Preliminary results from a two-dimensional model of wave-ice interactions in the Fram Strait

Abstract

We present numerical results arising from a parameterization of wave-ice interactions in a two-dimensional ice-ocean model of the Fram Strait (HYCOM: HYbrid Coordinate Ocean Model). The model takes wave predictions/hindcasts from the WAM wave model and these waves are advected into the ice, breaking it as they go. They in turn are attenuated by the ice using the model of Bennetts and Squire (2012). We use a truncated power law for the floe size distribution, following the observations of Toyota et al. (2011). The maximum floe size is determined by the dominant wavelength in the ice field. The maximum value increases with distance from the ice edge as shorter waves are attenuated more strongly than long ones. At some distance from the ice edge, breaking is no longer able to occur, and this marks the end of the Marginal Ice Zone (MIZ). Consequently, we now have a model that predicts the expected floe size and wave intensity at any point in the ice, something that current wave models are unable to do at present, and which is a notable weakness. Recognizing that a combination of large waves and ice can be extremely hazardous, Arctic operators who need to know both wave and ice conditions in ice-infested areas will use the model as a forecasting tool when it is fully operational.