Discrete element simulations of sea ice dynamics in the Nares Strait

Data-driven particle methods can provide detailed descriptions of sea ice dynamics that explicitly model fracture and discontinuities in the ice, which are difficult to capture with typical continuum approaches. We use the ParticLS software library to develop discrete element method (DEM) simulations of sea ice in the Nares Strait between Ellesmere Island and Greenland that are initialized from and driven by observed data. We model the sea ice as a collection of discrete rigid particles that are initially bonded together into floes. Ice fracture and lead formation are determined based on the local stress state around each particle. This allows us to model the ice as a continuous material while at the same time allowing it to fracture into smaller pieces that can then interact with each other as discrete bodies. In addition to modeling the dynamic sea ice patterns in the Nares Strait (arching, lead formation), our model provides a natural way to combine numerical simulations with observations. We generate realistic particle configurations by discretizing the ice extent in MODIS satellite imagery into polygonal floes, and then force the particles with wind and ocean data. We also investigate methods for validating regional-scale simulations, by quantitatively comparing model outputs to remote sensing measurements of the ice, which provides a rigorous approach for determining how well the model captures the dynamics observed in nature.