A model for waves-in-ice and sea ice dynamics in the marginal ice zone

Abstract

Wavescan drastically transform the properties and behavior of the ice cover in a very short time. Consequently, they potentially represent a severe threat for personnel and make offshore operations challenging (for example during platform evacuation) if not anticipated. Waves-in-ice and floe sizes also have implications for the design of marine structures and coastal management. Forecasting waves and their effects on sea ice thus becomes very important for risk assessment, safety and preparedness in the MIZ. In this paper, we present a strategy for including waves-in-ice processes in a sea ice model for a coherent description of the marginal ice zone dynamics. Open ocean wave forecasts are used to provide boundary conditions. Waves are then propagated and attenuated as they travel in sea ice with an attenuation coefficient that is computed by a wave scattering model. A floe breaking parameterization and a renormalization group method are used to provide information about the floe size distribution. Finally, the link between waves-in-ice and dynamics is done through the implementation of a floe size-dependent theology. Preliminary results are obtained from a high-resolution regional model of the Fram Strait, showing that floe size can be used as to discriminate the dynamical regimes. This model is designed to give access tothe waves-in-ice energy spectrum and information about the floe size distribution asprognostic outputs. Copyright 2011, Offshore Technology Conference.