[MITgcm-devel] spurious vertical diffusion

[Dimitris Menemenlis]

Alistair and Jean Michel, are any of your super-duper new tracer-advection 
schemes ready for prime time on the cube?

In the Arctic domain of the 18-km cube configuration, there seems to be too much 
vertical diffusion (or perhaps horizontal diffusion across sloping isopycnals). 
  We have started an integration where the explicit background vertical 
diffusion is much reduced (from 1.4e-5 to 1e-6 m^2/s) but that does not seem to 
impact the solutions very much.

Right now we use

  tempAdvScheme=33,
  saltAdvScheme=33,

and we have zero explicit horizontal diffusivity.

Two specific questions:

1) Is there a way to diagnose what is the effective vertical diffusivity in the 
integration?

2) Is there an advection scheme that will lead to less spurious vertical 
diffusion than flux-limited DST3?

Dimitris