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.pamm...@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_volume_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_expressed_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.pamm...@stfc.ac.uk
> STFC Rutherford Appleton Laboratory
> R25, 2.22
> Harwell Oxford, Didcot, OX11 0QX, U.K.
>
>
>> -----Original Message-----
>> From: John Graybeal [mailto:john.grayb...@marinexplore.com]
>> Sent: 04 November 2013 22:54
>> To: Lowry, Roy K.
>> Cc: Pamment, Alison (STFC,RAL,RALSP); cf-metadata@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." <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_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.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
>>>> --
>>
>
> --
> Scanned by iCritical.
> _______________________________________________
> CF-metadata mailing list
> CF-metadata@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
_______________________________________________
CF-metadata mailing list
CF-metadata@cgd.ucar.edu
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
