Trouble with continuing run: CESM2.1 with prescribed T,S field

[michelle_dvorak]

Hello,

I am trying to run a new piControl (B1850) startup simulation where I have reinitialized the ocean with a 3D T,S field from an average over the last 100 years of the existing piControl.

The simulation runs fine upon startup. I ran the model for 3 months. But then when I re-start the simulation, the model seems to have difficulty.

In the cesm.log file I see:

POP aborting...

Stopping in ecosys_tracers_and_saved_state_mod:ecosys_tracers_and_saved_state_init

In the POP log file, I find this:

Initial 3-d T,S read from file:/glade/work/mtdvorak/plio_tools/ocn_init/TSic_b21.PI.gx1v7.pop.h.1900-2000_Dec_ave.nc

(open_read_netcdf) nsize = 662
(open_read_netcdf) len(data_file%history) = 384

string too short; not enough room to read history attribute from /glade/work/mtdvorak/plio_tools/ocn_init/TSic_b21.PI.gx1v7.pop.h.1900-2000_Dec_ave.nc

Making the following change:

In ~/derecho_cases/my_cesm_sandbox/components/pop/source/io_netcdf.F90
Changed line 95 from characters = 80 to 512

As per previous guidance on this forum (ocn initialization. string too short; not enough room to read nc file).

And rebuilding the model did not solve the problem.

I am not sure why the model is trying to read the initial field for a restart run anyway -- shouldn't it read the restart file?

Thanks in advance for your help.

Michelle

 

[michelle_dvorak]

I solved my own problem by simply commenting out the reference to the initialization files in user_nl_pop for the continued run.

That was probably an obvious solution but I figured I'd leave this up here on the off-chance anyone runs into the same issue.

 

[mlevy]

Thanks for following up, and I'm glad you solved your problem! This is one of the most common issues users have with POP - unfortunately, setting the initialization files in user_nl_pop overrides initializing from restart files in continuation runs and often crashes with an error message that doesn't help find the actual problem. We had several discussions about possible fixes, but weren't able to settle on a solution before the announcement that MOM6 was going to replace POP as the CESM ocean component... at that point, we needed to shift our focus to the new ocean model.