Dear all,
O.K. I withdraw my suggestion to deprecate sea_surface_skin_temperature.
I do think the definitions should say how skin temperature differs from
surface temperature. Maybe someone can explain that in a few words.
As I understand it, temperature is only defined when molecules are
involved. So surface_temperature I think should be defined as the
temperature of the surface molecules on the ocean or land/vegetated
surface. I don't think there are any useful observational measurements
of this temperature either in the ocean or land. Models do calculate
these a surface temperature, and as I understand it models use this as
their surface radiating temperature so in that sense the temperature is
identical to skin_temperature, I would think.
It sounds to me like in land observations, at least, the
skin_temperature is not precisely defined because the effective
radiating layer depends presumably on what wavelengths are being
sensed. To precisely say what the temperature represents one would have
to show what fraction of the radiation originated from different
depths. saying 10-20 microns of course gives an idea about this, but it
isn't precise.
Also, the definition of land_surface_skin_temperature should clearly
indicate (when it represents an area mean) whether it is meant to be the
area mean of the soil or of the "solid or liquid surface" as seen from
above which might include vegetation, puddles, etc. [as an aside, I
wonder if the thickness of the layer producing the radiation varies much
from one material to the next.]
It does seem a shame to me that users looking for surface_temperature
information will now have to search both for surface_temperature and
surface_skin_temperature, but I'll accede to the clear majority that
thinks both are necessary.
best regards,
Karl
On 6/20/13 4:56 AM, Jonathan Gregory wrote:
> Dear Karl
>
> Like Roy, I don't think we should deprecate sea_surface_skin_temperature.
> Although I cannot remember the arguments - which must be apparent in the
> mailing list archive - I do recall that it was a careful and long discussion
> with Craig which led to the introduction of the various SST names.
>
> Therefore adding land_surface_skin_temperature seems fine to me if there is
> a need to be precise about this as an observable quantity, which relates
> to a particular layer, even though it's very thin. The definition should note
> that if this precise meaning is not intended, the name surface_temperature
> could be used, which strictly refers to the temperature at the interface.
>
> Best wishes
>
> Jonathan
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Received on Thu Jun 20 2013 - 10:15:36 BST
