Semi-automated open water iceberg detection from Landsat applied to Disko Bay, West Greenland
Semi-automated open water iceberg detection from Landsat applied to Disko Bay, West Greenland
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DOI：
10.1017/jog.2019.23
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发表时间：
2019-06-01
影响因子：
3.4
通讯作者：
Hamilton, Gordon
中科院分区：
文献类型：
--
作者：
Scheick, Jessica;Enderlin, Ellyn M.;Hamilton, Gordon
格陵兰海洋出口冰川的变化导致了进入格陵兰沿海水域的冰山流量的变化，然而冰山仍然是冰-海洋系统中一个相对较少研究的组成部分。我们为陆地卫星图像开发了一个简单的冰山描绘算法。将基于机器学习的云掩模结合到算法中，即使在部分多云的场景中，我们也可以从开放水域提取冰山大小分布。我们将该算法应用于覆盖西格陵兰岛迪斯科湾的Landsat档案，以获得2000-02年和2013-15年冰山大小分布的时间序列。时间序列捕获了冰山大小分布的变化，我们将其解释为母冰川Sermeq Kujalleq （Jakobshavn Isbrx）产冰状态变化的结果。产冰方式的变化与Sermeq Kujalleq浮冰舌的解体和消失有关，导致了更多小冰山的产生。小冰山数量的增加导致越来越多的负幂律斜率适合迪斯科湾的冰山大小分布，这表明冰山大小分布时间序列为裂冰动力学的变化提供了有用的见解。
Changes in Greenland's marine-terminating outlet glaciers have led to changes in the flux of icebergs into Greenland's coastal waters, yet icebergs remain a relatively understudied component of the ice-ocean system. We developed a simple iceberg delineation algorithm for Landsat imagery. A machine learning-based cloud mask incorporated into the algorithm enables us to extract iceberg size distributions from open water even in partially cloudy scenes. We applied the algorithm to the Landsat archive covering Disko Bay, West Greenland, to derive a time series of iceberg size distributions from 2000-02 and 2013-15. The time series captures a change in iceberg size distributions, which we interpret as a result of changes in the calving regime of the parent glacier, Sermeq Kujalleq (Jakobshavn Isbrx). The change in calving style associated with the disintegration and disappearance of Sermeq Kujalleq's floating ice tongue resulted in the production of more small icebergs. The increased number of small icebergs resulted in increasingly negative power law slopes fit to iceberg size distributions in Disko Bay, suggesting that iceberg size distribution time series provide useful insights into changes in calving dynamics.