Modelling ocean gravity wave dispersion of young sea ice in the MIZ

The young sea ice that develops in the marginal ice zones (MIZ) of the Polar Seas during the freezing period mainly consists of mixtures of grease-pancake ice and thin ice floes (GPTI). GPTI properties are exceedingly difficult to measure in situ, due to the small floe size, the transient nature of the processes involved and the hostile environment where they take place. As the surface gravity waves coming from the open ocean are affected by GPTI, a tool to infer GPTI properties could rely on waves' measurements. This procedure requires the application of a suitable model of wave propagation in the ice-covered ocean. Viscous wave propagation models have demonstrated their ability to predict the observed spectral wave attenuation in GPTI, although concerns remain about their calibration. The recently developed waves-in-ice model, called close packing model, has had reasonable success, at least in the case of very thin ice, in predicting both the attenuation and the dispersion of the waves as a function of the frequency. However, to apply the CP model to thicker sea ice, such as the one found in the Antarctica oceans, further theoretical efforts are required. With this research, we want to estimate the relative importance and the parametrization of those mechanisms that are not considered in close packing. This is the case of pancakes inertia and wave diffraction.