Negative tracer values

Hi all
My suite has failed to run atmos_main, and returning a “ERROR in UKCA_TRACERS_COPY_FROM_UM: negative tracer values”. I have already got several months of simulations without having this error and was wondering where it is coming from.
I see in a previous post that it might be possible to set BITCOMP_NRUN=False. or to perturb the dump. I was wondering what you be the best method in my case, and how to perturb the dump.

Hi Paul-Arthur

To perturb the dump: on ARCHER2

mv <dump> <dump>.orig
then use this batch script as a template: /work/y07/shared/umshared/scripts/submit_perturb.slurm
to run on your dump (change HISTORY_DATA, DUMP and account)


The negative tracer values error came from atmos_ens0 (that’s where the message appeared anyway), so try perturbing


Hi Grenville

Thank you, it worked! I have been able to run the suite after perturbing the dump.
This post was also useful for this issue: HadGEM3 crash (from NEMO) - #3 by racheldiamond