Dear Martin If it's OK for you as well, I'd prefer "uptake", which Michaela suggested as an alternative to "flux", because it indicates the sign convention. Or "uptake flux" if that's better - Google finds that as a phrase which is used.
Best wishes Jonathan ----- Forwarded message from Martin Juckes - UKRI STFC <[email protected]> ----- > Date: Fri, 20 Apr 2018 08:41:09 +0000 > From: Martin Juckes - UKRI STFC <[email protected]> > To: "[email protected]" <[email protected]>, > "[email protected]" <[email protected]> > Subject: Re: [CF-metadata] Four standard names for the AerChemMIP data > request > > Dear Jonathan, Michaela, > > > I agree that "integration_wrt_time_of_mole_stomatal_flux_of_ozone" would work > well. > > > We have a well established general approach of indicating threshold values in > a separate variable, and I would support the implication of Jonathan's > remarks that, if we include the threshold, it should be done using this > existing mechanism. The approach would be to append "_excess" or > "_above_threshold" to the name, and in the CF metadata add a coordinate > variable with standard name "stomatal_flux_of_ozone" and a data value > indicating the threshold value. > > > Within the data request we also have a "long name", where we have more > freedom to express full details of the variable. E.g. we might modify the > current long name "Phytotoxic ozone dose" to "Phytotoxic Ozone Dose above > Zero Threshold". > > > regards, > > Martin > > > > ________________________________ > From: CF-metadata <[email protected]> on behalf of Jonathan > Gregory <[email protected]> > Sent: 19 April 2018 16:26 > To: [email protected] > Subject: Re: [CF-metadata] Four standard names for the AerChemMIP data request > > Dear Martin and Michaela > > Thanks for your comments. If a non-zero threshold is sometimes used, I think > it's a reasonable future-proofing extension that we might allow it here, > although it's not yet been requested. I don't feel strongly either way. We > could omit that complexity at the moment, but introduce the name with _excess > and threshold later if required, and make the present name an alias. > > I think mole_stomatal_uptake_of_ozone, suggested by Michaela, would be good > because it indicates the sign convention. > > Best wishes > > Jonathan > > ----- Forwarded message from Michaela Hegglin Hegglin > <[email protected]> ----- > > > Date: Thu, 19 Apr 2018 09:51:16 +0000 > > From: Michaela Hegglin Hegglin <[email protected]> > > To: Martin Juckes - UKRI STFC <[email protected]> > > CC: Jonathan Gregory <[email protected]>, "[email protected]" > > <[email protected]> > > Subject: Re: [CF-metadata] Four standard names for the AerChemMIP data > > request > > > > Dear Martin, Jonathan, > > > > > 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. > > > > To my rather modest knowledge of plant physiology, the threshold in the POD > > is not necessarily 0, but may be dependent on the plant type and depending > > on its detoxification capacity. Hence is not necessarily 0. While CMIP6 may > > not use the POD at other thresholds, the wider community has done so in the > > past and may therefore ask what threshold was used for the variable output. > > To me it would hence be more logical to have the threshold indicated in the > > name. > > > > > 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). > > > > Sounds like a very good idea to me too. > > > > > 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, > > > > This is indeed a very long name. Is there a reason why not to simply name > > it after how researchers use it, namely stomatal flux or stomatal uptake? > > The full name could then read > > integration_wrt_time_of_mole_stomatal_flux_of_ozone? Whether to put in the > > ‘into_vegetation’ or ‘_with_threshold_0’ is possibly a matter of taste. > > Since only plants have stomata it should be clear that it’s meant to be > > vegetation, so not needed. > > > > Michaela > > > > > > > > > > > > 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 > > > > ----- End forwarded message ----- > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
