Dear Martin, Jonathan and Maarten,
Thank you Martin for making these proposals, and to you and Jonathan for the discussion of these and the related solid_precipitation name (now accepted in the other thread). I think Maarten may also be interested in this thread as it pertains to his 'semiheavy_water' proposal.
These proposals look good and I agree with Jonathan that the new constructions A_containing_B and isotope_ratio_of_A_to_B are useful and clear.
I have looked through all the proposals and changed precipitation_flux_of_solid_water_containing_X to solid_precipitation_flux_containing_X as discussed. For consistency I have also changed the precipitation_flux_of_water_containing_X names to say just precipitation_flux_containing_X, i.e. again no need to mention water. I see that in the standard name table we don't currently define 'precipitaton'. Based on the discussion here and in the solid_precipitation thread I suggest that we add a sentence ' "Precipitation" in the earth's atmosphere means precipitation of water in all phases." This could be added to all new and existing names that mention precipitation (except where the phase is explicitly mentioned, such as the solid_precipitation names). This would affect 25 existing names. Do others agree?
I have added full definitions to the proposals, including text for the new constructions and the various isotopes. I think six of the names are ready to be accepted (provided the definitions are okay). There is still a question regarding precipitation with one atom of hydrogen-2 isotope (1H 2H O, or HDO, or 'semiheavy water' as in Maarten's proposal for atmosphere_mole_content_of_semiheavy_water_vapor) - please see my comments on proposals 3, 4 and 9. I also have a question regarding the isotope ratio names in proposals 10 - 12.
(1) CMIP6 short name pr18O: Precipitation mass flux of water molecules that contain the oxygen-18 isotope (H2 18O), including solid and liquid phases.
precipitation_flux_of_water_containing_18O (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Precipitation" in the earth's atmosphere means precipitation of water in all phases. "O" means the element "oxygen" and "18O" is the stable isotope "oxygen-18".'
Okay?
(2) CMIP6 short name prsn18O: Precipitation mass flux of water molecules that contain the oxygen-18 isotope (H2 18O), including solid phase only.
precipitation_flux_of_solid_water_containing_18O (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Solid precipitation refers to the precipitation of water in the solid phase. Water in the atmosphere exists in one of three phases: solid, liquid or vapor. The solid phase can exist as snow, hail, graupel, cloud ice, or as a component of aerosol. The chemical formula for water is H2O. "O" means the element "oxygen" and "18O" is the stable isotope "oxygen-18".'
Okay?
(3) CMIP6 short name pr2h: Precipitation mass flux of water molecules that contain one atom of the hydrogen-2 isotope (1H 2H O), including solid and liquid phases.
If we treat this name just like proposals (1) and (2) we would have
precipitation_flux_containing_2H (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Precipitation" in the earth's atmosphere means precipitation of water in all phases. "H" means the element "hydrogen" and "2H" is the stable isotope "hydrogen-2", usually called "deuterium".
The problem is that if we say simply 'containing_2H' I would understand that to mean both 1H 2H O (semiheavy water, HDO) and 2H 2H O (heavy water, D2O) but this is clearly not the intention of the CMIP6 quantity. To make the name sufficiently clear we could either explicitly say precipitation_flux_containing_one_atom_of_2H or precipitation_flux_containing_semiheavy_water, or we could go with chemical systematic naming and say precipitation_flux_containing_deuterium_hydrogen_monoxide. Personally, I think the third option is horrible and many people are not going to instantly recognise it as water at all. If we go with option 1, and needed a name for heavy water then we could add precipitation_flux_containing_two_atoms_of_2H which would be okay I think. This system could also potentially be extended to other compounds containing different isotopes of their constituent elements, although chemists have their own naming conventions and if we had a lot of these it might be better to refer to external identifiers a
s is being suggested for biological taxon names. Option 2 is in some ways more elegant and we could also have names for heavy water - the terms 'semiheavy water' and 'heavy water' are both widely used. I could live with either of the first two options - what do others think?
This name is still under discussion.
(4) prsn2h: Precipitation mass flux of water molecules that contain one atom of the hydrogen-2 isotope (1H 2H O), including solid phase only.
precipitation_flux_of_solid_water_containing_2H (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Solid precipitation refers to the precipitation of water in the solid phase. Water in the atmosphere exists in one of three phases: solid, liquid or vapor. The solid phase can exist as snow, hail, graupel, cloud ice, or as a component of aerosol. The chemical formula for water is H2O. "H" means the element "hydrogen" and "2H" is the stable isotope "hydrogen-2", usually called "deuterium".'
As with proposal (3) we need to make clear that we are including 1H 2H O and excluding 2H 2H O. This name is still under discussion.
(5) pr17O: Precipitation mass flux of water molecules that contain the oxygen-17 isotope (H2 17O), including solid and liquid phases.
precipitation_flux_of_water_containing_17O (kg m-2 s-1)
' In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Precipitation" in the earth's atmosphere means precipitation of water in all phases. The chemical formula for water is H2O. "O" means the element "oxygen" and "17O" is the stable isotope "oxygen-17".'
Okay?
(6) prsn17O: Precipitation mass flux of water molecules that contain the oxygen-17 isotope (H2 17O), including solid phase only.
precipitation_flux_of_solid_water_containing_17O (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Solid precipitation refers to the precipitation of water in the solid phase. Water in the atmosphere exists in one of three phases: solid, liquid or vapor. The solid phase can exist as snow, hail, graupel, cloud ice, or as a component of aerosol. "O" means the element "oxygen" and "17O" is the stable isotope "oxygen-17".'
Okay?
(7) prw18O: Water vapor path for water molecules that contain oxygen-18 (H2 18O)
This proposal follows the pattern of mass_content_of_water_vapor_in_atmosphere_layer, with the "containing_18O" specialisation:
mass_content_of_water_vapor_containing_18O_in_atmosphere_layer (kg m-2)
' "Content" indicates a quantity per unit area. "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. The "content_of_X_in_atmosphere_layer" refers to the vertical integral between two specified levels in the atmosphere. The chemical formula for water is H2O. "O" means the element "oxygen" and "18O" is the stable isotope "oxygen-18".'
Okay?
(8) prw17O: Water vapor path for water molecules that contain oxygen-17 (H2 17O)
mass_content_of_water_vapor_containing_17O_in_atmosphere_layer (kg m-2)
' "Content" indicates a quantity per unit area. "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. The "content_of_X_in_atmosphere_layer" refers to the vertical integral between two specified levels in the atmosphere. The chemical formula for water is H2O. "O" means the element "oxygen" and "17O" is the stable isotope "oxygen-17".'
Okay?
(9) prw2H: Water vapor path for water molecules that contain one atom of the hydrogen-2 isotope (1H 2H O)
mass_content_of_water_vapor_containing_2H_in_atmosphere_layer (kg m-2)
' "Content" indicates a quantity per unit area. "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. The "content_of_X_in_atmosphere_layer" refers to the vertical integral between two specified levels in the atmosphere. The chemical formula for water is H2O. "H" means the element "hydrogen" and "2H" is the stable isotope "hydrogen-2", usually called "deuterium".'
As with proposal (3) we need to make clear that we are including 1H 2H O and excluding 2H 2H O. This name is still under discussion.
(10) sw18O: Ratio of abundance of oxygen-18 (18O) atoms to oxgen-16 (16O) atoms in sea water
isotope_ratio_of_18O_to_16O_in_sea_water (1)
'The phrase "ratio_of_X_to_Y" means X/Y. The phrase "isotope_ratio" is used in the construction isotope_ratio_of_A_to_B where A and B are both named isotopes. It means the ratio of the number of atoms of A to the number of atoms of B present within a medium. "O" means the element "oxygen" and "18O" is the stable isotope "oxygen-18". "16O" is the stable isotope "oxygen-16".'
I assume that here we mean the 18O and 16O that composes the sea water itself, but not including isotopes that may be part of dissolved or particulate substances. Is that correct?
This name is still under discussion.
(11) sw17O: Ratio of abundance of oxygen-17 (17O) atoms to oxgen-16 (16O) atoms in sea water
isotope_ratio_of_17O_to_16O_in_sea_water (1)
'The phrase "ratio_of_X_to_Y" means X/Y. The phrase "isotope_ratio" is used in the construction isotope_ratio_of_A_to_B where A and B are both named isotopes. It means the ratio of the number of atoms of A to the number of atoms of B present within a medium. "O" means the element "oxygen" and "17O" is the stable isotope "oxygen-17". "16O" is the stable isotope "oxygen-16".'
I assume that here we mean the 17O and 16O that composes the sea water itself, but not including isotopes that may be part of dissolved or particulate substances. Is that correct?
This name is still under discussion.
(12) sw2H: Ratio of abundance of hydrogen-2 (2H) atoms to hydrogen-1 (1H) atoms in sea water
isotope_ratio_of_2H_to_1H_in_sea_water (1)
' The phrase "ratio_of_X_to_Y" means X/Y. The phrase "isotope_ratio" is used in the construction isotope_ratio_of_A_to_B where A and B are both named isotopes. It means the ratio of the number of atoms of A to the number of atoms of B present within a medium. "H" means the element "hydrogen" and "2H" is the stable isotope "hydrogen-2", usually called "deuterium". "1H" is the stable isotope "hydrogen-1".'
I would understand this name to mean the ratio of all 2H to 1H in sea water, regardless of whether the 2H occurs in heavy or semiheavy water. Also, as with (11) and (12), I assume that here we mean the 2H and 1H that composes the sea water itself, but not including isotopes that may be part of dissolved or particulate substances. Is that correct?
This name is still under discussion.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/Centre for Environmental Data Archival Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
-----Original Message-----
From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Martin Juckes - UKRI STFC
Sent: 06 April 2018 14:56
To: Jonathan Gregory <j.m.gregory at reading.ac.uk>; cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] PMIP Standard names: isotopic fluxes, mass contents and ratios.
Dear Jonathan,
Thanks. I agree that "water" is redundant in these names (except where it occurs as "water_vapor"), so we can use, for example, precipitation_flux_containing_O17.
For the solid phase precipitation, I would prefer "solid_precipitation_flux_containing_O17", rather than "frozen_precipitation_flux_containing_O17" ... but perhaps we can complete that discussion in the other thread (
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2018/060000.html )
regards,
Martin
________________________________
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.gregory at reading.ac.uk>
Sent: 05 April 2018 18:41
To: cf-metadata at cgd.ucar.edu
Subject: [CF-metadata] PMIP Standard names: isotopic fluxes, mass contents and ratios.
Dear Martin
Thanks for these proposals. I think your new constructions A_containing_B and isotope_ratio_of_A_to_B are good ideas, which you need for these quantities.
My previous posting about "frozen" and precipitation always being water apply to some of these as well.
Best wishes
Jonathan
----- Forwarded message from Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk> -----
> Date: Tue, 3 Apr 2018 10:53:09 +0000
> From: Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk>
> To: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>
> CC: Jean-Yves Peterschmitt <Jean-Yves.Peterschmitt at lsce.ipsl.fr>, Didier
> Roche <Didier.Roche at lsce.ipsl.fr>
> Subject: [CF-metadata] PMIP Standard names: isotopic fluxes, mass contents
> and ratios.
>
> Dear All,
>
> I would like to propose the following 12 standard names on behalf of the PMIP team. They all relate to water molecules containing stable isotopes of oxygen or hydrogen (17O, 18O, and 2H [deuterium]).
>
> (1) pr18O: Precipitation mass flux of water molecules that contain the
> oxygen-18 isotope (H2 18O), including solid and liquid phases. [kg m-2
> s-1]
>
> There is no current CF construction to refer to water containing a specific isotope; the closest is ".._A_expressed_as_B", which refers to the amount of a component B in A. We propose a new construction "_A_containing_B" which refers to the amount of A which contains B:
>
> precipitation_flux_of_water_containing_18O
>
> (2) prsn18O: Precipitation mass flux of water molecules that contain
> the oxygen-18 isotope (H2 18O), including solid phase only. [kg m-2
> s-1]
>
> As (1), but for solid phase only. There does not appear to be a specific standard name construction for the solid phase of water, but "_liquid_phase" is used for the liquid phase, so "solid_phase" appears to be a natural extension.
>
> precipitation_flux_of_solid_water_containing_18O
>
> (3) pr2h: Precipitation mass flux of water molecules that contain one
> atom of the hydrogen-2 isotope (1H 2H O), including solid and liquid
> phases. [kg m-2 s-1]
>
> As (1), but for 2H
> precipitation_flux_of_water_containing_2H
>
> (4) prsn2h: Precipitation mass flux of water molecules that contain
> one atom of the hydrogen-2 isotope (1H 2H O), including solid phase
> only. [kg m-2 s-1]
>
> As (2), but for 2H
> precipitation_flux_of_solid_water_containing_2H
>
> (5) pr17O: Precipitation mass flux of water molecules that contain the
> oxygen-17 isotope (H2 17O), including solid and liquid phases. [kg m-2
> s-1]
>
> As (1), but for 17O
> precipitation_flux_of_water_containing_17O
>
> (6) prsn17O: Precipitation mass flux of water molecules that contain
> the oxygen-17 isotope (H2 17O), including solid phase only. [kg m-2
> s-1]
>
> As (2), but for 17O
> precipitation_flux_of_solid_water_containing_17O
>
> (7) prw18O: Water vapor path for water molecules that contain
> oxygen-18 (H2 18O) [kg m-2]
>
> This proposal follows the pattern of mass_content_of_water_vapor_in_atmosphere_layer, with the "containing_18O" specialisation:
>
> mass_content_of_water_vapor_containing_18O_in_atmosphere_layer
>
> (8) prw17O: Water vapor path for water molecules that contain
> oxygen-17 (H2 17O) [kg m-2]
>
> As (7), but for 17O
> mass_content_of_water_vapor_containing_17O_in_atmosphere_layer
>
> (9) prw2H: Water vapor path for water molecules that contain one atom
> of the hydrogen-2 isotope (1H 2H O) [kg m-2]
>
> As (7), but for 2H
> mass_content_of_water_vapor_containing_2H_in_atmosphere_layer
>
> (10) sw18O: Ratio of abundance of oxygen-18 (18O) atoms to oxgen-16
> (16O) atoms in sea water [1]
>
> "Isotope ratio" is a widely used concept which is not yet represented in the standard name list. Isotope ratios are the ratio of one isotope to another, usually the most stable isotope (e.g. 16O for oxygen). In the standard names we propose a cautious approach of explicitly stating both isotopes in the ratio:
>
> isotope_ratio_of_18O_to_16O_in_sea_water
>
> The construction "isotope_ratio_A_to_B_" refers to the ratio of the number of atoms of A to the number of atoms of B.
>
> (11) sw17O: Ratio of abundance of oxygen-17 (17O) atoms to oxgen-16
> (16O) atoms in sea water [1]
>
> As (10), but for 17O
> isotope_ratio_of_17O_to_16O_in_sea_water
>
> (12) sw2H: Ratio of abundance of hydrogen-2 (2H) atoms to hydrogen-1
> (1H) atoms in sea water [1]
>
> As (10), but for 2H
> isotope_ratio_of_2H_to_1H_in_sea_water
>
> regards,
> Martin
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
----- End forwarded message -----
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