Dear Jonathan,
those are good points. I've copied Michaela into the discussion as she knows more about the intended use of this variable. The generic quantity that AerChemMIP is interested in, Phytotoxic ozone dose, can be used with a non-zero threshold -- so there may be a requirement for this in the future, but for CMIP6 we only need the case of threshold=0. As you point out, we can simplify the CF metadata if we restrict ourselves to this case. I'd be happy with that approach. Looking at other CF names, I notice that we should be referring to the "_mole_flux_of_ozone_" rather than just the "ozone_flux" (to distinguish it from mass flux). I'm not sure about the phrase "flux_into_stomata": the stomata are the holes in the leaves, what we really mean is into the plant through the stomata. I'm not sure if "integration_wrt_time_of_mole_flux_of_ozone_into_vegetation" would be specific enough; "integration_wrt_time_of_mole_flux_of_ozone_into_vegetation_through_stomata" looks a bit long, but may be justified for a specialised quantity like this, regards, Martin ________________________________ From: CF-metadata <[email protected]> on behalf of Jonathan Gregory <[email protected]> Sent: 18 April 2018 17:41 To: [email protected] Subject: [CF-metadata] Four standard names for the AerChemMIP data request Dear Martin > Proposed name: integral_wrt_time_of_stomatal_ozone_flux_excess I appreciate that not all fluxes have their sign convention mentioned in the name, but in the case of precipitation, for example, I think it's obvious - that's not quite so with ozone_flux, I would say - on reflection, I guess that plants don't ever produce ozone, so the flux should be into the stomata, but although it can be clarified in the definition, as you say, I feel it would be even better to choose a word in the standard name which indicates which way the flux is going e.g. flux_into_stomata. There are existing names containing mole_flux_of_SPECIES. This is one of those so it might be good to follow that pattern too. I see that pod0 has a threshold of zero. You're proposing something more general, which could support any threshold, but is the threshold ever going to be non-zero? If zero is the only possibility, it doesn't need to be described as an excess. > (3b) stomatal_ozone_flux_threshold [mol m-2 s-1] > > A standard name to be used on variable specifying a threshold value of > stomatal ozone flux. This quantity would be more generally useful if "threshold" was omitted. I'm aware there is an air_temperature_threshold in the table, but I see no reason why a quantity used as a threshold must have "threshold" in its name. Best wishes and thanks Jonathan _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
