Influence of dynamics on glacier and ice-sheet mass balance

对未来冰冻圈质量平衡的估计将需要考虑冰川和冰盖的动态，即使是在短时间尺度上也是如此。拟议的研究将探讨动力在调节冰川和冰盖物质平衡方面所发挥的作用，这反过来又对淡水资源和全球海平面具有重要的科学和社会影响。由于水起到了润滑剂的作用，冰川水文学在很大程度上支持了我们对冰块流动的速度和方式的理解。因此，水文模型是拟议研究的核心。这项研究的首要目标是从机制上理解冰川动力学和物质平衡之间的关系，特别是对冰川水文学在这种关系中所起的作用提出理论和计算上的描述。这项研究的具体目标按尺度划分：(1)从理论上评估冰下水文对冰盖内快速流动的空间分布和时间变化的影响；(2)在流域尺度上识别和描述冰川动力学和物质平衡的相互影响，并评价这种关系对区域冰川物质平衡和径流的影响。研究方法包括实地数据收集和基于计算机的建模和分析。这项拟议的研究建立在过去八年丰富的冰川水力模拟经验的基础上，并利用了目前正在开发的最先进的冰川动力学模型。这项研究的大陆范围部分将依赖于已公布的数据集，并受益于几项新出现的和预期的合作。外地部分自然源于目前获得资助的外地方案，并受益于过去四年收集的基线数据。这项研究将增进我们对将冰川物质平衡与海平面变化联系起来的冰川-水力过程的理解，并将我们对这些过程的基本理解应用于淡水资源问题。拟议中的项目在很大程度上依赖于学生的参与，并提供从本科生到博士后的研究培训机会。

Estimates of the future mass balance of the cryosphere will require the dynamics of glaciers and ice sheets to be considered, even on short time scales. The proposed research will address the role that dynamics play in modulating glacier and ice-sheet mass balance, which in turn has scientifically and societally important implications for freshwater resources and global sea level. Because water acts as a lubricant, glacier hydrology underpins much of what we understand about how fast, and the way in which, ice masses flow. Hydrological modelling is therefore at the core of the proposed research. The overarching goal of this research is to develop a mechanistic understanding of the relationship between ice dynamics and mass balance, and in particular, to put forward theoretical and computational descriptions of the role that glacier hydrology plays in this relationship. The specific objectives of the research are divided by scale: (1) to theoretically assess the influence of subglacial hydrology on the spatial distribution and temporal variability of fast flow within ice sheets, and (2) to identify and characterize the mutual influence of glacier dynamics and mass balance at the basin scale, and evaluate the implications of this relationship for regional glacier mass balance and runoff. The research methodology includes both field data collection and computer-based modelling and analysis. The proposed research builds on extensive glaciohydraulic modelling experience over the last eight years, and capitalizes on state-of-the-art glacier dynamics models currently under development. The continental-scale component of the research will rely on published data sets and benefit from several emerging and prospective collaborations. The field component springs naturally from the currently funded field program, and benefits from baseline data collected over the last four years. This research would augment our understanding of the glaciohydraulic processes that link glacier mass balance to sea-level change, and apply our basic understanding of these processes to freshwater resource problems. The proposed program relies heavily on the participation of students, and offers research training opportunities from the undergraduate to postdoctoral levels.