Modelling glacier and ice sheet response to climate change

这项研究计划旨在提高对冰川和冰盖对气候变化的响应的了解。我的研究小组使用冰川学模型和冰川-气候实地研究相结合的方法来评估冰川物质平衡的变化，并研究冰川作为地球气候系统的一个动态组成部分的作用。就区域而言，冰川和冰原退缩影响到高山生态、旅游业、水力发电以及重要人口基地和农业活动的地表水供应。我们正在开发冰川学模型，以模拟冰川和冰盖在十年时间尺度上的演变。2009-2014年期间的实地研究将以我们对加拿大落基山脉黑格冰川的既定研究计划为基础，重点研究加拿大西部冰原的历史和未来变化以及水资源影响。从2009年春季开始，我们将把这些努力扩展到不列颠哥伦比亚省冰川国家公园的伊莱西莱韦特冰川。伊莱西莱韦特冰川是哥伦比亚河的源头地区，冰川覆盖率很高，气候受海洋影响更大。积雪和冰雪融化的气象控制可能与加拿大落基山脉的控制有很大不同。在全球范围内，冰川和冰盖的消退加快了海平面上升的速度，对于本世纪海平面还会上升多少还存在相当大的不确定性。为了解决这一问题，需要在冰川-气候耦合模型方面取得进展。这包括我们打算面对的一些数值模拟问题：在冰盖应力平衡中纳入高阶项，改进冰川和冰盖边缘的数字表示，以及在复杂地形地区的区域气候模式的缩减战略。气候场需要从稀少的观测记录中外推，或从气候模型(或重新分析)中内插到对冰川和冰盖质量平衡的影响范围，大约1-10公里。我们的实地研究通过检查物质平衡过程和高海拔温度和降水梯度来支持数值模拟，为区域和全球尺度冰川学模拟中的自由参数提供了约束。

This research program aims to improve understanding of glacier and ice sheet response to climate change. My research group uses a combination of glaciological modelling and glacier-climate field studies to assess changes in glacier mass balance and to examine the role of glaciers as a dynamic component of Earth's climate system. Regionally, glacier and icefield retreat affects alpine ecology, tourism, hydroelectric power generation, and the supply of surface water for significant population bases and agricultural activities. We are developing glaciological models to simulate glacier and ice sheet evolution over decadal time scales. Field studies for the period 2009-2014 will focus on historical and future icefield changes and water resource implications in western Canada, building on our established research program on the Haig Glacier, Canadian Rockies. Beginning in spring 2009, we will expand these efforts to the Illecillewaet Glacier, Glacier National Park, B.C. The Illecillewaet is a headwaters region of the Columbia River, with a high percentage of glacier cover and a more maritime-influenced climate. Meteorological controls of snow accumulation and snow/ice melt may differ significantly from those in the Canadian Rockies. Globally, glacier and ice sheet retreat has accelerated the rate of sea level rise, with considerable uncertainty as to how much additional sea-level rise can be expected this century. Advances in coupled glacier-climate modelling are needed to address this. This includes a number of numerical modelling issues that we aim to confront: the inclusion of higher-order terms in the ice sheet stress balance, improvements to the numerical representation of glacier and ice sheet margins, and downscaling strategies for regional climate patterns in areas of complex topography. Climate fields need to be extrapolated from sparse observational records or interpolated from climate models (or reanalyses) to the scale of influence for glacier and ice sheet mass balance, order 1-10 km. Our field studies support the numerical modelling through examination of mass balance processes and high-elevation temperature and precipitation gradients, providing constraints on free parameters in regional- and global-scale glaciological modelling.