Hi Alison,
My responses are below, but they mostly consist of "yes, I agree."
On Thu, Dec 1, 2016 at 4:00 PM, <alison.pamment at stfc.ac.uk> wrote:
> Dear Dave and Jonathan,
>
> Thank you for the discussion of the product names and I see that we have
> now settled on wood_and_agricultural_products, which I agree is easier to
> understand for the non-expert. This same terminology will also need to be
> adopted for C4MIP so that we have a consistent approach for all the names.
>
> Following on from our earlier discussion (http://mailman.cgd.ucar.edu/
> pipermail/cf-metadata/2016/059101.html) I have updated all the LUMIP
> names and definitions as detailed below. The majority of LUMIP names are
> now either agreed or very close to agreement. Dave, please could you check
> through the list once more and let me know if anything else needs changing
> for proposals 1 - 6. I do still have some outstanding questions regarding
> proposals 7 and 8.
>
> > > 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).
> > >
> > This is fine with me. Presumably this will affect not only LUMIP
> variable request but that of other MIPs like LS3MIP. But, main thing is
> getting a consistent naming
> > convention and this seems good.
>
> Following discussion with Jonathan it was agreed to change the order of
> the words in the second name as follows:
> mass_content_of_water_in_soil (kg m-2)
> ' "Water" means water in all phases. "Content" indicates a quantity per
> unit area. The mass content of water in soil 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.'
>
> Any changes to these names will affect all CF users. I will make sure that
> the LS3MIP team are aware of the change. The old versions of the names will
> be retained in the standard name table as aliases which means that any data
> already written with those names will not be invalidated. However, data
> written in the future should use the most up to date version of the names.
>
> These changes are accepted for publication in the standard name table and
> will be added at the next update, scheduled for December 13th.
>
> > > 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.
> > >
> > I would suggest changing to (note the unit change as well as name
> change), removing the term crop to be more general.
> >
> > surface_downward_mass_flux_of_water_due_to_irrigation (canonical_units:
> kg m-2 s-1 or kg s-1)
> > The description would then be: Irrigation flux including any irrigation
> for crops, trees, pasture, or urban lawns.
> > As with other flux variables, is the per unit area implied since this is
> a flux term?
>
> Yes, flux always does imply per unit area in standard names so the units
> should be kg m-2 s-1 as you say. The name looks fine. So then we would have:
> surface_downward_mass_flux_of_water_due_to_irrigation (canonical_units:
> kg m-2 s-1)
> ' "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. "Irrigation" includes water used to sustain crops, trees,
> pastures and urban lawns.'
>
> OK?
>
Yes, this is ok. The only issue is that I get confused about whether or
not m-2 should be in the units or not. For other variables (e.g. the
carbon mass flux variables listed below), you remove the m-2 because it is
implied by the term flux, but you have included it here for this variable.
>
> > > 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.
> > >
> > Anthropogenic heat flux generated from non-renewable human primary
> energy consumption, including energy use by vehicles, commercial and
> residential buildings,
> > industry, and power plants. Primary energy refers to energy in natural
> resources, fossil and nonfossil, before conversion into other forms, such
> as electricity.
>
> Thank you for supplying the definition. So, in full, we have:
> surface_upward_heat_flux_due_to_anthropogenic_energy_consumption
> (canonical units: W m-2)
> '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. The heat flux due to anthropogenic energy consumption
> results from non-renewable human primary energy consumption, including
> energy use by vehicles, commercial and residential buildings, industry, and
> power plants. Primary energy refers to energy in natural resources, fossil
> and non-fossil, before conversion into other forms, such as electricity.'
>
> OK?
>
Yes.
>
> > > 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'
>
> Following the discussion on product names, this proposal has now become:
> tendency_of_atmosphere_mass_content_of_carbon_dioxide_
> expressed_as_carbon_due_to_emission_from_wood_and_agricultural_products
> (canonical units: 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. Examples
> of "wood 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 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.
>
> OK?
>
Yes.
>
> For consistency with this discussion, the existing standard name
> carbon_content_of_products_of_anthropogenic_land_use_change will be made
> into an alias. The new version of the name will then be:
> carbon_content_of_wood_and_agricultural_products (kg m-2)
> ' "Content" indicates a quantity per unit area. Examples of "wood 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 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.'
>
> OK?
>
> Yes.
> > > 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'
>
> Following the discussion on product names, and the discussion about
> anthropogenic land use or land cover change (see proposal 7 below), this
> proposal has now become:
> mass_flux_of_carbon_into_wood_and_agricultural_products_due_
> to_anthropogenic_land_use_or_land_cover_change (canonical units: 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" means
> influenced, caused, or created by human activity. Examples of "wood 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 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.'
>
> OK?
>
>
Yes.
> > > 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?
> > >
> > It is more appropriate to refer to 'carbon' rather than
> 'carbon_dioxide_expressed_as_carbon'. Leaving out the word pool is
> fine. Changing to soil and litter is fine.
>
> Thanks for clarifying. Following the discussion about anthropogenic land
> use or land cover change (see proposal 7 below) I have added
> 'anthropogenic' into this name, so we now have:
> carbon_mass_flux_into_soil_and_litter_due_to_anthropogenic_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. "Anthropogenic" means
> influenced, caused, or created by human activity.'
>
> OK?
>
Yes.
>
> > > 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.
> > >
> > Natural fire or natural land cover change due to shifts in vegetation
> biogeography should not be included. Generally, the term land-use and
> land-cover change implies
> > anthropogenic, but to be more explicit, it would be appropriate to add
> 'anthropogenic' in front of land-use and land-cover change.
>
> Thanks for clarifying. I think it is useful to be explicit about which
> processes are natural and which are anthropogenic. Looking back through the
> standard name table, I now see that we have some existing names that refer
> to anthropogenic_land_use_change which I think were proposed for CMIP5. The
> definitions of these names all say '"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.' Does all of that apply to this name?
>
> Yes.
> > > 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.
> > Note that we want to track two variables separately, which we originally
> labeled something like:
> > tendency_of_area_fraction_transitioned_out_of_land_use_tile (s-1)
> > annual gross fraction that was transferred out of this tile to other
> land use tiles
> >
> > tendency_of_area_fraction_transitioned_into_land_use_tile (s-1)
> > annual gross fraction that was transferred into this tile from other
> land use tiles
> > The goal here is to be able to track the gross transitions. In
> principle, for example, in a grid cell you could have 50%
> primary_and_secondary_land and 50% cropland and
> > then transfer all of the primary_and_secondary_land to cropland and all
> of the cropland to primary_and_secondary_land giving a net change of zero
> but a gross change of
> > 50% in either direction. We want to be able to track the gross change
> so we need to know both what is being transferred out and transferred in
> for each land use tile.
>
> Thank you for explaining more about your use case - I hadn't understood it
> properly before. I think, on balance, the best way to handle this is to go
> back to your original idea of using two standard names to make the meaning
> as clear as possible. I think Jonathan's suggestion of having canonical
> units of s-1 is still a good one, because you can then use year-1 in your
> data files. For gross changes I think we need to be clear about the sign
> convention in the name itself, hence the following suggestions.
>
> gross_rate_of_increase_in_area_fraction (s-1)
> The "rate of increase in area fraction" is the fraction of a grid cell
> that transitions to a given area type per unit time, for example, as a
> result of land use changes. The quantity described by this standard name is
> a gross increase because it includes only land where the use transitions to
> the given area type and excludes land that transitions away from that area
> type during the same period. The area type should be specified using a
> coordinate or scalar coordinate variable with standard name area_type.
> There is also a standard name for gross_rate_of_decrease_in_area_fraction.
>
> gross_rate_of_decrease_in_area_fraction (s-1)
> The "gross rate of decrease in area fraction" is the fraction of a grid
> cell that transitions from a given area type per unit time, for example, as
> a result of land use changes. The quantity described by this standard name
> is a gross decrease because it includes only land where the use transitions
> away from the given area type and excludes land that transitions to that
> area type during the same period. The area type should be specified using a
> coordinate of scalar coordinate variable with standard name area_type.
> There is also a standard name for gross_rate_of_increase_in_area_fraction.
>
> Does that sound better?
>
Yes. I like this suggestion.
>
> Best wishes,
> Alison
>
> ------
> Alison Pamment Tel: +44
> 1235 778065
> Centre for Environmental Data Analysis Email:
> alison.pamment at stfc.ac.uk
> STFC Rutherford Appleton Laboratory
> R25, 2.22
> Harwell Campus, Didcot, OX11 0QX, U.K.
>
>
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