Model Studies of Surface Meltwater Lakes of the Greenland Ice Sheet

格陵兰冰盖表面融水湖模型研究

• 批准号: 0907834
• 负责人: Douglas MacAyeal
• 金额: $ 36.6万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0907834&HistoricalAwards=false
• 关键词: Model; Studies; Surface; Meltwater; Lakes

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).MacAyeal 0907834University of ChicagoFunds are provided to develop a better understanding of the processes and consequences of surface meltwater production on the Greenland ice sheet, particularly the development of surface lakes and their subsequent drainage to the subglacial bed, with the aid of numerical models designed to simulate the evolution of meltwater lakes on the Greenland Ice Sheet. The work effort will focus on: (a) establishing a self-consistent thermodynamic treatment that explicitly treats radiative forcing using a surface energy balance model, and (b) investigating new approaches to the dynamics of englacial water conduits that cause lake drainage to the subglacial bed. The surface energy balance formulation will specify the downward radiation from sun, clouds and clear sky in all the important wavelength bands (e.g., shortwave and longwave), use bulk transfer formulations to parameterize sensibleand latent-heat fluxes, and explicitly model heat transfer processes below the surface. The new approaches to englacial water conduit dynamics proposed will involve stochastic processes involved in activation of pre-existing crack systems assumed to have spatial density and orientations described by probability density functions. Two products will result from the model development and experimentation: (i) a series of numerical simulations designed to address basic questions concerning the formation of surface lakes on the Greenland Ice Sheet and their drainage to the ice-sheet bed and (ii) the development of a framework of diverse model approaches and their application to the sub-grid-scale parameterization of large-scale ice-sheet models, thereby coupling them to climate models.

该奖项是根据2009年美国复苏和再投资法案资助的（公法111-5）.MacAyeal 0907834芝加哥大学提供资金，以更好地了解格陵兰冰盖表面融水产生的过程和后果，特别是表面湖泊的发展及其随后向冰下床的排水，借助数值模型模拟格陵兰冰盖上融水湖的演变。工作重点将是：（a）建立一个自洽的热力学处理，明确处理辐射强迫使用表面能量平衡模型，和（B）调查新的方法来动态的冰川水导管，导致湖泊排水到冰下床。表面能量平衡公式将指定所有重要波段中来自太阳、云和晴空的向下辐射（例如，短波和长波），使用批量传输公式参数化的敏感和潜在的热通量，并明确地模拟热传递过程的表面以下。提出的新方法englacial水管动力学将涉及随机过程参与激活预先存在的裂纹系统假设有空间密度和概率密度函数描述的方向。模型开发和实验将产生两种产品：㈠进行一系列数值模拟，以解决有关格陵兰冰盖表面湖泊的形成及其向冰盖床排水的基本问题; ㈡建立一个各种模式方法框架，并将其应用于大规模冰盖模式的次网格尺度参数化，从而将其与气候模型相结合。