How a region of cracked sea ice affects ice-coupled wave propagation
How a region of cracked sea ice affects ice-coupled wave propagation
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DOI：
10.3189/172756401781818806
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发表时间：
2001
影响因子：
2.9
通讯作者：
V. Squire;T. Dixon
中科院分区：
文献类型：
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作者：
V. Squire;T. Dixon
摘要通过推导适当的格林函数，建立了一个模型，该模型允许对正常入射冰耦合波与任意数量裂缝的相互作用进行解析研究。对于单个裂缝，反射和透射系数R和T的简单公式出现了，它与Barrett和Squire（1996）的计算密集型工作产生相同的结果，但更容易应用。发现裂纹的行为就像一个陡峭的低通滤波器，允许长波通过，同时抑制短波，尽管响应曲线也有一些精细的结构。引入更多的裂缝是直截了当的。虽然在这种情况下，R和T的公式原则上也是可能的，但更容易将结果表示为2N阶的简单矩阵方程的解，其中N是裂纹的数量。发现完美传输（|R| = 0）发生在一组离散周期，以下称为梳状，对于N | 1，梳状随着周期的减小而变得更细。对于周期性分布的裂缝和随机分布的裂缝，响应曲线的总体形状是相似的。结果表明，通过北极盆地传播的波不太可能被用作确定平均冰厚的遥感媒介。本文中使用的格林函数技术为其他感兴趣的问题提供了解决方案。
Abstract By deriving the appropriate Green’s function, a model is developed that allows the interaction of normally-incident, ice-coupled waves with any number of cracks to be studied analytically. For a single crack a simple formula for the reflection and transmission coefficients, R and T, emerges that yields identical results to the computationally intensive work of Barrett and Squire (1996) but is much easier to apply. A crack is found to behave as a steep low-pass filter, allowing long waves through while inhibiting shorter waves, although there is also some fine structure to the response curve. The introduction of more cracks is straightforward. While in that case a formula for R and T is also possible in principle, it is easier to express the result as the solution of a simple matrix equation of order 2N, where N is the number of cracks. It is found that perfect transmission (|R| = 0) occurs at a set of discrete periods, hereinafter called a comb, for N > 1 and that the comb becomes finer as period decreases. For both periodically distributed cracks and ones that are randomly spaced, the gross shape of the response curve remains similar. The results suggest that it is improbable that waves travelling through the Arctic basin can be used as a remote-sensing agent to determine mean ice thickness. The Green’s function technique employed in this paper furnishes solutions to other problems of interest.