[MITgcm-support] Baroclinic instability with MPI run

[Noriyuki Yamamoto]

Hi all,

I'm running into a problem with MPI run.
Outputs from mpi and no-mpi run differ qualitatively.

This seems to be the same problem reported in "Independ Tiling" thread 
(http://forge.csail.mit.edu/pipermail/mitgcm-support/2014-March/009017.html).
Is there any progress about it?
If not, I hope this information will add some clues to fixing up.

The model has a zonally periodic channel and is forced by westerly wind 
and temperature restoring along the northen and southern wall in 
mid-high latitude.
I tested some cases with different topography.
In flat-bottomed case with no-mpi, baroclinic instability develops and 
cascades up to larger scales.
But with mpi, the zonal wavenumber of baroclinic instability is fixed to 
nPx during the 3000-day integration (I tested nPx = 16, 20) and doesn't 
cascade up.
In zonally wavy (sinusoidal wave whose k is not nPx) topography case 
with mpi using the same mpi executable file (compiled by genmake -mpi) 
as flat-bottomed case,
baroclinic instablity cascades up and the result seems to be similar to 
that of no-mpi run though I checked only early surface temperature 
distribution.

In MPI run I tried two patterns of (nPx, nPy) = (16, 4), (20,4).
I compiled MITgcm codes by Intel compiler 13.1.3 with Cray MPI library 
6.3.0 on SUSE Linux Enterprise Server 11 (x86_64).
MITgcm version is checkpoint64u (sorry that it's no latest version).
If necessary, I will attach data and SIZE.h files later.

Sorry for my poor English.
Noriyuki.

-- 
Noriyuki Yamamoto
PhD Student - Physical Oceanography Group
Division of Earth and Planetary Sciences,
Graduate School of Science, Kyoto University.
Mail:nymmto at kugi.kyoto-u.ac.jp
Tel:+81-75-753-3924