Dear All, I have received some comments via email from Pierre Friedlingstein regarding the carbon cycle names. I have taken the liberty of reproducing those comments below.
1) products_of_land_use_change_carbon_content Alison wrote: > I am unsure of the definition of the quantity in row 6 of the table (products > of land use > change) and would welcome any help in clarifying the explanation. Pierre wrote: > Variable line 6: > products_of_land_use_change_carbon_content seems OK to me, by "products" > here we means the > different end-products of wood removed from the field following > deforestation. These products > are for example paper, cardboard, furnitures, timber for construction,... > The models that do simulate land cover changes do have a (or several pools) > of carbon that > represent these products in order to conserve carbon and to eventually > release it to the > atmosphere (when papers or your ikea table ends up in a landfill ;-) I think the name will be fine provided the definition includes this information. 2) carbon flux quantities Alison wrote: >For the land-atmosphere carbon flux quantities (rows 4, 7-11 and 31-32) I have >given two > alternative proposals for each name. This is because these quantities > can be regarded either as surface fluxes of carbon, or as tendencies in > the atmosphere carbon content. For the many existing atmospheric > chemistry names it was decided to take the latter approach, e.g. > tendency_of_atmosphere_mass_content_of_ammonia_due_to_emission. > However, for the purposes of modelling the carbon cycle it may be more > convenient to regard the quantities as fluxes. Personally, I would find > either approach acceptable as long as we adopt a consistent standard for > dealing with these names. Pierre wrote: > For variables lines 7-10 I would suggest we use the first definition > surface_... as opposed > to the tendency_... which has no much meaning for us (land surface > modellers). I know it does > for chemists, but the chemists don't care about CO2 anyway, it's not a > reactive gas ! We do have chemistry/composition standard names such as mass_concentration_of_carbon_dioxide_in_air and mole_concentration_of_carbon_dioxide in air. However, I think the names surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_fires_excluding_land_use_change; kg m-2 s-1 surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_grazing; kg m-2 s-1 surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_crop_harvesting; kg m-2 s-1 surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_change; kg m-2 s-1 are fine. Pierre wrote: > Variable line 11: > surface_net_downward_flux_of_carbon_due_to_biospheric_processes + area_type > of 'land' > This is not really satisfactory. This flux is what we call the net biome > production, this is > the net flux exchanged between the land and the atmosphere (positive > downward) as a results > of ALL known processes. This is different from variable of line 36 which is > what we call the > Net Ecosystem Production, and this is the net flux exhanged between the land > and the > atmosphere (positive downward) excluding human induced land use change > fluxes. > Both quantities are related of course (var 11 = var 36 - var 10) but both are > useful to us. > As you have defined var 36 as : > surface_net_downward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_photosynthesis_and_respiration_and_fires_excluding_land_use_change > I would simply suggest to define var 11 as : > surface_net_downward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_photosynthesis_and_respiration_and_fires_including_land_use_change I am happy to use Pierre's suggestion for this variable, and will include the information about the relationship between the quantities in rows 10, 11 and 36 in the definitions. Pierre wrote: > Also to be consistent, between var 31 and 32, I would suggest: > 31: surface_upward_carbon_flux_due_to_plant_respiration_for_biomass_growth > 32: > surface_upward_carbon_flux_due_to_plant_respiration_for_biomass_maintenance I think this is an excellent suggestion! No other comments have been received regarding the carbon cycle names. If none are received by August 10th (when I return from annual leave) the full list of carbon cycle names, with the amendments suggested by Pierre, will be accepted for inclusion in the standard name table. Best wishes, Alison -- Scanned by iCritical. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
