > they mean MSL. That is, I'd propose we also add > > thermosteric_change_in_[mean_]sea_level > halosteric_change_in_[mean_]sea_level > steric_change_in_[mean_]sea_level > > I put [mean] in brackets because I'm not sure whether we've decided to include > "mean" in MSL names (that's a different discussion). The above quantities are > not global average; we already have global average names. > > Best wishes > > Jonathan > > > On Tue, Jun 13, 2017 at 01:22:31PM +, Sebastien Villaume wrote: > > Date: Tue, 13 Jun 2017 13:22:31 + > > From: Sebastien Villaume <sebastien.villa...@ecmwf.int> > > To: alison pamment <alison.pamm...@stfc.ac.uk> > > CC: Jonathan Gregory <j.m.greg...@reading.ac.uk>, cf- > metad...@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, > > > > thank you very much for your thorough search and the time spent on this! > > > > We are happy with the names and definitions. > > > > thanks again > > > > Best wishes, > > /Sébastien > > > > - Original Message - > > From: "alison pamment" <alison.pamm...@stfc.ac.uk> > > To: "sebastien villaume" <sebastien.villa...@ecmwf.int> > > Cc: "Jonathan Gregory" <j.m.greg...@reading.ac.uk>, cf- > metad...@cgd.ucar.edu > > Sent: Tuesday, 13 June, 2017 14:03:31 > > Subject: RE: [CF-metadata] New standard names for NEMO ocean model > output > > > > Dear Sebastien and Jonathan, > > > > Thank you for clarifying the definition of the > steric_change_in_sea_surface_height names. The only question now is > whether to use the word 'steric' to describe the concept. > > > > I did a brief internet search which turned up lots of links to articles > > about > global sea level change, so I then wondered if 'steric' is only used in > oceanography to talk about global and/or long term changes which might mean > we shouldn't use it for the NEMO names. However, I then found the following in > the AMS glossary which I often turn to as a reference: "Specific-volume > anomaly > (or anomaly of specific volume; also called steric anomaly; symbol δ.) In > oceanography, the excess of the actual specific volume of the seawater at any > point in the ocean over the specific volume of seawater of salinity 35 psu and > temperature 0°C at the same pressure." > (http://glossary.ametsoc.org/wiki/Steric_anomaly) (N.B. "Specific" means per > unit mass). This definition sounds exactly like that used in the NEMO > quantities > - it isn't only a global quantity and doesn't require mean sea level as a > baseline. > > > > Our existing 'steric' names use the term more loosely: > > global_average_steric_sea_level_change > > 'Global average steric sea level change is caused by changes in sea water > density due to changes in temperature (thermosteric) and salinity > (halost
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Alison and Sebastien I am happy too, with the clarification that it's SSH which is wanted in this case. Thanks for the discussion. Although I haven't an immediate use-case, I would say it's very likely that the corresponding stdnames for mean sea level change will be wanted sometime. They are quantities which I have often calculated and plotted, for example, but not yet archived in CF-netCDF files! If we add those quantities to the standard name table now as well, it might avoid people using the SSH names when really they mean MSL. That is, I'd propose we also add thermosteric_change_in_[mean_]sea_level halosteric_change_in_[mean_]sea_level steric_change_in_[mean_]sea_level I put [mean] in brackets because I'm not sure whether we've decided to include "mean" in MSL names (that's a different discussion). The above quantities are not global average; we already have global average names. Best wishes Jonathan On Tue, Jun 13, 2017 at 01:22:31PM +, Sebastien Villaume wrote: > Date: Tue, 13 Jun 2017 13:22:31 + > From: Sebastien Villaume <sebastien.villa...@ecmwf.int> > To: alison pamment <alison.pamm...@stfc.ac.uk> > CC: Jonathan Gregory <j.m.greg...@reading.ac.uk>, 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, > > thank you very much for your thorough search and the time spent on this! > > We are happy with the names and definitions. > > thanks again > > Best wishes, > /Sébastien > > - Original Message - > From: "alison pamment" <alison.pamm...@stfc.ac.uk> > To: "sebastien villaume" <sebastien.villa...@ecmwf.int> > Cc: "Jonathan Gregory" <j.m.greg...@reading.ac.uk>, cf-metadata@cgd.ucar.edu > Sent: Tuesday, 13 June, 2017 14:03:31 > Subject: RE: [CF-metadata] New standard names for NEMO ocean model output > > Dear Sebastien and Jonathan, > > Thank you for clarifying the definition of the > steric_change_in_sea_surface_height names. The only question now is whether > to use the word 'steric' to describe the concept. > > I did a brief internet search which turned up lots of links to articles about > global sea level change, so I then wondered if 'steric' is only used in > oceanography to talk about global and/or long term changes which might mean > we shouldn't use it for the NEMO names. However, I then found the following > in the AMS glossary which I often turn to as a reference: "Specific-volume > anomaly (or anomaly of specific volume; also called steric anomaly; symbol > δ.) In oceanography, the excess of the actual specific volume of the seawater > at any point in the ocean over the specific volume of seawater of salinity 35 > psu and temperature 0°C at the same pressure." > (http://glossary.ametsoc.org/wiki/Steric_anomaly) (N.B. "Specific" means per > unit mass). This definition sounds exactly like that used in the NEMO > quantities - it isn't only a global quantity and doesn't require mean sea > level as a baseline. > > Our existing 'steric' names use the term more loosely: > global_average_steric_sea_level_change > 'Global average steric sea level change is caused by changes in sea water > density due to changes in temperature (thermosteric) and salinity > (halosteric). Zero sea level change is an arbitrary level.' > global_average_thermosteric_sea_level_change > 'Global average thermosteric sea level change is the part caused by change in > density due to change in temperature i.e. thermal expansion. Zero sea level > change is an arbitrary level.' > I don't think this is inconsistent with the new names because of the sentence > about an arbitrary zero for the global sea level change. Also, in these names > we do say 'sea_level', so here we are definitely talking about the change in > mean sea level. > > So, for the NEMO names, I think we should stick with what we had previously > agreed (with the typo in the first definition now fixed). > 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 > nam
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Alison, thank you very much for your thorough search and the time spent on this! We are happy with the names and definitions. thanks again Best wishes, /Sébastien - Original Message - From: "alison pamment" <alison.pamm...@stfc.ac.uk> To: "sebastien villaume" <sebastien.villa...@ecmwf.int> Cc: "Jonathan Gregory" <j.m.greg...@reading.ac.uk>, cf-metadata@cgd.ucar.edu Sent: Tuesday, 13 June, 2017 14:03:31 Subject: RE: [CF-metadata] New standard names for NEMO ocean model output Dear Sebastien and Jonathan, Thank you for clarifying the definition of the steric_change_in_sea_surface_height names. The only question now is whether to use the word 'steric' to describe the concept. I did a brief internet search which turned up lots of links to articles about global sea level change, so I then wondered if 'steric' is only used in oceanography to talk about global and/or long term changes which might mean we shouldn't use it for the NEMO names. However, I then found the following in the AMS glossary which I often turn to as a reference: "Specific-volume anomaly (or anomaly of specific volume; also called steric anomaly; symbol δ.) In oceanography, the excess of the actual specific volume of the seawater at any point in the ocean over the specific volume of seawater of salinity 35 psu and temperature 0°C at the same pressure." (http://glossary.ametsoc.org/wiki/Steric_anomaly) (N.B. "Specific" means per unit mass). This definition sounds exactly like that used in the NEMO quantities - it isn't only a global quantity and doesn't require mean sea level as a baseline. Our existing 'steric' names use the term more loosely: global_average_steric_sea_level_change 'Global average steric sea level change is caused by changes in sea water density due to changes in temperature (thermosteric) and salinity (halosteric). Zero sea level change is an arbitrary level.' global_average_thermosteric_sea_level_change 'Global average thermosteric sea level change is the part caused by change in density due to change in temperature i.e. thermal expansion. Zero sea level change is an arbitrary level.' I don't think this is inconsistent with the new names because of the sentence about an arbitrary zero for the global sea level change. Also, in these names we do say 'sea_level', so here we are definitely talking about the change in mean sea level. So, for the NEMO names, I think we should stick with what we had previously agreed (with the typo in the first definition now fixed). 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_height 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.' For the existing steric names, I think we should add our usual text about 'sea_level' to the definitions: global_average_steric_sea_level_change 'Global average steric sea level change is caused by changes in sea water density due to changes in temperature (thermosteric) and salinity (halosteric). Zero sea level change is an arbitrary level. "Sea level" means mean sea level.' global_average_thermosteric_sea_level_change 'Global average thermosteric sea level change is the p
Re: [CF-metadata] New standard names for NEMO ocean model output
ailto:sebastien.villa...@ecmwf.int] > Sent: 13 June 2017 11:39 > To: Pamment, Alison (STFC,RAL,RALSP) > Cc: Jonathan Gregory; cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > 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_salinit > y > 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 > > > > >
Re: [CF-metadata] New standard names for NEMO ocean model output
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 + > > > From: Sebastien Villaume <sebastien.vill
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 + > > > 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...@readi
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 + > > 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_
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 + > 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
Re: [CF-metadata] New standard names for NEMO ocean model output
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 > > ster
Re: [CF-metadata] 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
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_salinity 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_salinity > 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 eithe
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_salinity 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_salinity > 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 discussi
Re: [CF-metadata] 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_salinity > 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. NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
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_salinity > 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 mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
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_salinity > 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
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Alison and Jonathan, thank you for your comments. @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_salinity change_in_sea_surface_height_due_to_change_in_sea_water_temperature 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. I am fine with both formulations and I agree with Kevin, we could keep both versions and make aliases. Best wishes, /Sébastien - 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 + > 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 updat
Re: [CF-metadata] New standard names for NEMO ocean model output
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 + > 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 hei
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 + > 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
Re: [CF-metadata] New standard names for NEMO ocean model output
- 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
Re: [CF-metadata] 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
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
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
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Sebastien, I have been discussing these names again off-list with the proposer Kevin Marsh over the last few days. I think we are making good progress and I am doing some more work on the definitions of the names. I will post a summary of progress on all these names within the next day or so. Thanks for looking at the names again. 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: 30 March 2017 09:08 > To: cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard names for NEMO ocean model output > > > Hi all, > > I would like to reactivate this specific thread in order to reach an agreement > and get these standard names accepted and published in the next version of > the table. > > I went through the whole thread and updated each proposed standard name > according to the comments/suggestions made (please see below). > > I have also added two new standard names: one to deprecate an existing > standard name that is not following the usual naming convention > (integral_of_sea_water_potential_temperature_wrt_depth_in_ocean_layer_exp > ressed_as_heat_content) and one derived from it to cover the whole sea water > column case. It is the last two of the list below. > > Since I am not an ocean model expert and in particular not a NEMO expert/user, > I am welcoming any relevant comments/suggestions, especially from the NEMO > community. > > thanks > > > NEMO variable: > somixhgt > standard name: > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_threshold > (originally proposed as ocean_turbocline_depth) > units: > m > > description: > The mixed layer thickness is estimated using the depth at which the vertical > eddy diffusivity coefficient (resulting from the vertical physics alone) fall > below > a given value defined locally. A coordinate variable or scalar coordinate > variable with standard name ocean_vertical_diffusivity can be specified to > indicate the value of the coefficient that was used to calculate the mixed > layer > thickness. > > other action to take (suggested by Jonathan Gregory): > rename the existing the standard > name ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity > which refers to the level at which the diffusivity differs from its surface > value by > a certain amount, as > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_deficit > > > > NEMO variable: > sobpheig > standard name: > sea_water_mass_per_unit_area_expressed_as_thickness > (originally proposed as bottom_pressure_equivalent_height) > units: > m > > description: > This is the mass of the water column expressed as a thickness using a given > reference density: > > sea_water_mass_per_unit_area_expressed_as_thickness = ( > sea_water_mass_per_unit_area / sea_water_density ) > > The thickness is the extent of a vertical column or layer. The sea water > density > used to do the conversion is assumed to be the density of water of standard > temperature T=0°C and practical salinity S=35.0. Otherwise it should be > provided as an auxiliary scalar using the standard name sea_water_density. > > > > NEMO variable: > sostheig > standard name: > ocean_steric_thickness > (originally proposed as ocean_steric_height) > units: > m > > description: > The ocean steric thickness measures the height by which a column of water > with standard temperature T=0°C and salinity S=35.0 expands if its temperature > and salinity are changed to the observed values. > > > > NEMO variable: > vosthsal > standard name: > ocean_halosteric_thickness > (originally proposed as ocean_steric_thickness_due_to_salinity) > units: > m > > description: > The quantity with standard name ocean_halosteric_thickness is a measure of > the change in thickness that would be undergone by a column of water of > standard temperature T=0°C and practical salinity S=35.0 if its salinity were > changed to the locally observed value. Thickness is the extent of a vertical > column or layer. > > > NEMO variable: > vosthtem > standard name: > ocean_thermosteric_thickness > (originally proposed as ocean_steric_thickness_due_to_temperature) > units: >
Re: [CF-metadata] New standard names for NEMO ocean model output
Hi all, I would like to reactivate this specific thread in order to reach an agreement and get these standard names accepted and published in the next version of the table. I went through the whole thread and updated each proposed standard name according to the comments/suggestions made (please see below). I have also added two new standard names: one to deprecate an existing standard name that is not following the usual naming convention (integral_of_sea_water_potential_temperature_wrt_depth_in_ocean_layer_expressed_as_heat_content) and one derived from it to cover the whole sea water column case. It is the last two of the list below. Since I am not an ocean model expert and in particular not a NEMO expert/user, I am welcoming any relevant comments/suggestions, especially from the NEMO community. thanks NEMO variable: somixhgt standard name: ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_threshold (originally proposed as ocean_turbocline_depth) units: m description: The mixed layer thickness is estimated using the depth at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) fall below a given value defined locally. A coordinate variable or scalar coordinate variable with standard name ocean_vertical_diffusivity can be specified to indicate the value of the coefficient that was used to calculate the mixed layer thickness. other action to take (suggested by Jonathan Gregory): rename the existing the standard name ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity which refers to the level at which the diffusivity differs from its surface value by a certain amount, as ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_deficit NEMO variable: sobpheig standard name: sea_water_mass_per_unit_area_expressed_as_thickness (originally proposed as bottom_pressure_equivalent_height) units: m description: This is the mass of the water column expressed as a thickness using a given reference density: sea_water_mass_per_unit_area_expressed_as_thickness = ( sea_water_mass_per_unit_area / sea_water_density ) The thickness is the extent of a vertical column or layer. The sea water density used to do the conversion is assumed to be the density of water of standard temperature T=0°C and practical salinity S=35.0. Otherwise it should be provided as an auxiliary scalar using the standard name sea_water_density. NEMO variable: sostheig standard name: ocean_steric_thickness (originally proposed as ocean_steric_height) units: m description: The ocean steric thickness measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values. NEMO variable: vosthsal standard name: ocean_halosteric_thickness (originally proposed as ocean_steric_thickness_due_to_salinity) units: m description: The quantity with standard name ocean_halosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its salinity were changed to the locally observed value. Thickness is the extent of a vertical column or layer. NEMO variable: vosthtem standard name: ocean_thermosteric_thickness (originally proposed as ocean_steric_thickness_due_to_temperature) units: m description: The quantity with standard name ocean_thermosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its temperature were changed to the locally observed value. Thickness is the extent of a vertical column or layer. NEMO variable: vottrdmp standard name: ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (originally proposed as temperature_profile_anomaly_correction) units: K s-1 description: This term is estimated as the deviation of the local sea water potential temperature from an ocean model with respect to an observation-based climatology (eg World Ocean Database) weighted by a user-specified relaxation coefficient in s-1 (1/(relaxation timescale)). NEMO variable: vostrdmp standard name: ratio_of_sea_water_practical_salinity_anomaly_to_relaxation_timescale (originally proposed as practical_salinity_profile_anomaly_correction) units: s-1 description: This term is estimated as the deviation of the local sea water practical salinity from an ocean model with respect to an observation-based climatology (eg World Ocean Database) weighted by a user-specified relaxation coefficient in s-1 (1/(relaxation timescale)). NEMO variables: sosal300, sosal700 standard name:
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Eric OK. In that case, I would suggest we rename the existing standard_name ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity which refers to the level at which the diffusivity differs from its surface value by a certain amount, as ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_deficit using an alias, and we introduce a new standard name for your definition of ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity_threshold which refers to the level at which the diffusivity falls below a threshold value (not referred to the surface). Woudl that be OK? Best wishes Jonathan On Wed, Jan 11, 2017 at 11:30:19AM +, Eric Boisseson wrote: > Date: Wed, 11 Jan 2017 11:30:19 + > From: Eric Boisseson <eric.boisse...@ecmwf.int> > To: j.m.greg...@reading.ac.uk, cf-metadata@cgd.ucar.edu > CC: Sebastien Villaume <sebastien.villa...@ecmwf.int>, Kevin Marsh > <kevin.ma...@ecmwf.int> > Subject: Re: [CF-metadata] Re: New standard names for NEMO ocean model > output > X-Mailer: Zimbra 8.6.0_GA_1200 (ZimbraWebClient - FF45 > (Linux)/8.6.0_GA_1200) > > Dear Johnatan, > > Sorry for the delayed answer. > > >> If we could clarify the "defined by" part, would you be content to > >> describe the turbocline as a mixed layer (with appropriate definition)? > > Yes, I'll be fine with that. > > Best regards, > > Eric > > - Forwarded Message - > From: "Jonathan Gregory" <j.m.greg...@reading.ac.uk> > To: cf-metadata@cgd.ucar.edu > Sent: Tuesday, 13 December, 2016 17:46:50 > Subject: [CF-metadata] Fwd: Re: New standard names for NEMO ocean model output > > Dear Eric > > Yes, I see what you mean. If we could clarify the "defined by" part, would you > be content to describe the turbocline as a mixed layer (with appropriate > definition)? > > Best wishes > > Jonathan > > > - ocean_turbocline_thickness in m > > The turbocline thickness is similar to the mixed layer thickness but is > > estimated in models as the thickness at which the vertical eddy diffusivity > > coefficient (resulting from the vertical physics alone) falls below a given > > value defined locally. > > > > You mentioned that this is the same as > > ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity. > > > > But the definition for this one in the CF 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, > > sigma_theta, or vertical diffusivity is the level at which the quantity > > indicated differs from its surface value by a certain amount. The amount by > > which the quantity differs can be specified by a scalar coordinate > > variable." > > > > Unlike with temperature or density criteria, the turbocline thickness is > > not estimated based on the difference with respect to the vertical > > diffusivity at the surface. As written in the definition we gave you, when > > the vertical diffusivity falls below a given value defined locally then we > > are at the turbocline depth. > > > > ######### > > > > I hope this helps. > > > > Best regards, > > > > Eric > > > > > > > > > > - Original Message - > > From: "Kevin Marsh" <kevin.ma...@ecmwf.int> > > To: "Eric Boisseson" <eric.boisse...@ecmwf.int> > > Sent: Tuesday, 13 December, 2016 14:35:48 > > Subject: Fwd: [CF-metadata] New standard names for NEMO ocean model output > > > > Hi Eric, > > some feedback on your feedback...feel free to send any responses directly > > to the list, or to me if you prefer and i will send the comments to the > > list. > > I think that he's happy with 1, so only need input for 2. and 3., > > Thanks, > > Kevin > > > > - Forwarded Message - > > From: "j m gregory" <j.m.greg...@reading.ac.uk> > > To: cf-metadata@cgd.ucar.edu > > Sent: Tuesday, 13 December, 2016 13:56:41 > > Subject: [CF-metadata] New standard names for NEMO ocean model output > > > > Dear Kevin > > > > > 1. bottom_pressure_equivalent_height (m) > > > 3. ocean_steric_height (m) > > > > > > The steric height is estimated as the vertical integral of the density > > > (relative to a reference density where T=0K and S=35psu). The bottom > > > pressure is the mass of the water column at a given location. > > > >
[CF-metadata] New standard names for NEMO ocean model output
Dear Kevin > 1. bottom_pressure_equivalent_height (m) > 3. ocean_steric_height (m) > > The steric height is estimated as the vertical integral of the density > (relative to a reference density where T=0K and S=35psu). The bottom pressure > is the mass of the water column at a given location. Ah, I see. For > 3. ocean_steric_height_above_sea_level (m) I would suggest > The ocean steric height above sea level measures the change in thickness of a > column of water when its temperature and salinity are changed from standard > values of 0°C and 0.035 to the actual values > The bottom pressure equivalent height is estimated indirectly as the > difference between the steric height and the sea level. I don't follow that, which sounds like the definition of ocean steric height again. However your alternative statement of its being the mass of the column makes sense to me. Going with the latter definition, I would suggest sea_water_mass_per_unit_area_expressed_as_thickness and presumably you have to state a standard density to be used in this conversion - what is that? NB sea_water_mass_per_unit_area (kg m-2) is already a standard name. > 2. Instead of "ocean_turbocline_depth (m)" we suggest: > ocean_turbocline_thickness (m) > 'The turbocline thickness is similar to the mixed layer thickness but is > estimated in models as the thickness at which the vertical eddy diffusivity > coefficient (resulting from the vertical physics alone) falls below a given > value defined locally.' Is there a difference between that and the existing ocean_mixed_layer_thickness_defined_by_vertical_tracer_diffusivity ? > ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (K > s-1) > > 'This term is estimated as the deviation of the local sea water potential > temperature from an ocean model wrt an observation-based climatology (eg > World Ocean Database) weighted by a user-specified relaxation coefficient in > s-1 (1/(relaxation timescale)). The relaxation coefficient depends on the > timescale on which the correction is applied.' It seems to me that the last sentence is probably not necessary, since the previous sentence says the same. Best wishes and thanks Jonathan ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] New standard names for NEMO ocean model output
Hi Jonathan, many thanks for your comments. I've been spoken to members of our NEMO team and their responses are below. ** For 1. bottom_pressure_equivalent_height (m) 'Difference between the sea level height and the ocean steric height.' and 3. ocean_steric_height (m) 'The steric measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values.' The idea behind these two variables is that local sea level variations can be divided into volume changes (or steric changes) and mass changes (visible in the eq bottom pressure height). The steric height is estimated as the vertical integral of the density (relative to a reference density where T=0K and S=35psu). The bottom pressure is the mass of the water column at a given location. The bottom pressure equivalent height is estimated indirectly as the difference between the steric height and the sea level. This is just a diagnostic variable we use to check the mass budget in our system. (we'll gladly accept you suggestion, and if 'ocean_steric_height' is a thickness we'd be happy to change it to 'ocean_steric_thickness' as long as the definition is correctly stated) so we suggest: 1. bottom_pressure_equivalent_height (m) 'Difference between the sea level height and the ocean steric height above sea level.' 3. ocean_steric_height_above_sea_level (m) 'The steric measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values.' ** 2. Instead of "ocean_turbocline_depth (m)" we suggest: ocean_turbocline_thickness (m) 'The turbocline thickness is similar to the mixed layer thickness but is estimated in models as the thickness at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) falls below a given value defined locally.' ** 6. temperature_profile_anomaly_correction (K s-1) This is a temperature difference in K weighted by a relaxation coefficient in s-1 (1/(relaxation timescale)). The relaxation timescale represents how strongly you want your model to be close to climatology. we would be happy with your suggestion: ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale (K s-1) 'This term is estimated as the deviation of the local sea water potential temperature from an ocean model wrt an observation-based climatology (eg World Ocean Database) weighted by a user-specified relaxation coefficient in s-1 (1/(relaxation timescale)). The relaxation coefficient depends on the timescale on which the correction is applied.' ** Thanks, Kevin - Original Message - From: "j m gregory" <j.m.greg...@reading.ac.uk> To: cf-metadata@cgd.ucar.edu Cc: "Kevin Marsh" <kevin.ma...@ecmwf.int> Sent: Thursday, 24 November, 2016 17:09:18 Subject: Re: [CF-metadata] New standard names for NEMO ocean model output Dear Kevin and Alison > 1. bottom_pressure_equivalent_height (m) > 'Difference between the sea level height and the ocean steric height.' Is that really what it means? The ocean steric height is already a difference from sea level by definition (see below). It sounds as though this ought to mean the ocean bottom pressure converted into a thickness of water of some standard density. > 2. ocean_turbocline_depth (m) > 'The turbocline depth is similar to the mixed layer depth but is estimated in > models as the depth at which the vertical eddy diffusivity coefficient > (resulting from the vertical physics alone) fall below a given value defined > locally. For consistent with the mixed layer names, this should perhaps be thickness, rather than depth e.g. ocean_mixed_layer_thickness. > 3. ocean_steric_height (m) > 'The steric measures the height by which a column of water with standard > temperature T=0°C and salinity S=35.0 expands if its temperature and salinity > are changed to the observed values.' I have found that definition in papers too. It's actually a thickness, as Alison notes, but we could maybe call it ocean_steric_height_above_sea_level, which would be consistent with some other std names. > 6. temperature_profile_anomaly_correction (K s-1) > 'Correction term estimated as the deviation the local sea water potential > temperature from an ocean model wrt to an observation-based climatology (eg > World Ocean Database) multiplied by an user-specified relaxation coefficient. > The relaxation coefficient depends on the timescale on which the correction > is applied.' I think there are number of problems with this name. (a) It should be sea_water_potential_temperature, not just temperature, (b) profile is not really part of the definition of the quantity - it de
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Kevin and Alison > 1. bottom_pressure_equivalent_height (m) > 'Difference between the sea level height and the ocean steric height.' Is that really what it means? The ocean steric height is already a difference from sea level by definition (see below). It sounds as though this ought to mean the ocean bottom pressure converted into a thickness of water of some standard density. > 2. ocean_turbocline_depth (m) > 'The turbocline depth is similar to the mixed layer depth but is estimated in > models as the depth at which the vertical eddy diffusivity coefficient > (resulting from the vertical physics alone) fall below a given value defined > locally. For consistent with the mixed layer names, this should perhaps be thickness, rather than depth e.g. ocean_mixed_layer_thickness. > 3. ocean_steric_height (m) > 'The steric measures the height by which a column of water with standard > temperature T=0°C and salinity S=35.0 expands if its temperature and salinity > are changed to the observed values.' I have found that definition in papers too. It's actually a thickness, as Alison notes, but we could maybe call it ocean_steric_height_above_sea_level, which would be consistent with some other std names. > 6. temperature_profile_anomaly_correction (K s-1) > 'Correction term estimated as the deviation the local sea water potential > temperature from an ocean model wrt to an observation-based climatology (eg > World Ocean Database) multiplied by an user-specified relaxation coefficient. > The relaxation coefficient depends on the timescale on which the correction > is applied.' I think there are number of problems with this name. (a) It should be sea_water_potential_temperature, not just temperature, (b) profile is not really part of the definition of the quantity - it depends on depth, but standard names do not usually indicate which coordinates are relevant, (c) it's not obvious what an "anomaly correction" means. It might equally well mean something in K, for instance, because all other "corrections" are in fact quantities with the same units as the thing being corrected. I would suggest calling this ratio_of_sea_water_potential_temperature_anomaly_to_relaxation_timescale Best wishes Jonathan ___ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
Re: [CF-metadata] New standard names for NEMO ocean model output
Dear Kevin, Thank you for your proposals and apologies for the delay in responding. Your proposals have all been added to the CEDA vocabulary editor and can be viewed at the following link: http://cfeditor.ceda.ac.uk/proposals/1?status=active==Marsh+and+display=Filter. Please see below for my detailed comments on each name. 1. bottom_pressure_equivalent_height (m) 'Difference between the sea level height and the ocean steric height.' Units of m are fine. Thinking first about the definition, in CF standard names we always use 'sea level' to mean mean sea level and 'steric' is defined in sea level change names as 'Global average steric sea level change is caused by changes in sea water density due to changes in temperature (thermosteric) and salinity (halosteric).' From this I would understand your quantity to be the difference between mean sea level and the local sea level due to the temperature and salinity of the water column. Is that correct? If so, then as a non-ocean expert I find the name rather confusing and I'd prefer something more explicit, e.g., difference_of_ocean_steric_height_from_sea_level and we'd add a sentence to the definition explaining that 'steric height' refers to temperature and salinity effects on the density of the water column. Does that sound OK? 2. ocean_turbocline_depth (m) 'The turbocline depth is similar to the mixed layer depth but is estimated in models as the depth at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) fall below a given value defined locally. I think the name and units look fine. If you wanted to also be able to specify what value of the vertical eddy diffusivity coefficient was used to calculate the turbocline depth, it could be specified in a scalar coordinate variable and I'd suggest adding some words to the definition along those lines: 'The turbocline depth is similar to the mixed layer depth but is estimated in models as the depth at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) fall below a given value defined locally. A coordinate variable or scalar coordinate variable with standard name ocean_vertical_diffusivity can be specified to indicate the value of the coefficient that was used to calculate the turbocline depth.' ocean_vertical_diffusivity already exists as a standard name and is defined as ' "Vertical diffusivity" means the vertical component of diffusivity due to motion which is not resolved on the grid scale of the model.' OK? 3. ocean_steric_height (m) 'The steric measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values.' To make this name consistent with proposals 4 and 5 below, I'd call this one ocean_steric_thickness because it's really referring to changes in the thickness of the water column rather than a height above any particular surface. Then the definition could read: 'The quantity with standard name ocean_steric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its temperature and salinity were changed to the locally observed values. Thickness is the extent of a vertical column or layer.' OK? 4. ocean_steric_thickness_due_to_salinity (m) 'Contribution of the salinity of the water column to the Ocean steric height.' In an off list discussion prior to the submission of these names I suggested 'due_to_salinity' for this name, but I am now having a rethink because most often we use the phrase 'due_to' to refer to some process in the model (e.g. due_to_convection) which isn't quite the case here. Also, when reading through our existing steric sea level change names the definitions refer to thermosteric and halosteric components, which do apply to this case. Hence, I'd suggest changing the name to ocean_halosteric_thickness which also has the advantage of being shorter. Then the definition could read: 'The quantity with standard name ocean_halosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical salinity S=35.0 if its salinity were changed to the locally observed value. Thickness is the extent of a vertical column or layer. There are also standard names for ocean_steric_thickness and ocean_halosteric_thickness.' OK? 5. ocean_steric_thickness_due_to_temperature (m) 'Contribution of the temperature of the water column to the Ocean steric height.' As per my comments on proposal 4, I suggest changing this name to 'ocean_thermosteric_thickness' and then the definition would be: 'The quantity with standard name ocean_thermosteric_thickness is a measure of the change in thickness that would be undergone by a column of water of standard temperature T=0°C and practical
[CF-metadata] New standard names for NEMO ocean model output
Hello all, We are working with some NEMO ocean model output data and would like to request new standard names for a number of the NEMO variables. The list of these variables is below, in the form: NEMO variable name : proposed CF Standard name proposed definition. proposed units. # sobpheig: bottom_pressure_equivalent_height Difference between the sea level height and the ocean steric height. (units = m) somixhgt: ocean_turbocline_depth The turbocline depth is similar to the mixed layer depth but is estimated in models as the depth at which the vertical eddy diffusivity coefficient (resulting from the vertical physics alone) fall below a given value defined locally. (units = m) vostheig: ocean_steric_height The steric measures the height by which a column of water with standard temperature T=0°C and salinity S=35.0 expands if its temperature and salinity are changed to the observed values (units = m) vosthsal: ocean_steric_thickness_due_to_salinity Contribution of the salinity of the water column to the Ocean steric height. (units = m) vosthtem: ocean_steric_thickness_due_to_temperature Contribution of the temperature of the water column to the Ocean steric height. (units = m) vottrdmp: temperature_profile_anomaly_correction Correction term estimated as the deviation the local sea water potential temperature from an ocean model wrt to an observation-based climatology (eg World Ocean Database) multiplied by an user-specified relaxation coefficient. The relaxation coefficient depends on the timescale on which the correction is applied. (units = K/s) vostrdmp: practical_salinity_profile_anomaly_correction Correction term estimated as the deviation the local sea water salinity from an ocean model wrt to an observation-based climatology (eg World Ocean Database) multiplied by an user-specified relaxation coefficient. The relaxation coefficient depends on the timescale on which the correction is applied. (units = s-1) sosal[300,700]: integral_of_sea_water_practical_salinity_wrt_depth (units = m ) This quantity is calculated as the integral, of the sea water salinty wrt depth, over the specified layer of the ocean from the surface to the level indicated by the vertical coordinate or scalar coordinate variable. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. Practical Salinity, S_P, is a determination of the salinity of sea water, based on its electrical conductance. The measured conductance, corrected for temperature and pressure, is compared to the conductance of a standard potassium chloride solution, producing a value on the Practical Salinity Scale of 1978 (PSS-78). This name should not be used to describe salinity observations made before 1978, or ones not based on conductance measurements. Conversion of Practical Salinity to other precisely defined salinity measures should use the appropriate formulas specified by TEOS-10. Other standard names for precisely defined salinity quantities are sea_water_absolute_salinity (S_A); sea_water_preformed_salinity (S_*), sea_water_reference_salinity (S_R); sea_water_cox_salinity (S_C), used for salinity observations between 1967 and 1977; and sea_water_knudsen_salinity (S_K), used for salinity observations between 1901 and 1966. Salinity quantities that do not match any of the precise definitions should be given the more general standard name of sea_water_salinity. Reference: www.teos-10.org; Lewis, 1980 doi:10.1109/JOE.1980.1145448. sosalbtm: integral_of_sea_water_practical_salinity_wrt_total_depth This quantity is calculated as the integral, of the sea water salinty, over of the ocean from the sea surface to the sea bed. "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds. "wrt" means with respect to. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Depth is the vertical distance below the surface. Practical Salinity, S_P, is a determination of the
