Dear Jonathan,
I support this proposal, except I'd suggest defining also
"reference_pressure_for_potential_density". Hopefully, an ocean modeler
will weigh in on this, but I think potential density may be directly
calculated in ocean models, in which case it would be odd to assume that
one should use the reference pressure for temperature in your definition
of potential_density.
Best regards,
Karl
On 12/3/10 1:19 PM, Jonathan Gregory wrote:
> Dear Karl
>
> I would suggest that we change the definition of potential temperature so that
> it says *by default* the reference pressure is 1e5 Pa, but that the data var
> could also have a size-one coordinate variable or a scalar coordinate variable
> with the standard_name of reference_pressure_for_potential_temperature, which
> I am proposing as an addition to the standard_name table, that would specify
> the reference pressure. This would be backward-compatible because any existing
> use of sea_water_potential_temperature would be with the default reference
> pressure by definition. I agree that the definition should have said 1e5 Pa,
> not sea level pressure, but I am sure that people will have used it as 1e5 Pa
> and not worried about the difference. If anyone had noticed the definition and
> been concerned, they would have queried it before.
>
> The same issue arises for potential density. Is it OK to use a
> reference_pressure_for_potential_temperature
> to define potential density? I think so. It is the temperature which changes;
> the potential density is computed from the potential temperature.
>
> Cheers
>
> Jonathan
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Received on Mon Dec 13 2010 - 13:11:03 GMT
