Dear Martin I agree with you that frozen_precipitation_flux seems a bit more surprising in some way than solid_precipitation_flux. If we put "solid" instead of "frozen", should we change (by alias) the existing names that have "frozen", which are
frozen_water_content_of_soil_layer lwe_thickness_of_frozen_water_content_of_soil_layer mass_fraction_of_frozen_water_in_soil_moisture mass_fraction_of_unfrozen_water_in_soil_moisture soil_frozen_water_content surface_frozen_carbon_dioxide_amount volume_fraction_of_frozen_water_in_soil I'm sure there must be others with useful comments to make about this. Best wishes Jonathan ----- Forwarded message from Martin Juckes - UKRI STFC <[email protected]> ----- > Date: Fri, 6 Apr 2018 15:06:15 +0000 > From: Martin Juckes - UKRI STFC <[email protected]> > To: Jonathan Gregory <[email protected]> > Subject: Re: [CF-metadata] CMIP6 data request: Precipitation of solid phase > water > > Dear Jonathan, > > > It may be that the situation of interest in soil is a change brought about by > decreasing temperature, and that the nature of the resulting substance is > somewhat complex because of the matrix of soil that is carrying it. In the > atmosphere I feel that applying the term "frozen" is a bit of a stretch, > though I agree that it would be possible to state that as our intended > meaning within the CF convention. On the other hand, we already use "liquid" > (as in cloud_liquid_water) and "vapor" for the other two phases, so there is > an argument for sticking to the standard partition solid/liquid/vapor. > > > Taking your other comments into account, the term would be either > "frozen_precipitation_flux" or "solid_precipitation_flux". > "frozen_precipitation" looks misleading to me, but perhaps that is a matter > of taste. > > > As you say, it would be good to hear other opinions (I'll be on leave for the > next few days, and will pick up the discussion at the end of next week), > > > regards, > > Martin > > > > ________________________________ > From: CF-metadata <[email protected]> on behalf of Jonathan > Gregory <[email protected]> > Sent: 06 April 2018 14:38 > To: [email protected] > Subject: Re: [CF-metadata] CMIP6 data request: Precipitation of solid phase > water > > Dear Martin > > That's a good point about snow and ice. I think we should use modified help- > text to make clear that "frozen water" means any form of solid water. I can't > recall the reason for "frozen" rather than "solid" - I guess because it felt > more obvious, if less systematic. I think I'm happy to understand "frozen > water" as "water in the solid phase", however it got into that state. I wonder > if others feel differently. > > Best wishes > > Jonathan > > ----- Forwarded message from Martin Juckes - UKRI STFC > <[email protected]> ----- > > > Date: Thu, 5 Apr 2018 17:29:08 +0000 > > From: Martin Juckes - UKRI STFC <[email protected]> > > To: "[email protected]" <[email protected]>, > > "[email protected]" <[email protected]> > > Subject: Re: [CF-metadata] CMIP6 data request: Precipitation of solid phase > > water > > > > Dear Jonathan, > > > > > > I hadn't spotted the existing usage of frozen_water. My only reservation is > > that for such names the help text says '"frozen_water" means ice', which > > would exclude snow. The existing usages of "frozen_water" are all soil > > quantities for which the subtlety of the distinction between ice and snow > > is irrelevant. We could modify the help text for atmospheric variables, but > > is the term "frozen" appropriate for all solid phase water in the > > atmosphere? Freezing is a process of transforming to solid phase through a > > reduction in temperature, which might be considered inappropriate for some > > atmospheric ice and snow formation pathways ... I'm not sure about this, > > what do you think? > > > > > > regards, > > > > Martin > > > > > > ________________________________ > > From: CF-metadata <[email protected]> on behalf of Jonathan > > Gregory <[email protected]> > > Sent: 05 April 2018 18:18 > > To: [email protected] > > Subject: [CF-metadata] CMIP6 data request: Precipitation of solid phase > > water > > > > Dear Martin > > > > I agree with the need, but I note that the guidelines propose the phrase > > frozen_water for solid water, and this is already used in several standard > > names. > > > > Although "precipitation" is used in the world at large for species other > > than > > water, so far in CF standard names it's used only for water. Hence we can > > omit > > "water" for consistency. > > > > In view of these two points, would frozen_precipitation_flux be OK? > > > > Best wishes > > > > Jonathan > > > > ----- Forwarded message from Martin Juckes - UKRI STFC > > <[email protected]> ----- > > > > > Date: Tue, 3 Apr 2018 11:46:50 +0000 > > > From: Martin Juckes - UKRI STFC <[email protected]> > > > To: "[email protected]" <[email protected]> > > > Subject: [CF-metadata] CMIP6 data request: Precipitation of solid phase > > > water > > > > > > Dear All, > > > > > > > > > The CMIP6 data request includes a request for a variable representing the > > > precipitation flux of water in a solid phase (including snow and ice). > > > This variable was also in CMIP5. The current CMIP6 data request follows > > > CMIP5 usage in adopting the standard name "snowfall_flux" for this > > > variable, which is not really correct. There may have been a time when > > > all solid precipitation in CMIP models was snow, but I think we need a > > > more precise name now. > > > > > > > > > We have "rainfall_flux" for precipitation of liquid phase water, but in > > > other terms the construction "liquid_water" is used to refer to the > > > liquid phase, e.g. "mass_concentration_of_liquid_water_in_air", so > > > "solid_water" is a natural extension. > > > > > > > > > I propose a new standard name for solid phase precipitation: > > > > > > > > > precipitation_flux_of_solid_water [kg m-2 s-1] > > > > > > In accordance with common usage in geophysical disciplines, "flux" > > > implies per unit area, called "flux density" in physics. "solid_water" > > > refers to all forms of the solid phase of water. > > > > > > > > > regards, > > > > > > Martin > > > _______________________________________________ > > > 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 ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
