Fracture of sea ice by ocean surface waves in CESM3

When ocean surface waves are present in ice-covered seas, they can cause sea ice to bend and fracture. Wave-induced fracture of sea ice could play an increasingly important role in the evolution of the Arctic and Antarctic sea ice covers. We present coupled simulations using the development version of the Community Earth System Model (CESM3) that now includes interactions between waves and sea ice, coupled via the sea ice floe size distribution. In particular, we show the influence of a unified sea ice fracture model based on elastic beam theory for the bending of a sea ice plate. This fracture model is valid for all wavelengths and spans the fully flexible and fully rigid limits, unlike previous approaches. Early results suggest that this model improves simulation of sea ice fracture and the floe size distribution, with implications for sea ice feedbacks. Further, we demonstrate a machine-learning-based emulation of the fracture scheme to reduce computational expense.