[CF-metadata] New standard names for C4MIP

From: alison.pamment at stfc.ac.uk <alison.pamment>
Date: Fri, 9 Mar 2018 07:57:03 +0000

Dear Chris,

Thanks for getting back to me. We seem to be making good progress with these names.

For those you haven't commented on (1, 6 - 9, 28) is it safe to assume you are happy with the names, definitions and units? If so, I think these can be formally accepted for inclusion in the standard name table. I will be preparing an update on Monday (12th March) so any names accepted by then can be published. (There will be another update in April, so it's fine if some names still need further discussion).

We have agreed the isotope names (15 - 22) - thank you - these are now accepted and will definitely go into the March update.

For the others, I've given individual comments below. I think we are pretty much agreed on a lot of them and they could also go into the update, provided you are happy with my changes. Please let me know what you think.

> 4, 5 - veg and litter fires. These are not really from "vegetation fires" and "litter fires" (this description makes it sounds like these are separate fires), but rather when there is a fire, some of the carbon burnt comes from the vegetation and some from the
> litter. So these are a way to split those (i.e. they sum to the total fCfire). So maybe phrase as surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_carbon_due_to_fire ?
>
> should we specify somewhere that fCVegFire + fCLitterFire = fCfire?
>
I agree we don't want to give the impression that vegetation and litter fires are somehow separate. Rather than having two "due_to" phrases, how about we change these names to say "in_fires" as in the following. (The last sentence of the definitions is intended to express ' fCVegFire + fCLitterFire = fCfire' in terms of the standard names rather than the CMIP6 short names as the latter wouldn't be meaningful to a general user of CF).

4. surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_in_fires
'The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. "Vegetation" means any living plants e.g. trees, shrubs, grass. The term "fires" means all
biomass fires, whether naturally occurring or ignited by humans. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_in_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_in_fires.'

5. surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_in_fires
'The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. "Litter" is dead plant material in or above the soil. The quantity with standard name surfa
ce_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_in_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_in_fires.'

Are these okay?

Previously I think I had muddled up the definitions of 'natural_fires' and 'fires' by saying that 'natural_fires' was the sum of the veg and litter fires, when it should simply have been 'fires'. I've changed this now:

2. surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_natural_fires
'The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely dist
inct from "re-emission" which is used in some standard names. "Natural fires" means burning of biomass, whether living or dead, excluding fires ignited by humans, e.g. for agricultural purposes.'

3. surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires
' "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. The term "
fires" means all biomass fires, whether naturally occurring or ignited by humans. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_in_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_in_fires.

Okay?

> 10 - probably true that most models have the runoff going into rivers, but maybe not all - some might go straight into the ocean, and some might simply lose the
> water/carbon from the system without closing the budget. So perhaps instead of "into_rivers" how about "out_of_soil". From a diagnostic point of view this
> diagnostic is there to represent a loss term from soil, rather than input to rivers, so it makes sense that way too.
>
That sounds fine to me - thanks for the clarification. So then the name would be:
mass_flux_of_carbon_out _of_soil_due_to_leaching_and_runoff
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Leaching" means the loss of water soluble chemical species from soil. Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage.'

I think we're agreed on this one. This name is accepted and will be included in the March update.

> 11 - which LUMIP variable do you think this tallies with? I think, yes I agree, that fCAnthDisturb (C4MIP) = fLulccAtmLut (LUMIP). So OK to use the same name.
> Do we need to specify that this is "into the atmosphere" or does "upwards" explicitly mean that?
Okay, thank you, so we're agreed on using the existing name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change. Yes, the fact that we are calling this a surface_upward flux means that it is 'into the atmosphere'. In CF standard names we always use 'surface' to mean 'the lower boundary of the atmosphere' and 'upward' means we are specifying the sign convention such that positive fluxes are upwards.

>12 - yes, OK. Out of interest, why is this one a "tendency of atmosphere" and not a "flux" - is there a subtle difference?
Okay, thank you, so we're agreed on using the existing name tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_forestry_and_agricultural_products. Conceptually there is absolutely no difference between a surface_upward_mass_flux and a tendency_of_atmosphere_mass_content for any gaseous material. The nomenclature is more a question of your point of view. A land surface modeller tends to be more interested in fluxes out of the surface whereas an atmospheric chemist thinks in terms of how that flux changes the composition of the atmosphere, even though they are exactly the same quantity. In CF standard names we always try to use consistent syntax for similar quantities and, because the first standard names involving surface carbon dioxide fluxes happened to have been introduced from a chemistry point of view, we have stuck with that approach ever since. So I suppose the short answer to your question is simply that we have a precedent for doing it that way :)

> 13, 14 - no, these are not quite what we want. Both of these represent a flux from the vegetation/litter/soil into the product pools, but from different processes.
> So fDeforestToProduct should be around land_use_CHANGE or land_cover_CHANGE, whereas fCHarvestToProduct is not an upwards flux to the atmosphere,
> but a flux into the product pools due to harvest (either crop or wood harvest) (for example commercial logging to make furniture would go here).

Okay, certainly we need to change 14 if it's a flux into the product pools, so then I'd suggest
14. (CMIP6 short name fCHarvestToProduct)
carbon_mass_flux_into_forestry_and_agricultural_products_due_to_crop_harvesting (kg m-2 s-1)
'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Examples of "forestry and agricultural products" are paper, cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The definition of "crops" is model dependent, for example, some models may include fruit trees as crops. "Crop harvesting" means the human activity of collecting plant materials for the purpose of turning them into forestry or agricultural products.'

Okay?

If 13 is a flux into the product pools from land use change, then I think my previous suggestion for this quantity would be the correct one, wouldn't it?
> 13. (CMIP6 short name fDeforestToProduct)
> Existing name:
> carbon_mass_flux_into_forestry_and_agricultural_products_due_to_anthropogenic_land_use_or_land_cover_change (kg m-2 s-1)
> 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process
> by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by
> omitting the phrase. "Anthropogenic" means influenced, caused, or created by human activity. Examples of "forestry and agricultural products" are paper,
> cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools
> of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products
> decompose in landfill sites. "Anthropogenic land use change" means human changes to land, excluding forest regrowth. It includes fires ignited by humans for
> the purpose of land use change and the processes of eventual disposal and decomposition of wood products such as paper, cardboard, furniture and timber for > construction.'

> 23-25 - nitrogen ones - not quite right wording. The aim here is to capture nitrogen compounds stored as inorganic compounds in the soil. This tends to be as
> ammonium ions or nitrate ions. This pool (nMineral) is the sum of both and complements the organic nitrogen pool nSoil. The sub-components then separately
> capture the reduced and oxidised forms. We suggest:
>
> 23. (CMIP6 short name nMineral)
> soil_mass_content_of_mineral_nitrogen_expressed_as_nitrogen (canonical units: kg m-2) '
> "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil
> model. The term "mineral" refers to the total nitrogen occurring in any inorganic chemical species. The phrase "expressed_as" is used in the construction
> A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B
> contained in A, neglecting all other chemical constituents of A.' soil_mass_content_of_mineral_nitrogen_expressed_as_nitrogen should be equal to the sum of
> soil_mass_content_of_mineral_ammonium_expressed_as_nitrogen and soil_mass_content_of_mineral_nitrate_expressed_as_nitrogen.
> The counterpart to nMineral is the organic nitrogen pool nSoil.

Thank you for your explanation, I think I understand these names now!

Currently we have five existing standard names that refer to organic/inorganic_nitrogen. If 'mineral' really just means 'inorganic' then for consistency with the existing names perhaps we could make this one
soil_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen
' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. "Inorganic nitrogen" describes a family of chemical species which, in soil, usually consists of nitrate and ammonium compounds which act as nitrogen nutrients. The quantity with standard name soil_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen is the sum of the quantities with standard names soil_mass_content_of_inorganic_ammonium_expressed_as_nitrogen and soil_mass_content_of_inorganic_nitrate_expressed_as_nitrogen.'

If, however, there is a strong reason for preferring 'mineral' to 'inorganic' then I'd be happy to go with your version of the name and adjust the definition to agree. Whichever naming convention we choose to adopt for proposal 23 should of course be applied to 24 and 25 as well.

> 24. (CMIP6 short name nMineralNH4)
> soil_mass_content_of_mineral_ammonium_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of
> a quantity refers to the vertical integral from the surface down to the bottom of the soil model. The term "mineral_ammonium" refers to the total nitrogen
> occurring in reduced form as ammonium species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of > A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents > of A.'
>
> 25. (CMIP6 short name nMineralNO3)
> soil_mass_content_of_mineral_nitrate_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a
> quantity refers to the vertical integral from the surface down to the bottom of the soil model. The term "mineral_nitrate" refers to the total nitrogen occurring
> in oxidised form as nitrate species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means
> that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'


> 26 and 27 - all wetland methane ones - chemists prefer mass of species, so the units of these ones should be "expressed as CH4" rather than "expressed as
> carbon".
>

Because these are fluxes of methane my suggestions were for names that refer only to that species (without any use of 'expressed_as' because we don't need it here). There's no need to say, for example, 'methane_expressed_as_methane'. If all we mention in the name is methane, then that is the mass we are referring to.

> 27 - wetlandCH4cons - please can this specify explicitly it is a flux out of the atmosphere (and/or "downward") because it represents a loss term. i.e. a positive
> value of wetlandCH4cons implies the amount of methane in the atmosphere is decreasing

If there's any likelihood of ambiguity about the sign convention then I agree that having this one as a flux would make that clearer so we'd have:
27. (CMIP6 short name wetlandCH4cons)
surface_downward_mass_flux_of_methane_due_to_wetland_biological_consumption (canonical units: kg m-2 s-1)
 'The surface called "surface" means the lower boundary of the atmosphere. "Downward" indicates a vector component which is positive when directed downward (negative upward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The chemical formula for methane is CH4. The mass is the total mass of the molecules. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. The precise conditions under which wetlands produce and consume methane can vary between models.'

Okay?

In this instance, because 26 and 27 are a 'pair' of names, then it would make sense to write 26 as a surface flux too:

26. (CMIP6 short name wetlandCH4prod)
surface_upward_mass_flux_of_methane_due_to_emission_from_wetland_biological_production (canonical units: kg m-2 s-1)
''The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The chemical formula for methane is CH4. The mass is the total mass of the molecules. The phrase "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil al
l year or for varying periods of time during the year, including during the growing season. The precise conditions under which wetlands produce and consume methane can vary between models.'

Okay?

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: Jones, Chris D [mailto:chris.d.jones at metoffice.gov.uk]
Sent: 06 March 2018 12:55
To: Pamment, Alison (STFC,RAL,RALSP) <alison.pamment at stfc.ac.uk>; cf-metadata at cgd.ucar.edu
Subject: RE: New standard names for C4MIP

Hi Alison,

thanks so much for starting this thread going to approve these new names. I've suggested a few edits/changes below and await comments from others.

For info for those on this list who haven't seen the C4MIP GMD paper, we tried to explicitly show all these diagnostics in our figures which we found a good way to help explain them, the sign convention, which are stores/fluxes, how they relate to each other etc. So that reference may help interpret this discussion too. See especially figures 5-8 of:
https://www.geosci-model-dev.net/9/2853/2016/

Many thanks,
Chris

Numbers below refer to Alison's email:

4, 5 - veg and litter fires. These are not really from "vegetation fires" and "litter fires" (this description makes it sounds like these are separate fires), but rather when there is a fire, some of the carbon burnt comes from the vegetation and some from the litter. So these are a way to split those (i.e. they sum to the total fCfire). So maybe phrase as surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_carbon_due_to_fire ?

should we specify somewhere that fCVegFire + fCLitterFire = fCfire?

10 - probably true that most models have the runoff going into rivers, but maybe not all - some might go straight into the ocean, and some might simply lose the water/carbon from the system without closing the budget. So perhaps instead of "into_rivers" how about "out_of_soil". From a diagnostic point of view this diagnostic is there to represent a loss term from soil, rather than input to rivers, so it makes sense that way too.

11 - which LUMIP variable do you think this tallies with? I think, yes I agree, that fCAnthDisturb (C4MIP) = fLulccAtmLut (LUMIP). So OK to use the same name. Do we need to specify that this is "into the atmosphere" or does "upwards" explicitly mean that?

12 - yes, OK. Out of interest, why is this one a "tendency of atmosphere" and not a "flux" - is there a subtle difference?

13, 14 - no, these are not quite what we want. Both of these represent a flux from the vegetation/litter/soil into the product pools, but from different processes. So fDeforestToProduct should be around land_use_CHANGE or land_cover_CHANGE, whereas fCHarvestToProduct is not an upwards flux to the atmosphere, but a flux into the product pools due to harvest (either crop or wood harvest) (for example commercial logging to make furniture would go here).

15-22: isotope ones - all good

23-25 - nitrogen ones - not quite right wording. The aim here is to capture nitrogen compounds stored as inorganic compounds in the soil. This tends to be as ammonium ions or nitrate ions. This pool (nMineral) is the sum of both and complements the organic nitrogen pool nSoil. The sub-components then separately capture the reduced and oxidised forms. We suggest:

23. (CMIP6 short name nMineral)
soil_mass_content_of_mineral_nitrogen_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. The term "mineral" refers to the total nitrogen occurring in any inorganic chemical species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.' soil_mass_content_of_mineral_nitrogen_expressed_as_nitrogen should be equal to the sum of soil_mass_content_of_mineral_ammonium_expressed_as_nitrogen and soil_mass_content_of_mineral_nitrate_expressed_as_nitrogen.
The counterpart to nMineral is the organic nitrogen pool nSoil.

24. (CMIP6 short name nMineralNH4)
soil_mass_content_of_mineral_ammonium_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. The term "mineral_ammonium" refers to the total nitrogen occurring in reduced form as ammonium species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'

25. (CMIP6 short name nMineralNO3)
soil_mass_content_of_mineral_nitrate_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. The term "mineral_nitrate" refers to the total nitrogen occurring in oxidised form as nitrate species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'


26 and 27 - all wetland methane ones - chemists prefer mass of species, so the units of these ones should be "expressed as CH4" rather than "expressed as carbon".

27 - wetlandCH4cons - please can this specify explicitly it is a flux out of the atmosphere (and/or "downward") because it represents a loss term. i.e. a positive value of wetlandCH4cons implies the amount of methane in the atmosphere is decreasing

--
Dr Chris Jones
Head, Earth System and Mitigation Science Team Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, U.K. 
Tel: +44 (0)1392 884514  Fax: +44 (0)1392 885681
E-mail: chris.d.jones at metoffice.gov.uk  http://www.metoffice.gov.uk 
-----Original Message-----
From: alison.pamment at stfc.ac.uk [mailto:alison.pamment at stfc.ac.uk]
Sent: 23 February 2018 11:44
To: Jones, Chris D <chris.d.jones at metoffice.gov.uk>; cf-metadata at cgd.ucar.edu
Subject: New standard names for C4MIP
Dear Chris, All,
I am proposing these standard names on behalf of Chris Jones. They are needed for the CMIP6 C4MIP experiment.
I am sure that Chris will comment on the names and definitions in due course and other comments and suggestions for improvement are always welcome.
 
Chris, you will see that some of the names have evolved again from the versions in our offlist discussion. This is partly due to the fact that I understand the quantities better now - thank you for providing information for the definitions - and partly because I have modified some of them to be more consistent with existing names. Please have a look through the proposals and let me know if you are happy with them.
1. (CMIP6 short name fCLandToOcean)
mass_flux_of_carbon_into_sea_water_from_rivers (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.'
2. (CMIP6 short name fCFireNat)
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_natural_fires (canonical units: kg m-2 s-1) ' "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. "Natural fires" means burning of biomass, whether living or dead, excluding fires ignited by humans, e.g. for agricultural purposes. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_natural_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_fires.'
3. (CMIP6 short name fCFire)
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires (canonical units: kg m-2 s-1) ' "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. The term "fires" means all biomass fires, whether naturally occurring or ignited by humans.'
4. (CMIP6 short name fCVegFire)
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_fires (canonical units: kg m-2 s-1) ' "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. "Vegetation" means any living plants e.g. trees, shrubs, grass. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_natural_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_fires.'
5. (CMIP6 short name fCLitterFire)
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_fires (canonical units: kg m-2 s-1) ' "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. "Litter" is dead plant material in or above the soil. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_natural_fires is the sum of the quantities with standard names surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_vegetation_fires and surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_litter_fires.'
6. (CMIP6 short name fCVegLitterSenescence) mass_flux_of_carbon_into_litter_from_vegetation_due_to_senescence (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The term "senescence" means loss of living biomass excluding plant death, e.g. leaf drop and other seasonal effects. The term refers to changes in the whole plant and is not confined only to leaf drop.'
7. (CMIP6 short name fCVegLitterMortality) mass_flux_of_carbon_into_litter_from_vegetation_due_to_mortality (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The term "mortality" means the loss of living biomass due to plant death. It refers to the death of the whole plant, not only the leaves.'
8. (CMIP6 short name fCVegSoilSenescence) mass_flux_of_carbon_into_soil_from_vegetation_due_to_senescence (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Vegetation" means any living plants e.g. trees, shrubs, grass. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The term "senescence" means loss of living biomass excluding plant death, e.g. leaf drop and other seasonal effects. The term refers to changes in the whole plant and is not confined only to leaf drop.'
9. (CMIP6 short name fCVegSoilMortality) mass_flux_of_carbon_into_soil_from_vegetation_due_to_mortality (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Vegetation" means any living plants e.g. trees, shrubs, grass. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. The term "mortality" means the loss of living biomass due to plant death. It refers to the death of the whole plant, not only the leaves.'
10. (CMIP6 short name fCleach)
mass_flux_of_carbon_into_rivers_from_soil_due_to_leaching_and_runoff (canonical units: kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Leaching" means the loss of water soluble chemical species from soil. Runoff is the liquid water which drains from land. If not specified, "runoff" refers to the sum of surface runoff and subsurface drainage.'
I have described this as a mass flux into rivers as I assume that is where the runoff will eventually go. Is that okay?
11. (CMIP6 short name fCAnthDisturb)
I see now that this quantity and those in 12 - 14 below look like ones I have already added to the standard name table for the CMIP6 LUMIP experiment. Please check that they meet your needs, and assuming they do, please use the existing names.
Existing name:
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change (kg m-2 s-1) 'The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Anthropogenic" means influenced, caused, or created by human activity. "Anthropogenic land use change" means human changes to land, excluding forest regrowth. It includes fires ignited by humans for the purpose of land use change and the processes of eventual disposal and decomposition of wood products such as paper, cardboard, furniture and timber for construction.'
Okay?
12. (CMIP6 short name fCProductDecomp)
 Existing name:
tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_forestry_and_agricultural_products (kg m-2 s-1) ' "tendency_of_X" means derivative of X with respect to time. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. The chemical formula for carbon dioxide is CO2. "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. Examples of "forestry and agricultural products" are paper, cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites.'
Okay?
13. (CMIP6 short name fDeforestToProduct) Existing name:
carbon_mass_flux_into_forestry_and_agricultural_products_due_to_anthropogenic_land_use_or_land_cover_change (kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Anthropogenic" means influenced, caused, or created by human activity. Examples of "forestry and agricultural products" are paper, cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. "Anthropogenic land use change" means human changes to land, excluding forest regrowth. It includes fires ignited by humans for the purpose of land use change and the processes of eventual disposal and decomposition of wood products such as paper, cardboard, furniture and timber for construction.'
N.B. Alias this to mass_flux_of_carbon... for more consistent syntax (introducing alias won't be a problem for LUMIP)
Okay?
14. (CMIP6 short name fCHarvestToProduct)  Existing name:
surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_crop_harvesting (kg m-2 s-1) ' "Upward" indicates a vector component which is positive when directed upward (negative downward). The phrase 'expressed_as' is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A. In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. The surface called "surface" means the lower boundary of the atmosphere. The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. earth's surface). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. The chemical formula for carbon dioxide is CO2.'
Okay?
15. (CMIP6 short name c14Veg)
vegetation_mass_content_of_14C  (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. "Vegetation" means any living plants e.g. trees, shrubs, grass. "C" means the element carbon and "14C" is the radioactive isotope "carbon-14", having six protons and eight neutrons and used in radiocarbon dating.'
I have changed from writing the isotope name as carbon14 to 14C to be consistent with the large number of  radioactive isotope names that were added to the standard name table last week. In the discussion of those names we agreed to use the chemical symbol for the element and have mixed case standard names whenever we want to describe a particular isotope. The CMIP names should now follow this agreed syntax. This applies to all the 14C and 13C names in proposals 15 - 22.
16. (CMIP6 short name c14Litter)
litter_mass_content_of_14C (canonical units: kg m-2) '"Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "C" means the element carbon and "14C" is the radioactive isotope "carbon-14", having six protons and eight neutrons and used in radiocarbon dating.'
17. (CMIP6 short name c14Soil)
soil_mass_content_of_14C (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. "C" means the element carbon and "14C" is the radioactive isotope "carbon-14", having six protons and eight neutrons and used in radiocarbon dating.'
18. (CMIP6 short name c14Land)
mass_content_of_14C_in_vegetation_and_litter_and_soil_and_forestry_and_agricultural_products (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. Examples of "forestry and agricultural products" are paper, cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. "C" means the element carbon and "14C" is the radioactive isotope "carbon-14", having six protons and eight neutrons and used in radiocarbon dating.'
I realise this name doesn't look very elegant but there is a reason for writing it in this way! Firstly, this quantity is defined as the sum of all the other 'land' components of 14C, i.e., vegetation + litter + soil + products, and that is explicitly stated in my suggested name. I hesitate to just call it mass_content_of_14C_on_land because we tend to use 'land' in CF as an area type meaning not sea or sea-ice. Also, the way the quantity is defined doesn't include, for example, carbon in bedrock so I think calling it 'land' is a bit too vague and general. We do have a precedent for combining multiple phrases with more than one _and_ in a standard name: tendency_of_ocean_mole_content_of_elemental_nitrogen_due_to_deposition_and_fixation_and_runoff. Again this is an example of where there didn't seem to be an appropriate succinct term. I'm very open to discussion on this proposal - can anyone think of a better  term than 'land' to summarize the sum of the various components?
19. (CMIP6 short name c13Veg)
vegetation_mass_content_of_13C (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. "Vegetation" means any living plants e.g. trees, shrubs, grass. "C" means the element carbon and "13C" is the stable isotope "carbon-13", having six protons and seven neutrons.'
20. (CMIP6 short name c13Litter)
litter_mass_content_of_13C (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "C" means the element carbon and "13C" is the stable isotope "carbon-13", having six protons and seven neutrons.'
21. (CMIP6 short name c13Soil)
soil_mass_content_of_13C (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. "C" means the element carbon and "13C" is the stable isotope "carbon-13", having six protons and seven neutrons.'
22. (CMIP6 short name c13Land)
mass_content_of_13C_in_vegetation_and_litter_and_soil_and_forestry_and_agricultural_products (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. Examples of "forestry and agricultural products" are paper, cardboard, furniture, timber for construction, biofuels and food for both humans and livestock. Models that simulate land use changes have one or more pools of carbon that represent these products in order to conserve carbon and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. "C" means the element carbon and "13C" is the stable isotope "carbon-13", having six protons and seven neutrons.'
Similar to proposal 18, this quantity is the sum of the various land based carbon budget components for 13C. Again, if we can come up with a more succinct term for the sum of the components we could use it in this name.
23. (CMIP6 short name nMineral)
soil_mass_content_of_minerals_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. The term "mineral" means a solid, naturally occurring inorganic chemical species. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'
24. (CMIP6 short name nMineralNH4)
soil_mass_content_of_ammonium_minerals_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. The term "mineral" means a solid, naturally occurring inorganic chemical species. "Ammonium minerals" means mineral compounds containing ammonium. The chemical formula for the ammonium cation is NH4+. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'
25. (CMIP6 short name nMineralNO3)
soil_mass_content_of_nitrate_minerals_expressed_as_nitrogen (canonical units: kg m-2) ' "Content" indicates a quantity per unit area. The "soil content" of a quantity refers to the vertical integral from the surface down to the bottom of the soil model. For the content between specified levels in the soil, standard names including "content_of_soil_layer" are used. The term "mineral" means a solid, naturally occurring inorganic chemical species. "Nitrate minerals" means mineral compounds containing nitrate. The chemical formula for the nitrate anion is NO3-. The phrase "expressed_as" is used in the construction A_expressed_as_B, where B is a chemical constituent of A. It means that the quantity indicated by the standard name is calculated solely with respect to the B contained in A, neglecting all other chemical constituents of A.'
26. (CMIP6 short name wetlandCH4prod)
tendency_of_atmosphere_mass_content_of_methane_due_to_emission_from_wetland_biological_production (canonical units: kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. The chemical formula for methane is CH4. The mass is the total mass of the molecules. The phrase "tendency_of_X" means derivative of X with respect to time. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. "Emission" means emission from a primary source located anywhere within the atmosphere, including at the lower boundary (i.e. the surface of the earth). "Emission" is a process entirely distinct from "re-emission" which is used in some standard names. Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. The precise conditions under which wetlands produce and consume methane can vary between models.'
I got the definition of 'wetland' from https://www.epa.gov/wetlands/what-wetland - I wanted to find something that wasn't too tied in to CMIP6 definitions. Okay?
27. (CMIP6 short name wetlandCH4cons)
tendency_of_atmosphere_mass_content_of_methane_due_to_wetland_biological_consumption (canonical units: kg m-2 s-1) ' "Content" indicates a quantity per unit area. The "atmosphere content" of a quantity refers to the vertical integral from the surface to the top of the atmosphere. For the content between specified levels in the atmosphere, standard names including "content_of_atmosphere_layer" are used. The chemical formula for methane is CH4. The mass is the total mass of the molecules. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. The precise conditions under which wetlands produce and consume methane can vary between models.'
28. (CMIP6 short name wtd)
water_table_depth (canonical units: m)
'Depth is the vertical distance below the surface. The water table is the surface below which the soil is saturated with water such that all pore spaces are filled.'
Okay?
Best wishes,
Alison

Received on Fri Mar 09 2018 - 00:57:03 GMT