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NSF-NERC: Disintegration of Marine Ice-sheets using Novel Optimised Simulations (DOMINOS)

NSF-NERC：使用新型优化模拟 (DOMINOS) 解体海洋冰盖

基本信息

批准号：
1738896
负责人：
Jeremy Bassis
金额：
$ 65.96万
依托单位：
Regents of the University of Michigan - Ann Arbor
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1738896&HistoricalAwards=false
关键词：
NSF NERC Disintegration Marine Ice

项目摘要

This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. There is growing consensus that Thwaites Glacier is unstable and vulnerable to collapse. However, there is significant disagreement in projections of rates of mass loss, with some studies suggesting century to millennial scale retreat and others forecasting more catastrophic disintegration. These disagreements are significant because rapid disintegration of Thwaites and adjacent glaciers could potentially trigger or accelerate collapse of significant portions of the West Antarctic Ice Sheet with implications for global mean sea-level rise in the coming decades. Predicting rates of ice loss from Thwaites Glacier is currently hampered by a lack of reliable models of ice fracture and breakaway--called iceberg calving--and the interactions between calving and climate change. This study addresses this major knowledge gap, and is motivated by the need to improve sea-level projections critical for policy and planning. Moreover, there is also a gap between what scientists assert about the usefulness of sea-level rise predictions and stakeholder's perceptions of the usability of that work. This project is also geared to address this gap, by identifying the information that is accessible and usable to a broad community of stakeholders whilst proactively engaging with under-represented communities at nearby community colleges and school districts, engaging community college students in research. Projected rates of sea-level rise from the West Antarctic Ice Sheet (and Thwaites Glacier in particular) have large uncertainties due to difficulties in understanding and projecting the calving and dynamic processes that control the ice-sheet stability. This uncertainty is magnified by the poorly understood connection between calving processes, ice-sheet stability and climate. To address these uncertainties, this project seeks to explicitly resolve the processes that could cause retreat and collapse of Thwaites Glacier using a novel ice-dynamics model suite. This model suite includes a discrete element model capable of simulating coupled fracture and ice-flow processes, a 3D full Stokes continuum model, and the continental scale ice-dynamics model (BISICLES). Ice-dynamics models will be coupled to an ocean forcing model suite including simple plume models, intermediate complexity 2-layer ocean models and fully 3D regional ocean models. This hierarchical approach will use high-fidelity process models to inform and constrain the sequence of lower-order models needed to extrapolate improved understanding to larger scales and has the potential to radically reduce uncertainty of rates of marine ice-sheet collapse and associated sea-level rise. The large-scale modeling approach will be tested and implemented within the open source BISICLES ice dynamics model and made publicly available to other researchers via a "calving package".This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目是美国国家科学基金会（NSF）和英国自然环境研究委员会（NERC）联合发起的一项倡议的一部分，该倡议旨在实质性地改进西南极洲思韦茨冰川的冰损失和海平面上升的十年和长期预测。越来越多的人认为斯韦茨冰川不稳定，容易崩塌。然而，对质量损失率的预测存在重大分歧，一些研究表明，一个世纪到千年规模的退缩，而另一些研究则预测更灾难性的解体。这些分歧意义重大，因为思韦茨冰川和邻近冰川的迅速崩解可能引发或加速南极西部冰原的大部分崩解，从而影响未来几十年全球平均海平面的上升。目前，由于缺乏可靠的冰断裂和分离模型（称为冰山崩解）以及崩解与气候变化之间的相互作用，预测思韦茨冰川的冰损失率受到了阻碍。这项研究解决了这一主要的知识差距，其动机是需要改进对政策和规划至关重要的海平面预测。此外，科学家对海平面上升预测有用性的断言与利益相关者对这项工作可用性的看法之间也存在差距。该项目还旨在解决这一差距，通过确定广泛的利益相关者社区可以访问和使用的信息，同时积极参与附近社区学院和学区的代表性不足的社区，让社区大学生参与研究。由于难以理解和预测控制冰盖稳定性的产犊和动力过程，南极西部冰盖（特别是思韦茨冰川）海平面上升速率的预估具有很大的不确定性。由于人们对产犊过程、冰盖稳定性和气候之间的联系知之甚少，这种不确定性被放大了。为了解决这些不确定性，该项目试图使用一套新的冰动力学模型来明确解决可能导致思韦茨冰川退缩和崩塌的过程。该模型套件包括一个能够模拟耦合断裂和冰流过程的离散单元模型、一个三维全Stokes连续体模型和一个大陆尺度冰动力学模型（BISICLES）。冰动力学模型将与一个海洋强迫模型套件耦合，包括简单的羽流模型、中等复杂的两层海洋模型和全三维区域海洋模型。这种分层方法将使用高保真过程模型来通知和约束低阶模型的顺序，这些低阶模型需要将改进的认识外推到更大的尺度上，并且有可能从根本上减少海洋冰盖崩塌率和相关海平面上升率的不确定性。大规模建模方法将在开源的BISICLES冰动力学模型中进行测试和实施，并通过“calving package”向其他研究人员公开。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。