run failure with Error Message: Convergence failure in BiCGstab

[dpolson]

Hi,

I'm running an N216 version of HadGEM3-A for 01/09/2000 to 01/09/2001 and it's crashing after a couple of months with the error:

? Error in routine: eg_sl_helmholtzApplication 21617299 is crashing. ATP analysis proceeding…

? Error Code: 1
? Error Message: Convergence failure in BiCGstab

job is xmqwa,
output is in ~dpolson/output/xmqwa003.xmqwa.d16133.t014453.leave
and /work/n02/n02/dpolson/xmqwa/

I'm not familiar with why the model would be crashing so I'm hoping you can point me in the right direction.

Thanks
Debbie

[grenville]

Debbie

This is typically the result of some numerical instability in the model. It's hard to say why this has happened. You need some more diagnostics — try dumping on a few time steps prior to the failure and examine examine the fields.

How does this model differ from the standard HadGEM3-A if at all.

Grenville

[dpolson]

Is should be a pretty standard run, the only thing I really changed was to add some aerosol related diagnostics.

IS there a way to perturb the data from the previous month slightly to avoid encountering the same instability?

Debbie

[grenville]

Debbie

Changing dump frequency may be enough to do that. Alternatively if you write a dump just prior to the failure, then reconfigure that dump and carry on the run with it, that may work.

You could also try reducing the time step - maybe just to get past the instability, then return it to it's normal value.

Grenville

[grenville]

Closed for lack of activity