Create new land only initial conditions (ongoing)

[wwieder]

As we move to CTSM5.2 datasets and introduce CLM6_0 physics options, it seems like it would also be helpful to provide new initial conditions files. @dlawrenncar noted, this may be most important for coupled model simulations, so we can provide more realistic land states in F and B cases as we move forward with CESM3 development runs.

Given very high productivity biases in CRU-JRA forced runs, I'd suggest we provide 1850 initial conditions forced with GSWP3 using CTSM5.2 surface data. It may be most straight forward to do this after #2348 comes to main?

Looking through the LMWG-Dev issues, I don't think we have a GSWP3 forced run that's similar to this case, #54, do we @olyson? If not, we can create a new issue on LWMG-Dev for this.

We should make sure that isotopes (e.g. see #3311), tillage, and residue removal are all on for these spin ups.

Definition of done:

• Decide on which LND_TUNING_MODES will have initial conditions (clm5_0_GSWP3, clm6_0_CRUJRA, clm5_0_cam6, clm6_0_cam7?)
• Which resolutions will be run? ne30pg3, f09, f19, f45? What about NEON sites?
• Run all the configurations needed
• Preliminary finidat file in place for clm5_1/clm6_0 all forcing options: lnd/clm2/initdata_esmf/ctsm5.2/clmi.I1850Clm60BgcCrop-ciso.1361-01-01.ne30pg3_mg17_c240317.nc
• Put files in place and in XML and into a tag

[ekluzek]

Since, this requires CTSM5.2 it actually should wait for #2372. If we need it sooner it could be added to CESM3_dev. But, I'd like to avoid that if we can. This was also on the CTSM5.2 board as a post-5.2 activity, so I'm linking this there.

Also this relates to #554, so linking it here.

[olyson]

@wwieder and I discussed this and thought that we could just clone the most recent deadveg branch simulation and switch from CRUJRA to GSWP3. In that recent simulation, tillage and residue removal was on. And I have been using CTSM5.2 surface datasets, i.e., for that run I used

/glade/campaign/cesm/cesmdata/cseg/inputdata/lnd/clm2/surfdata_esmf/ctsm5.2.0/surfdata_0.9x1.25_hist_78pfts_CMIP6_1850_c230517.nc

I know that @slevis-lmwg has recently re-generated all of the datasets, so I was planning to use that version which appears to be:

/glade/campaign/cesm/cesmdata/cseg/inputdata/lnd/clm2/surfdata_esmf/ctsm5.2.0/surfdata_0.9x1.25_hist_1850_78pfts_c240216.nc

Is there another reason to wait for #2372 ?

[ekluzek]

Nope that makes perfect sense @olyson. Better to not have to wait when you don't have to.

[olyson]

See NCAR/LMWG_dev#57

[olyson]

I initially set this up as an f09 (1deg) simulation, but I think it should actually be an ne30 since we'll use it as initial conditions for the ne30 F- and B-cases coming up. I don't think the finidat interpolation will handle going from 1deg to ne30. Is that a correct assumption @ekluzek and @billsacks ?

[ekluzek]

@olyson it should be fine to interpolate from f09 to ne30np4.pg3 grid. The interpolation is just nearest neighbor so it will work between any type of grid.

But, I agree that we should spinup the land with the workhorse ne30 grid rather than f09. We'll interpolate to f09 from it for the land only simulations.

[billsacks]

I agree with @ekluzek .

[olyson]

Here is an ne30 spunup initial file for 1850 with configuration as noted above:

/glade/campaign/cgd/tss/people/oleson/CLM5_restarts/ctsm51_ctsm51d166deadveg_ne30pg3ne30pg3mg17_GSWP3V1_ABsnoCDE_blk_A5BCD_1850pAD.clm2.r.1361-01-01-00000.nc

[wwieder]

Thanks @olyson should this be the default finidat file we point to for simulations with 'modern' tags? Here I'm especially thinking about the CESM alpha (or beta) 17 tag that's upcoming?

[olyson]

Yes, I think it will be suitable for the upcoming CESM tags.