Ron,
Good idea. I am conducting an informal survey of biological oceanographers here -- however two of the biologists that I'd really like to ask are on a ship off the coast of Peru, so I'd be happy to table this discussion for about a week until they return. Meanwhile, I am also attempting to contact a few of the biological model developers to get their input.
Regards, Mike
-----Original Message-----
From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Roy Lowry
Sent: Monday, December 04, 2006 9:09 AM
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] Proposed standard names for biological model outputs
Jonathan,
The purpose of Standard Names is to identify comparable quantities, which may include comparisons between model output and observational data. Even if the modelling terms are vague they should be accompanied by sufficient description to allow comparable observational data to be be identified.
My worries over the concentration/biomass naming are:
I can see a future request for 'Nitrogen_molar_biomass_of_phytoplankton' and nobody realising that it is the same thing as the pre-existing 'molar_concentration_of_nitrogen_in_sea_water_due_to_phytoplankton'.
Very few people searching for biomass data would realise data sets labelled "concentration" were relevant
I have been handling various types of biomass data for years and have worked with a lot of biological modellers in that time and have never seen biomass described as concentration. I guess it's a bit like a physical oceanographer coming across 'concentration_of_salt' instead of 'salinity'. I expect the biologists on this list are limited in number, but Mike must have a lot of biological oceanographer colleagues at MBARI who could maybe give their views.
Having looked at Steve's reference I can see where the "molar_concentration" and if we have "mass_concentration" then it makes sense. Having misread them all too often in the past I agree that avoiding molarity/molality and spelling things out was the most sensible thing to do.
Cheers, Roy.
>>> Jonathan Gregory <j.m.gregory at reading.ac.uk> 12/4/2006 3:59 pm >>>
Dear Roy
> It would be helpful to have definitions with the standard name for the biological entities ( "diatom", "phytoplankton" etc.) as there is some inconsistency in usage. In particular, whether phytoplankton includes cyanobacteria and/or free-floating macroalgae, the size limits of microzoo and mesozoo and the meaning of detritus (dead biological material?).
It might be that models are rather vague about these categories. For standard names, that does not matter, since their aim is to establish which quantities from different sources are to be regarded as comparable. For example, if cyanobacteria do not exist in the model world, it is not really defined whether phytoplankton include cyanobacteria, and this vagueness is no problem for comparing model results. However for observational purposes the same names may need more precise definitions.
> We also need to be aware of how the observational biological community
> would describe the measurand - my guess is 90% would go for 'Nitrogen
> biomass' rather than a concentration based term
We give standard names to whatever quantities people want to name, in principle. The choice of which quantities it would be better to use in models or datasets is not really within our remit, I tend to think.
> Note that we already have
> "moles_of_nitrate_per_unit_mass_in_sea_water" and therefore the syntax
> "moles_of_nitrate_per_unit_volume_in_sea_water" would be more
> consistent
That is true. The reason for those was that molarity and molality didn't seem self-explanatory terms. However I would suspect mole_concentration (= molarity isn't it) is pretty obvious, and we do already have some mass_concentration standard names (kg m-3) with which it would be consistent.
Cheers
Jonathan
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Received on Mon Dec 04 2006 - 14:55:58 GMT
