Antarctic Submarine Melt Variability from Remote Sensing of Icebergs

该奖项支持一个项目，该项目将使用一种新的遥感方法，该方法最初用于调查格陵兰岛周围冰山的融化，以检查南极冰盖周边海洋强迫的时空变化。南极冰盖的近四分之三被漂浮的冰川冰区所包围，这些冰川冰被称为冰架。这些冰架在调节冰从冰盖内部流向海岸方面发挥着重要作用，类似于水坝调节水库下游水流的方式。因此，由于空气和海洋温度的变化而导致的冰架尺寸的缩小可能对到达南极海岸的冰川冰通量产生严重影响，从而对海平面变化产生严重影响。最近对阿蒙森海海洋变暖、冰架变薄以及南极西部冰盖内部冰通量增加的观测表明，海洋变暖引发的冰架不稳定可能已经在某些地区开始了。虽然在阿蒙森海地区有详细的观测资料，但我们对海洋条件的时空变化及其对冰架稳定性的影响的理解受到跨越冰架外围的观测资料的缺乏的限制。该项目将深入了解海底冰架融化的可变性，并将有助于在男性主导的领域推进女性早期职业科学家的职业生涯。该项目将使用WorldView卫星获得的重复高分辨率（约0.5 m像素宽度和长度）卫星图像来估计南极洲周围主要沿海地区冰山融化的速度。卫星图像将用于构建冰山表面高程图，这些地图将在时间上进行差分，从而得出冰山体积变化和面积平均融化速率的时间序列。在有海洋数据的地方，将把融化速率与这些数据进行比较，以评估海洋温度的变化是否可以解释观测到的冰山融化变化。融化速率的大空间梯度将与冰山漂移速率的估计进行比较，这将从重复卫星图像中推断出来，以及由（未资助的）合作者制作的数值模拟漂移速率，以量化水剪切对冰山融化速率的影响。冰山融化的时空格局也将与独立导出的冰架厚度数据集进行比较。总的来说，这一分析应该能够深入了解海洋强迫变化对南极冰架和冰山海底融化的影响。该项目不需要在南极洲进行实地工作。

Enderlin/1643455This award supports a project that will use a novel remote sensing method, which was initially developed to investigate melting of icebergs around Greenland, to examine spatial and temporal variations in ocean forcing around the Antarctic ice sheet periphery. Nearly three-quarters of the Antarctic ice sheet is fringed by regions of floating glacier ice called ice shelves. These ice shelves play an important role in modulating the flow of ice from the ice sheet interior towards the coast, similar to how dams regulate the downstream flow of water from reservoirs. Therefore, a reduction in ice shelf size due to changing air and ocean temperatures can have serious implications for the flux of glacier ice reaching the Antarctic coast, and thus, sea level change. Observations of recent ocean warming in the Amundsen Sea, thinning of the ice shelves, and increased ice flux from the West Antarctic ice sheet interior suggests that ice shelf destabilization triggered by ocean warming may already be underway in some regions. Although detailed observations are available in the Amundsen Sea region, our understanding of spatial and temporal variations in ocean conditions and their influence on ice shelf stability is limited by the scarceness of observations spanning the ice sheet periphery. The project will yield insights into variability in the submarine melting of ice shelves and will help advance the career of a female early-career scientist in a male-dominated field.The project will use repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images will be used to construct maps of iceberg surface elevation, which will be differenced in time to derive time series of iceberg volume change and area-averaged melt rates. Where ocean data are available, the melt rates will be compared to these data to assess whether variations in ocean temperature can explain observed iceberg melt variability. Large spatial gradients in melt rates will be compared to estimates of iceberg drift rates, which will be inferred from the repeat satellite images as well as numerically modeled drift rates produced by (unfunded) collaborators, to quantify the effects of water shear on iceberg melt rates. Spatial and temporal patterns in iceberg melting will also be compared to independently derived ice shelf thickness datasets. Overall, the analysis should yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.