[MITgcm-devel] big improvement with SEAICE_CGRID

[Jean-Michel Campin]

Hi, 

I think I have to report on this huge improvement (10^60)
I noticed when switching on SEAICE_CGRID:

It started with those MPI+MTH tests, all 4 lab_sea tests 
get stuck somewhere, and today I noticed that 
offline_exf_seaice.seaicetd has the same problem (whereas
the standard offline_exf_seaice, which does not use any seaice,
is passing well the MPI+MTH test).
The option file SEAICE_OPTIONS.h from offline_exf_seaice/code
is out of date, so I started to switch to an up-to date version,
keeping most options just #undef. The only one I turned on
(compared to the old version) is "SEAICE_CGRID".
And guess what ? 
The results improve by 60 order of magnitude !
Before, HEFF was reaching ~10^120 after 1 iteration (and stopping
before the end of the 2nd one), but now it's only 10^61, and can 
even go through the 2nd iteration, with only a moderate increase
(in log scale) at the end of the 2nd iter (10^62).

More seriously, an advise on where to start to look at ?
(works well with MPI alone, MTH alone, but not with both)

Thanks,
Jean-Michel