[Mitgcm-support] Re: testscript FAIL

[mitgcm-support at dev.mitgcm.org]

>> Seems like lab_sea is extremely sensitive.
>> For the identical code that I obtained 16 digits accuracy (also linux)
>> Dimitris got as low as low as only 5 on an O2K.

Jean-Michel, just to reinforce Patrick's statement, these are the numbers I
get for "testscript lab_sea" on an SGI Origin 2000:

Y Y Y Y  5  5  7  7  7  8 10  9  6  6  6  6  7  5  7  5  7 FAIL  lab_sea

and on Linux using g77:

Y Y Y Y 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 pass  lab_sea

for the same code (release1_p8).  I tried turning off sea-ice dynamics, but
the high sensitivity remains.  During next couple of weeks, I plan to work on
development of adjoint for sea-ice thermodynamics.  Hopefully I will be able
to identify and reduce this high sensitivity.

D.

-- 
Dimitris Menemenlis                      menemenlis at jpl.nasa.gov
Jet Propulsion Lab, MS 300-323           tel: 818-354-1656
4800 Oak Grove Dr, Pasadena CA 91109     fax: 818-393-6720