Collaborative Research: Byrd Glacier Flow Dynamics

该奖项支持一个项目，该项目旨在了解排干东南极冰盖的大型快速出口冰川的流动动力学。该项目包括对伯德冰川的综合野外、遥感和模型研究，伯德冰川是东南极冰盖向海洋排放物质的主要途径。最近的研究表明，冰川可能会因其边界条件的扰动而经历短暂但重大的流速变化。由于出口冰川速度对冰盖物质平衡起着主要控制作用，并调节了冰盖对海平面上升的贡献，因此正确理解冰川出口速度对一系列动态过程的敏感性并将其纳入预测冰盖模型是至关重要的。该项目的学术价值在于，这项研究的结果将提供关于大型EAIS出口冰川流动动力学的至关重要的信息。这项拟议的研究旨在解决冰川行为在几分钟到几年的时间尺度上的变化。位于冰川地面主干和漂浮部分的密集的全球定位卫星(GPS)仪器网络将在26个月的时间内提供连续的、高分辨率的水平和垂直运动时间序列。这些结果将放在覆盖更大空间范围的更长的遥感观测记录的背景下，组合的数据集将被用来约束冰川流动动力学的数字模型。这项工作的更广泛影响是，该项目将产生成果，这些成果很可能成为下一代冰盖模型的重要组成部分，这些模型试图预测南极冰盖的演变和未来海平面上升的速度。政府间气候变化专门委员会(IPCC)的最新报告强调，对出口冰川动态的了解不够完善，这是编制准确的海平面上升预测的主要障碍。该项目将为几位职业生涯早期的科学家提供重要的研究机会，包括该提案的首席PI(她既是一名新的研究员，也是一所大型研究型大学的初级教员)和两名博士水平的研究生。这些学生将接受冰川学、大地测量学和数值建模方面的培训，以满足社会对这些领域专家的需求。此外，该项目还将加强美国和西班牙极地科学家和测地仪之间的国际合作。研究小组将与冰盖遥感中心(CReSIS)推广计划的科学教育工作者密切合作，向非专业受众传播项目成果。

This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier's flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society's need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.