A floe size dependent scattering model in two- and three-dimensions for wave attenuation by ice floes

Abstract Two- and three-dimensional models are proposed for ocean-wave attenuation due to scattering by ice floes in the marginal ice zone, in which the attenuation rate depends on the horizontal size of the individual floes. The scattering models are shown to reproduce the behaviour of wave attenuation over short wave periods. However, it is shown that scattering alone cannot explain the observed asymptotic dependence of attenuation at long wave periods. Based on these findings, it is proposed that attenuation models consist of a scattering component supplemented by an empirical damping term based on measurements, so that attenuation over all periods is correctly modelled. Computer code to calculate wave attenuation through a field of ice floes is provided in the supplementary material.