Ice-penetrating radar for glacier dynamics studies

冰川和冰原的持续消退导致海平面上升，并导致加拿大西部和世界大部分高山地区的水流减少。冰川或冰原的面积可以通过遥感非常精确地绘制出来，而近几十年观察到的面积变化为冰川消退提供了很好的信息。然而，除非知道冰川的厚度，否则这不能转换为对冰川体积变化的估计。尽管影响水资源和海平面上升的是冰块的体积(或质量)。冰川动力学的模型还需要详细的冰层厚度和冰床地形的空间知识，由于冰的变形和通量随冰厚度的四次方而变化。因此，所提出的冰层穿透雷达系统能够探测到数百米厚的冰层下的冰层地形。这将用于绘制加拿大西部几个关键指标冰川的基岩和冰层厚度。这些地点的冰川厚度目前尚不清楚。该雷达系统将与UBC、UNBC、SFU和卡尔加里大学的小组共享，预计将在接下来的几个野外季节全面投入使用，因为我们获得了我们小组目前正在研究的冰川的基本信息。这些测量将提供给在CFCAS资助的加拿大西部冰冻圈网络(2006-2010)范围内启动的冰川学研究。(B.Menounos，我们在该网络中的任务之一是解释最近的变化，并提供对21世纪可能的冰川变化的预测。这项研究需要包括建模工作，以捕捉随着冰川几何形状的演变与冰动力学变化相关的重要反馈。还需要建立模型来研究不同冰川对特定气候扰动(例如，大雪年或温暖的夏季)的反应时间。冰川区域或末端位置的变化与冰川对气候变化的动态响应有内在的时间滞后，如果没有冰动力学模型，就无法解释。由于此类模型需要冰厚度数据，拟议的雷达系统是该项目进展的核心。

The ongoing retreat of glaciers and icefields is contributing to sea-level rise and causing reduced streamflow in western Canada and most of the world's alpine regions.  The area of a glacier or icefield can be mapped with great precision through remote sensing, and observed areal changes in recent decades provide good information on glacier retreat.  Unless ice thickness is known, however, this cannot be converted to an estimate of glacier volume change.  It is the volume (or mass) of ice that matters for impacts on water resources and sea-level rise.  Models of glacier dynamics also require detailed spatial knowledge of ice thickness and subglacial bed topography, as the deformation and flux of ice scales with ice thickness to the fourth power.  The proposed ice-penetrating radar system is capable of sounding subglacial bed topography through several 100 m of ice. This will be deployed to map bedrock and ice thickness on several key index glaciers in western Canada.  Glacier thickness is presently unknown at these sites.  The radar system will be shared with groups at UBC, UNBC, SFU, and the University of Calgary and is expected to be fully committed over the next several field seasons, as we acquire this primary information on glaciers that are currently under study in our groups.  These measurements will feed into glaciological studies that have been initiated under the purview of the CFCAS-funded Western Canadian Cryospheric Network, 2006-2010 (B. Menounos, PI).  Part of our mandate within the network is to interpret recent changes and to provide forecasts of likely 21st-century glacier change. This study needs to include modelling efforts to capture important feedbacks associated with changes in ice dynamics as glacier geometry evolves.  Modelling is also needed to study the response time of different glaciers to specific climate perturbations (e.g., a heavy snow year or a warm summer).  Changes in glacier area or terminus position have an intrinsic time lag associated with the dynamical glacier response to climate change, and cannot be interpreted without models of ice dynamics.  Because such models require ice thickness data, the proposed radar system is central to progress within this project.