Interim update of default values

[gold2718]

What is the feature/what would you like to discuss?

There is a call to update default values for CAM.
In order to update default values in CAM, I need atm_in files for all the relevant combinations to be updated:

• N(F)1850 + ne30pg3: n1850.ne30pg3_tn14.noresm3_0_beta18.20260606 noresm3_dev_simulations#447
• N(F)1850esm + ne30pg3
• N(F)HIST + ne30pg3: n1850.ne30pg3_tn14.noresm3_0_beta18.20260606 noresm3_dev_simulations#447
• N(F)HISTesm + ne30pg3
• N(F)1850 + ne16pg3: /cluster/work/projects/nn9560k/kjetisaa/n1850.ne16pg3_tn14.noresm3_0_beta19.Run15.Olivia.2026-06-08
• N(F)1850esm + ne16pg3
• N(F)HIST + ne16pg3: /cluster/work/projects/nn9560k/kjetisaa/n1850.ne16pg3_tn14.noresm3_0_beta19.Run15.Olivia.2026-06-08
• N(F)HISTesm + ne16pg3

Please add pointers and/or experiment numbers for each of these cases. For now at least, one atm_in file may be applied to more than one of the above configurations. In particular, Files for 1850 and HIST should have the same tunings but may have different initial condition and forcing files.

Is there anyone in particular you want to be part of this conversation?

@oyvindseland
@DirkOlivie

Will this change (regression test) answers?

Yes

Will you be implementing this enhancement yourself?

Yes

[oyvindseland]

Are there any beta19 simulations that can be used.

NorESMhub/noresm3_dev_simulations#449 ?
It is historical so not quite the same, but non-forcing number may be used?

Any n1850 simulations @Ovewh ? @DirkOlivie

[oyvindseland]

In the process of creating an issue testing N1850 with beta19 but as for now I will just add the case path on Betzy here
/cluster/work/users/oyvinds/noresm3/n1850.ne16pg3_tn14.noresm3_0_beta19.setdefnml.2026-06-11

[gold2718]

Note that I have some deviations:
ncdata: The values in the case files are from interim restarts. I do not think these are intended to be final initial data files yet
bndtvg: This is only used for GHG chemistry so it does not need to be set
use_aerocom: Is this really supposed to be .false.? I'm leaving it .true. for now.

[oyvindseland]

I think use_aerocom should be false for the default set-up but we should set-up the two use_cases already in this tag. One default and one which is basically use_aerocom=true It will be more fields defined in the final set-up anyway.

[gold2718]

I think use_aerocom should be false for the default set-up but we should set-up the two use_cases already in this tag. One default and one which is basically use_aerocom=true It will be more fields defined in the final set-up anyway.

Which two use cases are these?

[gold2718]

I also do not plan to change the tracer_cnst_file since the one used in NorESMhub/noresm3_dev_simulations#447 is from beta18 and we are using an updated (2026) file now.

[oyvindseland]

I think use_aerocom should be false for the default set-up but we should set-up the two use_cases already in this tag. One default and one which is basically use_aerocom=true It will be more fields defined in the final set-up anyway.

Which two use cases are these?

It was pointing to categories 2 and 4 of the use cases in the list: Base - Aerosol - HiFreq - Aerosol+ HiFreq, but perhaps it is better to connect it to noresm_to_cmip7_aerosol.yaml If this file is used to create fincl then use_aerocom=.true.

[gold2718]

It was pointing to categories 2 and 4 of the use cases in the list: Base - Aerosol - HiFreq - Aerosol+ HiFreq, but perhaps it is better to connect it to noresm_to_cmip7_aerosol.yaml If this file is used to create fincl then use_aerocom=.true.

Aha! What I can do is have the script check to see if any aerocom variables are in a use case and set use_aerocom = .true. in those files.

[oyvindseland]

Sounds good, If we end up with aerocom in all use cases we need to go back to see if aerocom should be divided into more categories to save throughput time for long simulations. It will also save some storage space but throughput is most critical.