High-resolution sea ice dynamics modeling using the discrete element method

Abstract:

As sea ice model grid resolution moves to shorter length scales, we enter a scale regime where the continuum assumption breaks down and is no longer mechanically equivalent to the physical system. We present a sea ice dynamics model based on the discrete element method (DEM), as an alternative numerical framework for high-resolution modeling of sea ice dynamics. The CRREL Sea Ice DEM model treats the ice pack and floes as a collection of ice “grains” to describe the sea ice as a system where the effects of element-to-element interaction significantly influence the mechanical behavior of the bulk material. Our modeling approach has been successfully applied to model sea ice processes such as pressure ridging (Hopkins 1998), aggregation due to wave-ice interaction (Hopkins & Shen 2001), and the mesoscale evolution of the floe size distribution (Hopkins & Thorndike 2006). These ice elements have sufficiently small length scales to capture meter scale heterogeneity of the ice pack, which may govern the bulk behavior at the scale of interest (10-1000 km scale). We will present simulations of ice motion for the Beaufort Sea for the summer 2014 that are initialized and validated from high-resolution synthetic aperture radar acquired from the RADARSAT-2 and TerraSAR-X (200 to 1 m pixel resolution, respectively) satellite platforms to evaluate the ability of a DEM sea ice model to provide accurate forecasts of the ice pack evolution.