ERROR: remap transport: negative area

[birdsfriend]

when I perform a 1990 control run of ccsm3 , the model failed in 311 year with the error remap transport: negative area. I haved made no change with the model downloaded from homepage . I can't find the reason caused
this error. who can give a hint?
the log is follow:
New area < 0, istep = 2721095
(my_task,i,j,n) = 11 7 379 0
Old area = -0.607508500481154651E-01
New area = -0.607508500481154651E-01
Net flux = 0.000000000000000000E+00
(shr_sys_abort) ERROR: remap transport: negative area
(shr_sys_abort) WARNING: calling shr_mpi_abort() and stopping
(shr_mpi_abort):remap transport: negative area 0

[dbailey]

That message indicates a CFL instability problem in the ice (CSIM). What tag, machine and compset are you using? What grid and what initial conditions? Out of the box, the timestep should be sufficient to maintain CFL stability.

Dave

[birdsfriend]

Thank you , Dave . I have solved the problem by changing the parameter ndyn_dt in ice_in file.

[ckcastillo]

Hi, I seem to encountering the same problem. May I know exactly how you solved it? Where do I find that parameter and what do I change it to? Will this necessitate re-doing the entire model run or can I just re-build and restart from where it left off?

[dbailey]

In the CSIM build-namelist (csim.buildnml_prestage.csh) there is a namelist flag called ndyn_dt. Switch this to 2 instead of 1. This will decrease the dynamic timestep and usually get you through a CFL timestep instability issue. Are you doing anything unusual with the CAM configuration? The ice is very sensitive to changes in the atmosphere.

Dave

[ckcastillo]

Thanks! I'm actually perturbing the land surface in CLM-DGVM, not CAM.