# Modelling wave-induced sea ice breakup in the marginal ice zone

## TL;DR

This paper presents a coupled wave scattering and flexural failure model to simulate how ocean waves induce ice floe breakup, revealing how wave characteristics and ice properties influence floe size distribution evolution in the marginal ice zone.

## Contribution

It introduces a novel coupled model combining wave scattering and fracture mechanics to study ice floe breakup dynamics under wave forcing.

## Key findings

- Multiple scattering enhances breakup for long waves and thin ice.
- Short waves and thick ice experience reduced breakup due to wave attenuation.
- A forward-moving breakup front weakens ice cover, allowing deeper wave penetration.

## Abstract

A model of ice floe breakup under ocean wave forcing in the marginal ice zone (MIZ) is proposed to investigate how floe size distribution (FSD) evolves under repeated wave breakup events. A three-dimensional linear model of ocean wave scattering by a finite array of compliant circular ice floes is coupled to a flexural failure model, which breaks a floe into two floes provided the two-dimensional stress field satisfies a breakup criterion. A closed-feedback loop algorithm is devised, which (i)~solves wave scattering problem for a given FSD under time-harmonic plane wave forcing, (ii)~computes the stress field in all the floes, (iii)~fractures the floes satisfying the breakup criterion and (iv)~generates an updated FSD, initialising the geometry for the next iteration of the loop.The FSD after 50 breakup events is uni-modal and near normal, or bi-modal. Multiple scattering is found to enhance breakup for long waves and thin ice, but to reduce breakup for short waves and thick ice. A breakup front marches forward in the latter regime, as wave-induced fracture weakens the ice cover allowing waves to travel deeper into the MIZ.