Interactions between irregular wave fields and sea ice: A physical model for wave attenuation and ice breakup in an ice tank

TL;DR

This study uses physical modeling in an ice tank to investigate how irregular waves interact with sea ice, affecting wave attenuation and ice breakup, with findings relevant to real-world ocean-ice dynamics.

Contribution

It introduces a physical model experiment to analyze wave-ice interactions, including wave attenuation and ice breakup, with empirical attenuation coefficients comparable to field data.

Findings

Wave spectrum evolves with distance into ice cover.

Empirical attenuation coefficient follows a power-law dependence on frequency.

Wave properties influence ice breakup and floe size distribution.

Abstract

Irregular, unidirectional surface water waves incident on model ice in an ice tank are used as a physical model of ocean surface wave interactions with sea ice. Results are given for an experiment consisting of three tests, starting with a continuous ice cover and in which the incident wave steepness increases between tests. The incident waves range from causing no breakup of the ice cover to breakup of the full length of ice cover. Temporal evolution of the ice edge, breaking front and mean floe sizes are reported. Floe size distributions in the different tests are analysed. The evolution of the wave spectrum with distance into the ice-covered water is analysed in terms of changes of energy content, mean wave period and spectral bandwidth relative to their incident counterparts, and pronounced differences are found between the tests. Further, an empirical attenuation coefficient is derived from the measurements and shown to have a power-law dependence on frequency comparable to that found in field measurements. Links between wave properties and ice breakup are discussed.