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

摘要格陵兰冰盖的淡水排放对全球海平面产生直接和立即的影响，有可能通过扰动附近海洋深水形成的敏感区域来影响全球气候，并且是泛北极地区的重要但尚未量化的部分水平衡。研究人员将使用多种方法综合一系列现有的数据集。由地表数据校准的遥感和大气模型准确地揭示了格陵兰几十年来地表融化的空间分辨历史，沿海气象站将观测时间延长到世纪以上。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到特定的冰芯融化记录，学习如何广泛的信号被存档。导出的传递函数，百年的冰芯记录，百年的海岸站记录，然后将允许放大，以确定融水的变化在更长的时间比现在可用。遥感变化的冰架/舌头和出口冰川流速将结合同期的历史表面融化，并分析使用诊断冰流模型，结合纵向应力，了解如何融水的变化和冰架的变化力冰流的变化。如果成功的诊断是实现的，那么从冰芯的较长的融化历史可以用来估计在同一时间间隔的冰流量的变化，冰流量和融化变化之间的关系也可以用来评估未来的变化，在冰盖影响淡水通量的解释。

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.