[Mitgcm-support] RE: advection schemes

[mitgcm-support at dev.mitgcm.org]

The answer is it shouldn't happen so something is wrong.

Hope that helps!  :-)

Is this very high res.?

A.

> -----Original Message-----
> From: Martin Losch [mailto:mlosch at awi-bremerhaven.de]
> Sent: Thursday, May 08, 2003 8:37 AM
> To: support at mitgcm.org
> Subject: advection schemes
> 
> 
> Hi again,
> 
> this time I have a question about advection schemes:
> I have replaced the default advection (2nd order, centered)
> by the DST-3 
> with flux limiter (temp/salt/tracerAdvScheme=33, by the way, not very 
> well documented which idenifying number belongs to which 
> scheme). In my 
> channel, I start from a zonally homogeneous (symmetric) state, with a 
> strong vertical stratification (similar to Wardle and 
> Marshall, 2000, JPO).
> 
> I expect (and this is true for the 2nd centered scheme) that,
> starting 
> from rest, I spinup my channel ad infinitum, until the CFL 
> criterium is 
> violated the model explodes.
> 
> With the DST-3 with flux limiter, this is NOT what happens,
> instead the 
> whole system becomes unstable almost immediately (even if I have some 
> explicity bi-harmonic friction), I get deep mixing until the 
> channel is 
> basically homogenized and then slowly the flow restratifies 
> according to 
> my buoyancy forcing, but the zonal symmetry is broken 
> forever. Is that 
> supposed to happen?
> 
> Martin
> 
> --
> Martin Losch
> Alfred Wegener Institute for Polar and Marine Research
> Postfach 120161, 27515 Bremerhaven, Germany;
> Tel./Fax: ++49(0471)4831-1872/1797
> 
>