Standard names: New Ocean BGC tracer variables (MPI-ESM)

[SwatiGehlot]

The below proposed are 5 new standard names for bio-geo-chemical tracer variables as a part of MPI-ESM model development within the German paleo-climate initiative, Project PalMod (www.palmod.de)

Proposer's name: Swati Gehlot, DKRZ, Hamburg (technical description via Bo Liu - bo.liu@mpimet.mpg.de)

Date 2024-01-17

1. Preformed Phosphate Concentration Term mole_concentration_of_preformed_dissolved_inorganic_phosphorus_in_sea_water Description The fraction of the dissolved inorganic phosphorus which is subducted from the sea surface and transported into the ocean interior. Units mol m-3 CMOR name preformed_po4

2. Preformed Oxygen Concentration Term mole_concentration_of_preformed_dissolved_molecular_oxygen_in_sea_water Description The fraction of the dissolved oxygen which is subducted from the sea surface and transported into the ocean interior. Units mol m-3 CMOR name preformed_o2

3. Preformed Dissolved Inorganic Carbon Concentration Term mole_concentration_of_preformed_dissolved_inorganic_carbon_in_sea_water Description The fraction of the dissolved inorganic carbon which is subducted from the sea surface and transported into the ocean interior. Units mol m-3 CMOR name preformed_dissic

4. Preformed Dissolved Inorganic Carbon-13 Concentration Term mole_concentration_of_preformed_dissolved_inorganic_13C_in_sea_water Description The fraction of the dissolved inorganic 13C which is subducted from the sea surface and transported into the ocean interior. Units mol m-3 CMOR name preformed_dissic13

5. Preformed Alkalinity Concentration Term sea_water_preformed_alkalinity_expressed_as_mole_equivalent Description The fraction of alkalinity which is subducted from the sea surface and transported into the ocean interior. Units mol m-3 CMOR name preformed_talk

[github-actions[bot]]

Thank you for your proposal. These terms will be added to the cfeditor (http://cfeditor.ceda.ac.uk/proposals/1) shortly. Your proposal will then be reviewed and commented on by the community and Standard Names moderator.

[JonathanGregory]

Dear @SwatiGehlot

Thanks for your proposals. I have a few comments, as a non-expert:

• In the first one, do you mean phosphorus (as in the proposed standard name and description) or phosphate (as in the title and the CMOR name)?

• What does preformed mean? It would be useful to have an explanation of this word in the description. What is the difference between mole_concentration_of_preformed_X_in_sea_water and mole_concentration_of_X_in_sea_water? There are also a couple of standard names for preformed_salinity and I must confess I don't understand what it means there either.

• Existing mole_concentration standard names contain the following explanation in their description: _Mole concentration means number of moles per unit volume, also called "molarity", and is used in the construction mole_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_asnitrogen'.

Best wishes

Jonathan

[efisher008]

Dear @SwatiGehlot,

I have now added your proposed names into the CF editor. You can view them here. 1) mole_concentration_of_preformed_dissolved_inorganic_phosphorus_in_sea_water link: https://cfeditor.ceda.ac.uk/proposal/5133/edit 2) mole_concentration_of_preformed_dissolved_molecular_oxygen_in_sea_water link: https://cfeditor.ceda.ac.uk/proposal/5134/edit 3) mole_concentration_of_preformed_dissolved_inorganic_carbon_in_sea_water link: https://cfeditor.ceda.ac.uk/proposal/5135/edit 4) mole_concentration_of_preformed_dissolved_inorganic_13C_in_sea_water link: https://cfeditor.ceda.ac.uk/proposal/5136/edit 5) sea_water_preformed_alkalinity_expressed_as_mole_equivalent link: https://cfeditor.ceda.ac.uk/proposal/5137/edit

I would agree with @JonathanGregory's questions. I think 'preformed' might need its own definition in the description. If this is related to its origin from subducted material, this needs to be specifically stated i.e. '"preformed" refers to a quantity which has been subducted from a pre-existing form at the sea surface' or something similar as you'd prefer. The standard name sea_water_preformed_salinity that Jonathan mentioned is described as 'Absolute Salinity ... minus all contributions to sea water composition from biogeochemical processes.' To me this also seems somewhat confusing in overlap with your usage so I'd be grateful if you could clarify this!

I would also second Jonathan's recommendation to add the mole_concentration definition to the description for each standard name. This is a standard and commonly used phrase for all mole_concentration names.

From a quick search, it would seem that @SwatiGehlot might be referring to phosphate ions in seawater (PO43−), which are "a dominant form of inorganic phosphorus in natural waters" (doi:10.1016/C2009-0-01718-8). I think this could be referred to as DIP, unless this is a differently-defined quantity? But would appreciate any explanation you can give here.

Thanks and best regards, Ellie

[BoLiu-MPIM]

Dear @JonathanGregory, dear @efisher008,

Thank you for the valuable input! @SwatiGehlot kindly submitted the new variables from my model data. In the following, I will address your questions.

In the first term, “phosphorus” is meant for “dissolved inorganic phosphorus”, the sum of all inorganic phosphorus in solution (including phosphate, hydrogen phosphate, dihydrogen phosphate, and phosphoric acid), following the description of the existing standard name “po4”( https://clipc-services.ceda.ac.uk/dreq/u/ba9e25a4-e5dd-11e5-8482-ac72891c3257.html).

I agree with both of you about adding the mole_concentration definition to the description for each standard name.

Indeed, the definition of “preformed” should be elaborated. I adopt the definition by Redfield (1942), which is similar to what @efisher008 wrote: The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of nutrients, which are entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such nutrients are termed “preformed” nutrients.

Redfield, A. C., The processes determining the concentration of oxygen, phosphate and other organic derivatives within the depths. Papers in Physical Oceanography and Meteorology, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, Vol. 9, No. 2, 1942.

Considering the above suggestions, I have updated the descriptions of the new variables; see below. I'd be happy to hear your further comments/suggestions!

Cheers, Bo

Preformed Dissolved Inorganic Phosphorus Concentration Term: mole_concentration_of_preformed_dissolved_inorganic_phosphorus_in_sea_water Description: "Mole concentration" means the number of moles per unit volume, also called "molarity", and is used in the construction "mole_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Dissolved inorganic phosphorus" means the sum of all inorganic phosphorus in solution (including phosphate, hydrogen phosphate, dihydrogen phosphate, and phosphoric acid). The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of nutrients, which are entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such nutrients are termed “preformed” nutrients. Units: mol m-3 CMOR name: preformed_po4

Preformed Dissolved Oxygen Concentration Term: mole_concentration_of_preformed_dissolved_molecular_oxygen_in_sea_water Description: "Mole concentration" means the number of moles per unit volume, also called "molarity", and is used in the construction "mole_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of dissolved oxygen, which are entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such dissolved oxygen is termed “preformed” dissolved oxygen. Units: mol m-3 CMOR name: preformed_o2

Preformed Dissolved Inorganic Carbon Concentration Term: mole_concentration_of_preformed_dissolved_inorganic_carbon_in_sea_water Description: "Mole concentration" means the number of moles per unit volume, also called "molarity", and is used in the construction "mole_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Dissolved inorganic carbon" is the sum of CO3, HCO3 and H2CO3. The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of dissolved inorganic carbon, which is entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such dissolved inorganic carbon is termed “preformed” dissolved inorganic carbon. Units: mol m-3 CMOR name: preformed_dissic

Preformed Dissolved Inorganic Carbon-13 Concentration Term: mole_concentration_of_preformed_dissolved_inorganic_13C_in_sea_water Description: "Mole concentration" means the number of moles per unit volume, also called "molarity", and is used in the construction "mole_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Dissolved inorganic carbon-13" is the sum of CO3_13C, HCO3_13C and H2CO3_13C. The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of dissolved inorganic carbon-13, which is entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such dissolved inorganic carbon-13 is termed “preformed” dissolved inorganic carbon-13. Units: mol m-3 CMOR name: preformed_dissic13

Preformed Alkalinity Concentration Term: sea_water_preformed_alkalinity_expressed_as_mole_equivalent Description: "Mole concentration" means the number of moles per unit volume, also called "molarity", and is used in the construction "mole_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Alkalinity" refers to total alkalinity equivalent concentration, including carbonate, borate, phosphorus, silicon, and nitrogen components. The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of alkalinity, which is entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such alkalinity is termed “preformed” alkalinity. Units: mol m-3 CMOR name: preformed_talk

[efisher008]

Hi @BoLiu-MPIM,

I've updated the descriptions of those standard names in the editor. Thanks very much for your input.

Indeed, the definition of “preformed” should be elaborated. I adopt the definition by Redfield (1942), which is similar to what @efisher008 wrote: The subduction and subsequent transport of surface water carry into the interior ocean considerable quantities of nutrients, which are entirely independent of biological activity (such as organic decomposition and oxidation) after the water leaves the sea surface. Such nutrients are termed “preformed” nutrients.

Redfield, A. C., The processes determining the concentration of oxygen, phosphate and other organic derivatives within the depths. Papers in Physical Oceanography and Meteorology, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, Vol. 9, No. 2, 1942.

I would further suggest adding this citation to the text i.e. "(Redfield,1942).", which has been common practice for other standard names to trace the origin of the definition.

Best wishes, Ellie

[BoLiu-MPIM]

Hi @efisher008,

Yes, I fully agree with you to add the citation "(Redfield, 1942)" in the text!

Bests, Bo

[efisher008]

Hi Bo,

I'm glad you agree! I will add this to the end of the description for each of the 5 proposed names. If there are no further comments after 7 days, these names will be accepted and published in the next standard names table release. Thanks again for the proposal and enjoy your weekend.

Best wishes, Ellie

[BoLiu-MPIM]

Thank you, @efisher008, for the prompt response! You too have a lovely weekend! -Bo

[efisher008]

Hi Bo,

Apologies for the late reply. I've accepted these names now, and they will be added to the next release of the standard names table, which is planned for mid-May. Thanks again for the proposal!

Best regards, Ellie

[efisher008]

Closing this issue as these names have been accepted in version 85 of the CF standard names table, published on 21 May 2024 (https://cfconventions.org/Data/cf-standard-names/85/build/cf-standard-name-table.html).