A high-resolution discrete element sea ice model for simulating sea ice dynamics

This work developed a high-resolution discrete element sea ice model for simulating sea ice dynamics in the arctic area. In this method, sea ice is treated as a collection of sea ice floes with power-law floe size distribution. Through resolving interactions between two floes in contact, the deformation and flow of regional or global sea ice under driving forces can be obtained. The local floe/particle interaction is modeled by bonded contact models for frozen joint and unbonded contact models for granular floes without bond. A simplified bond model accounting for normal, tangential and rolling interactions is proposed based on the laboratory mechanical tests. The unbonded Hopkins contact model is employed to simulate interactions between unbonded floes, where a riding model is proposed for updating the variation of thickness distribution of floes. The feedback of ridging to sea ice dynamic deformation is achieved through updating the sea ice strength and related plastic hardening parameters using contact thickness. Preliminarily, the proposed sea ice model is validated through a series of uniaxial and biaxial tests, where the sea ice failure criteria can be obtained by plotting the peak shear strength and corresponding normal stress. The sea ice failure criteria obtained from numerical results agree with the failure criteria observed by satellite data well. Then, the initiation and propagation mechanism and mechanical behaviors of sea ice are investigated by the proposed discrete element sea ice model.