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

From: Jonathan Gregory <j.m.gregory>
Date: Tue, 5 Apr 2005 08:07:29 +0100

Dear John

> Normally I dont see information in the netCDF file on the assumed shape
> of the Earth, eg ellipsoidal flattening or even spherical radius. Is
> that because it doesnt matter that much? Or is there an assumed standard
> that everyone just knows about?

For climate models it just doesn't matter that much. Models have their own idea
about the radius of the Earth for calculating grid spacings and so on, but its
exact value will not make a significant difference to the climate, certainly
not compared with all the other approximations and unknowns in parameterisation
schemes. The radius and non-sphericity affect the local g as well, but I guess
this number is probably separately specified rather than computed by the model.
Again its precise value is unlikely to be critical.

Cheers

Jonathan
Received on Tue Apr 05 2005 - 01:07:29 BST