[MITgcm-support] problem in pkg/seaice

[Thomas Haine]

Hi, 

I've been having a problem in pkg/seaice that causes a sudden divergence
of T & S adjacent to the ice edge under strong winds:

The resolution is 2km horizontal with 2m thick upper level. I've run
fine with NCEP 6-hrly forcing (atmospheric state) and have now switched
to a 1/4 deg-resolution 6-hrly satellite-derived 10m wind product (only
change). This has caused the trouble. At the time of the crash the wind
speed is ~40m/s with strong gradients (an intense polar low - the
numbers are realistic!).

Code is: checkpoint57y_post.

Symptom: Both S & T go wild (+/- 10^6) in 2 cells at the sea floor in a
single step. The ~80m deep column is adjacent to ice with thickness of
~40cm. 

Switching off pkg/seaice allows the code to carry on fine for at least
several more steps.

Switching off seaice dynamics makes only small changes (survives 1 more
step, symptoms the same).

So, it looks to me like this is a seaice thermodynamics issue.

Any suggestions?

Thanks, Tom.
-- 
--------------------------------------------
 Thomas W. N. Haine
                                                                                                                                                              
 Professor of Physical Oceanography,
 Department of Earth & Planetary Sciences,
 329 Olin Hall, The Johns Hopkins University,
 Baltimore, MD 21218, USA.
 Tel : 410 516 7048,   Fax : 410 516 7933
 Thomas.Haine at jhu.edu
 http://www.jhu.edu/~eps/faculty/haine
--------------------------------------------