Part II: An initial evaluation of the QuSI-DEM Discrete Element model using idealized and realistic test cases for sea ice

Abstract. Sea ice is a quasi-brittle material that cracks, deforms, and flows under the load of wind and ocean currents. In part I we introduced QuSI-DEM, a model designed to capture crack patterns that develop as a result of sea ice fracture that depend critically on the elastic and dissipative response of the material at the location of failure. Parameters were introduced to the contact physics in QuSI-DEM to provide control of the failure rate and timing of transitions in contact response and to constrain the amount of energy and momentum transfer as elements interact. The sensitivity of the model response to these parameters is first demonstrated here in a set of idealized experiments involving the interactions of a few elements. The model is then applied to realistic simulations of sea ice response to northerly wind stress in the southern Chukchi Sea and Bering Strait. Here again, the parameter space is explored along with sensitivity to element size and arrangement through sets of ensemble simulations to explore the phenomenology of ice arching. Post-failure parameters such as the strength of the sea ice at the transition from bonded to frictional sliding, and the residual sea ice strength for heavily impacted ice are found to significantly impact model response.