Hello Maureen, Been a while since BOFS! A systematic approach attempting to cover all bases isn't the established CF Standard Name management approach - it's a much more responsive way of doing things.
I'm also a little unclear about some of your proposals. For example, consider 'sinking_flux_isotope ratio_nitrogen_total_15_14'. To me, a sinking flux as canonical units of mass/quantity per unit area per unit time and the concept of a ratio per unit area per unit time doesn't make sense. Do you mean the isotopic ratio in the particulate material comprising the sinking flux? If so, it needs to be described more like '15/14_ratio_of_total_nitrogen_in_SPM'. However, the is off-topic for Matthias's request which is to cover mass of a range of species sinking though unit area per unit time. I would also say to Tom that people should be allowed to express as biogenic silica (aka opal), lithogenic silica or silicon (with Standard Names to suit) depending on their analytical procedure. This avoids issues - that I have known get controversial - such as conversion of opal to elemental silicon. Cheers, Roy. ________________________________ From: CF-metadata [cf-metadata-boun...@cgd.ucar.edu] On Behalf Of Maureen Conte [mco...@mbl.edu] Sent: 10 October 2013 13:49 To: Thomas Trull Cc: cf-metadata@cgd.ucar.edu; OceanSITES Data Management Team; mlankhorst Subject: Re: [CF-metadata] standard names for sediment trap data Hi Matthias I like Tom's suggestion for naming sediment trap data. It is very clear and matches the organization of most sediment trap data. However, I suggest using "massflux", "concentration" and "isotope ratio" as delimiters as these are well defined terms and unambiguous (I assume there is a descriptive file associated with the data that provides the units?). Also, as most elements aren't divided into "lithogenic", "biogenic" etc., perhaps switching the order makes more sense, so all the elements would be at the same hierarchical unit, using "total" when elements are not separated into operational fractions, ie sinking_flux_massflux_silicon_lithogenic sinking_flux_concentration_silicon_lithogenic sinking_flux_isotope ratio_silicon_lithogenic_30_28 sinking_flux_isotope ratio_carbon_organic_13_12 sinking_flux_isotope ratio_nitrogen_total_15_14 Cheers Maureen Conte (PI of the Oceanic Flux Program time-series) ________________________________ From: "Thomas Trull" <tom.tr...@utas.edu.au> To: "<mlankho...@ucsd.edu>" <mlankho...@ucsd.edu> Cc: cf-metadata@cgd.ucar.edu, "OceanSITES Data Management Team" <oceansites-...@jcommops.org> Sent: Thursday, October 10, 2013 5:28:08 AM Subject: Re: standard names for sediment trap data Hi Matthias, I like your proposed canonical units and terms. The names are also systematic and clear. I do not see the need to include the word total when an elemental flux is not split into molecular or other components. Items that I think might need further consideration: 1. In the list of XXX items, would it be clearer to specify silicon rather than silica for all terms related to silica (since the molecular composition of lithogenic, biogenic silica forms are often unknown)? Or do we have to write XXX as '_biogenic_silica_as_silicon' 2. Is it worth settling on a standard approach to isotopic (and other) compositions ? For example, 13C-POC. Units of flux rather than composition would be somewhat unusual for isotopes, making variables starting with 'sinking_mass_flux' somewhat odd. That is unfortunate, since indicating sinking flux as the overall sample type seems to be the top category worth retaining. One way around this would be a slight reordering to two groups of variables, e.g.: sinking_flux_mass_lithogenic_silicon sinking_flux_composition_lithogenic_silicon_isotopic_ratio_30_28 Or is that clumsy? Of course we could force all compositional information (isotopes, diatom species relative abundances, etc. )into mass flux units, with satisfyingly simple units, but then they all have to be reconverted into units people want to use. This would mean carrying absolute isotopic abundance for standards within the files for completeness. As usual there are many ways to skin a cat, but none are easy when the cat sees you coming! Best wishes, Tom On 10/10/2013, at 10:16, "Matthias Lankhorst" <mlankho...@ucsd.edu> wrote: Dear CF community, in the OceanSITES project, we would like to publish data from sediment traps in files, using the CF conventions. Sediment traps are devices moored underwater in the ocean, which collect sinking particles (detritus) in a funnel and into sample bottles for later analyses. Analyses can be done for a variety of substances. It looks like we need a few more standard names for these, and possibly a discussion whether some of them should be expressed as mass fluxes or as substance amount (mole) fluxes. I noticed that CF already has these standard names, all as mole fluxes with canonical units of mol m-2 s-1: sinking_mole_flux_of_aragonite_expressed_as_carbon_in_sea_water sinking_mole_flux_of_calcite_expressed_as_carbon_in_sea_water sinking_mole_flux_of_particulate_iron_in_sea_water sinking_mole_flux_of_particulate_organic_matter_expressed_as_carbon_in_sea_water sinking_mole_flux_of_particulate_organic_nitrogen_in_sea_water sinking_mole_flux_of_particulate_organic_phosphorus_in_sea_water sinking_mole_flux_of_particulate_silicon_in_sea_water Here is the list of quantities that we need to address in OceanSITES. My initial proposal is to introduce them all as mass fluxes with canonical units of kg m-2 s-1. If we should rather go with mole fluxes like the ones above, please chime in. Total/organic mass: Propose new standard names: sinking_mass_flux_of_particulate_matter_in_sea_water sinking_mass_flux_of_particulate_organic_matter_in_sea_water (I suppose these are understood as dry mass, i.e. weighed after water has evaporated.) Particulate organic, inorganic, total carbon: Propose new standard names: sinking_mass_flux_of_particulate_organic_carbon_in_sea_water sinking_mass_flux_of_particulate_inorganic_carbon_in_sea_water sinking_mass_flux_of_particulate_carbon_in_sea_water (or should we include "total" somewhere in the latter?) Particulate organic, inorganic, total nitrogen: Propose new standard names: sinking_mass_flux_of_particulate_organic_nitrogen_in_sea_water sinking_mass_flux_of_particulate_inorganic_nitrogen_in_sea_water sinking_mass_flux_of_particulate_nitrogen_in_sea_water (or should we include "total" somewhere in the latter?) Other particulate substances from a list: Propose new standard names for each of the following, to be constructed as: sinking_mass_flux_of_particulate_XXX_in_sea_water, where XXX is: - aluminum - iron - phosphorous - silica - biogenic_silica - lithogenic_silica - calcium - titanium - manganese - barium - magnesium Your expert comments are highly appreciated! Respectfully, Matthias -- _______________________________________ Dr. Matthias Lankhorst Scripps Institution of Oceanography 9500 Gilman Drive, Mail Code 0230 La Jolla, CA 92093-0230 USA Phone: +1 858 822 5013 Fax: +1 858 534 9820 E-Mail: mlankho...@ucsd.edu http://www-pord.ucsd.edu/~mlankhorst/ Cliquez sur l'url suivante https://www.mailcontrol.com/sr/lY1WG0lkPnzGX2PQPOmvUpJBCTqJzJUe2yY2IM9UP7ZY+SeOyXIDbMOdGGRUOm5ehsBIKC7m4TwFoPzuIXnePg== si ce message est indésirable (pourriel). -- ******************************************* Dr. Maureen H. Conte Ecosystems Center MBL Woods Hole MA 02543 508/289-7744 (office) 508/457-1548 (FAX) mco...@mbl.edu http://ecosystems.mbl.edu/conte/index.html ******************************************* ________________________________ This message (and any attachments) is for the recipient only. NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system.
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