Dear Jonathan,

On Mon, 2008-08-11 at 11:26 +0100, Jonathan Gregory wrote:
> Dear Ian
> 
> > So, apart from T14, I think we're agreed.
> 
> Splendid. On T14, I'll agree with you that it is helpful to indicate what sort
> of depth it is. The fact that it is the depth of an isotherm is a main point 
> of
> the definition of the quantity, whereas temperature on sigma levels and
> temperature on pressure levels are really the same quantity, just like
> temperature on a lat-lon grid and temperature on a tripolar grid are the
> same quantity.
> 

Yes - that's what I was trying to get at. 

> However I'd like to suggest an alternative to ocean_isotherm_depth. What do
> you think of depth_of_isosurface_of_sea_water_temperature? This is of course
> not the common term but my aim is not to be obscure. I am thinking of
> (a) precision; "isotherm" might mean potential or in-situ temperature, I 
> guess.
> (b) generality. Any quantity that is defined as a function of z might be
> inverted in this way. While "isotherm" is a fairly familiar word, we don't
> want to have to depend on the existence of a Greek-based "iso" word in order
> to name a quantity. Does "isosurface" have an obvious meaning to you? 

The meaning is clear, even though I hadn't seen it before. I think
"contour level" and "isopleth" (which might be more familiar to
meteorologists) probably have 1D connotations (wikipedia defines lots of
isos as "a line through ...").  I think your suggestion is admirably
clear.

> It turns
> out to be a word that is in common use with this meaning e.g. IDL and ncar
> graphics both use the term, and it's in wikipedia.
> 
> If this is too user-unfriendly I'll settle for ocean_isotherm_depth and if we
> have later problems we can sort it out with aliases.
> 

No, that's fine - except that in NEMO it's defined in terms of theta,
not in-situ temp, so we want

T14 depth_of_isosurface_of_sea_water_potential_temperature (m)

(This sets an obvious precedent if someone wants to propose a standard
name based on in-situ T later.)

Is that OK?

Thanks,
Ian.

> Cheers
> 
> Jonathan
-- 
Ian Culverwell B-2-81 Ocean and Sea Ice Modelling
Met Office  FitzRoy Road  Exeter  Devon  EX1 3PB  United Kingdom
Tel: +44 (0)1392 884017                 Fax: +44 (0)1392 885861
E-mail: [EMAIL PROTECTED] http://www.metoffice.gov.uk

Met Office climate change predictions can now be viewed on Google Earth 
http://www.metoffice.gov.uk/research/hadleycentre/google/

_______________________________________________
CF-metadata mailing list
[email protected]
http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata

Reply via email to