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 <martin.juc...@stfc.ac.uk> ----- > Date: Thu, 5 Apr 2018 17:29:08 +0000 > From: Martin Juckes - UKRI STFC <martin.juc...@stfc.ac.uk> > To: "cf-metadata@cgd.ucar.edu" <cf-metadata@cgd.ucar.edu>, > "j.m.greg...@reading.ac.uk" <j.m.greg...@reading.ac.uk> > 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 <cf-metadata-boun...@cgd.ucar.edu> on behalf of Jonathan > Gregory <j.m.greg...@reading.ac.uk> > Sent: 05 April 2018 18:18 > To: cf-metadata@cgd.ucar.edu > 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 > <martin.juc...@stfc.ac.uk> ----- > > > Date: Tue, 3 Apr 2018 11:46:50 +0000 > > From: Martin Juckes - UKRI STFC <martin.juc...@stfc.ac.uk> > > To: "cf-metadata@cgd.ucar.edu" <cf-metadata@cgd.ucar.edu> > > 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 > > CF-metadata@cgd.ucar.edu > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > ----- End forwarded message ----- > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
