Icebergs around Antarctica: size distributions, mass fluxes, and local calving rates by using remote sensing and drift modeling

拟议的研究涉及南大洋冰山的探测和跟踪，以及产犊锋的分类和当地产犊率的估计。该项目的目标是通过调查不同大小的冰山，为估计南极洲的质量排放做出贡献。将利用覆盖整个南极海岸线和邻近南大洋的合成孔径雷达图像镶嵌图，对冰山的空间分布以及大小进行分类。这种马赛克将在不同的年份产生。南极洲的数字高程模型将被用来推导出冰解前沿的冰厚度。借助冰山漂移模型、浮标数据和文献结果，将几个冰山追溯到它们的裂解前缘，以获得有关它们裂解时冰山厚度的信息。通过将冰山总面积与冰山厚度估计相结合，可以确定给定时间段内调查区域内的冰山总质量。比较不同年份的冰山总质量、冰山总面积和冰山大小分布，可以估计年际冰山质量通量，并对冰山总面积变化或大小分布的变化进行趋势分析。将利用高分辨率合成孔径雷达图像和冰山漂移模型对南极冰架区域的局部产犊率进行估计，从而对所调查区域的质量排放进行估计。

The proposed study deals with the detection and tracking of icebergs in the Southern Ocean, as well as the classification of calving fronts and the estimation of local calving rates. The goal of this project is to contribute to the estimations of mass discharge from Antarctica, by investigating icebergs at various sizes. The spatial distribution of icebergs, as well as a size classification will be carried out by using SAR image mosaics, which cover the whole Antarctic coastline and the adjacent Southern Ocean. Such mosaics will be generated for different years. Digital elevation models of Antarctica will be employed to derive the ice thicknesses at the calving fronts. With the aid of an iceberg drift model, buoy data and results from literature several icebergs will be tracked back to their calving fronts to get information about the thickness of the icebergs as they calved. From the combination of total iceberg areas with iceberg thickness estimations, the total iceberg mass within the area of investigation can be determined for a given time period. A comparison of total iceberg masses, total iceberg areas and iceberg size distributions between different years enables the estimation of inter-annual iceberg mass flux and trend analyses of total iceberg area change or a shift in size distribution. Local calving rates from regions of the Antarctic ice shelves will be estimated by using high-resolution SAR images and the iceberg drift model and will result in an estimation of mass discharge for the investigated region.