The floe size distribution (FSD) is an important characteristics of sea ice, influencing several physical processes that take place in the oceanic and atmospheric boundary layers under/over sea ice, as well as within sea ice itself. Through complex feedback loops involving those processes, FSD might modify the short-term and seasonal evolution of the sea ice cover, and therefore significant effort is undertaken by the scientific community to better understand FSD-related effects and to include them in sea ice models. An important part of that effort is analyzing the FSD properties and variability in different ice and forcing conditions, based on airborne and satellite imagery. In this work we analyze a very high resolution (pixel size: 0.3 m) satellite image of sea ice from a location off the East Antarctic coast (65.6°S, 101.9°E), acquired on 16. Feb. 2019. Contrary to most previous studies, the ice floes in the image have angular, polygonal shapes and a narrow size distribution. We show that the observed FSD can be represented as a weighted sum of two probability distributions, a Gaussian and a tapered power law, with the Gaussian part clearly dominating in the size range of floes that contribute over 90% to the total sea ice surface area. Based on an analysis of the weather, wave and ice conditions in the period preceding the day in question, we describe the most probable scenario that led to the breakup of landfast ice into floes visible in the image. Finally, theoretical arguments backed up by a series of numerical simulations of wave propagation in sea ice performed with a scattering model based on the the Matched Eigenfunction Expansion Method, are used to show that the observed dominating floe size in the three different regions of the image (18 m, 13 m and 51 m, respectively) agree with those expected as a result of wave-induced breaking of landfast ice.

中文翻译：

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被海浪打破的海浮冰的大小和形状-以南极东部海岸为例

絮凝物粒度分布（FSD）是海冰的重要特征，它影响着在海冰下面/上方以及在海冰自身内部的海洋和大气边界层中发生的几个物理过程。通过涉及这些过程的复杂反馈回路，FSD可能会修改海冰覆盖层的短期和季节性变化，因此科学界做出了巨大的努力，以更好地了解与FSD相关的影响并将其纳入海冰模型中。这项工作的重要组成部分是根据机载和卫星图像分析FSD在不同冰层和强迫条件下的特性和可变性。在这项工作中，我们分析了来自南极东部海岸（65.6°S，101.9°E）的某个位置的海冰高分辨率图像（像素大小：0.3 m），该图像是在16日获得的。2019年2月。与以前的大多数研究相反，图像中的浮冰呈角形，多边形形状和窄尺寸分布。我们表明，观测到的FSD可以表示为两个概率分布（高斯和锥形幂定律）的加权总和，其中高斯部分显然在絮凝物的尺寸范围内占主导地位，对整个海冰表面积的贡献超过90％ 。在对有关问题的前一天的天气，海浪和冰层状况进行分析的基础上，我们描述了导致陆上耐火层冰破碎成图像中可见的絮凝物的最可能情况。最后，通过基于匹配特征函数展开法的散射模型进行的一系列海冰波传播数值模拟，为理论论证提供了支持，