Earth radius constant

[mwarusz]

GlobalConstants.h contains Earth's radius.

Omega/components/omega/src/ocn/GlobalConstants.h

Lines 44 to 45 in e6e7b09

	constexpr Real REarth = pcd::mean_radius; // Mean radius of the Earth ~ m (from
	// Physical Constants Dictionary)

However, MPAS meshes define an attribute called sphere_radius, which is consistent with the input coordinates, but different from REarth. Omega currently does not read the radius attribute. How do we want to handle this ? The computation of reconstruction weights in high-order tracer advection needs the radius and needs it to be consistent to match MPAS-O convergence rates.

[xylar]

Yes, this is something we're working on. The Omega one from PCD is what we should also be using in Polaris when we make the meshes. I had a PR to update this but then got side tracked by updating PCD itself to include more constants. I can get back to working on it. The fix would be on the Polaris side, I think.

[xylar]

@mwarusz, could you check if Polaris now behaves as you expect after E3SM-Project/polaris#468?