Wave Propagation under Ice Covers

• Main Author: Zhao, Xin
• Format: Thesis
• Language: English
• Published: Clarkson University 2014
• Subjects: Geophysics|Civil engineering|Ocean engineering; Pancake; Ice Sheet; Sea ice
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=3667183

The operational ocean wave model needs a sea ice component to simulate the global ocean waves. Current ocean wave models treat ice covered regions crudely. The purpose of this thesis is to provide a unified continuum model for the wave ice interaction. Sea ice is constantly subject to environmental forcing. As a result, its physical appearance and mechanical properties vary dynamically. There are three existing classic wave ice interaction models: viscous layer, mass loading, and thin elastic plate models. Viscous layer models may be used to simulate grease ice, mass loading model is probably suitable for pancake ice, and thin elastic plate model may be used to describe a continuous ice sheet floating in water. This situation means that for different kind of sea ice we need different wave ice interaction models. Recently, a proposed viscoelastic wave ice interaction model synthesized the three classic models into one model. Under suitable limiting conditions this model converges to the three previous models. Based on this new development, the present study expands the viscoelastic model for wave propagation through two connected ice covered ocean regions. By doing so, the complete theoretical framework for evaluating wave propagation through various ice covers may be implemented in the operational ocean wave models. In this thesis, we introduce a three-layer viscoelastic model to include the eddy viscosity in turbulent boundary layer under the ice cover into previous viscoelastic model and the methods to calculate wave reflection and transmission. We also use recent results of a laboratory study to determine the viscoelstic model parameters with an inverse method. The thesis concludes with a numerical procedure for implementing the viscoelastic dispersion relation into the ocean wave model and some ideas of model parameterization.