Dear Dave, Thank you for proposing new standard names for LUMIP and apologies for the delay in responding. Thanks also to Jonathan for commenting in this discussion.
I have added the LUMIP proposals to my list of standard names under discussion and you can view a summary of them all here: http://cfeditor.ceda.ac.uk/proposals/1?status=active&namefilter=&proposerfilter=&descfilter=&unitfilter=&yearfilter=&commentfilter=LUMIP&filter+and+display=Filter. This shows the latest status of the names, including changes that have already been agreed during the discussion. I have not added an entry for surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes because, as Jonathan pointed out, this is actually an existing name. Regarding your other proposals, please see below for my comments on the individual names. 1. moisture_content_of_soil_layer (canonical units: kg m-2) 'Moisture in top 10 cm of soil column of land use tile.' soil_moisture_content (canonical units: kg m-2) 'Total soil moisture'. Jonathan is correct that these two names already exist. However, the reason I suggested raising them on the mailing list is that I think we should improve the wording of the existing names by changing them to mass_content_of_water_in_soil_layer and soil_mass_content_of_water respectively. This would make the syntax of the soil names more consistent with other existing names such as atmosphere_mass_content_of_water and mass_content_of_water_vapor_in_atmosphere_layer, for example. There are also existing soil names that refer to "frozen_water" and "condensed_water" rather than "moisture" so I think it would be sensible to standardize the terminology used across all the names. The soil names could continue to use their existing definitions as follows: mass_content_of_water_in_soil_layer (kg m-2) ' "Water" means water in all phases. "Content" indicates a quantity per unit area. "Layer" means any layer with upper and lower boundaries that have constant values in some vertical coordinate. There must be a vertical coordinate variable indicating the extent of the layer(s). If the layers are model layers, the vertical coordinate can be model_level_number, but it is recommended to specify a physical coordinate (in a scalar or auxiliary coordinate variable) as well. Quantities defined for a soil layer must have a vertical coordinate variable with boundaries indicating the extent of the layer(s).' soil_mass_content_of_water (kg m-2) ' "Water" means water in all phases. "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.' Is this OK? If so, I think these names can be accepted for inclusion in the standard name table (the older versions of the names would be retained as aliases). 2. surface_downward_mass_flux_of_water_due_to_crop_irrigation (canonical_units: kg m-2) 'cropland irrigation flux' I think the name and units are fine. We need to expand the definition and based on text used for existing names I would suggest: ' "Downward" indicates a vector component which is positive when directed downward (negative upward). The surface called "surface" means the lower boundary of the atmosphere. 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.' Is this OK? I am wondering if this name refers to any particular definition of 'crop', for example, arable crops, fruit trees, trees grown for timber, or perhaps all of the above? It would be useful to add that into the text too. 3. surface_upward_sensible_heat_flux_due_to_anthropogenic_energy_consumption (canonical units: W m-2) ' anthropogenic heat flux' I note that after discussion with Jonathan, Dave has agreed that the name should be more general, i.e., it is not only a sensible heat flux and the proposal is now surface_upward_heat_flux_due_to_anthropogenic_energy_consumption (Wm-2). That name and the units are fine, so now we need a definition. Based on the definitions of existing names we would have the following: 'The surface called "surface" means the lower boundary of the atmosphere. "Upward" indicates a vector component which is positive when directed upward (negative downward). The vertical heat flux in air is the sum of all heat fluxes i.e. radiative, latent and sensible. 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.' Does 'anthropogenic_energy_consumption' mean all anthropogenic processes, e.g., domestic, industrial, transport, agriculture, and so on? It would make the definition (and hence the name) more useful if we can say something about which processes are included or excluded. 4. tendency_of_atmosphere_mass_content_of_carbon_due_to_emission_from_anthropogenic_product_pool (canonical units: kg s-1) ' flux from anthropogenic pools on land use tile into atmosphere' Jonathan asked whether this name should really be carbon_dioxide_expressed_as_carbon and Dave has agreed, so the proposal is now tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_anthropogenic_product_pool (kg s-1). Jonathan asked about the meaning of the term "anthropogenic_product_pool" and David replied as follows: > Anthropogenic product pools are carbon pools where carbon from wood or crop > harvest is put. I am not sure that there is a generally accepted term for > this, but anthropogenic product pools is commonly used and should be > understood (with the additional comments) by those in the land modeling > community. We do have one existing standard name, introduced for CMIP5, carbon_content_of_products_of_anthropogenic_land_use_change with the following definition: ' "Content" indicates a quantity per unit area. "products_of_anthropogenic_land_use_change" means the different end-products of wood that has been removed from the environment by deforestation. Examples are paper, cardboard, furniture and timber for construction. 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" means influenced, caused, or created by human activity.' I think the existing definition sounds very similar to Dave's description, so I suggest we keep it and use it in all the anthropogenic product names. For consistency with the LUMIP proposals, I suggest we change the existing name to carbon_content_of_anthropogenic_product_pool. So the LUMIP name and definition would then be as follows: tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_emission_from_anthropogenic_product_pool (kg 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. "anthropogenic_product_pool" means the different end-products of wood that has been removed from the environment by deforestation or harvesting. Examples are paper, cardboard, furniture and timber for construction. 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" means influenced, caused, or created by human activity.' Is this OK? If so, I think this name (and the creation of an alias for the existing product pool name) can be accepted for publication in the standard name table. 5. carbon_mass_flux_into_anthropogenic_product_pools_due_to_land_use_land_cover_change (canonical units: kg s-1) 'carbon harvested due to land-use or land-cover change process that enters anthropogenic product pools on tile' In this case is it correct to refer simply to 'carbon' rather than carbon_dioxide_expressed_as_carbon? (Either would be OK, we just need to choose the most appropriate phrase). Following one of Jonathan's comments should we refer to 'land_use_or_land_cover_change'? Thus the name and definition would then be: mass_flux_of_carbon_into_anthropogenic_product_pool_due_to_land_use_or_land_cover_change (kg 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_product_pool" means the different end-products of wood that has been removed from the environment by deforestation or harvesting. Examples are paper, cardboard, furniture and timber for construction. 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" means influenced, caused, or created by human activity.' OK? 6. carbon_mass_flux_into_soil_or_litter_pools_due_to_land_use_land_cover_change (canonical_units: kg s-1) 'carbon transferred to soil or litter pools due to land-use or land-cover change processes on tile' As with the previous proposal, is it correct to refer simply to 'carbon' rather than carbon_dioxide_expressed_as_carbon? Dave and Jonathan agreed that we should refer to 'land_use_or_land_cover_change. Perhaps the name should say soil_and_litter, rather than soil_or_litter because presumably the carbon is going into both pools? Also, existing names refer simply to 'soil' and/or 'litter' without using the word 'pool', so I think we should leave that word out for consistency. So then the name would be: carbon_mass_flux_into_soil_and_litter_due_to_land_use_or_land_cover_change (kg 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. 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.' OK? 7. carbon_mass_flux_direct_to_atmosphere_due_to_land_use_land_cover_change (canonical units: kg s1) 'carbon transferred directly to atmosphere due to any land-use or land-cover change activities including deforestation or agricultural fire' Jonathan suggested that this name would be better expressed as surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_land_use_or_land_cover_change for consistency with other surface flux names and Dave agreed with this change. For the definition, I note that agricultural fires are included but what about natural ones? Do all these 'land_use_or_land_cover_change' names really refer to anthropogenic changes rather than natural ones? If so, we should really say 'anthropogenic_land_use_or_land_cover_change' in all of them. 8. change_over_time_in_area_fraction (canonical units: 1) 'annual gross fraction of land use tile that was transferred into other land use tiles' Jonathan suggested that this quantity could be described as tendency_of_area_fraction (canonical unit: s-1) and that units of yr-1 could be used in the data files. Dave agreed that this would be an acceptable approach. Thus the name, units and definition would be: tendency_of_area_fraction (s-1) ' "tendency_of_X" means derivative of X with respect to time. "X_area_fraction" means the fraction of horizontal area occupied by X. Annual gross fraction of land use tile that was transferred into other land use tiles.' OK? If so, I think this one can be accepted for inclusion in the standard name table. Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 Centre for Environmental Data Analysis Email: [email protected] STFC Rutherford Appleton Laboratory R25, 2.22 Harwell Campus, Didcot, OX11 0QX, U.K. From: CF-metadata [mailto:[email protected]] On Behalf Of David Lawrence Sent: 29 September 2016 23:10 To: Jonathan Gregory; Elena Shevliakova Cc: [email protected] Subject: Re: [CF-metadata] New LUMIP variables Thanks for your detailed assessment Jonathan, Answers embedded below. Thanks, Dave On Tue, Sep 27, 2016 at 7:37 AM, Jonathan Gregory <[email protected]> wrote: Dear Dave Thanks for the text listing of your proposals. Here are a few comments: These ones are existing standard names: surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_all_land_processes moisture_content_of_soil_layer soil_moisture_content OK. Alison Pamment suggested that we post these to the list, so I did, but I think you are right. I see that there is already a standard name of surface_downward_water_flux. For consistency, I think the existing standard name should be changed (by alias) to surface_downward_mass_flux_of_water for consistency with your proposal surface_downward_mass_flux_of_water_due_to_crop_irrigation or yours should be changed to surface_downward_water_flux_due_to_crop_irrigation Changing our name to surface_downward_water_flux_due_to_crop_irrigation is good. * surface_upward_sensible_heat_flux_due_to_anthropogenic_energy_consumption In the definition you call this "anthropogenic heat flux". That sounds more general. Is it really an upward sensible heat flux specifically - no latent heat flux, for instance? Or do you mean the heat released per unit area and per unit time by anthropogenic energy use, no matter what happens to it? Yes, this should be more general: surface_upward_heat_flux_due_to_anthropogenic_energy_consumption * tendency_of_atmosphere_mass_content_of_carbon_due_to_emission_from_anthropogenic_product_pool Is this really carbon and not carbon_dioxide_expressed_as_carbon, like others? What is the difference between this and the existing standard name tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_emission Actually I don't know what "anthropogenic product pool" means. It isn't a phrase known to Google. Is there an alternative? Consequently I also don't understand this one carbon_mass_flux_into_anthropogenic_product_pools_due_to_land_use_land_cover_change Anthropogenic product pools are carbon pools where carbon from wood or crop harvest is put. I am not sure that there is a generally accepted term for this, but anthropogenic product pools is commonly used and should be understood (with the additional comments) by those in the land modeling community. So, the term tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_emission would include tendency_of_atmosphere_mass_content_of_carbon_due_to_emission_from_anthropogenic_product_pool as one of it's components. Agreed about adding _of_carbon_dioxide_expressed_as_carbon to this standard name. * carbon_mass_flux_into_soil_or_litter_pools_due_to_land_use_land_cover_change I guess this should be ..._due_to_land_use_or_land_cover_change Correct. * carbon_mass_flux_direct_to_atmosphere_due_to_land_use_land_cover_change By analogy with several existing names of the form surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_X could this one be surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_land_use_or_land_cover_change Yes, if this is the common form, then that would be correct. * change_over_time_in_area_fraction It is OK for this to be change_over_time but would it be better as a rate i.e. tendency_of_area_fraction for which the canonical unit would be s-1? It could still be expressed as yr-1 so numerically the same. I think that this would be ok, especially if that is how other area_fraction change variables are reported. Best wishes Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
