CESM 2.0.0: ERROR No default value found for ncdata when using BHIST+

[abhirami.m]

What version of the code are you using?​

I am using CESM 2.0.0.

The case I am trying to create/use is:

BHIST+fo2_g17
I understand that BHIST+fo2_g17 is an unsupported compset combination, and I am testing this combination intentionally.

Have you made any changes to files in the source tree?​

No changes have been made to the CESM source tree.

Describe every step you took leading up to the problem​

I created a case using the BHIST+fo2_g17 compset.
./create_newcase --case --compset BHIST --res f02_g17
After attempting to create/configure the case, I received the following error:

ERROR: No default value found for ncdata
The CESM version is:

CESM 2.0.0
I then checked the CESM input-data repository and confirmed that the relevant NetCDF input data appears to be present in the repository.

This makes me unsure whether the error is caused by the input data actually being missing, or whether CESM is unable to determine the appropriate ncdata value for this particular unsupported compset.

Log files​

The relevant error is:

ERROR: No default value found for ncdata
I can provide the complete error output and relevant log files if needed.

Describe your problem or question​

I am trying to understand why CESM 2.0.0 reports:

ERROR: No default value found for ncdata
when I use the unsupported BHIST+fo2_g17 compset combination.

I checked the CESM input-data repository and found that the relevant NetCDF input data is present.

Could someone please clarify:

1. What exactly does "No default value found for ncdata" mean in CESM 2.0.0?
2. Is this error expected because BHIST+fo2_g17 is an unsupported compset combination?
3. If the required input data is already present in the CESM input-data repository, how can I determine which ncdata value CESM is expecting?

I would appreciate any guidance on how to trace where the missing ncdata default is coming from and whether this unsupported compset can be configured manually.

 

[hplin]

Thanks for writing. No default value found for ncdata means that namelist_defaults_cam.xml (where the defaults for each namelist option may be specified based on the combination of compset/grid/physics options/...) has no match for your particular compset+grid combination, which you mentioned, is unsupported.

If the required input data is already present, then you can add to user_nl_cam

ncdata = '/path/to/the/inputfile/you/want/to/use/here'