Thermo-Mechanics and Hydrology of Western Antarctic Ice Stream Margins

南极西部冰流边缘的热力学和水文学

• 批准号: 1341499
• 负责人: James Rice
• 金额: $ 38.45万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1341499&HistoricalAwards=false
• 关键词: Thermo; Mechanics; Hydrology; Western; Antarctic

Rice/1341499Flow of glacial ice along the Siple Coast, West Antarctica, localizes into fast-flowing ice streams of 20-80 km width, moving at speeds of 100s of m/yr as the ice streams approach the sea. These ice streams are bordered by ridges of nearly stagnant ice and no topographic feature in the ice sheet bed has been identified as guiding that width, which instead seems to be chosen dynamically. Using theoretical modeling and computational physics, this study aims to understand (1) the mechanical, hydrologic and thermal processes active within the ice streams, (2) the origin of the stream morphology and what controls the margin locations of the fast-flowing ice, and (3) how ice discharge from the West Antarctic Ice Sheet will respond to climate-related changes in atmospheric and ocean temperatures and precipitation. Preliminary studies suggest that the margins of all active ice streams in the Siple Coast have substantial ?temperate zones?, i.e., ice is at the melting point for several dozens to hundreds of meters above the bed. Temperate ice contains melt water, and thus a first focus is to understand how water generation and transport near the bed in the shear margins might partially stabilize the margin locations and control the speed of ice discharge within the ice stream.The intellectual merit of these studies is that it will contribute to understanding what controls the channelization of ice flow in the West Antarctic Ice Sheet (WAIS) and the rate at which its ice is discharged to the adjacent ocean. The broader impacts of the work are that advancing our knowledge of ice-stream dynamics is crucial for predicting how ice discharge will be impacted by future variations in atmospheric and ocean temperatures, ocean currents, precipitation, and solar radiation. Based on the results from this study, the investigators will attempt to develop a mathematical model of ice stream and their shear margins, that can be included in larger scale numerical simulations of ice sheet processes and climate models. This project will contribute to the training of two graduate students.This award does not have any field work in Antarctica.

米/1341499沿Siple海岸的冰川冰流到南极洲西部，将其定位于20-80 km宽的快速流动冰流，随着冰流接近海上的速度，以100 m/yr的速度移动。这些冰流与几乎停滞的冰脊接壤，冰盖床中没有地形特征被确定为指导该宽度，而似乎是动态地选择的。 使用理论建模和计算物理学，本研究旨在了解（1）冰流中活跃的机械，水文和热过程，（（2）流形态的起源以及控制快速流冰的边缘位置的原因，以及（3）从西部反冰层中冰出的冰出对气候和气候质量的变化对大气和大气中的危险响应。初步研究表明，Siple海岸所有活性冰流的边缘都有大量的温带区域？温带冰中含有融化水，因此，首先要了解剪切边缘的床附近的水产生和运输方式可能会部分稳定边缘位置并控制冰流中冰出的速度。这些研究的智力优点在于，它将有助于理解西方南方冰冰冰台的冰的通道（WAIS）的速度（WAIS）的速度（冰上的速度）和冰上的速度有助于其速度（冰）和冰上的速度。这项工作的更广泛的影响是，促进我们对冰流动力学的了解对于预测冰出对未来的大气和海洋温度，洋流，降水和太阳辐射的变化的影响至关重要。根据这项研究的结果，研究人员将尝试开发一个冰流的数学模型及其剪切边缘，这些模型可以包含在冰盖工艺和气候模型的大规模数值模拟中。该项目将有助于对两名研究生的培训。该奖项在南极洲没有任何现场工作。