Dear Karl and Jonathan,
water_sublimation_flux appears to have been present as far back as
version 1 of the standard name table, so it was probably there even
before the CF website was moved to PCMDI.
surface_snow_and_ice_sublimation_flux first appeared in version 8 of the
table, dated 15th April 2008.
The definition of water_sublimation_flux says " 'water' means water in
all phases. Sublimation is the conversion of solid into vapor." These
two sentences seem somewhat contradictory to me so I don't much like the
definition anyway.
I suppose 'surface frozen water' could include frost as well as snow and
ice. In any case, I suggest that the more recent name is the clearer as
to its meaning and the fact that it is intended to apply only at the
surface. I suggest that we keep surface_snow_and_ice_sublimation_flux
as the name for the quantity needed in CMIP5. (N.B. In LImon the
quantity appears in row 28, not 22 as stated).
Personally, I wouldn't have guessed that water_sublimation_flux was only
intended to apply to the surface. If it is, then we should make it an
alias of the other name, but are we sure that we don't need a name for
sublimation in the atmosphere?
Best wishes,
Alison
------
Alison Pamment Tel: +44 1235 778065
NCAS/British Atmospheric Data Centre Fax: +44 1235 446314
Rutherford Appleton Laboratory Email: alison.pamment at stfc.ac.uk
Chilton, Didcot, OX11 0QX, U.K.
> -----Original Message-----
> From: cf-metadata-bounces at cgd.ucar.edu [mailto:cf-metadata-
> bounces at cgd.ucar.edu] On Behalf Of Jonathan Gregory
> Sent: 22 November 2010 10:11
> To: Karl Taylor
> Cc: cf-metadata at cgd.ucar.edu; Denis.Nadeau at nasa.gov
> Subject: [CF-metadata] sublimation
>
> Dear Karl
>
> > I would appreciate advice concerning the attached email. What is
the
> difference between the following 2 standard names:
> >
> > 1) "water_sublimation_flux"
> > 2) "surface_snow_and_ice_sublimation flux"
> >
> > 2) clearly refers to surface sublimation. Is 1) meant exclusively
> for ice suspended in the atmosphere, or could it also apply to the
> surface?
>
> I think these are almost synonyms. The first is the original name; it
> is
> like water_evaporation_flux. Here water refers to the species i.e. it
> doesn't
> mean the sublimation of carbon dioxide, for example! Both of them
refer
> to
> the surface. We perhaps should clarify that for evaporation as well,
> which
> likewise could occur in mid-air, by putting "surface" in the names.
>
> If sublimation of water occurs from the surface, could the source be
> anything
> other than surface snow or ice? Does that phrase cover every possible
> form of
> frozen surface water one might consider? If so, they are synonyms and
> we should
> make one the alias of the other.
>
> Best wishes
>
> Jonathan
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Received on Mon Nov 22 2010 - 03:59:35 GMT
