Abstract

I will summarise progress towards modelling wave overwash of ice floes, which (after breakup) is arguably the most important nonlinear phenomenon in wave–ice interactions, and certainly the most striking one. The phenomenon is unique to wave–ice interactions, occurring because the small freeboards of ice floes allow waves with relatively modest (non-extreme) amplitudes to wash over their upper surfaces when differential motion between the floe and the surrounding wave field exists. Overwash impacts floes thermodynamically, and dissipates wave energy, thus reducing the distances waves penetrate into the ice-covered ocean. From a mathematical modelling perspective, it is a highly nonlinear phenomenon, meaning it cannot be captured by standard perturbation techniques. I will present a bespoke overwash model, along with supporting laboratory experiments and numerical CFD simulations. Applying the methodology to simplified versions of the problem will be shown to provide insights into model performance. 

Co-authors: David Skene (Uni Adelaide); Michael Meylan (Uni Newcastle); Alessandro Toffoli (Uni Melbourne); Filippo Nelli (Swinburne Uni Tech); Kevin Maki (Uni Michigan)