[CF-metadata] New standard names for C4MIP - part 2
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-- 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: Martin Juckes - UKRI STFC [mailto:martin.juckes at stfc.ac.uk] Sent: 12 April 2018 15:53 To: Alison Pamment - UKRI STFC <alison.pamment at stfc.ac.uk>; Jones, Chris D <chris.d.jones at metoffice.gov.uk>; cf-metadata at cgd.ucar.edu Subject: Re: New standard names for C4MIP - part 2 Dear Chris, Alison, We do have a requirement for "raOther" in CMIP6, so please go ahead. But, for consistency with the others I think it should be "_due_to_plant_respiration_", rather that just "_due_to_respiration_", and include a phrase on plant respiration in the help text. I've checked some background, to fill in gaps in my education, and learned that fungi are no longer plants ... at least not in the strict sense of the accepted scientific classification system. In order for these standard names to be correct for the requested variables, which are for autotrophic fluxes, I think we should make clear that we are using "plant" in this scientific sense, rather than in the broader sense following the pre-1960 classification. With this meaning, I think we can strengthen the statement about autotrophs since, as far as I can tell, all plants are autotrophs. The current help text for "plant_respiration_carbon_flux" implies that plants respire biomass, which doesn't look right to me. The current text used in the description of "plant_respiration_carbon_flux" is: "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." Following the discussion below, I think it would be worth modifying this to: "Plant respiration is the sum of respiration by parts of plants both above and below the soil. It is assumed that all the respired carbon dioxide is emitted to the atmosphere. Plants refers to the kingdom of plants in the modern classification which excludes fungi. Plants are autotrophs i.e. "producers" of the biomass using carbon obtained from carbon dioxide." I agree with the suggestion on modification of names for surface upward fluxes, regards, Martin ________________________________ From: Pamment, Alison (STFC,RAL,RALSP) Sent: 12 April 2018 12:45 To: 'Jones, Chris D'; Juckes, Martin (STFC,RAL,RALSP); cf-metadata at cgd.ucar.edu Subject: RE: New standard names for C4MIP - part 2 Dear Chris and Martin, Thanks for the discussion of proposals 21, 22, 23. I think we are agreed to modify these as follows: 21: raStem surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_stems should be surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_in_stems 22: raLeaf surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_leaves should be surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_in_leaves 23: raRoot surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_roots should be surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_in_roots These names had already been accepted. I have now modified them to include 'expressed_as' and inserted the appropriate sentence in the definitions. These names will still be included in the April 16th update. Regarding the discussion of ra and raOther: We have an existing standard name plant_respiration_carbon_flux which I think is the correct one to use for ra (ra = raStem + raLeaf + raRoot + rOther). This is why, originally, I didn't have the 'expressed_as' bit in proposals 21-23 - I was following the pattern of the existing name. In fact, we should now turn the existing one into an alias so that plant_respiration_carbon_flux becomes surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration for consistency with the new C4MIP names. Do you agree? As far as I can see, we don't currently have a standard name (either existing or proposed) that would correspond to raOther. Do we need one for the CMIP6 data request? If so, then we should do as you have both suggested and follow the standard name we have agreed for nppOther. It would then be something like the following: surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_respiration_in_miscellaneous_living_matter (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 carbon dioxide is CO2. 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. "Miscellaneous living matter" means all those parts of living vegetation that are not leaf, wood, root or other separately named components.' If we are turning plant_respiration_carbon_flux into an alias, there are some other existing respiration names that should also be updated to make them into surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon names: heterotrophic_respiration_carbon_flux -> surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_heterotrophic_respiration soil_respiration_carbon_flux -> surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_respiration_in_soil surface_upward_carbon_mass_flux_due_to_plant_respiration_for_biomass_growth -> surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_for_biomass_growth surface_upward_carbon_mass_flux_due_to_plant_respiration_for_biomass_maintenance -> surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_for_biomass_maintenance. Do others agree? If so, I can add the aliases (and the extra name, if needed) in the April update of the standard name table. 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: 05 April 2018 13:13 To: Juckes, Martin (STFC,RAL,RALSP) <martin.juckes at stfc.ac.uk>; Pamment, Alison (STFC,RAL,RALSP) <alison.pamment at stfc.ac.uk>; cf-metadata at cgd.ucar.edu Subject: RE: New standard names for C4MIP - part 2 Sounds good on all fronts! Thanks Chris -- 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: Martin Juckes - UKRI STFC [mailto:martin.juckes at stfc.ac.uk] Sent: 05 April 2018 13:09 To: Jones, Chris D <chris.d.jones at metoffice.gov.uk>; Alison Pamment - UKRI STFC <alison.pamment at stfc.ac.uk>; cf-metadata at cgd.ucar.edu Subject: Re: New standard names for C4MIP - part 2 Hello Chris, thanks. The proposed standard name for raRoot (with the modification suggested in my Q1) is consistent with your answer to Q2, so I support going forward with that: surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_plant_respiration_in_roots Your answers suggest that there is a case for revisiting the standard name used for "ra", as it would be nice to have a consistent approach for ra and the 4 new components, and we also need an additional name for raOther. I suggest we defer this to a separate discussion, so that Alison can move forward with the names agreed here, regards, Martin ________________________________ From: Jones, Chris D <chris.d.jones at metoffice.gov.uk> Sent: 05 April 2018 12:48 To: Juckes, Martin (STFC,RAL,RALSP); Pamment, Alison (STFC,RAL,RALSP); cf-metadata at cgd.ucar.edu Subject: RE: New standard names for C4MIP - part 2 Thanks Martin - good questions! Q1 - that's a good point. Yes I think these should take that form too unless there's a reason not too - but yes, this is a CO2 flux into the atmosphere and we want it in terms of mass of carbon lost. Q3 - I'll answer this first - yes, rOther is also required in parallel to nppOther. These are then sub-components of the total plant respiration: ra = raStem + raLeaf + raRoot + rOther Q2 - that sounds rather nuanced! So, yes, "ra" is an existing variable, and these new ones are sub components of it (as per Q3). It would be much neater if we could label this (all components) as a flux to the atmosphere. Technically the respiration from roots goes happens under ground, but "into soil" is a very bad description because that implies the carbon goes into the soil carbon pool, rather than being CO2 gas within the pores of the soil. It eventually escapes into the atmosphere and I've never heard of a model which tries to simulate any sort of storage of CO" gas trapped within soil. So this would be better simply labelled as a flux to the atmosphere. Does that make sense? Chris -- 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: Martin Juckes - UKRI STFC [mailto:martin.juckes at stfc.ac.uk] Sent: 05 April 2018 08:25 To: Alison Pamment - UKRI STFC <alison.pamment at stfc.ac.uk>; Jones, Chris D <chris.d.jones at metoffice.gov.uk>; cf-metadata at cgd.ucar.edu Subject: Re: New standard names for C4MIP - part 2 Dear Alison, Chris, I have a few questions about items 21, 22, 23: 21: raStem surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_stems: 22: raLeaf surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_leaves 23: raRoot surface_upward_mass_flux_of_carbon_due_to_plant_respiration_in_roots Q1: Such terms, which relate to the CO2 flux into the atmosphere, are usually of the form "..flux_of_carbon_dioxide_expressed_as_carbon...". Have you decided that the longer form is redundant here? Q2: We also have an existing name "plant_respiration_carbon_flux" which is used for variable "ra", as in CMIP5. "plant_respiration_carbon_flux" is described as a mass flux of carbon into the atmosphere and soil: would it be safe to assume that the carbon respiration flux into soil is the component from the roots? Shouldn't this be something like plant_respiration_carbon_flux_from_roots_into_soil? Q3: there should be a name for "raOther" somewhere, which would follow the pattern established for "nppOther" in this discussion, but does "raOther" include fluxes into soil and atmosphere, as "ra", or is it just a flux into the atmosphere, as "raLeaf" and "raStem"? regards, MartinReceived on Thu Apr 12 2018 - 10:16:33 BST
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