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.

该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金。MacAyeal 0907834芝加哥大学提供资金用于更好地了解格陵兰冰盖表面融水产生的过程和后果，特别是开发借助旨在模拟格陵兰冰盖上融水湖泊演化的数值模型，研究了地表湖泊及其随后流向冰下床的情况。这项工作的重点是：（a）建立一种自洽的热力学处理方法，使用地表能量平衡模型明确处理辐射强迫，以及（b）研究导致湖泊排水到冰下的冰川水管道动力学的新方法。床。表面能量平衡公式将指定所有重要波段（例如短波和长波）中来自太阳、云和晴空的向下辐射，使用体传递公式来参数化感热和潜热通量，并明确模拟下面的传热过程表面。所提出的冰川水管动力学的新方法将涉及随机过程，该过程涉及激活预先存在的裂缝系统，假设具有由概率密度函数描述的空间密度和方向。模型开发和实验将产生两个产品：（i）一系列数值模拟，旨在解决有关格陵兰冰盖上表面湖泊的形成及其向冰盖床排水的基本问题，以及（ii）开发不同模型方法的框架及其在大型冰盖模型的亚网格尺度参数化中的应用，从而将它们与气候模型结合起来。