Quantifying Growth of Pancake Sea Ice Floes Using Images From Drifting Buoys
Quantifying Growth of Pancake Sea Ice Floes Using Images From Drifting Buoys
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使用漂流浮标的图像量化薄饼海浮冰的生长
DOI：
10.1002/2017jc013693
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发表时间：
2018
影响因子：
--
通讯作者：
S. Dean
中科院分区：
文献类型：
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作者：
L. Roach;M. Smith;S. Dean
在秋季和冬季，极地地区的新海冰通常以小的薄饼状浮冰开始，然后横向生长并焊接在一起形成更大的浮冰。然而，极地海洋在冻结期间的条件是恶劣的，使得对小规模海冰生长过程的原位观测困难且不频繁。在这里，我们将图像处理技术应用于在秋季北冰洋部署的漂流波浮标（SWIFT）获得的图像，以量化这些过程首次在原地。观察到小煎饼浮冰在冻结，低波条件下逐渐形成和生长。我们发现，煎饼絮凝物的直径是有限的波场，使絮凝物的直径是成比例的波长和振幅随时间的推移。浮冰焊接与海冰密集度有很好的相关性，观测结果可用于估计浮冰尺寸演变的关键模型参数。有一些协议之间观察到的横向增长率和预测使用的理论模型的基础上热流平衡，但模型的横向增长率在这些条件下过于保守。这些结果将被用来通知描述的横向浮冰增长和浮冰焊接在新的模式，发展海冰浮冰大小分布。
New sea ice in the polar regions often begins as small pancake floes in autumn and winter that grow laterally and weld together into larger floes. However, conditions in polar oceans during freezeup are harsh, rendering in situ observations of small‐scale sea ice growth processes difficult and infrequent. Here we apply image processing techniques to images obtained by drifting wave buoys (SWIFTs) deployed in the autumn Arctic Ocean to quantify these processes in situ for the first time. Small pancake ice floes were observed to form and grow gradually in freezing, low‐wave conditions. We find that pancake floe diameters are limited by the wave field, such that floe diameter is proportional to wavelength and amplitude over time. Floe welding correlates well with sea ice concentration, and the observations can be used to estimate a key model parameter for floe size evolution. There is some agreement between observed lateral growth rates and those predicted using a theoretical model based on heat flux balance, but the model lateral growth rates are too conservative in these conditions. These results will be used to inform description of lateral floe growth and floe welding in new models that evolve sea ice floe size distribution.