Hi Alison,
>From an oceanographic biogeochemist's perspective (and hence not applicable to atmospheric Standard Names which do include particulate_organic_matter) particulate_organic_matter is the material trapped on a filter after a seawater sample has been filtered and the inorganic carbon has been removed as CO2, usually by fuming with a strong acid. It will comprise the corpses of planktonic organisms (some of whom may have been alive at the time of sampling) plus their faecal material (and possibly faecal material from higher organisms such as fish) plus the body parts of organisms that have died and broken up in the water column.
organic_detritus includes faecal material and body parts but explicitly excludes living organisms. In observational oceanography it is sometimes assumed that living plankton is able to avoid sediment traps and so the organic component of the material collected by these devices, especially those deployed at depths >500m, is detritus. In biological models living biomass and detritus may be compartmentalised and so considered separately.
I have never actually encountered the term particulate_biogenic_matter, but unless informed otherwise I would consider it in the oceanographic context to be an exact synonym of particulate_organic_matter.
Cheers, Roy.
Please note that I now work part-time from Tuesday to Thursday. E-mail response on other days is possible but not guaranteed!
-----Original Message-----
From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of alison.pamment at stfc.ac.uk
Sent: 18 December 2013 12:26
To: mggr at pml.ac.uk; OLauret at cls.fr; frederic.melin at jrc.ec.europa.eu; cf-metadata at cgd.ucar.edu
Cc: victoria.bennett at stfc.ac.uk
Subject: [CF-metadata] Ocean colour standard names
Dear Mike, Olivier, Frederic, All,
I've been doing some detective work in response to an enquiry from Mike Grant of Plymouth Marine Laboratory regarding some ocean colour standard names that were causing the CF checker to fail because they are not present in the standard name table. Apologies for the length of this email, but the picture regarding these names is rather complicated. I would appreciate some help in sorting them out.
The names causing the checker to fail are:
> ERROR (3.3): Invalid standard_name:
>
> volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_ph
> ytoplankton
>
> ERROR (3.3): Invalid standard_name:
>
> volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water
> _due_to_particles
Mike has pointed out that these names were proposed in 2009/10. In fact, they seem to have been proposed twice, first by Frederic Melin and again by Olivier Lauret along with a few other names, but they were never properly agreed which I think is the reason they never made it into the standard name table. Clearly, however, there is a need to revisit the discussions.
Olivier proposed the following names in December 2010:
number_content_of_icebergs (m-2)
mass_concentration_of_inorganic_particles_in_sea_water (kg m-3) volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_dissolved_organic_matter_and_non_algal_particles (m-1) volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_phytoplankton (m-1) volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water_due_to_particles (m-1)
Of these, the first name was discussed, eventually accepted in the form of number_of_icebergs_per_unit_area and added to the standard name table. The other four proposals do not seem to have received any comment at that time.
Earlier, in September 2009 (
http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2009/053225.html) Frederic had proposed:
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_dissolved_organic_matter_and_non_algal_particles
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_phytoplankton
volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water_due_to_particles
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_non_algal_particles
the first three of which are also in Olivier's list.
The only discussion centred on whether the coefficients were spectral quantities (per_unit_wavelength) or whether they simply needed a coordinate variable of radiation_wavelength specifying to which wavelength they apply. I think the latter was decided.
In June 2010 Frederic re-proposed the names:
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_dissolved_organic_matter_and_non_pigmented_particles;
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_phytoplankton;
volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water_due_to_particles;
volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_non_pigmented_particles;
in which it appears that 'non_algal_particles' had been replaced by 'non_pigmented_particles', but again there don't seem to have been any comments.
I'm not sure why one set of proposals refers to 'non_algal' and the other refers to 'non-pigmented' and no definitions ever seem to have been supplied for either. Perhaps Mike, Frederic or Olivier can help with this? Also are these particles organic or inorganic or perhaps both?
The two names that Mike is currently trying to use are volume_absorption_coefficient_of_radiative_flux_in_sea_water_due_to_phytoplankton and volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water_due_to_particles, which actually look OK to me.
We have existing phytoplankton names with the definition: 'Phytoplankton are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis.' I think the phytoplankton name can be accepted and added at the next update of the standard name table.
I would assume that 'particles' refers to all particles, whether organic/inorganic, algal/non-algal, pigmented/non-pigmented. If Mike, Frederic or Olivier could confirm my assumption then I think volume_backwards_scattering_coefficient_of_radiative_flux_in_sea_water_due_to_particles could also be accepted and added to the table.
The other names look reasonable, but we do need to be clear about the definitions before they can be accepted (and also whether they are 'non_algal' or 'non_pigmented').
I should also mention that in the new year I would like to review the way we refer to particles in sea_water as we seem to have a varied terminology: particulate_organic_matter, organic_detritus and particulate_biogenic_matter all seem to be in current use. I'd like to establish whether we need all these or whether we can standardise the names further, particularly as the question is relevant to a current set of proposals from John Graybeal.
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.
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Received on Wed Dec 18 2013 - 05:56:13 GMT
