Hi Jonathan (Wrotny), Jonathan (Gregory), et al.,
I am a little surprised.
It is explicitly stated in the proposed description that land_surface_skin_temperature "can be taken to be equivalent to" surface_temperature over land areas.
In the description for surface_temperature, it indicates that it can apply to just land using cell_methods. Indeed, in the CF convention, example 7.6 explicitly states this:
Example 7.6. Mean surface temperature over land and sensible heat flux averaged separately over land and sea.
float surface_temperature(lat,lon);
surface_temperature:cell_methods="area: mean where land";
I also note that surface_temperature is already an alias for surface_temperature_where_land (which I think is deprecated)
Why is a new std_name needed? What am I missing?
It is true that there is a variable called sea_surface_skin_temperature, but it appears that this was introduced for different reasons. Specifically, it looks like sea_surface_temperature was created to refer to the water _near_ the surface to distinguish it from the 'skin'. sea_surface_skin_temperature then differs from surface_temperature because it refers to the interface under sea-ice rather than above sea-ice.
Best wishes, as always :-),
Philip
-----------------------------------------------------------------------
Dr Philip Cameron-Smith, pjc at llnl.gov, Lawrence Livermore National Lab.
-----------------------------------------------------------------------
> -----Original Message-----
> From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf
> Of Jonathan Gregory
> Sent: Thursday, October 03, 2013 9:35 AM
> To: cf-metadata at cgd.ucar.edu
> Subject: Re: [CF-metadata] Surface temperatures
>
> Dear Jonathan
>
> The new proposal looks fine to me. Thanks. I see that you don't have to
> define the thickness of the layer; instead, you are defining it implicitly
> through the method of diagnosis. Others may have views, of course.
>
> Cheers
>
> Jonathan
>
> ----- Forwarded message from Jonathan Wrotny <jwrotny at aer.com> -----
>
> > Date: Wed, 2 Oct 2013 11:26:27 -0400
> > From: Jonathan Wrotny <jwrotny at aer.com>
> > User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130801
> > Thunderbird/17.0.8
> > To: Jonathan Gregory <j.m.gregory at reading.ac.uk>, "cf-
> metadata at cgd.ucar.edu"
> > <cf-metadata at cgd.ucar.edu>
> > Subject: Re: [CF-metadata] Surface temperatures
> >
> > Dear Jonathan Gregory,
> >
> > I am getting back to this reply after a long time - sorry, I was
> > pulled in a few different directions lately. Hopefully, it is
> > possible to bring back to life a submission that I had made for the
> > land_surface_skin_temperature.
> >
> > Revisiting my previous proposal and a few e-mails by Karl Taylor and
> > Evan Manning, I have made some modifications to the definition of this
> > standard name so that I can incorporate some suggestions by Karl and
> > Evan. Here is my current proposal:
> >
> > Standard Name:land_surface_skin_temperature
> >
> > Definition:The land surface skin temperature is the temperature of a
> > land point or the land portion of a region as inferred from infrared
> > radiation emitted directly towards space through the atmosphere. Not
> > all of the emitted surface radiation originates at the soil.Some may
> > come from various terrestrial features (e.g., vegetation, rivers,
> > lakes, ice, snow cover, man-made objects).Thus, the land surface skin
> > temperature is the aggregate temperature of an effective layer which
> > includes the soil and terrestrial features at the surface (if they
> > occur).In models, the radiating temperature of the surface is usually
> > the "surface_temperature", which then can be taken to be equivalent to
> > land_surface_skin_temperature or sea_surface_skin temperature,
> > depending on the underlying medium.
> >
> > Canonical Units:K
> >
> > Thanks for still considering this proposal. Sincerely,
> >
> > Jonathan Wrotny
> >
> > On 8/1/2013 12:56 PM, Jonathan Gregory wrote:
> > >Dear all
> > >
> > >I agree with Karl than in CF standard names "land" means "non-sea",
> > >whereas sea-ice is part of sea. Hence I would support adding
> > >land_surface_skin_ temperature, for use by applications which classify
> locations as land or sea.
> > >
> > >However I also agree with Evan that one can approach this more
> > >generally, and therefore I would also support the addition of
> > >surface_skin_temperature, with which an area-type could be specified,
> > >if anyone wants to follow that approach (we only add names when they
> are needed).
> > >
> > >The quotations that Evan made show that we need to change the
> > >definitions where they mention "skin". This is because in these new
> > >names "skin" is being given a more precise and practical meaning,
> > >motivated by observational methods, whereas the surface_temperature
> > >names were introduced for models, in which the skin can be a notional
> and infinitesimally thin layer.
> > >
> > >Best wishes
> > >
> > >Jonathan
> > >_______________________________________________
> > >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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Received on Thu Oct 03 2013 - 11:30:08 BST
