Collaborative Research: A Synthesis of Rapid Meltwater and Ice Discharge Changes: Large Forcings from the Ice with Impacts on Global Sea Level and North Atlantic Freshwater Budgets

合作研究：快速融水和冰排放变化的综合：来自冰的巨大强迫对全球海平面和北大西洋淡水预算的影响

• 批准号: 0531250
• 负责人: Mark Fahnestock
• 金额: $ 17.39万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0531250&HistoricalAwards=false
• 关键词: Collaborative; Research; Synthesis; Rapid; Meltwater

AbstractFreshwater discharge from the Greenland ice sheet has a direct and immediate effect on global sea level, has the potential to impact global climate by perturbing nearby sensitive regions of oceanic deep-water formation, and is an important but as yet poorly quantified part of the pan-Arctic water balance. The investigators will synthesize a range of extant data sets using numerous methods. Remote sensing and atmospheric modeling calibrated by surface data accurately reveal a spatially resolved history of surface melting on Greenland over decades, and coastal weather stations extend observations to more than a century. Sophisticated transfer techniques, including nonlinear approaches, will be used to downscale from these instrumental data to specific ice-core records of melt, learning how the widespread signal is archived. The derived transfer functions, the centuries-long ice-core records, and the century-length coastal-station records then will allow upscaling to determine meltwater variability over longer times than now available. Remotely sensed changes in ice shelves/tongues and outlet-glacier flow speeds will be combined with the contemporaneous histories of surface melting, and analyzed using diagnostic ice-flow modeling incorporating longitudinal stresses to learn how meltwater variability and ice shelf changes force ice-flow variability. If successful diagnosis is achieved, then the longer melt history from the ice-cores can be used to estimate the ice-flow variability over the same interval; the relations between ice-flow and melt changes also can be used prognostically in assessing future changes in the ice sheet affecting freshwater fluxes.

摘要格陵兰冰盖的淡水排放对全球海平面有直接和直接的影响，有可能通过扰乱附近海洋深水形成的敏感区域来影响全球气候，是泛北极水平衡的重要组成部分，但量化程度较低。研究人员将使用多种方法合成一系列现有的数据集。通过地面数据校准的遥感和大气建模准确地揭示了格陵兰几十年来表面融化的空间分辨历史，沿海气象站的观测时间延长到一个多世纪。复杂的传输技术，包括非线性方法，将被用来从这些仪器数据缩小到特定的冰芯融化记录，学习如何将广泛的信号存档。由此得出的传递函数、数百年的冰芯记录和百年的沿海站记录，将使我们能够在比现在更长的时间内确定融水的可变性。遥感的冰架/冰舌和出口冰川流动速度的变化将与同期的表面融化历史相结合，并使用结合纵向应力的诊断冰流模型进行分析，以了解融水变化和冰架变化如何迫使冰流变化。如果诊断成功，那么来自冰芯的较长的融化历史可以用来估计同一时间间隔内的冰流变化；冰流和融化变化之间的关系也可以用来预测性地评估未来影响淡水通量的冰盖变化。