Sandbox needed for WIE-MIP simulations

[wwieder]

Given the tight timeline requested for WIE-MIP simulation (July 2026) I thought it would be help to track details of the model setup we'll need. This may end up being the parent issue that references other tasks that are needed. It also could end up being it's own project board. The project is basically set up like TRENDY (with constant land use)+ future scenarios:

1. Spinup (1850 land use, CO2 & NDEP)
2. Idealized experiments to diagnose TCRE

• Control (extend spinup)
• BGC (1% CO2 for BGC + control climate)
• COU (fully coupled 1% CO2 for BGC & Climate) *uses 3 DATM variants
• RAD (optional)
  2b. Ongoing discussion in WIEMIP about turning off features (e.g. N or fire), retuning?, and repeating spinup and 1% experiments

3. HIST? (constant land use)
4. Scenario MIP extensions (2025-2300)

• 4 scenarios * 3 DATM variants

---

Here's an on going list for what we may need:

• Branch tag: We'll want Sean's hillslope hydrology / methane branch brought up to the current master tag see Setup wetlands branch on ESCOMP #3906
• Surface Dataset, see WIE-MIP surface data needs #3912
• DATM: Supplied by WIE-MIP, which has both 0.5 degree and 1.0 degree options with 6 hr resolution
  • Check that we're using direct and diffuse DATM
• Aerosols, NDEP, population density, these can be 1850, although WIE-MIP has it's own NDEP data?
  • where are we supposed to get aerosol data from?
  • what NDEP data is proposed for 1% CO2.
• CO2, need 1% CO2 data for idealized simulations & scenarioMIP data for future scenarios
• Parameter file, ideally using the latest from CLM6, but may need CH4 tunings and others from @swensosc?
  • Testing this in the 'flat' case in LMWG_dev#156
  • Need to calibrate for hillslope?
• User Mods to set this all up, including history fields and frequency being requested
• Post processing scripts to generate single variable time series, convert units, rename variables per TRENDY & regrid to regular 1 degree dataset

Lot's of people have experience here or can help
@adrifoster, @swensosc, @lawrencepj1, @linniahawkins, @dlawrenncar, @ekluzek, @slevis-lmwg, @olyson

[swensosc]

user_nl_clm:

! hillslope and vegetation data
hillslope_file = '/glade/derecho/scratch/swensosc/WIEMIP/hillslope_geo_params_trapezoid_worldcover_0.9x1.25_Global_FAB.nc'

use_hillslope = .true.
use_hillslope_routing = .true.

! with bgc active
finundation_method = 'h2osfc'

hillslope_fsat_equals_zero = .true.

n_dom_pfts = 2

[swensosc]

branch, updated to escomp/master

https://github.com/swensosc/ctsm/tree/wetland_update

[ekluzek]

@swensosc is your wetland_update branch something that could come into master soonish? Or is it something that shouldn't be part of cesm3.0? From looking at it -- it's not enormous, but not trivial. But, if it shouldn't come to master It would be best to make it an official branch on escomp that we support for this work as well as yours. And then bring it in post ctsm6.0.000.

We'll want to at least have branch tags for the WIE-MIP work, and we will likely want to have it based off a fixed version at some point. So having it as an official branch might make the most sense.

[wwieder]

This should likely be a supported branch, but maybe could come to master? Depends how much Sean's PR will change answers. @wwieder can compare a 5.4.024 case vs. 5.4.024_wetland PR to see how much this changes answers and assess results for merging to master.