[MITgcm-support] Re: MITgcm files

[Martin Losch]

Hi Renske,

I am returning your files with my modficiations, but all of these are  
related to general stability of the code. I could not reproduce the  
problem that you described, namely that a non-zero heat flux does not  
change the surface temperature. For testing, try a non-uniform heat  
flux that introduces a horizontal pressure gradient and immediate  
flow. With a uniform heat flux and uniform initial conditions (in the  
horizontal) and a stable water column you should never get any flow.  
(as a side remark: I did get non-zero velocities after the second  
timestep, which should not happen, but that's not your problem. Is  
that a problem with step topography, and vertical diffusion? very  
worrying).

a couple of problems:
SIZE.h: you set the overlaps to 0, that will probably not work ( and  
did not work for me, the model blows up immediately, I am surprised  
that we don't have a catch for that, maybe it is allowed?). I changed  
them to 4 (but 2 should be enough).

data:
- deltaT = 86400 is much too large a time step and will also lead to  
the model blowing up immediately (once there is motion), but you  
probably knew that
- I put sref = 15*0.0, (although some compiler will probably take  
sref=0.0 as well)
- diffKzT = 20., is awfully large if implicitVerticalDiffusion is not  
turned on (default). I set it to 1.e-5 for now.

topography:
- I usually try to set a minimum depth which should be at least the  
thickness of the top-most grid cell, can be set in "data" by hFacMinDz



-------------- next part --------------
A non-text attachment was scrubbed...
Name: renske.tgz
Type: application/octet-stream
Size: 23594 bytes
Desc: not available
URL: <http://mitgcm.org/pipermail/mitgcm-support/attachments/20080526/0cc18d7b/attachment.obj>
-------------- next part --------------


On 23 May 2008, at 17:50, Gelderloos, Renske (KNMI) wrote:

> Dear Martin,
>
> Here are all the files you requested. I would really appreciate it  
> if you would want to take a look at it, I'm pretty stuck... Hope  
> you can help me!
>
> Renske
>
> ________________________________
>
> From: Gelderloos, Renske (KNMI)
> Sent: Fri 5/23/2008 2:09 PM
> To: Gelderloos, Renske (KNMI)
> Subject: MITgcm files
>
>
>
> <data><data.mnc><data.pkg><eedata><Qnetuniform.bin><topogOBCmatlab.bin 
> ><packages.conf><SIZE.h><LabradorOBC.m><heatuniform.m>