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.juckes at stfc.ac.uk> -----
> Date: Thu, 5 Apr 2018 17:29:08 +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] 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-bounces at cgd.ucar.edu> on behalf of Jonathan Gregory <j.m.gregory at reading.ac.uk>
> Sent: 05 April 2018 18:18
> To: cf-metadata at 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.juckes at stfc.ac.uk> -----
>
> > Date: Tue, 3 Apr 2018 11:46:50 +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>
> > 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 at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
> ----- End forwarded message -----
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----- End forwarded message -----
Received on Fri Apr 06 2018 - 07:38:46 BST
