[MITgcm-support] Re: [MITgcm-cvs] MITgcm/model/src CVS Commit

[Martin Losch]

Hi Jean-Michel,

the problem occurs only on curvilinear grids (that's why  
ini_curvilinear_grid), and it happens somewhere in mom_common/ 
mom_calc_visc.F. Basically, L2rdt (and other similar terms) are zero  
at some points in the overlaps, I think the corners, so i,j=-2, or so  
and then, when there is a division by L2rdt, then the sxf90 compiler  
complains/code crashes. The problem goes away with my fix (and we  
talked about this some time ago, but obviously since then nothing has  
changed in terms of exchanges) and the actual value of the  
initialization does not have an impact on the solution at all.

You should be able to reproduce this with any cubed sphere grid  
(although I only get crashes with sxf90).

Martin

On Feb 12, 2009, at 6:02 PM, Jean-Michel Campin wrote:

> Hi Martin,
>
> I am little bit confused:
> - we do have the proper exchange for dxV & dyU (In fact, I think we
>  now have the full familly of exch S/R), may be not the adjoint  
> version.
> - If there is a division by zero somewhere in the code, I would prefer
>  to fix it (for all platforms, not only for NEC_SX) rather than
>  leave with it.
> Can you point where the problem was ?
> Thanks,
> Jean-Michel
>
> On Thu, Feb 12, 2009 at 02:51:56AM -0500, Martin Losch wrote:
>> Update of /u/gcmpack/MITgcm/model/src
>> In directory forge:/tmp/cvs-serv13873/model/src
>>
>> Modified Files:
>> 	ini_curvilinear_grid.F
>> Log Message:
>> check my hack for SX8 compiler, because I keep stumbling over it.
>> (forgive me, Jean-Michel):
>> terrible hack to make sure that recip_dxV and recip_dyU are never  
>> zero,
>> until we have a proper exchange for them. Most compilers do not seem
>> to mind divisions by zero in the overlaps, as long as the results are
>> not used anywhere, but sxf90 does.
>>
>> _______________________________________________
>> MITgcm-cvs mailing list
>> MITgcm-cvs at mitgcm.org
>> http://mitgcm.org/mailman/listinfo/mitgcm-cvs
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support