Dear Pierre et al, I have been checking through the definitions of the carbon cycle names and I think the name surface_upward_mass_flux_of_carbon_due_to_emission_from_natural_sources should more properly be called surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_em ission_from_natural_sources. Any objections?
Best wishes, Alison ------ Alison Pamment Tel: +44 1235 778065 NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 Rutherford Appleton Laboratory Email: [email protected] Chilton, Didcot, OX11 0QX, U.K. > -----Original Message----- > From: [email protected] [mailto:cf-metadata- > [email protected]] On Behalf Of [email protected] > Sent: 27 September 2010 13:13 > To: [email protected] > Cc: [email protected]; [email protected]; > [email protected] > Subject: Re: [CF-metadata] CMIP5 carbon cycle standard names > > Dear Pierre, Philip and Robert, > > I think Philip's last email pretty much sums up the position as I > understand it. There are two standard names involved, one describing > carbon release from all anthropogenic emissions and another describing > carbon release from fossil fuels alone. The only question is whether > these two quantities should most appropriately be named as surface > fluxes or atmospheric tendencies. The other carbon cycle emissions > names > are unaffected by this discussion as they are clearly surface > quantities. > > Pierre has explained that the anthropogenic/fossil fuel quantities do > both include emissions from airborne sources such as aircraft and > chimneys. The former are certainly not surface emissions; we could > debate the latter. I think it would be misleading to label the > emissions > purely as surface fluxes and we should instead call them atmospheric > tendencies. This way we are not tying the emissions to any particular > vertical location. In fact, the definition of 'emission' in CF standard > names is as follows: ' "Emission" means emission from a primary source > located anywhere within the atmosphere, including at the lower boundary > (i.e. earth's surface),' so it explicitly copes with the case of > emissions aloft. Also, to answer Pierre's point regarding the meaning > of > tendency, in standard names it is defined as follows: ' "tendency_of_X" > means derivative of X with respect to time.' > > I agree with Philip's point that it would be worth expanding the > definitions where appropriate to explain more fully the relationship > between surface upward fluxes and emissions into the atmosphere as a > whole. I suppose that a surface downward flux would be considered > equivalent to the contributions from various deposition processes. > > I think this has been a useful discussion as it has helped to clarify > the definitions of the names as well as arriving at the most > appropriate > terminology. I think we should stick with the names as originally > accepted: > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carb > o > n_due_to_anthropogenic_emission; kg m-2 s-1 > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carb > o > n_due_to_emission_from_fossil_fuel_combustion; kg m-2 s-1. > > Robert contacted me by email with some comments regarding the > consistency of the carbon cycle names: > > > Carbon_content > > 1. leaf_carbon_content; kg m-2 > > 2. wood_carbon_content; kg m-2 > > 3. root_carbon_content; kg m-2 > > 4. carbon_content_of_miscellaneous_living_matter; kg m-2 > > 5. wood_debris_carbon_content; kg m-2 > > > > 1, 2. 3 and 5 have the structure "X_carbon_content", while 4 has the > structure "carbon_content_of_X". Is there any particular reason for > not > giving > 4 the name: > > 4. miscellaneous_living_matter_carbon_content, > > which would conform to the pattern? > > I think it was Jonathan who suggested > carbon_content_of_miscellaneous_living_matter as an improvement on my > original proposal of miscellaneous_living_compartments_carbon_content. > However, I think that Robert is correct that we could take Jonathan's > wording and change the order without loss of clarity. Does anyone > object to using miscellaneous_living_matter_carbon_content? > > > Fluxes of carbon > > 1. surface_upward_flux_of_carbon_dioxide_expressed_as_carbon > > [_due_to_emission_from_fires_excluding_land_use_change]; kg > m-2 s-1 2. > > surface_upward_mass_flux_of_carbon > > [_due_to_natural_emission]; kg m-2 3. > > surface_upward_carbon_flux > > [_due_to_plant_respiration_for_biomass_growth]; kg m-2 s-1 (I > have bracketted [...] the part of the name which is not relevant to my > > question.) > > > > Is there any difference in meaning between these three syntactic > forms > > > for carbon flux? It's not my field, but on the face of it they > appear > > to be alternative way of expressing the same quantity. > > > > I presume that there is a principle that, where possible, names > should > be constructed according to a consistent pattern (especially in the > light of > Jonathan's work on rules for formulating names), so my guess > is that there are some reasons for the above differences but I am not > sure > > what they are. As you've probably guessed, my interest in this > relates > > to my own work on developing a grammar for standard names, and it is > clearly desirable to reduce the number of grammar rules to a minimum. > > I agree that wherever possible we should stick to using a small set of > grammar rules. However, there are occasions where being too rigid > about > the syntax can result in immensely long and unwieldy (and therefore > difficult to understand) names. Often it is just a question of > readability. > > I think we could call the second quantity > surface_upward_mass_flux_of_carbon[_due_to_emission_from_natural_source > s > ] > to make it more consistent with the first without any loss of > readability. Does anyone object to this change? > > Looking at the third name and trying to squeeze it into the same > pattern > would give something like: > surface_upward_carbon_mass_flux_due_to_emission_from_plant_respiration_ > f > or_biomass_growth > which I think is less readable, so I prefer the syntax without the > 'emission'. Do others agree? > (Incidentally, this would also affect another related name: > surface_upward_carbon_mass_flux_due_to_plant_respiration_for_biomass_ma > i > ntenance). > > Robert's email has caused me to re-read the names more carefully and I > realise that I have neglected to make clear that many of the carbon > fluxes are in fact mass fluxes (as opposed to mole fluxes, for > example). > I would like to slightly revise some of the names already accepted to > include the word 'mass': > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_e > m > ission_from_fires_excluding_land_use_change; kg m-2 s-1 > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_e > m > ission_from_grazing; kg m-2 s-1 > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_e > m > ission_from_crop_harvesting; kg m-2 s-1 > surface_net_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_ > t > o_emission_from_anthropogenic_land_use_change; kg m-2 s-1 > surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_du > e > _to_photosynthesis_and_respiration_and_fires_including_land_use_change; > kg m-2 s-1 > carbon_mass_flux_into_soil_from_litter; kg m-2 s-1 > carbon_mass_flux_into_soil_from_vegetation_excluding_litter; kg m-2 s-1 > surface_upward_carbon_mass_flux_due_to_plant_respiration_for_biomass_gr > o > wth; kg m-2 s-1 > surface_upward_carbon_mass_flux_due_to_plant_respiration_for_biomass_ma > i > ntenance; kg m-2 s-1 > surface_net_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon_du > e > _to_photosynthesis_and_respiration_and_fires_excluding_land_use_change; > kg m-2 s-1. > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 > Rutherford Appleton Laboratory Email: > [email protected] > Chilton, Didcot, OX11 0QX, U.K. > > > > -----Original Message----- > > From: Cameron-smith, Philip [mailto:[email protected]] > > Sent: 23 September 2010 19:48 > > To: Pierre Friedlingstein; Pamment, Alison (STFC,RAL,SSTD) > > Cc: [email protected] > > Subject: RE: [CF-metadata] CMIP5 carbon cycle standard names > > > > Hi Pierre, > > > > Sorry for causing confusion. > > > > I understood that the question was whether to introduce the following > > two standard names (for your purpose) > > > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carb > > on_due_to_anthropogenic_emission; kg m-2 s-1 > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_carb > > on_due_to_emission_from_fossil_fuel_combustion; kg m-2 s-1 > > > > Or these two, > > > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_a > > nthropogenic_emission; kg m-2 s-1 > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_e > > mission_from_fossil_fuel_combustion; kg m-2 s-1. > > > > Alison had originally proposed the former (tendency_), and you > (Pierre) > > argued for the latter (surface_). > > > > What I liked was Alison's description of why these tendency_ and > > surface_ quantities are physically different because the tendency_ > > quantity also includes non-surface emissions. > > > > My first point was that your application included aircraft emissions > so > > that the tendency_ quantity is the correct physical quantity for your > > application (even if your data may put the aircraft emissions in the > > wrong box). Hence, I recommended we add the tendency_ names to the > > standard name list, rather than the surface_ names (following CF > > tradition of not adding names unless needed). > > > > My second point was that we already have both tendency_ and surface_ > > names in the list, and many users could easily miss the physical > > distinction. Hence, I suggested that we expand the descriptions of > > these names in the list (when they occur) to highlight the > distinction > > (because, as you say, many people are likely to look for the surface_ > > names). > > > > My third point was just to note that the one example of a standard > name > > similar to the surface_ names proposed above actually specifies the > > _downward_ direction. > > > > I am somewhat sensitive to this issue because I am currently trying > to > > use various emission estimates and it is often hard to tell what is > and > > isn't included, and hence whether or not I am double counting. > > > > Best wishes :-), > > > > Philip > > > > > ----------------------------------------------------------------------- > > Dr Philip Cameron-Smith, [email protected], Lawrence Livermore National > Lab. > > > ----------------------------------------------------------------------- > > > > > > > -----Original Message----- > > > From: Pierre Friedlingstein [mailto:[email protected]] > > > Sent: Thursday, September 23, 2010 10:50 AM > > > To: Cameron-smith, Philip; [email protected] > > > Cc: [email protected] > > > Subject: Re: [CF-metadata] CMIP5 carbon cycle standard names > > > > > > Hi all, > > > I'm getting confused now. > > > I understood Alison last proposal as keeping only one name : > > > > > > > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_a > > > nthropogenic_emission; kg m-2 s-1 > > > > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to_e > > > mission_from_fossil_fuel_combustion; kg m-2 s-1. > > > > > > Philip's mail, seemed to imply that both names could be used as > he > > > liked Alison's distinction... > > > > > > Could you clarify what the final decision? > > > > > > For info, yes the data do include aircraft, chimneys,... emissions > as > > > these data are derived from country based reporting of fossil fuel > > > trades. > > > Hence the aircraft emissions from US carriers are in the US numbers > > and > > > hence assigned on the US territory. This might be OK for US as > most > > of > > > the flight are domestic, but I'm sure this is 99.9 % wrong for > > Belgium > > > ;-). > > > Saying emissions are a vertical integral here would imply that > planes > > > are only flying up and down ! > > > > > > Anyway, I will leave with either or definition (you'll just have to > > > explain what the "tendency" one mean to non-chemists...) > > > > > > Best > > > Pierre > > > > > > > > > > > > On 22/09/2010 17:28, Cameron-smith, Philip wrote: > > > > Hi All, > > > > > > > > Even if the dataset doesn't have vertical information, if it > > includes > > > > aircraft emissions then the physical quantity it is quantifying > is > > > the > > > > vertical integral rather than the surface emission. In which > case > > I > > > > would favour tendency_of_atmosphere_mass_content_ > > > > > > > > If there are no aircraft in the data, then do smoke stacks > produce > > > 'surface emissions'? An interesting question that could be > debated. > > > Hence, another advantage of tendency_of_atmosphere_mass_content_ is > > > that it makes the question moot. > > > > > > > > BTW, FWIW, I note that the closest related standard name already > in > > > the table specifies the downward direction > > > (surface_downward_mass_flux_of_carbon_dioxide_expressed_as_carbon). > > > > > > > > On a different note, I like Alison's distinction between > > > > > > > > > > > > > > tendency_of_atmosphere_mass_content_of_..._due_to_anthropogenic_emissi > > > > on > > > > > > > > and > > > > > > > > surface_upward_mass_flux_of_..._due_to_anthropogenic_emission > > > > > > > > Perhaps we should cross-reference such standard names in their > > > descriptions to help future users? > > > > > > > > Best wishes, > > > > > > > > Philip > > > > > > > > > ------------------------------------------------------------------- > > -- > > > - > > > > -- Dr Philip Cameron-Smith, [email protected], Lawrence Livermore > Nat. > > > > Lab. > > > > > ------------------------------------------------------------------- > > -- > > > - > > > > -- > > > > > > > > > > > > > > > >> -----Original Message----- > > > >> From: [email protected] [mailto:cf-metadata- > > > >> [email protected]] On Behalf Of Pierre Friedlingstein > > > >> Sent: Wednesday, September 22, 2010 6:01 AM > > > >> To: [email protected] > > > >> Cc: [email protected] > > > >> Subject: Re: [CF-metadata] CMIP5 carbon cycle standard names > > > >> > > > >> Alison, > > > >> I see your point. > > > >> As far as I know the anthropogenic emissions data will be > surface > > > >> fluxes. Data are based on country level consumption of fossil > > fuel, > > > >> they don't have the info on where in the air it is released... > > > >> Pierre > > > >> > > > >> On 22/09/2010 13:04, [email protected] wrote: > > > >> > > > >>> Hi Pierre, > > > >>> > > > >>> My thinking here was that 'anthropegenic emissions' (which > > > >>> presumably include fossil fuel emissions) and 'fossil fuel' > > > >>> emissions themselves do not necessarily always occur at the > > earth's > > > >>> surface. For example, emissions from tall chimneys and > aircraft > > > may > > > >>> occur at many levels in the atmosphere. It was not clear to me > > > that > > > >>> these particular quantities in the CMIP5 tables are intended > only > > > to > > > >>> account for > > > >>> > > > >> surface emissions. > > > >> > > > >>> If that is the case, then we certainly need to make it clear > and > > I > > > >>> agree with your suggestion to label them as surface fluxes. So > > > >>> > > > >> instead > > > >> > > > >>> of introducing > > > >>> > > > >>> > > > >>> > > > >> > > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_ca > > > >> r > > > >> > > > >>> bo n_due_to_anthropogenic_emission; kg m-2 s-1 > > > >>> > > > >>> > > > >> > > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_ca > > > >> r > > > >> > > > >>> bo n_due_to_emission_from_fossil_fuel_combustion; kg m-2 s-1 > > > >>> > > > >>> I will add > > > >>> > > > >>> > > > >> > > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to > > > >> _ > > > >> > > > >>> an > > > >>> thropogenic_emission; kg m-2 s-1 > > > >>> > > > >>> > > > >> > > > > surface_upward_mass_flux_of_carbon_dioxide_expressed_as_carbon_due_to > > > >> _ > > > >> > > > >>> em ission_from_fossil_fuel_combustion; kg m-2 s-1. > > > >>> > > > >>> OK? > > > >>> > > > >>> Best wishes, > > > >>> Alison > > > >>> > > > >>> ------ > > > >>> Alison Pamment Tel: +44 1235 778065 > > > >>> NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 > > > >>> Rutherford Appleton Laboratory Email: > > > >>> > > > >> [email protected] > > > >> > > > >>> Chilton, Didcot, OX11 0QX, U.K. > > > >>> > > > >>> > > > >>> > > > >>> > > > >>>> -----Original Message----- > > > >>>> From: Pierre Friedlingstein > > [mailto:[email protected]] > > > >>>> Sent: 21 September 2010 16:41 > > > >>>> To: Pamment, Alison (STFC,RAL,SSTD) > > > >>>> Cc: [email protected]; [email protected] > > > >>>> Subject: Re: [CF-metadata] CMIP5 carbon cycle standard names > > > >>>> > > > >>>> Hi Alison, > > > >>>> Just wondering, why are the first two variables below named as > > > >>>> "tendency_of_atmosphere_mass_content_of..." > > > >>>> while all others are named as "surface_upward_mass_flux_of_ > > ..." > > > >>>> Any reason ? > > > >>>> I know the "tendency..." is used for other chemical species... > > But > > > >>>> > > > >>>> > > > >>> here > > > >>> > > > >>> > > > >>>> for CO2 variables, I think intra-consistency should be > favoured. > > > No > > > >>>> > > > >> ? > > > >> > > > >>>> Best > > > >>>> Pierre > > > >>>> > > > >>>> On 21/09/2010 13:40, [email protected] wrote: > > > >>>> > > > >>>> > > > >>>>> Dear Jonathan and Pierre, > > > >>>>> > > > >>>>> Thank you both for your comments on the CMIP5 carbon cycle > > names. > > > >>>>> Looking back through this thread I think we have resolved all > > the > > > >>>>> outstanding issues and so the following names are now > accepted > > > for > > > >>>>> inclusion in the standard name table: > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_ca > > > >> > > > >>>> r > > > >>>> > > > >>>> > > > >>>>> bo n_due_to_anthropogenic_emission; kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > tendency_of_atmosphere_mass_content_of_carbon_dioxide_expressed_as_ca > > > >> > > > >>>> r > > > >>>> > > > >>>> > > > >>>>> bo n_due_to_emission_from_fossil_fuel_combustion; kg m-2 s-1 > > > >>>>> surface_upward_mass_flux_of_carbon_due_to_natural_emission; > > kg m- > > > >>>>> > > > >>>>> > > > >>>> 2 > > > >>>> > > > >>>> > > > >>>>> s-1 > > > >>>>> atmosphere_mass_of_carbon_dioxide; kg > > > >>>>> carbon_content_of_products_of_land_use_change; kg m-2 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emis > > > >> > > > >>>> s > > > >>>> > > > >>>> > > > >>>>> io n_from_fires_excluding_land_use_change; kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emis > > > >> > > > >>>> s > > > >>>> > > > >>>> > > > >>>>> io > > > >>>>> n_from_grazing; kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_emis > > > >> > > > >>>> s > > > >>>> > > > >>>> > > > >>>>> io > > > >>>>> n_from_crop_harvesting; kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_net_upward_flux_of_carbon_dioxide_expressed_as_carbon_due_to_ > > > >> > > > >>>> e > > > >>>> > > > >>>> > > > >>>>> mi ssion_from_anthropogenic_land_use_change; kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_net_downward_flux_of_carbon_dioxide_expressed_as_carbon_due_t > > > >> > > > >>>> o > > > >>>> > > > >>>> > > > >>>>> _p > > > >>>>> > > > >>>>> > > > >>> > > hotosynthesis_and_respiration_and_fires_including_land_use_change; > > > >>> > > > >>> > > > >>>>> kg > > > >>>>> m-2 s-1 > > > >>>>> carbon_flux_into_soil_from_litter; kg m-2 s-1 > > > >>>>> carbon_flux_into_soil_from_vegetation_excluding_litter; kg m- > 2 > > s- > > > 1 > > > >>>>> leaf_carbon_content; kg m-2 wood_carbon_content; kg m-2 > > > >>>>> root_carbon_content; kg m-2 > > > >>>>> carbon_content_of_miscellaneous_living_matter; kg m-2 (N.B. > > > >>>>> 'miscellaneous' means carbon content of living matter apart > > from > > > >>>>> > > > >>>>> > > > >>>> those > > > >>>> > > > >>>> > > > >>>>> individually named in the preceding three items) > > > >>>>> wood_debris_carbon_content; kg m-2 > > surface_litter_carbon_content; > > > >>>>> > > > >> kg > > > >> > > > >>>>> m-2 subsurface_litter_carbon_content; kg m-2 > > > >>>>> fast_soil_pool_carbon_content; kg m-2 > > > >>>>> > > > >>>>> > > > >>>> medium_soil_pool_carbon_content; > > > >>>> > > > >>>> > > > >>>>> kg m-2 slow_soil_pool_carbon_content; kg m-2 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_upward_carbon_flux_due_to_plant_respiration_for_biomass_growt > > > >> > > > >>>> h > > > >>>> > > > >>>> > > > >>>>> ; > > > >>>>> kg m-2 s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_upward_carbon_flux_due_to_plant_respiration_for_biomass_maint > > > >> > > > >>>> e > > > >>>> > > > >>>> > > > >>>>> na > > > >>>>> nce; kg m-2 s-1 > > > >>>>> net_primary_productivity_of_carbon_accumulated_in_leaves; kg > m- > > 2 > > > >>>>> s- > > > >>>>> > > > >> 1 > > > >> > > > >>>>> net_primary_productivity_of_carbon_accumulated_in_wood; kg m- > 2 > > s- > > > 1 > > > >>>>> net_primary_productivity_of_carbon_accumulated_in_roots; kg > m-2 > > > >>>>> s-1 > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>> > > > >> > > > > surface_net_downward_flux_of_carbon_dioxide_expressed_as_carbon_due_t > > > >> > > > >>>> o > > > >>>> > > > >>>> > > > >>>>> _p > > > >>>>> > > > >>>>> > > > >>> > > hotosynthesis_and_respiration_and_fires_excluding_land_use_change; > > > >>> > > > >>> > > > >>>>> kg > > > >>>>> m-2 s-1. > > > >>>>> > > > >>>>> To cope with the various fractional vegetation coverage > > > quantities > > > >>>>> > > > >>>>> > > > >>> we > > > >>> > > > >>> > > > >>>>> will use the existing standard name area_fraction and > introduce > > > >>>>> new entries of primary_evergreen_trees, > > > secondary_deciduous_trees, > > > >>>>> secondary_evergreen_trees, C3_plant_functional_types, > > > >>>>> C4_plant_functional_types into the area_type table. > > > >>>>> > > > >>>>> Best wishes, > > > >>>>> Alison > > > >>>>> > > > >>>>> ------ > > > >>>>> Alison Pamment Tel: +44 1235 778065 > > > >>>>> NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 > > > >>>>> Rutherford Appleton Laboratory Email: > > > >>>>> > > > >>>>> > > > >>>> [email protected] > > > >>>> > > > >>>> > > > >>>>> Chilton, Didcot, OX11 0QX, U.K. > > > >>>>> > > > >>>>> > > > >>>>> > > > >>>>> > > > >>> > > > > > > -- > Scanned by iCritical. > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- Scanned by iCritical. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
