Modeling Sea Ice Fracture in a Discrete Element Framework with a Cohesive Contact Model

As sea ice deforms it can fracture and create what are called leads. The opening of leads exposes ocean water to the atmosphere, providing an opportunity for ocean-atmosphere energy exchange. When thermodynamic conditions are right, the water in a lead can refreeze and when compressed ice can create a pressure ridge. These processes while difficult to describe are important components of sea ice models and Earth System Models (ESM). In this work we present a new sea ice failure model in our discrete element framework for the prediction of lead development. Inspired by flat joint models in Discrete Element Methods (DEM) and cohesive zone models, the model includes a pressure-dependent mixed-mode bi-linear cohesive law with damage initiation defined by a Mohr-Coulomb model. The model is implemented in the Discrete Element Model of Sea Ice (DEMSI) code that is being developed by Los Alamos and Sandia National Labs. Model predictions are compared against available compressive and flexural lab-scale experimental data. Regional scale sea ice dynamic simulations are presented, and lead predication is compared against available satellite imagery.