[MITgcm-support] noise again, coarse resolution

[mlosch at awi-bremerhaven.de]

Yes, it is coarse: "1deg" (76 by 111km)

The standard question about the CD scheme: How to choose tauCD? Just take the value from global_ocean.90x40x15? 
or from one of the verification/global2x2/1x1_tot experiments?

M.

Martin Losch
Alfred Wegener Institute 
Postfach 120161, 27515 Bremerhaven, Germany; 
Tel./Fax: ++49(0471)4831-1872/1797



----- Original Message -----
From: Patrick Heimbach <heimbach at mit.edu>
Date: Tuesday, May 2, 2006 7:00 pm
Subject: Re: [MITgcm-support] noise again, coarse resolution

> 
> Hi Martin,
> 
> I presume it's relatively coarse-res(?).
> Definetely worth trying the one thing you haven't,
> i.e. use C-D scheme.
> 
> -p.
> 
> 
> 
> On Tue, 2006-05-02 at 12:08, Martin Losch wrote:
> > Hi there,
> > 
> > I am trying to reproduce the results of
> > Pacanowski and Gnanadesikan 1998: Transient response in a z-level 
> 
> > ocean model that resolves topography with partial-cells. MWR, Vol 
> 
> > 126, No 12, December 1998.
> > with the MITgcm (checkpoint58b_post). I tried to copy the  
> > configuration as closely as possible (running into all sorts of  
> > trouble, there is a typo in the equation for lambda and the 
> density  
> > perturbation may be too large), but the model becomes unstable 
> after  
> > 50 days or so (visible in a peak in kinetic energy and a deltaX  
> > pattern in temperature). I tried free slip, no slip, 
> JamartWetPoints,  
> > staggering the time step (but not CD-scheme), different advection 
> 
> > schemes, increased friction by factor 10, timesteps between 3600 
> and  
> > 900 seconds, but nothing improves the situation. I have attached 
> my  
> > configuration (code and input directory, need to regenerate input 
> 
> > files with matlab), which is very simple and takes about 60sec to 
> 
> > run. Can anybody see what I am doing wrong?
> > 
> > Martin
> > 
> > 
> ______________________________________________________________________> 
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> -- 
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> Patrick Heimbach   Massachusetts Institute of Technology
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