Georgy Manucharyan, Brandon Montemuro 

Sea ice dynamics exhibit granular behavior as individual floes and fracture networks become particularly evident at length scales O(10--100) km and smaller. However, climate models do not resolve floes and represent sea ice as a continuum, while existing floe-scale sea ice models tend to oversimplify floes using discrete elements of predefined simple shapes. The idealized nature of climate and discrete element sea ice models presents a challenge of comparing the model output with floe-scale sea ice observations. Here we present SubZero, a conceptually new sea ice model geared to explicitly simulate the life cycles of individual floes by using complex discrete elements with time-evolving shapes. This unique model uses parameterizations of floe-scale processes, such as collisions, fractures, ridging, and welding, to simulate a wide range of evolving floe shapes and sizes. We demonstrate the novel capabilities of the SubZero model in idealized experiments, including uniaxial compression, the summer-time sea ice flow through the Nares Strait, and winter-time sea ice growth. The model naturally reproduces the statistical behavior of the observed sea ice, such as the power-law appearance of the floe size distribution and the long-tailed ice thickness distribution. The SubZero model could provide a valuable alternative to existing discrete element and continuous sea ice models for simulations of floe interactions.