[CF-metadata] CMIP5 carbon cycle standard names
alison.pamment at stfc.ac.uk
alison.pamment at stfc.ac.uk
Thu Jul 29 03:53:38 MDT 2010
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.
> 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.
> 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
>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.
> 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.
> 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
> 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 :
> I would simply suggest to define var 11 as :
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.
> 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.
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