Continental scale, high order, high spatial resolution, ice sheet modeling using the Ice Sheet System Model (ISSM)
Continental scale, high order, high spatial resolution, ice sheet modeling using the Ice Sheet System Model (ISSM)
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DOI：
10.1029/2011jf002140
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发表时间：
2012-03-10
影响因子：
3.9
通讯作者：
Rignot, E.
中科院分区：
文献类型：
--
作者：
Larour, E.;Seroussi, H.;Rignot, E.
用于预测格陵兰和南极冰盖质量平衡的冰流模型通常依赖于浅冰近似（SIA）和浅架近似（SSA），有时结合成所谓的“混合”模型。这种模式，而计算效率，是基于一套简化的物理假设的机械制度的冰流，这并不均匀地适用于冰盖/冰架系统，特别是近接地线，其中正在发生迅速的变化，目前。在这里，我们提出了一个新的热力学有限元模型的冰流命名为ISSM（冰盖系统模型），包括高阶应力，高空间分辨率的能力和数据同化技术，以更好地捕捉冰动力学，并产生现实的模拟冰盖流在大陆尺度。ISSM包括几个近似的动量平衡方程，从二维SSA到三维全斯托克斯公式。它还依赖于大规模并行化架构和最先进的可扩展工具。ISSM采用数据同化技术，在各级近似的动量平衡方程，推断基础阻力在冰床界面从卫星雷达干涉仪派生的观测冰的运动。ISSM与标准基准验证后，我们提出了一个演示的情况下，格陵兰冰盖的能力。我们表明，ISSM能够以高空间分辨率逼真地模拟整个冰盖的冰流，具有高阶物理学，从而为改善气候变暖中冰盖演变的预测提供了一条途径。
Ice flow models used to project the mass balance of ice sheets in Greenland and Antarctica usually rely on the Shallow Ice Approximation (SIA) and the Shallow-Shelf Approximation (SSA), sometimes combined into so-called "hybrid" models. Such models, while computationally efficient, are based on a simplified set of physical assumptions about the mechanical regime of the ice flow, which does not uniformly apply everywhere on the ice sheet/ice shelf system, especially near grounding lines, where rapid changes are taking place at present. Here, we present a new thermomechanical finite element model of ice flow named ISSM (Ice Sheet System Model) that includes higher-order stresses, high spatial resolution capability and data assimilation techniques to better capture ice dynamics and produce realistic simulations of ice sheet flow at the continental scale. ISSM includes several approximations of the momentum balance equations, ranging from the two-dimensional SSA to the three-dimensional full-Stokes formulation. It also relies on a massively parallelized architecture and state-of-the-art scalable tools. ISSM employs data assimilation techniques, at all levels of approximation of the momentum balance equations, to infer basal drag at the ice-bed interface from satellite radar interferometry-derived observations of ice motion. Following a validation of ISSM with standard benchmarks, we present a demonstration of its capability in the case of the Greenland Ice Sheet. We show ISSM is able to simulate the ice flow of an entire ice sheet realistically at a high spatial resolution, with higher-order physics, thereby providing a pathway for improving projections of ice sheet evolution in a warming climate.