run_tower fails out-of-the-box due to use_c13 incompatability

[rhallmark]

Code version: ctsm5.3.061 on Derecho, no changes to the source tree

Running into a issue when using run_tower out-of-the box. When I run the following command: ./run_tower --neon-sites ABBY --output-root /glade/work/rhallmark/new_simulations the run fails during initialization and gives the following issue in the lnd log:
Cannot initialize from a run without c13 to a run with c13,
due to <C isotope fields get bad values after a few time steps when starting from initial conditions without C isotopes · Issue #2119 · ESCOMP/CTSM>.
Either use an input initial conditions file with c13 information,
or re-spinup from cold start.
ENDRUN: ERROR in CNVegCarbonStateType.F90 at line 2656

My current workaround is using run_tower with --setup-only, changing use_c13 and use_c14 =.false. in user_nl_clm in the case directory, and then manually building and submitting the case. This seems to be working for now.

I wanted to post here since the error seems to be pointing to a known issue from a few years ago. Is run_tower expected to work out-of-the-box with default settings or does it need to be manually configured? Thanks!

 

[slevis]

@rhallmark thank you for pointing out this error and your workaround. Could you also include a link to the issue that you referenced?

 

[rhallmark]

@rhallmark thank you for pointing out this error and your workaround. Could you also include a link to the issue that you referenced?

here is the issue referenced in the lnd log: C isotope fields get bad values after a few time steps when starting from initial conditions without C isotopes · Issue #2119 · ESCOMP/CTSM

 

[slevis]

No guarantee in what I will say here, but this may end up being a temporary problem while we advance the model to the next release. The error you got means that the model now defaults to active c13/c14 flags while we have not, yet, updated the default finidat files to be consistent with that. Your workaround is perfect if you are not interested in active c13/c14.