Move ndep files to CAM section of inputdata

[cacraigucar]

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

ndep was historically under CLM2 in inputdata. Now that CAM is supplying the nitrogen deposition, we agreed that the files should reside under CAM's inputdata.

The previous file was in: atm/cam/chem/trop_strat_mam5_ts4_aero_spinup/ndep (see below for @fvitt comment on correct location)
Also change the namelist defaults file to point to this new location.

@fvitt - please confirm this directory is where the two ndep files should be stored.

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

No response

Will this change (regression test) answers?

No

Will you be implementing this enhancement yourself?

Yes

[fvitt]

My preference is

 inputdata/atm/cam/chem/ndep/

[ekluzek]

Just FYI, I need to have DATM point to the same files that CAM will be using. At least the final cesm3.0 release version should have CAM and DATM point to the same version. Until we get there we might be out of sync, but we'll want the end result to agree.

For DATM I am for example pointing to this file right now:

$DIN_LOC_ROOT/atm/ndep/cmip7/ndep_input4MIPs_surfaceFluxes_CMIP_FZJ-CMIP-nitrogen-1-2_gn_185001-185012-clim_c20251222.nc

which is now out of date, but I'll update DATM to point to what the latest CAM is using.

[ekluzek]

And another FYI, we had it under "CLM"'s space, because it was being read in by CLM, and CLM scientists Keith had created the files by averaging WACCM ensembles together. Now, both the file creation and post processing is done by CAM, as well as the reading done by either CAM or DATM. So this is a process that CAM "owns". Which physically is the best way to look at it as well.

Here's the CTSM issue on how we are transferring to have NDEP sent by the ATM model rather than read by CTSM.

ESCOMP/CTSM#1900

[ekluzek]

Also in my mind this should JUST be done for NEW files. There's no need to copy the old files over to the new location, that will just end up confusing things. I think it would be best to just do this for the new files that are created with spinup simulations. IMHO.