Model Studies of Surface Water Behavior on Ice Shelves

该奖项支持一个项目，以更好地了解触发冰架不稳定和爆炸性解体的过程和条件。提出的研究的一个重要成果将是建立用于预测未来海平面上升的大尺度冰盖模型所需的微尺度和中尺度冰架表面过程的参数化。拟议的研究是对南极冰架表层水演化的6个方面进行为期3年的数值模式研究的成果。这6个模型研究领域包括：融化冰架表面的能量平衡模型，包括表面池塘和充满水的裂缝的处理；分布式、模拟初始融化、盐水渗透、池塘排水和裂缝填充的达西水流模型；基于相变（表面融化和冻结）的冰架表面地形演化模型；地表径流驱动的侵蚀和渗流；地表水荷载与挠曲应力的反馈；构成诱发地表裂缝机制的地表水、冰和下伏海洋可能出现的淤积现象。地表池塘和裂缝对流，以及基底裂缝热盐对流（与上文第5区有关的现象）。拟议工作的更广泛影响涉及气候变化和海平面上升的社会环境问题，并将有助于为公共政策提供咨询的重要目标。该课题将成为一名研究生的论文课题的基础，该研究生的训练将为国家的科学劳动力做出贡献，此外，PI和研究生将参加由芝加哥大学同事组织的暑期高中教师科学充实计划。

MacAyeal/0944248This award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.