Thanks Roy, Karl, and Jonathan -
I guess I was hoping for confirmation that one or both terms
(air_pressure_at_sea_level and surface_air_pressure) would be
analogous to sea_surface_temperature, which is defined as
being *near the surface*. In the case of SST, a depth coordinate
is allowed, as far as I can tell from the standard name table.
It looks like surface_temperature would be used without a
depth coordinate, based on the definition below, and I'm
not exactly sure about sea_surface_skin_temperature, which
includes a depth (10 - 20 micrometers) in its definition.
For in situ data, it's preferable to record the measured barometric
pressure and provide a sensor height, rather than correct to sea
level, because the correction algorithm is inexact and because
sensor height can be fully described using attributes - important
on a surface buoy, where the waterline may not be perfectly known.
We could use the standard name air_pressure, but some systems, like
SeaDataNet, distinguish between pressures used as Z coordinate variables
(for balloon or sonde measurements) and pressures that are 'science
observables'. This is a valid distinction, and I'd like to maintain it -
although
that may not be part of the CF approach.
> *Sea surface temperature* is usually abbreviated as "SST". It is the
> temperature of sea water near the surface (including the part under
> sea-ice, if any), and not the skin temperature, whose standard name
> is surface_temperature. For the temperature of sea water at a
> particular depth or layer, a data variable of sea_water_temperature
> with a vertical coordinate axis should be used.
> *surface_temperature* The surface called "surface" means the lower
> boundary of the atmosphere. The surface temperature is the
> temperature at the interface, not the bulk temperature of the medium
> above or below.
Thanks for your input on this -
Nan
On 3/15/12 2:27 PM, Jonathan Gregory wrote:
> Dear Nan
>
> If the quantity has "surface" in its standard name, it should not have a
> z-coordinate, because "surface" quantities are defined as being values on
> "the surface" (i.e. bottom of the atmosphere) z(x,y). Given x and y, z
> is known. The same applies to quantities with standard names that contain
> other named surfaces, such as toa (rather a vague surface!) or sea_floor.
>
> Best wishes
>
> Jonathan
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* Nan Galbraith (508) 289-2444 *
* Upper Ocean Processes Group Mail Stop 29 *
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Received on Thu Mar 15 2012 - 13:17:12 GMT
