[MITgcm-devel] changing exch-1

[Menemenlis, Dimitris (3248)]

Jean-Michel, we'll give the updated code a try.
It's a huge computation, 1 week on ~4000 cpus,
so my preference is to move forward one iteration.
If things don't work out, we could come back and
try some shorter tests on the CS510 with old and
with new code.  Dimitris

On May 4, 2010, at 6:26 PM, Jean-Michel Campin wrote:

> Hi Dimitris,
> 
> I think it would be better to re-do one iteration you already done
> (onless you don't have time to do it) so that we can be sure. 
> I think it's worth to try, since you have this tiling problem. 
> And no need to do more than 1 iteration. 
> 
> I only did very short test (1 time step, using lab_sea/input_ad.noseaice
> and switching on EXCH2), but I was seeing differences at tile edges
> in the forcing sensitivity (which make sense since it was in exf),
> same as you listed, and not in Precip.
> But don't know how this propagate.
> 
> Cheers,
> Jean-Michel
> 
> PS: there was also the AD global sum issue (which relates to 
> MPI domain decomposition) which has been fixed, but no idea if this
> could be the cause of tile-edge discontinuity.