Opened 5 years ago

Closed 5 years ago

Last modified 3 years ago

#1547 closed Bug (fixed)

Uninitialised values in lim_thd_dif

Reported by: ufla Owned by: nemo
Priority: normal Milestone:
Component: LIM3 Version: trunk
Severity: Keywords: LIM*


The model crashes with floating point exception.

The usual dance shows that this line

IF ( ln_it_qnsice ) hfx_err_dif_1d(:) = hfx_err_dif_1d(:) - ( qns_ice_1d(:) - zqns_ice_b(:) ) * a_i_1d(:)

from lim_thd_dif (limthd_dif.F90) accesses arrays that have uninitialised values. Initialising all arrays allocated in thd_ice_alloc (thd_ice.F90) to HUGE shows the bug reliably. Setting them to zero right after allocation prevents the crash reliably.

The following arrays carry the HUGE() values according to the debugger: a_i_1d, qns_ice_1d, and hfx_err_dif_1d. Note that not all of the array elements are uninitialised. There seems to be a certain array index (dependent on the MPI rank) from which on elements are not initialised. Elements with lower index are zero.

Commit History (2)


bug fix concerning precipitation distribution over ice/ocean after wind blowing. see ticket #1547


correct limthd_dif to avoid floating point exception. see ticket #1547

Change History (4)

comment:1 Changed 5 years ago by clem

  • Resolution set to fixed
  • Status changed from new to closed

Yes, thanks again Uwe. In the thermodynamics of LIM, we should not use the entirety of the 1D arrays (:) but only the range from kideb to kiut since arrays are not defined outside these boundaries. I corrected limthd_dif at revision 5474. There may be other parts of the code where it is the case. I'll have a look

comment:2 Changed 5 years ago by ufla

  • Resolution fixed deleted
  • Status changed from closed to reopened

Here seems to be another case (limthd_dh.F90):

CALL lim_thd_snwblow( 1. - at_i_1d, zsnw ) ! snow distribution over ice after wind blowing

at_i_1d is apparently not initialised for non-oce points.

Can be fixed by

CALL lim_thd_snwblow( 1. - at_i_1d(kideb:kiut), zsnw(kideb:kiut) ) ! snow distribution over ice after wind blowing
Last edited 5 years ago by ufla (previous) (diff)

comment:3 Changed 5 years ago by clem

  • Resolution set to fixed
  • Status changed from reopened to closed

Ok. It has been fixed in revision 5487. I supposed the distribution of snow over ice/ocean was not right (not sure though)

comment:4 Changed 3 years ago by nemo

  • Keywords LIM* added
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