[CF-metadata] What do models assume for the shape of the Earth?

[Karl Taylor]

Dear all,

I also think we should discuss this further at the GO-ESSP meeting, but 
just one preliminary thought ...

What would be important to know as models go to higher resolutions is 
how the topography is specified in the model.  My understanding is that 
modelers simply transfer the latitude/longitude locations of 
topographical features and surface characteristics from the 
non-spherical earth to his idealized spherical model earth without 
correction.  Thus, surely one should simply compare modeled and observed 
fields at corresponding longitudes and latitudes (without adjustment). 
I don't think 20 km errors are introduced by this procedure.

Maybe I'm missing something.

cheers,
Karl

Jonathan Gregory wrote:
> Dear John
> 
> 
>>Now when I send that info to a GIS package that uses an 
>>ellipsoidal earth, presumably they will correct the coordinates to take 
>>this into account.
> 
> 
> It shouldn't alter the lat and lon coords; they are what the model believes
> it is using on a spherical Earth.
> 
> 
>>If CF doesnt want to cope with this, it would be helpful if CF stated 
>>that the scope of its mission is to deal with model data with resolution 
>>greater than such and such.
> 
> 
> That would be not satisfactory, I don't think. 
> 
> 
>>Perhaps these are issues to be discussed at the GO-ESSP conference?
> 
> 
> Good idea.
> 
> Best wishes
> 
> Jonathan
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