Model Studies of Surface Water Behavior on Ice Shelves

MacAyeal/0944248该奖项支持一个项目，该项目旨在更好地了解引发冰架不稳定和爆炸性解体的过程和条件。拟议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型冰盖模型所需的微观和中尺度冰架表面过程的参数。这项拟议的研究代表了一项为期3年的努力，即对南极冰架上地表水演变的6个方面进行数值模式研究。这6个模型研究领域包括：冰架表面融化的能量平衡模型，表面池塘和充满水的裂缝的处理，分布式，达西水流模拟初始积雪融化，卤水入渗，池塘排水和裂缝填充，冰架表面地形演变的相变(表面融化和冻结)模拟，地表径流驱动的侵蚀和渗流，冰架和冰山表面的质量负荷和弯曲效应，地表水负荷和弯曲应力之间的反馈；地表水、冰和下伏海洋可能出现的海冰现象，这些现象构成了导致地表破裂的机制、表面池塘和裂缝对流以及底部裂缝温盐对流(作为与上述区域5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引起的社会环境关切，并将有助于实现为公共政策提供咨询的重要目标。该项目将成为一名研究生的学位论文项目的基础，该研究生的培训将为美国的科学劳动力做出贡献，这名PI和研究生还将参加由芝加哥大学的同事为高中教师组织的暑期科学充实计划。

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.