[MITgcm-support] noise again, coarse resolution

[Patrick Heimbach]

Martin,

verification/global1x1_tot/input/data
is a good start
(until I have time to find better reference).

-p.



On Tue, 2006-05-02 at 15:13, mlosch at awi-bremerhaven.de wrote:
> 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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> > -- 
> > --------------------------------------------------------
> > Patrick Heimbach   Massachusetts Institute of Technology
> > FON: +1/617/253-5259                  EAPS, Room 54-1518
> > FAX: +1/617/253-4464             77 Massachusetts Avenue
> > mailto:heimbach at mit.edu               Cambridge MA 02139
> > http://www.mit.edu/~heimbach/                        USA
> > 
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-- 
--------------------------------------------------------
Patrick Heimbach   Massachusetts Institute of Technology
FON: +1/617/253-5259                  EAPS, Room 54-1518
FAX: +1/617/253-4464             77 Massachusetts Avenue
mailto:heimbach at mit.edu               Cambridge MA 02139
http://www.mit.edu/~heimbach/                        USA