Dear Martin,
Thank you for the proposals for one new standard name and one new area type for LUMIP.
1. Proposed area_type: herbaceous_vegetation
'Herbaceous plants are plants with very flexible stems. Their leaves and stems die down to soil level at the end of every growing season. Herbaceous plants can be annual, biennial or perennial.'
This proposal has not received any comments on the list, however I think it looks fine so it is accepted. I will update the area_type table at the same time as the standard name table on 14th May.
2. Proposed standard name: surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change_excluding_forestry_and_agricultural_products (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 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. 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. "Anthropogenic land use change" means human changes to land, excluding forest regrowth. It includes fires ignited by h
umans for the purpose of land use change. The quantity with standard name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change_excluding_forestry_and_agricultural_products excludes the carbon dioxide flux into the atmosphere due to the processes of eventual disposal and decomposition of wood products such as paper, cardboard, furniture and timber for construction. The standard name for the quantity that includes product decomposition is surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change.'
This proposal has not received any comments on the list. As you pointed out in the proposal, this one is simply an extension of the existing name surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change that includes product decomposition. I have constructed the definition so as to explain the difference between the two.
The name, units and definition are fine so this one is accepted and will be included in the May standard name table update.
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: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Martin Juckes - UKRI STFC
Sent: 18 April 2018 07:48
To: CF Metadata List <cf-metadata at cgd.ucar.edu>
Subject: [CF-metadata] Herbaceous vegetation area type and a new LULCC carbon flux standard name for LUMIP
Hello All,
We have two outstanding CF metadata requirements for the LUMIP CMIP6 data request.
(1) An area type is needed for non-woody, or herbaceous, vegetation.
LUMIP variable: nwdFracLut Percentage of land use tile that is non-woody vegetation ( e.g. herbaceous crops)
Plants can be divided into "woody" and "herbaceous" categories. The "woody" plants have stems which are adapted to survive harsh winters without any leaf cover.
Proposed area_type: herbaceous_vegetation
Herbaceous plants are plants with very flexible stems. Their leaves and stems die down to soil level at the end of every growing season. Herbaceous plants can be annual, biennial or perennial.
(2) fLulccAtmLut carbon transferred directly to atmosphere due to any land-use or land-cover change activities including deforestation or agricultural fire [kg m-2 s-1]
The new requirement here is the identification of "direct" transfer into the atmosphere, which means direct from the soil and vegetation to the atmosphere, excluding fluxes that enter the atmosphere through a pathway which involves intermediary stages as forestry and agricultural products (e.g. wood harvested for energy generation).
There is an existing name for a flux which includes the fluxes via forestry and agricultural products:
"surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change".
I propose extending this name to express the exclusion of the "products":
"surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change_excluding_forestry_and_agricultural_products"
regards,
Martin
________________________________
From: David Lawrence <dlawren at ucar.edu>
Sent: 17 April 2018 22:04
To: Juckes, Martin (STFC,RAL,RALSP)
Cc: Pamment, Alison (STFC,RAL,RALSP)
Subject: Re: LUMIP data request: CF metadata
For (1), yes herbaceous vegetation would be fine.
For (2), yes, the units should be kg m-2 s-1. The revised standard name is fine.
Thanks,
Dave
On Tue, Apr 17, 2018 at 8:08 AM, Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk<mailto:martin.juckes at stfc.ac.uk>> wrote:
Hello David,
I have a couple of questions we need to clear up to finalise the CF metadata for the LUMIP data request.
(1) nwdFracLut Percentage of land use tile that is non-woody vegetation ( e.g. herbaceous crops)
What is meant by "non-woody vegetation"? We will probably deal with this variable by defining an area type in the CF area type table:
http://cfconventions.org/Data/area-type-table/7/build/area-type-table.html.
Could we use the phrase "herbaceous_vegetation"?
(2) fLulccAtmLut carbon transferred directly to atmosphere due to any land-use or land-cover change activities including deforestation or agricultural fire [ kg s-1]
This variable looks similar to fLulccProductLut<
http://clipc-services.ceda.ac.uk/dreq/u/3e26b8a6-b89b-11e6-be04-ac72891c3257.html>, but the latter has units kg m-2 s-1: should fLulccAtmLut have the same units, kg m-2 s-1 (it is currently specified with kg s-1)?
If that is the case, we could use a standard name of the form "Surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change_excluding_forestry_and_agricultural_products", which is adapted from the existing name "surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_anthropogenic_land_use_or_land_cover_change"
This approach results in a very long name, but I think we need it in this case to avoid confusion about the different pathways for emission to the atmosphere,
regards,
Martin
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Received on Wed May 02 2018 - 08:35:53 BST
