The Age Structure of the Greenland ice sheet from Airborne Radar Data (ASGARD)

最近的观测表明，格陵兰冰盖正在以加速的速度失去冰。由于冰盖包含285万立方公里，相当于全球海平面上升7.2米，这种融化可能会大大有助于未来海平面上升。尽管如此，目前的海平面预测特别排除了格陵兰冰盖冰流的变化。这是因为很难知道预测的冰盖变化是否被正确模拟。提高格陵兰岛冰流动力学模型的能力是一个紧迫的问题。为了量化格陵兰岛对长期全球海平面上升的潜在威胁，我们需要对内部冰盖结构有更深入的了解。这将有助于了解冰盖如何应对气候变化。航空地球物理学提供了一种观测格陵兰冰盖内部结构的手段。以前，由于在提取信息方面存在技术困难，无法利用现有的航空地球物理数据。在此，建议采用新的手段来克服这些困难。新方法是基于使用已在其他研究领域开发的技术。他们将在这里应用到这个新的冰盖航空地球物理问题，从而有助于充分利用现有的昂贵的航空地球物理观测。新方法将定量描述冰盖的内部年龄。提取的新年龄信息将使冰川学家能够在大陆尺度上测试冰流模型是否正确。这将有助于更好地了解格陵兰冰盖的持续变化，帮助了解过去和预测未来。这是减少格陵兰质量损失预测不确定性的必要步骤。

Recent observations suggest that the Greenland Ice Sheet, is losing ice at an accelerating rate. Because the ice sheet contains 2.85 million cubic km, equivalent to a global sea level rise of 7.2 m, this melting could contribute substantially to future sea level rise. Despite this, current sea level projections specifically exclude changes in the ice flow of the Greenland ice sheet. This is because of difficulties in knowing whether projected changes in the ice sheet are being correctly modelled. Improving the ability to be able to model ice flow dynamics in Greenland is an urgent problem.To quantify the potential threat that Greenland poses to longer-term global sea-level rise we need a more profound understanding of the internal ice sheet structure. This will help inform how the ice sheet may responses to changing climate. Airborne geophysics provides a means to observe the internal structure of the Greenland ice sheet. Previously, technical difficulties in extracting information, have prevented the use of existing aerogeophysical data. Here, it is proposed to apply new means to overcome these difficulties. The new methods are based on using techniques which have been developed in other research fields. They will be applied here to this new ice sheet aerogeophysical problem, thereby helping to make the best use of pre-existing expensive aerogeophyscial observations. The new methods will describe quantitatively the internal ages of the ice sheet. The new age information extracted will allow glaciologists to test, at the continental-scale, whether models of ice flow are correct. This will help to provide a better understanding of ongoing Greenland ice sheet changes, helping to understand the past and predict the future. This is a necessary step in reducing uncertainties on Greenland mass loss predictions.