Sorry, that was a copying error: I accept the use of "uptake" is better,
Martin
________________________________
From: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.gregory at reading.ac.uk>
Sent: 20 April 2018 13:28
To: cf-metadata at cgd.ucar.edu
Subject: Re: [CF-metadata] Four standard names for the AerChemMIP data request
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 <martin.juckes at stfc.ac.uk> -----
> Date: Fri, 20 Apr 2018 08:41:09 +0000
> From: Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk>
> To: "cf-metadata at cgd.ucar.edu" <cf-metadata at cgd.ucar.edu>,
> "j.m.gregory at reading.ac.uk" <j.m.gregory at reading.ac.uk>
> 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 <cf-metadata-bounces at cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.gregory at reading.ac.uk>
> Sent: 19 April 2018 16:26
> To: cf-metadata at cgd.ucar.edu
> 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 <m.i.hegglin at reading.ac.uk> -----
>
> > Date: Thu, 19 Apr 2018 09:51:16 +0000
> > From: Michaela Hegglin Hegglin <m.i.hegglin at reading.ac.uk>
> > To: Martin Juckes - UKRI STFC <martin.juckes at stfc.ac.uk>
> > CC: Jonathan Gregory <j.m.gregory at reading.ac.uk>, "cf-metadata at cgd.ucar.edu"
> > <cf-metadata at cgd.ucar.edu>
> > 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 <cf-metadata-bounces at cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.gregory at reading.ac.uk>
> > > Sent: 18 April 2018 17:41
> > > To: cf-metadata at cgd.ucar.edu
> > > 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
> > > CF-metadata at cgd.ucar.edu
> > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >
>
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Received on Fri Apr 20 2018 - 06:32:32 BST
