An investigation into the dispersion of ocean surface waves in sea ice

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• 作者：Clarence Olin Collins III ; William Erick Rogers ; Björn Lund
• 关键词：Dispersion ; Ocean surface waves ; Sea ice ; Marginal ice zone ; Attenuation ; Flexural ; gravity waves ; Snell’s law ; Wavelength ; Viscosity ; Shear modulus ; Elastic modulus ; SAR ; Marine radar ; Buoy measurements
• 刊名：Ocean Dynamics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：67
• 期：2
• 页码：263-280
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Oceanography; Geophysics/Geodesy; Atmospheric Sciences; Fluid- and Aerodynamics; Monitoring/Environmental Analysis;
• 出版者：Springer Berlin Heidelberg
• ISSN：1616-7228
• 卷排序：67

文摘

This investigation considers theoretical models and empirical studies related to the dispersion of ocean surface gravity waves propagating in ice covered seas. In theory, wave dispersion is related to the mechanical nature of the ice. The change of normalized wavenumber is shown for four different dispersion models: the mass-loading model, an elastic plate model, an elastic plate model extended to include dissipation, and a viscous-layer model. For each dispersion model, model parameters are varied showing the dependence of deviation from open water dispersion on ice thickness, elasticity, and viscosity. In all cases, the deviation of wavenumber from the open water relation is more pronounced for higher frequencies. The effect of mass loading, a component of all dispersion models, tends to shorten the wavelength. The Voigt model of dissipation in an elastic plate model does not change the wavelength. Elasticity in the elastic plate model and viscosity in the viscous-layer model tend to increase the wavelength. The net effect, lengthening or shortening, is a function of the particular combination of ice parameters and wave frequency. Empirical results were compiled and interpreted in the context of these theoretical models of dispersion. A synopsis of previous measurements is as follows: observations in a loose pancake ice in the marginal ice zone, often, though not always, showed shortened wavelengths. Both lengthening and shortening have been observed in compact pancakes and pancakes in brash ice. Quantitative matches to the flexural-gravity model have been found in Arctic interior pack ice and sheets of fast ice.