Sea-ice deformation in a coupled ocean–sea-ice model and in satellite remote sensing data
Sea-ice deformation in a coupled ocean–sea-ice model and in satellite remote sensing data
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DOI：
10.5194/tc-11-1553-2017
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发表时间：
2016-02
期刊：
影响因子：
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通讯作者：
G. Spreen;R. Kwok;D. Menemenlis;A. Nguyen
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文献类型：
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作者：
G. Spreen;R. Kwok;D. Menemenlis;A. Nguyen
抽象的。海冰变形在模式中的真实表现对于准确模拟海冰质量平衡是非常重要的。将4.5、9和18公里水平网格间距和粘塑性(VP)海冰流变数值模拟的海冰变形与合成孔径雷达(SAR)卫星观测(RGPS、RADARSAT地球物理处理器系统)在1996-2008年间进行了比较。这三种模拟都可以再现大尺度的海冰变形模式，但不能充分再现小尺度的海冰变形和线性运动学特征(LKF)。平均海冰总变形率在所有模式解中都比卫星观测低约40%，特别是在季节性海冰带。然而，模型网格间距的减小会产生更高的密度和更局部化的冰变形特征。4.5公里的模拟产生了一些线性运动学特征，但频率不正确。这三个模型解对绝对散度和切变的长度尺度和概率密度函数(PDF)的依赖关系显示出与RGPS观测值类似的幂函数标度行为，这与以前的一些研究发现的相反。总体而言，与RGPS数据相比，4.5公里的模拟产生了最真实的散度、涡度和切变。本研究基于空间分布、时间序列和幂函数尺度对高分辨率和粗分辨率的粘塑性海冰模拟进行了评价。
Abstract. A realistic representation of sea-ice deformation in models is important for accurate simulation of the sea-ice mass balance. Simulated sea-ice deformation from numerical simulations with 4.5, 9, and 18 km horizontal grid spacing and a viscous–plastic (VP) sea-ice rheology are compared with synthetic aperture radar (SAR) satellite observations (RGPS, RADARSAT Geophysical Processor System) for the time period 1996–2008. All three simulations can reproduce the large-scale ice deformation patterns, but small-scale sea-ice deformations and linear kinematic features (LKFs) are not adequately reproduced. The mean sea-ice total deformation rate is about 40 % lower in all model solutions than in the satellite observations, especially in the seasonal sea-ice zone. A decrease in model grid spacing, however, produces a higher density and more localized ice deformation features. The 4.5 km simulation produces some linear kinematic features, but not with the right frequency. The dependence on length scale and probability density functions (PDFs) of absolute divergence and shear for all three model solutions show a power-law scaling behavior similar to RGPS observations, contrary to what was found in some previous studies. Overall, the 4.5 km simulation produces the most realistic divergence, vorticity, and shear when compared with RGPS data. This study provides an evaluation of high and coarse-resolution viscous–plastic sea-ice simulations based on spatial distribution, time series, and power-law scaling metrics.