The latest generation of Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) has improved owing to a combination of increased model resolution and more advanced parameterization of unresolved physical processes, such as those for convection, cloud microphysics, or surface processes. More advanced models may not be synonymous with reduced uncertainty; increasing complexity may be associated with increased uncertainty in model parameters or structural choices. It is crucial that methodologies are developed for systematically improving models to ensure the reliability of climate projections and refinement of climate sensitivity estimates. In this session, we welcome presentations on advances in developing and calibrating models using observations (e.g. satellite, airborne, or ground-based) and/or high-resolution model simulations. Presentations that focus on ESM parameter estimation, autotuning, and emulator/surrogate based tuning, as well as methods that directly address structural errors in models (e.g., using machine learning) or observational uncertainties are welcomed.

• AMS: American Meteorological Society -