Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System

该奖项支持一项为期三年的研究，该研究利用一套现有的数值模型，结合现有的和国际极年(IPY)建议的数据集，分离出影响西南极阿蒙森海湾(ASE)Thwaites冰川(Tg)的基本物理过程。四个不同的模式将被用来探索海湾几何形状、冰架支撑、基面应力分布、地表质量平衡、地表气候和内陆动力扰动对Tg现在和未来动态的影响。这组特殊的模型非常适合于这项研究的广泛性质，因为它们纳入了应力场(浅冰和陆架流)、系统几何结构(一维和二维平面图和流线；深度积分和深度相关)以及质量-动量能量耦合(机械和热机械)的有效和互补简化。这些模型将受到数据集(包括冰厚度、表面高度、基础地形、冰表面速度和势场的区域图)和地球物理数据分析(包括提高表面高度的空间分辨率、改进对地热通量的区域估计、描述冰层下界面以及冰层与浮冰之间的过渡带)的限制和验证。这项研究的学术价值集中在NSF冰川学计划的几个重点上，包括：冰动力学、数值模拟和冰盖遥感。此外，这项研究还直接涉及国家科学基金会的下列具体目标：“调查快速冰川流动的物理过程，重点是冰川床的过程”；“调查冰架稳定性”；以及“确定和量化冰川动力学和气候变化之间的反馈”。这项研究工作的更广泛影响将有助于回答未来冰盖稳定性和海平面变化等与社会相关的问题。这项研究还将有助于两名年轻研究人员的早期职业发展，并将有助于直接参与研究的研究生和本科生的教育，结果将纳入课程和非正式报告。

This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.