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." <r...@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-boun...@cgd.ucar.edu] On Behalf Of John
> Graybeal [john.grayb...@marinexplore.com]
> Sent: 04 November 2013 15:55
> To: alison.pamm...@stfc.ac.uk
> Cc: cf-metadata@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.pamm...@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_diatoms and
>> your proposed name would b
e
> co
>> me
>> net_primary_production_of_biomass_expressed_as_carbon_per_unit_volume_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.pamm...@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-boun...@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 <grayb...@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@cgd.ucar.edu
>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>> --
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