Multi-variable Hard Physical Constraints for Climate Model Downscaling
This addresses the need for accurate local-scale climate projections by ensuring physical consistency across variables, which is crucial for climate scientists and policymakers, though it appears incremental as it builds on existing downscaling methods.
The study tackled the problem of statistical downscaling in climate models, where independent downscaling of variables leads to physical inconsistencies, and introduced a framework with multi-variable hard constraints to ensure physical relationships, demonstrated through an application on temperature.
Global Climate Models (GCMs) are the primary tool to simulate climate evolution and assess the impacts of climate change. However, they often operate at a coarse spatial resolution that limits their accuracy in reproducing local-scale phenomena. Statistical downscaling methods leveraging deep learning offer a solution to this problem by approximating local-scale climate fields from coarse variables, thus enabling regional GCM projections. Typically, climate fields of different variables of interest are downscaled independently, resulting in violations of fundamental physical properties across interconnected variables. This study investigates the scope of this problem and, through an application on temperature, lays the foundation for a framework introducing multi-variable hard constraints that guarantees physical relationships between groups of downscaled climate variables.