Assessment of a porous viscoelastic model for wave attenuation in ice-covered seas

TL;DR

This paper evaluates a porous viscoelastic model for wave attenuation in ice-covered seas by comparing theoretical predictions with laboratory and field data, highlighting its effectiveness and parameter sensitivities.

Contribution

It provides a comprehensive assessment of a two-layer porous viscoelastic model against experimental and observational data, including parameter estimation and sensitivity analysis.

Findings

Model reasonably reproduces Arctic wave attenuation features.

Estimated rheological parameters vary among models but are consistent within orders of magnitude.

Sensitivity analysis identifies key parameters influencing wave attenuation.

Abstract

Chen et al. (Eur. J. Mech. B/Fluids 78, pp. 88-105, 2019) recently proposed a two-dimensional continuum model for linear gravity waves propagating in ice-covered seas. It is based on a two-layer formulation where the ice cover is viewed as a porous viscoelastic medium. In the present paper, extensive tests against both laboratory experiments and field observations are performed to assess this model's ability at describing wave attenuation in various types of sea ice. The theoretical predictions are fitted to data on attenuation rate via error minimization and numerical solution of the corresponding dispersion relation. Detailed comparison with other existing viscoelastic theories is also presented. Estimates for effective rheological parameters such as shear modulus and kinematic viscosity are obtained from the fits and are found to vary significantly among the models. For this poroelastic system, the range of estimated values turns out to be relatively narrow in orders of magnitude over all the cases considered. Against field measurements from the Arctic Ocean, this model is able to reasonably reproduce the roll-over of attenuation rate as a function of frequency. Given the rather large number of physical parameters in such a formulation, a sensitivity analysis is also conducted to gauge the relevance of a representative set of them to the attenuation process.