Ice thickness, remote sensing and sensitivity experiments using ice-flow modelling for major outlet glaciers of the Southern Patagonian Icefield (ITERATE)

该项目旨在增进我们对冰川变化及其对未来潜在扰动的制约和敏感性的了解。为了实现这些目标，我们将获得新的数据，更新我们现有的综合空间数据库，并将信息结合到当地规模的冰流模拟和不同强迫情景的分析中。具体地说，我们将使用基于直升机的冰穿透雷达测量以及机载激光扫描测量来获取更多的冰厚度数据。航空调查是在我们的国际合作伙伴密切合作下进行的。我们将从光学卫星数据中在时间上致密我们关于冰川范围的空间信息，通过从常规哨兵1号雷达图像进行强度偏移跟踪来计算表面速度场，并计算改进的表面高度和质量变化估计。我们将用最先进的冰厚重建方法同化我们的空间场。后者将受到来自不同群体的新的和现有的冰厚度测量以及新的测深数据的限制，以便生成新的基岩地形图。我们将调整我们现有的重建方法，因为我们将不得不根据不同的冰厚度测量结果的质量对其进行加权。最后一项任务包括建立特定冰川的高分辨率冰动力学模型，即佩里托·莫雷诺冰川、乌普萨拉冰川和维德玛冰川。我们将专门测试在Elmer/Ice中实施的不同崩解程序，并进行扰动实验，以测试冰川对某些变量和参数的敏感性，如海床高度、基面摩擦、湖平面、崩解参数和锋面消融。

The project aims at improving our process understanding of glacier changes and their constraints and sensitivities to potential future perturbations. In order to achieve those goals we will acquire new data, update our existing comprehensive spatial databases and combine information into local-scale ice-flow modelling and an analysis of different forcing scenarios. Specifically we will acquire additional ice thickness data using helicopter-based ice penetrating radar surveys as well as airborne laser scanning surveys. The airborne surveys are carried our in close cooperation our international partners. We will temporally densify our spatial information on glacier extent from optical satellite data, compute surface velocity fields by intensity offset tracking from regular Sentinel-1 radar imagery and compute improved surface elevation and mass change estimates. We will assimilate our spatial fields in a state-of-the-art ice thickness reconstruction approach. Latter will be constraint by the new and existing ice thickness measurements from different groups as well as by novel bathymetric data in order to generate a new map of the bedrock topography. We will adapt our existing reconstruction approach since we will have to weight the different ice thickness measurements in regard to their quality. The last task comprises the setup of high-resolution ice dynamic models for specific glaciers, namely Perito Moreno, Upsala and Viedma glaciers. We will specifically test different calving routines implemented in ELMER/Ice and perform perturbation experiments in order to test the glaciers’ sensitivity on certain variables and parameters like bed elevation, basal friction, lake level, calving parameters and frontal ablation.