Dear John,
Thanks for your reply. The name
net_primary_production_of_biomass_expressed_as_carbon_per_unit_volume_in_sea_water (kg m-3 s-1)
is accepted for inclusion in the standard name table and will be added at the next update.
I have modified the definition as suggested by John and added the usual explanatory sentence for 'expressed_as', thus the full definition is now as follows:
' "Production of carbon" means the production of biomass expressed as the mass of carbon which it contains. Net primary production is the excess of gross primary production (rate of synthesis of biomass from inorganic precursors) by autotrophs ("producers"), for example, photosynthesis in plants or phytoplankton, over the rate at which the autotrophs themselves respire some of this biomass. In the oceans, carbon production per unit volume is often found at a number of depths at a given horizontal location. That quantity can then be integrated to calculate production per unit area at the location. Standard names for production per unit area use the term "productivity". 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 constiuents of A.'
In addition I will modify the definitions of the eleven existing primary_production and primary_productivity names to make sure that they all use consistent wording as discussed under this thread.
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Oxford, Didcot, OX11 0QX, U.K.
> -----Original Message-----
> From: John Graybeal [mailto:john.graybeal at marinexplore.com]
> Sent: 26 November 2013 16:23
> To: Pamment, Alison (STFC,RAL,RALSP)
> Cc: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] new standard name for primary production of
> carbon per unit volume
>
> Alison, sorry for the delay, This proposal is great, though I suggest
> wordsmithing the added explanation to be more generic (models as well as
> observations).
>
> "In the oceans carbon production is often found for multiple depths in a
> given horizontal location, giving a production per unit volume. The quantity
> can then be integrated..."
>
> Hopefully this is minor enough to not arouse any concerns....
>
> john
>
> On Nov 5, 2013, at 04:48, alison.pamment at stfc.ac.uk wrote:
>
> > Dear John and Roy,
> >
> > I think, then, that we are agreed the name should be:
> >
> net_primary_production_of_biomass_expressed_as_carbon_per_unit_volu
> me_in_sea_water (kg m-3).
> >
> > Sorry if I wasn't clear about the definitions. John is correct that we need to
> distinguish between "productivity" and "production" because they have
> different implications for the units. "Productivity" has long been defined in
> standard names as meaning "production per unit area" which implies units
> of m-2. I am not suggesting any change to this. The quantity of "production",
> for example, in existing names such as
> tendency_of_mole_concentration_of_particulate_organic_matter_expresse
> d_as_carbon_in_sea_water_due_to_net_primary_production_by_diatoms,
> has not in fact been used to specify "per unit volume". It implies only that a
> quantity of biomass carbon is being produced; the quantity itself may be
> measured as mass in kg or amount of substance in moles. The "m-3" in the
> existing names comes from the definition of mole concentration: ' "Mole
> concentration" means number of moles per unit volume'.
> >
> > The upshot of this is that we do need different wording for the definitions
> of production and productivity names. Production names would contain the
> following:
> > ' "Production of carbon" refers to the production of biomass expressed as
> the mass of carbon which it contains. Net primary production is the
> > excess of gross primary production (rate of synthesis of biomass from
> inorganic precursors) by autotrophs ("producers"), for example,
> photosynthesis in plants or phytoplankton, over the rate at which the
> autotrophs themselves respire some of this biomass.'
> >
> > For productivity names we would add an additional explanatory sentence
> (as already used in standard names definitions):
> > ' "Production of carbon" refers to the production of biomass expressed as
> the mass of carbon which it contains. Net primary production is the
> > excess of gross primary production (rate of synthesis of biomass from
> inorganic precursors) by autotrophs ("producers"), for example,
> photosynthesis in plants or phytoplankton, over the rate at which the
> autotrophs themselves respire some of this biomass. "Productivity" means
> production per unit area.'
> >
> > All mention of "per unit mass" or "per unit volume" is then removed from
> the definition of production itself, which I think it should be. Also, these
> definitions would allow standard wording regardless of whether the
> production is land or ocean based, which was my original intention. I would
> need to go through the eleven existing names to make sure their
> definitions all follow one or other of the above templates.
> >
> > For John's new name we can certainly add some extra explanation to the
> definition as to how the parameter might be used. Based on Roy's
> explanation I suggest the following:
> > ' In the oceans it is usual to measure carbon production per unit volume at
> a number of depths for a given horizontal location. The quantity can then be
> integrated to calculate production per unit area at that location. Standard
> names for production per unit area use the term "productivity".'
> >
> > This would be appended to the earlier text about production.
> >
> > All OK? If so, I will include these changes in the next standard name table
> update which is currently in preparation, hopefully to be published this
> week.
> >
> > Best wishes,
> > Alison
> >
> > ------
> > Alison Pamment Tel: +44 1235 778065
> > NCAS/British Atmospheric Data Centre Email:
> alison.pamment at stfc.ac.uk
> > STFC Rutherford Appleton Laboratory
> > R25, 2.22
> > Harwell Oxford, Didcot, OX11 0QX, U.K.
> >
> >
> >> -----Original Message-----
> >> From: John Graybeal [mailto:john.graybeal at marinexplore.com]
> >> Sent: 04 November 2013 22:54
> >> To: Lowry, Roy K.
> >> Cc: Pamment, Alison (STFC,RAL,RALSP); cf-metadata at cgd.ucar.edu
> >> Subject: Re: [CF-metadata] new standard name for primary production of
> >> carbon per unit volume
> >>
> >> Hi Roy,
> >>
> >> The indication I had received from other sources (when I asked them why
> CF
> >> didn't seem to have any production per unit volume names that I could
> find)
> >> was that this parameter was generally measured only at the ocean
> surface,
> >> via satellites -- hence per unit area was the common unit. Your
> explanation
> >> adds a lot to my understanding -- and maybe should be reflected in the
> >> descriptions!
> >>
> >> Thanks!
> >>
> >> John
> >>
> >> On Nov 4, 2013, at 14:18, "Lowry, Roy K." <rkl at bodc.ac.uk> wrote:
> >>
> >>> Hi John,
> >>>
> >>> Production per unit volume is the usual parameter measured in the
> >> oceans. What is usually done is to measure this at maybe half a dozen
> >> depths at a given position between the surface and 100m and then there
> is
> >> an integration procedure that can be done on this dataset to produce a
> >> single value of production per unit area for that position - I guess with
> the
> >> objective of making oceanographic data compatible with terrestrial for
> >> global aggregates.
> >>>
> >>> The tow oceanographic parameters have different dimensionality and
> >> therefore need to be described by different standard names.
> >>>
> >>> Cheers, Roy.
> >>>
> >>> ________________________________________
> >>> From: CF-metadata [cf-metadata-bounces at cgd.ucar.edu] On Behalf Of
> >> John Graybeal [john.graybeal at marinexplore.com]
> >>> Sent: 04 November 2013 15:55
> >>> To: alison.pamment at stfc.ac.uk
> >>> Cc: cf-metadata at cgd.ucar.edu
> >>> Subject: Re: [CF-metadata] new standard name for primary production
> of
> >> carbon per unit volume
> >>>
> >>> Hi Alison,
> >>>
> >>> First change is fine by me.
> >>>
> >>> Second change is fine for _my_ request. I note that most terms to date
> >> (and all terrestrial terms?) consider productivity per unit area; mine is
> the
> >> first, or one of the first, that is per unit volume. (The difference is
> reflected
> >> in the units.) The definition of "net primary production" needs to either
> be
> >> written generically (e.g., "per unit area or volume according to the
> units"),
> >> or we'll need two different concepts. (I vaguely recall a notion that
> >> productivity could be by unit area and production by unit volume, but
> have
> >> no personal expertise.)
> >>>
> >>> John
> >>>
> >>>
> >>> On Nov 4, 2013, at 01:33, alison.pamment at stfc.ac.uk wrote:
> >>>
> >>>> Dear John G.,
> >>>>
> >>>> Some time ago you proposed a standard name
> >> net_primary_production_of_carbon_per_unit_volume_in_sea_water
> with
> >> canonical units of kg m-3 s-1.
> >>>>
> >>>> The proposal is certainly consistent with the syntax of existing
> >> productivity_of_carbon names. However, there ensued some discussion
> as
> >> to whether production|productivity_of_carbon means the same as
> >> production|productivity_of_biomass_expressed_as_carbon. I think the
> >> answer to this question is actually 'yes'. The definitions even say '
> >> "Production of carbon" refers to the production of biomass expressed as
> the
> >> mass of carbon which it contains.' I think we need to be careful to retain
> the
> >> terms "productivity" or "production" of carbon as part of the names
> because
> >> these are the terms widely used and understood by the land surface
> >> modellers and ocean biogeochemists. However, in the interests of
> making
> >> standard names as standard as possible, I suggest that we should in fact
> >> insert "expressed_as". For example,
> >> net_primary_mole_productivity_of_carbon_by_diatoms would become
> >>
> net_primary_mole_productivity_of_biomass_expressed_as_carbon_by_diat
> >> oms and your proposed name would be
> >>> co
> >>>> me
> >>
> net_primary_production_of_biomass_expressed_as_carbon_per_unit_volu
> >> me_in_sea_water. The change would affect eleven existing names.
> Would
> >> that be acceptable? Does anyone else object to the change?
> >>>>
> >>>> Regarding the definition of the proposed name, I see that you have
> tried
> >> to make it consistent with existing net_primary_productivity names.
> >> Looking through the standard name table I have found that we have two
> >> versions of the wording that have been tailored to land based or ocean
> >> based photosynthesis, respectively. See, for example, the definition of
> >> net_primary_mole_productivity_of_carbon_by_diatoms versus that of
> >> net_primary_productivity_of_carbon_accumulated_in_leaves. I think it
> >> would be better to settle on a single wording for all
> >> net_primary_production/productivity names, regardless of where the
> >> process is taking place, so I suggest the following:
> >>>> " "Production of carbon" refers to the production of biomass expressed
> >> as the mass of carbon which it contains. Net primary production is the
> >> excess of gross primary production (rate of synthesis of biomass per unit
> >> volume from inorganic precursors) by autotrophs ("producers"), for
> >> example, photosynthesis in plants or phytoplankton, over the rate at
> which
> >> the autotrophs themselves respire some of this biomass. "
> >>>>
> >>>> Is this OK? If so, I will amend the definitions of the existing names to
> all
> >> have consistent wording.
> >>>>
> >>>> Thanks for your patience,
> >>>> Alison
> >>>>
> >>>> ------
> >>>> Alison Pamment Tel: +44 1235 778065
> >>>> NCAS/British Atmospheric Data Centre 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 John Graybeal
> >>>>> Sent: 02 July 2013 22:56
> >>>>> To: CF Metadata List
> >>>>> Subject: Re: [CF-metadata] new standard name for primary
> production
> >> of
> >>>>> carbon per unit volume
> >>>>>
> >>>>> As of June 5 this revised name was requested to go with the
> previously
> >>>>> submitted definition:
> >>>>>
> >>>>> On Jun 5, 2013, at 11:38, John Graybeal <graybeal at marinexplore.com>
> >>>>> wrote:
> >>>>>> So I think we have the replacement name of
> >>>>>> net_primary_production_of_carbon_per_unit_volume_in_sea_water
> >>>>>> pending further thoughts and responses.
> >>>>>
> >>>>> There has been some discussion (thank you), but to my knowledge,
> no
> >>>>> outstanding requests for changes since that posting.
> >>>>>
> >>>>> In the definition below, I've modified bits of that definition to match
> >> the
> >>>>> new term (production). Is this request approvable at this point?
> >>>>>
> >>>>> Name:
> >> net_primary_production_of_carbon_per_unit_volume_in_sea_water
> >>>>> Units: kg m-3 s-1
> >>>>> Definition: Net primary production is the excess of gross primary
> >> production
> >>>>> (rate of synthesis of biomass per unit volume from inorganic
> precursors
> >> by
> >>>>> autotrophs, or "producers", especially by photosynthesising plants
> using
> >>>>> sunlight for energy) over the rate at which they themselves respire
> >> some of
> >>>>> this biomass (plant_respiration, assuming all producers to be plants).
> >>>>> "Production of carbon" refers to the production of biomass expressed
> as
> >> the
> >>>>> mass of carbon which it contains.
> >>>>>
> >>>>> John
> >>>>>
> >>>>> ------------------------------------
> >>>>> John Graybeal
> >>>>> Senior Data Manager, Metadata and Semantics
> >>>>>
> >>>>> Marinexplore
> >>>>> 920 Stewart Drive
> >>>>> Sunnyvale, CA
> >>>>>
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> CF-metadata mailing list
> >>>>> CF-metadata at cgd.ucar.edu
> >>>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >>>> --
> >>
> >
> > --
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> > _______________________________________________
> > CF-metadata mailing list
> > CF-metadata at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
> ------------------------------------
> John Graybeal
> Sr. Data Manager, Metadata & Semantics
>
> M +1 408 675-5445
> skype: graybealski
> Marinexplore
> 920 Stewart Drive
> Sunnyvale 94085
> California, USA
> www.marinexplore.com
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Received on Wed Nov 27 2013 - 04:24:09 GMT
