2025 CTSM PPE Meeting Notes

February 13, 2025

Agenda: Update on the history matching process for calibrating CLM6. Slides are here

Announcements:

Land Model and Biogeochemistry Working Group winter meeting is happening February 24-26, agenda is online
Calibrated Land Model Intercomparison Project (CalLMIP) is happening March-April 2025

Notes:

Discussed selection of which parameters to vary by PFT, see column F in this spreadsheet
Discussed overall history matching strategy: i.e. waves, sample selection
Redesigning biomes for Wave 2 to select only a few (3-4) PFTs coexisting in each biome
- Adrianna has seen something similar work in FATES-SP mode with a "dominant PFT grid"
- Still have the 400 gridcells from the sparse grid and need to check representativeness
- Daniel: Treating biomes as equally important vs. weighting by GPP, for example?
- One way to split up high carbon area would be by continent (had previously explored this biome definition)
One benefit of the PPE/calibration work is that we highlight model structural and infrastructural deficits
Will: What if we stop at Wave 1? Results look pretty good. What can we learn in Wave 2?
- Linnia: we will try to calibrate based on Wave 1 PFT-based LAI, perhaps with other metrics
- In general, trying to apply spatially targeted constraints and add parameter sets to "good" part of parameter space
Spread across ET products means that it's not a useful constraint. Perhaps use latent heat or evaporative fraction?
- Junjie: Even LH products are still model generated. For ET - suggest Ecostress product (not global though, 50S-50N)