Hello Alison,
I would like to return to the "product_of" terms because Jonathan has, in another thread, drawn attention to the guidelines on the ordering of "X" and "Y" in "product_of_X_and_Y", namely: If X and Y are both scalars or both components of vectors, they are put in alphabetical order. If one of them is the component of a vector, it is put first i.e. the vector component is X, the scalar is Y. (http://cfconventions.org/Data/cf-standard-names/docs/guidelines.html) The terms we have discussed below involve products of the "lagrangian_tendency_of_air_pressure" .. which I would interpret as the vertical component of the velocity vector in pressure coordinates. I am not convinced that it appropriate to follow the guidelines rigidly here, as that would imply product_of_eastward_wind_and_lagrangian_tendency_of_air_pressure and product_of_lagrangian_tendency_of_air_pressure_and_northward_wind. It would surely be better to use the ordering (1) horizontal, (2) vertical for these terms. -- This specific problem goes away if we regard "lagrangian_tendency_of_air_pressure" as a scalar .. but we run into a similar issue with terms such as product_of_geopotential_height_and_lagrangian_tendency_of_air_pressure and product_of_lagrangian_tendency_of_air_pressure_and_specific_humidity. These are essentially advective fluxes, so I believe we should place the air pressure tendency first. This would improve consistency with existing terms such as product_of_upward_air_velocity_and_air_temperature. I.e. I suggest the following names ... the first two as you approved earlier, and the last 3 reversing the order of "X" and "Y": * product_of_eastward_wind_and_lagrangian_tendency_of_air_pressure * product_of_northward_wind_and_lagrangian_tendency_of_air_pressure * product_of_lagrangian_tendency_of_air_pressure_and_specific_humidity * product_of_lagrangian_tendency_of_air_pressure_and_air_temperature * product_of_lagrangian_tendency_of_air_pressure_and_geopotential_height regards, Martin ________________________________ From: CF-metadata <cf-metadata-boun...@cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.greg...@reading.ac.uk> Sent: 09 May 2019 13:56 To: cf-metadata@cgd.ucar.edu Subject: Re: [CF-metadata] Some standard name updates to improve consistency. Dear Martin OK. Thanks for explaining and sorry I didn't notice the correct point. I am happy then. Best wishes Jonathan On Thu, May 09, 2019 at 12:26:40PM +0000, Martin Juckes - UKRI STFC wrote: > Date: Thu, 9 May 2019 12:26:40 +0000 > From: Martin Juckes - UKRI STFC <martin.juc...@stfc.ac.uk> > To: Jonathan Gregory <j.m.greg...@reading.ac.uk>, > "cf-metadata@cgd.ucar.edu" <cf-metadata@cgd.ucar.edu> > Subject: Re: [CF-metadata] Some standard name updates to improve > consistency. > > Dear Jonathan, > > > On the question of the use of the phrase "ambient_aerosol" when referring to > the aerosol itself, rather than to the particles within the aerosol, I fear > that my comment which you quote may have become detached from the intended > context. > > > I am happy with the distinction between "aerosol" (the suspension of particle > in air) and "aerosol_particles" (the particles which are suspended). My > comment to Alison referred to the use of the qualifier "ambient" when talking > about the aerosol itself: is it necessary or useful? > > > The issue cam up because there are 5 standard names using the phrase > "dust_ambient_aerosol_particles_direct_radiative_effect" which I suggested > changing to "dust_aerosol_direct_radiative_effect". This would be consistent > with the usage in the literature, which would, I believe, make the terms > easier to read. In this case, there is nothing wrong with referring to the > aerosol suspension. Alison agreed with these points, but would like to retain > "ambient", as in "dust_ambient_aerosol_direct_radiative_effect". When talking > about particles within an aerosol it is very important to distinguish between > measurements representative of their state in the atmospheric suspension vs. > the state they might be in after sampling. "ambient", when qualifying > "aerosol_particles", means that we are describing the particles as they exist > in the aerosol. As a qualification of "aerosol" I can't see that it has any > meaning. > > > The 4 terms which you refer to using "aerosol" rather than > "aerosol_particles" are ones which Alison agreed to change to include > "particles" earlier in this thread. These are all terms which are clearly > intended to refer only to the particles. > > > regards, > > Martin > > > ________________________________ > From: CF-metadata <cf-metadata-boun...@cgd.ucar.edu> on behalf of Jonathan > Gregory <j.m.greg...@reading.ac.uk> > Sent: 07 May 2019 18:19 > To: cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] Some standard name updates to improve consistency. > > Dear Martin and Alison > > Thank you for carefully pursuing this detailed discussion. The degree of > consistency which Martin remarked upon initially is encouraging, but it's also > evident that we have to work very hard to achieve that, and any tools that we > can put in place to make it easier (as Martin is thinking about, I believe) > are well worth considering. > > I have some small points. > > > 1. I've looked into the elemental/black carbon issue briefly > ... > > it may make sense to deal with that in a separate discussion and try to get > > some relevant experts involved. > > I agree with that conclusion. > > > 9. I'm still a little uncomfortable with the idea of "ambient_aerosol" > > referring to the suspension of particles in air. The phrase > > "ambient_aerosol_particles" is used when we are referring to properties of > > the particles rather than the suspension > > This is like the distinction between ocean vs sea_water and atmosphere vs air. > > > I can't think of a meaningful interpretation of a "dry aerosol" (I think > > dust_dry_aerosol is only used in the form dust_dry_aerosol_particles). > > We have the following names which mention dry_aerosol without particles: > > mass_concentration_of_biomass_burning_dry_aerosol_in_air > mass_fraction_of_mercury_dry_aerosol_in_air > tendency_of_atmosphere_mass_content_of_mercury_dry_aerosol_due_to_emission > tendency_of_atmosphere_mass_content_of_sulfate_dry_aerosol_expressed_as_sulfur_due_to_wet_deposition > > > For "relative_humidity_for_aerosol_particle_size_selection", I recognise > > that this would be the only use of "particle" in the singular. > > This is a minor concern, but to avoid introducing it in the singular we could > write relative_humidity_for_size_selection_of_aerosol_particles - that might > be easier to read as well. > > > I suggest we add 'A positive radiative forcing or radiative effect is > equivalent to a downward radiative flux and contributes to a warming of the > earth system.' > > I agree that for the sake of clarity it would be good to add this. It's > consistent with literature, as you say, and also with the IPCC AR5 glossary, > which says, "Radiative forcing is the change in the net, downward minus > upward, > radiative flux ...". > > Best wishes > > Jonathan > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
