Apologies - it seems all of my formatting got stripped from the email - I hope it's OK to attach a word document that should be easier to read...
-- 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.jo...@metoffice.gov.uk http://www.metoffice.gov.uk -----Original Message----- From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of Jones, Chris D Sent: 20 March 2018 17:21 To: alison.pamm...@stfc.ac.uk; cf-metadata@cgd.ucar.edu Subject: Re: [CF-metadata] New standard names for C4MIP - part 2 That's a really comprehensive first go Alison - thank you so much. Here are my responses, with yellow highlighting anything I've typed, and strike-through anything I removed. Email is not the best at track-changes, so I hope these are clear. Regards, Chris General note: as far as possible all carbon pools and most fluxes have been given a nitrogen equivalent. So nVeg parallels cVeg for example, and the sub-components nVeg=nStem+nLeaf+nRoot+nOther parallel the carbon equivalents. The overriding request if a model doesn't map neatly to these is that all carbon and nitrogen is reported somewhere so that subsequent analysis tracks conservation. 1-3 are sub components of nLitter: nLitter = nLitterCwd + nLitterSurf + nLitterSubSurf (nLitterCwd) 1. wood_debris_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Wood debris" means dead organic matter composed of coarse wood. It is distinct from fine litter. Definition of "fine" and "coarse" litter are up to each model group, but as for the parallel carbon pools the sum should agree with the total nLitter.' (nLitterSurf) 2. surface_litter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "Surface litter" means the part of fine litter resting above the soil surface.' (nLitterSubSurf) 3. subsurface_litter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "Subsurface litter" means the part of fine litter mixed within the soil below the surface.' 4-7 are sub-components of nVeg (nStem) 4. wood_biomass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' This is by analogy with the existing standard name 'wood_carbon_content'. Although we don't currently define 'wood' in this context I am sure it means 'living wood' as opposed to wood_debris. The CMIP6 data request talks about 'stem'. I appreciate that 'stem' could refer to more than just trees, whose stems are living wood', but I think these names are essentially trying to describe the same thing. For this name we could perhaps even say living_wood_mass_content_of_nitrogen (and make an alias for the carbon name so that it follows the same pattern). What do you think? Yes, we mean living biomass and not dead wood (covered in nLitterCwd above). Hence we prefer Stem to Wood for this reason (as per carbon pool too). (nLeaf) 5. leaf_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' OK (nRoot) 6. root_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' OK (nOther) 7. miscellaneous_living_matter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Miscellaneous living matter" means all those parts of living vegetation that are not leaf, wood or root or other separately named components.' This is by analogy with the existing name miscellaneous_living_matter_carbon_content. There are no other separately named pools, so nStem+nLeaf+nRoot+nOther should identically equal the total in nVeg (and parallel for carbon pools and cVeg) (fNVegSoil) 8. nitrogen_mass_flux_into_soil_from_vegetation_excluding_litter (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.' By analogy with the existing name carbon_mass_flux_into_soil_from_vegetation_excluding_litter. OK (fNVegLitter) 9. nitrogen_mass_flux_into_litter_from_vegetation (kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Litter" is dead plant material in or above the soil. "Vegetation" means any living plants e.g. trees, shrubs, grass. OK (fNLitterSoil) 10. nitrogen_mass_flux_into_soil_from_litter (kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Litter" is dead plant material in or above the soil.' OK (fBNF) 11. tendency_of_terrestrial_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen_due_to_fixation (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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. "Nitrogen fixation" means the production of ammonia from nitrogen gas. Organisms that fix nitrogen are termed "diazotrophs".' Was I right to call this one 'inorganic_nitrogen'? I borrowed the last two sentences of the definition from an ocean name. Do they accurately describe land based nitrogen fixation? My understanding is that 'diazotrophs' is a general term and not confined to ocean organisms but I'd be pleased if someone could confirm that! I suggest we: - Say "terrestrial" instead of "soil" because this term is mainly about plants fixing nitrogen directly from N2 in the atmosphere. Some models may have it as a term going into the vegetation, some into the soil. We need to capture either/both, so it's not just the tendency of the soil nitrogen. - Don't specify organic/inorganic. If the fixed N goes into the vegetation it will not be in inorganic form, so again we need to leave this open to cover any form of uptake. - Don't mention anything about ammonia or diazotrophs - the terrestrial uptake doesn't go via ammonia, and I'm not sure the exact name of the organisms that do it are relevant. (fNLandToOcean) 12. mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_into_sea_from_rivers (kg m-2 s-1) '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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' OK Are the nitrogen species and its definition the right ones? We just want to track the amount of nitrogen - so the species don't matter as long as all nitrogen is reported. I don't think we need to list any specifically in the variable definition. (fNOx) 13. mass_flux_of_nox_expressed_as_nitrogen_out_of_vegetation_and_litter_and_soil (kg m-2 s-1) '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. "Nox" means a combination of two radical species containing nitrogen and oxygen NO+NO2. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil.' OK (fNloss) 14. mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_out_of_vegetation_and_litter_and_soil (kg m-2 s-1) '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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil.' OK - but this should exclude anything to do with land-use/cover change as these are covered below in fAnthDisturb/fNProduct Are the nitrogen species and its definition the right ones? We just want to track the amount of nitrogen - so the species don't matter as long as all nitrogen is reported. I don't think we need to list any specifically in the variable definition. (fNdep) Is this really a new variable? I'm surprised the chemistry community don't already have nitrogen deposition? 15. tendency_of_atmosphere_mass_content_of_reactive_nitrogen_expressed_as_nitrogen_due_to_deposition (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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 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. "Deposition" is the sum of wet and dry deposition.' Sounds OK, but our intended sign convention is a positive flux into vegetation, so this could be tendency of terrestrial nitrogen? Rather than tendency of the atmosphere We don't currently have any definition for 'reactive_nitrogen'. Please could you provide one? Basically, anything that's not N2 gas (fNfert) 16. tendency_of_soil_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen_due_to_fertilization (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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. "Fertilization" means the addition of artificial fertilizers and animal manure to soil for the purpose of increasing plant nutrient concentrations, and could by model choice be either into nSoil or nMineral pools.' Is it right to say 'inorganic_nitrogen' for this one? Is the definition of 'fertilization' okay? Yes - definition of fertilisation is OK. No - it doesn't have to be inorganic. Again this might differ by model, and we just want to capture how much N is going into the system. I've suggested we should also be specific that it includes either organic or inorganic pool in case the term "tendency of soil mass content of nitrogen" is taken to refer to nSoil and not nMineral. (fNgasFire) 17. surface_upward_mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_due_to_emission_from_fires (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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably p eroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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.' Are the nitrogen species and its definition the right ones? We just want to track the amount of nitrogen - so the species don't matter as long as all nitrogen is reported. I don't think we need to list any specifically in the variable definition. (fNgasNonFire) 18. surface_upward_mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_due_to_all_land_processes_excluding_fires (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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are inc luded. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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. "All land processes" means plant and soil respiration, photosynthesis, animal grazing, crop harvesting, natural fires and anthropogenic land use change.' We just want to track the amount of nitrogen - so the species don't matter as long as all nitrogen is reported. I don't think we need to list any specifically in the variable definition. This one is by analogy with the existing names surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes and surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes_excluding_anthropogenic_land_use_change. Are the nitrogen species and its definition the right ones? (fNAnthDisturb) 19. tendency_of_atmosphere_mass_content_of_nitrogen_compounds_expressed_as_nitrogen_due_to_anthropogenic_land_use_or_land_cover_change (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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 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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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 b y 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.' OK Are the nitrogen species and its definition the right ones? We just want to track the amount of nitrogen - so the species don't matter as long as all nitrogen is reported. I don't think we need to list any specifically in the variable definition. (fNProduct) 20. nitrogen_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. 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 nitrogen that represent these products in order to conserve nitrogen and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. "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.' OK 21-23, combines with raOther to sum to give total autotrophic respiration: ra = raStem + raLeaf + raRoot + raOther (raStem) 21. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_wood (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' OK As for proposal (4), 'wood' means living wood. (We should adopt consistent terminology for both). There are existing names for plant respiration - 'plants' is currently the term used in standard names for 'autotrophs'. (raLeaf) 22. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_leaves (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' OK (raRoot) 23. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_roots (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' OK 24, combine with other npp components to sum to give total npp: npp = nppStem + nppLeaf + nppRoot + nppOther (nppOther) 24. net_primary_productivity_of_biomassvegetation_expressed_as_carbon_accumulated_in_miscellaneous_living_matter (kg m-2 s-1) ' "Miscellaneous living matter" means all those parts of living vegetation that are not leaf, wood, root or other separately named components. 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. "Production of carbon" means the production of biomass expressed as the mass of carbon which it contains. Net primary production is the excess of gross primary production (rate of synthesis of biomass from inorganic precursors) by autotrophs ("producers"), for example, photosynthesis in plants or phytoplankton, over the rate at which the autotrophs themselves respire some of this biomass. "Productivity" means production per unit area.' OK - but suggest "of vegetation" rather than "of biomass" 25, 26 are sub-components of rh, and sum to give the total: rh = rhLitter + rhSoil (rhLitter) 25. surface_upward_mass_flux_of_carbon_due_to_heterotrophic_respiration_in_litter (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 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. "Litter" is dead plant material in or above the soil. Heterotrophic respiration is respiration by heterotrophs ("consumers"), which are organisms (including animals and decomposers) that consume other organisms or dead organic material, rather than synthesising organic material from inorganic precursors using energy from the environment (especially sunlight) as autotrophs ("producers") do. Heterotrophic respiration goes on both above and within the soil and litter pools.' OK We have one existing name for 'heterotrophic_respiration'. Yes - these are sub-components of it (rhSoil) 26. surface_upward_mass_flux_of_carbon_due_to_heterotrophic_respiration_in_soil (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 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. Heterotrophic respiration is respiration by heterotrophs ("consumers"), which are organisms (including animals and decomposers) that consume other organisms or dead organic material, rather than synthesising organic material from inorganic precursors using energy from the environment (especially sunlight) as autotrophs ("producers") do. Heterotrophic respiration goes on both above and within the soil and litter pools.' OK (tSoilPools) 27. soil_pool_carbon_decay_rate (kg m-2 s-1) ' "Soil carbon" is the organic matter present in soil quantified by the mass of carbon it contains. Soil carbon is returned to the atmosphere as the organic matter decays. The decay process takes varying amounts of time depending on the composition of the organic matter, the temperature and the availability of moisture. A carbon "soil pool" means the carbon contained in organic matter which has a characteristic period over which it decays and releases carbon into the atmosphere.' This is a new quantity, although we do have some existing names that refer to soil_pools. I guessed the unit from the quantity - is it correct? This quantity is meant to complement the respiration one and give the turnover rate, hence units simply "per second, s-1". Each modelled soil carbon pool will have a characteristic turnover time, which is then modified by environmental conditions such as temperature and moisture so that the turnover time varies in space and time. Hence it is requested as a new variable. We request here the turnover RATE rather than TIME, defined as 1/(turnover time). Use the same pools reported under cSoilPools. (co23D) 28. mass|mole_concentration_of_carbon_dioxide_passive_tracer_in_air What are the units of this quantity? Knowing the unit will allow us to decide if this should be a mass or a mole concentration (or something else). I wasn't really sure of the purpose of this name - by using carbon dioxide as a tracer I assume that means it is conserved by being treated as chemically inert. Can you give me some more details about this one please? This is requested to be a mass mixing ratio in kg CO2 / kg dry air. Report 3D field of model simulated atmospheric CO2 mass mixing ration on model levels. -- 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.jo...@metoffice.gov.uk http://www.metoffice.gov.uk -----Original Message----- From: alison.pamm...@stfc.ac.uk [mailto:alison.pamm...@stfc.ac.uk] Sent: 16 March 2018 14:19 To: Jones, Chris D <chris.d.jo...@metoffice.gov.uk>; cf-metadata@cgd.ucar.edu Subject: New standard names for C4MIP - part 2 Dear All, I am proposing some further standard names for the C4MIP project in CMIP6 - this should complete the list of quantities needed. I'm sure Chris will comment on these in due course and any other comments and suggestions for improvement are always welcome. Quite a lot of these names are for nitrogen contents and fluxes in and out of the atmosphere and various land surface components. Chris, please could you check in particular that I have named the nitrogen species correctly in each case? For some names I think it's fine just to say 'nitrogen' but in others I have said inorganic_nitrogen or nitrogen_compounds_expressed_as_nitrogen depending on what seemed most appropriate, but I may not have chosen the best alternative in every case and I'd appreciate some advice about this. An additional wrinkle to this is that there are two alternative pieces of text that I could use to define nitrogen_compounds_expressed_as_nitrogen. One of them was introduced for OMIP, i.e. ocean, nitrogen quantities: ' "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' This is generic so could easily be applied to all the nitrogen_compounds names, but it doesn't give any hint about what individual species are actually involved. There is another, more detailed definition that was introduced last year for various atmospheric nitrogen terms: ' "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' I have used the more detailed definition where I thought it might apply (fluxes into/ out of the atmosphere, atmospheric tendencies) and the generic definition elsewhere. Again, I'd appreciate advice on whether I've made the correct choices in each case. 1. wood_debris_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Wood debris" means dead organic matter composed of coarse wood. It is distinct from litter.' 2. surface_litter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "Surface litter" means the part of the litter resting above the soil surface.' 3. subsurface_litter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Litter" is dead plant material in or above the soil. "Subsurface litter" means the part of the litter mixed within the soil below the surface.' 4. wood_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' This is by analogy with the existing standard name 'wood_carbon_content'. Although we don't currently define 'wood' in this context I am sure it means 'living wood' as opposed to wood_debris. The CMIP6 data request talks about 'stem'. I appreciate that 'stem' could refer to more than just trees, whose stems are living wood', but I think these names are essentially trying to describe the same thing. For this name we could perhaps even say living_wood_mass_content_of_nitrogen (and make an alias for the carbon name so that it follows the same pattern). What do you think? 5. leaf_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' 6. root_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area.' 7. miscellaneous_living_matter_mass_content_of_nitrogen (kg m-2) ' "Content" indicates a quantity per unit area. "Miscellaneous living matter" means all those parts of living vegetation that are not leaf, wood, root or other separately named components.' This is by analogy with the existing name miscellaneous_living_matter_carbon_content. 8. nitrogen_mass_flux_into_soil_from_vegetation_excluding_litter (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.' By analogy with the existing name carbon_mass_flux_into_soil_from_vegetation_excluding_litter. 9. nitrogen_mass_flux_into_litter_from_vegetation (kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Litter" is dead plant material in or above the soil. "Vegetation" means any living plants e.g. trees, shrubs, grass. 10. nitrogen_mass_flux_into_soil_from_litter (kg m-2 s-1) 'In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. "Litter" is dead plant material in or above the soil.' 11. tendency_of_soil_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen_due_to_fixation (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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. "Nitrogen fixation" means the production of ammonia from nitrogen gas. Organisms that fix nitrogen are termed "diazotrophs".' Was I right to call this one 'inorganic_nitrogen'? I borrowed the last two sentences of the definition from an ocean name. Do they accurately describe land based nitrogen fixation? My understanding is that 'diazotrophs' is a general term and not confined to ocean organisms but I'd be pleased if someone could confirm that! 12. mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_into_sea_from_rivers (kg m-2 s-1) '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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute.' Are the nitrogen species and its definition the right ones? 13. mass_flux_of_nox_expressed_as_nitrogen_out_of_vegetation_and_litter_and_soil (kg m-2 s-1) '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. "Nox" means a combination of two radical species containing nitrogen and oxygen NO+NO2. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil.' 14. mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_out_of_vegetation_and_litter_and_soil (kg m-2 s-1) '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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. "Vegetation" means any living plants e.g. trees, shrubs, grass. "Litter" is dead plant material in or above the soil.' Are the nitrogen species and its definition the right ones? 15. tendency_of_atmosphere_mass_content_of_reactive_nitrogen_expressed_as_nitrogen_due_to_deposition (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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 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. "Deposition" is the sum of wet and dry deposition.' We don't currently have any definition for 'reactive_nitrogen'. Please could you provide one? 16. tendency_of_soil_mass_content_of_inorganic_nitrogen_expressed_as_nitrogen_due_to_fertilization (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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. "Fertilization" means the addition of artificial fertilizers and animal manure to soil for the purpose of increasing plant nutrient concentrations.' Is it right to say 'inorganic_nitrogen' for this one? Is the definition of 'fertilization' okay? 17. surface_upward_mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_due_to_emission_from_fires (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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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.' Are the nitrogen species and its definition the right ones? 18. surface_upward_mass_flux_of_nitrogen_compounds_expressed_as_nitrogen_due_to_all_land_processes_excluding_fires (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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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. "All land processes" means plant and soil respiration, photosynthesis, animal grazing, crop harvesting, natural fires and anthropogenic land use change.' This one is by analogy with the existing names surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes and surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes_excluding_anthropogenic_land_use_change. Are the nitrogen species and its definition the right ones? 19. tendency_of_atmosphere_mass_content_of_nitrogen_compounds_expressed_as_nitrogen_due_to_anthropogenic_land_use_or_land_cover_change (kg m-2 s-1) 'The phrase "tendency_of_X" means derivative of X with respect to time. "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 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 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. "Nitrogen compounds" summarizes all chemical species containing nitrogen atoms. Usually, particle bound and gaseous nitrogen compounds, such as atomic nitrogen (N), nitrogen monoxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), nitric acid (HNO3), nitrate (NO3-), peroxynitric acid (HNO4), ammonia (NH3), ammonium (NH4+), bromine nitrate (BrONO2), chlorine nitrate (ClONO2) and organic nitrates (most notably peroxyacetyl nitrate, sometimes referred to as PAN, (CH3COO2NO2)) are included. The list of individual species that are included in this quantity can vary between models. Where possible, the data variable should be accompanied by a complete description of the species represented, for example, by using a comment attribute. 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.' Are the nitrogen species and its definition the right ones? 20. nitrogen_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. 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 nitrogen that represent these products in order to conserve nitrogen and allow its eventual release into the atmosphere, for example, when the products decompose in landfill sites. "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.' 21. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_wood (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' As for proposal (4), 'wood' means living wood. (We should adopt consistent terminology for both). There are existing names for plant respiration - 'plants' is currently the term used in standard names for 'autotrophs'. 22. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_leaves (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' 23. surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_roots (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 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. Plant respiration is the sum of respiration by parts of plants both above and below the soil. Plants which photosynthesise are autotrophs i.e. "producers" of the biomass which they respire from inorganic precursors using sunlight for energy.' 24. net_primary_productivity_of_biomass_expressed_as_carbon_accumulated_in_miscellaneous_living_matter (kg m-2 s-1) ' "Miscellaneous living matter" means all those parts of living vegetation that are not leaf, wood, root or other separately named components. 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. "Production of carbon" means the production of biomass expressed as the mass of carbon which it contains. Net primary production is the excess of gross primary production (rate of synthesis of biomass from inorganic precursors) by autotrophs ("producers"), for example, photosynthesis in plants or phytoplankton, over the rate at which the autotrophs themselves respire some of this biomass. "Productivity" means production per unit area.' 25. surface_upward_mass_flux_of_carbon_due_to_heterotrophic_respiration_in_litter (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 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. "Litter" is dead plant material in or above the soil. Heterotrophic respiration is respiration by heterotrophs ("consumers"), which are organisms (including animals and decomposers) that consume other organisms or dead organic material, rather than synthesising organic material from inorganic precursors using energy from the environment (especially sunlight) as autotrophs ("producers") do. Heterotrophic respiration goes on both above and within the soil.' We have one existing name for 'heterotrophic_respiration'. 26. surface_upward_mass_flux_of_carbon_due_to_heterotrophic_respiration_in_soil (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 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. Heterotrophic respiration is respiration by heterotrophs ("consumers"), which are organisms (including animals and decomposers) that consume other organisms or dead organic material, rather than synthesising organic material from inorganic precursors using energy from the environment (especially sunlight) as autotrophs ("producers") do. Heterotrophic respiration goes on both above and within the soil.' 27. soil_pool_carbon_decay_rate (kg m-2 s-1) ' "Soil carbon" is the organic matter present in soil quantified by the mass of carbon it contains. Soil carbon is returned to the atmosphere as the organic matter decays. The decay process takes varying amounts of time depending on the composition of the organic matter, the temperature and the availability of moisture. A carbon "soil pool" means the carbon contained in organic matter which has a characteristic period over which it decays and releases carbon into the atmosphere.' This is a new quantity, although we do have some existing names that refer to soil_pools. I guessed the unit from the quantity - is it correct? 28. mass|mole_concentration_of_carbon_dioxide_passive_tracer_in_air What are the units of this quantity? Knowing the unit will allow us to decide if this should be a mass or a mole concentration (or something else). I wasn't really sure of the purpose of this name - by using carbon dioxide as a tracer I assume that means it is conserved by being treated as chemically inert. Can you give me some more details about this one please? Best wishes, Alison _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
CF_nVariable_Names_March2018.docx
Description: CF_nVariable_Names_March2018.docx
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