On the formulation of snow thermal conductivity in large-scale sea ice models
On the formulation of snow thermal conductivity in large-scale sea ice models
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DOI：
10.1002/jame.20039
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发表时间：
2013-07-01
影响因子：
6.8
通讯作者：
Barriat, P. Y.
中科院分区：
文献类型：
--
作者：
Lecomte, O.;Fichefet, T.;Barriat, P. Y.
本文对一个最先进的大尺度海冰-海洋耦合模型的性能进行了评估，其中包括一个新的雪多层热力学方案。4个长达29年的模拟相互比较，并与海冰厚度和范围观测值进行比较。每个模拟使用一个单独的参数化雪的热物理性质。第一个模拟使用恒定的热导率和规定的密度剖面。第二个和第三个参数化使用典型的幂律关系，将热导率直接与密度联系起来（在第一个模拟中规定）。第四个参数化是新发展的，由两个关于雪的热导率和密度与平均季节风速的线性方程组组成。结果表明，由于高估了热导率，模拟1导致海冰厚度显著高估，特别是在北半球。参数化2和4对北极海冰平均状态进行了真实的模拟。模拟3的结果低估了两个半球的海冰基础增长，但南半球的侧向增长和雪冰形成部分补偿了这一点。最后，参数化4通过包括风的积雪堆积改善了模拟的雪深分布，并显示出在未来工作中使用的潜力。所有模拟的相互比较表明，海冰模型对北极地区的雪表现比在南大洋更为敏感，在南大洋，海冰厚度不受雪中的温度分布的驱动。
An assessment of the performance of a state-of-the-art large-scale coupled sea ice-ocean model, including a new snow multilayer thermodynamic scheme, is performed. Four 29 year long simulations are compared against each other and against sea ice thickness and extent observations. Each simulation uses a separate parameterization for snow thermophysical properties. The first simulation uses a constant thermal conductivity and prescribed density profiles. The second and third parameterizations use typical power-law relationships linking thermal conductivity directly to density (prescribed as in the first simulation). The fourth parameterization is newly developed and consists of a set of two linear equations relating the snow thermal conductivity and density to the mean seasonal wind speed. Results show that simulation 1 leads to a significant overestimation of the sea ice thickness due to overestimated thermal conductivity, particularly in the Northern Hemisphere. Parameterizations 2 and 4 lead to a realistic simulation of the Arctic sea ice mean state. Simulation 3 results in the underestimation of the sea ice basal growth in both hemispheres, but is partly compensated by lateral growth and snow ice formation in the Southern Hemisphere. Finally, parameterization 4 improves the simulated Snow Depth Distributions by including snow packing by wind, and shows potential for being used in future works. The intercomparison of all simulations suggests that the sea ice model is more sensitive to the snow representation in the Arctic than it is in the Southern Ocean, where the sea ice thickness is not driven by temperature profiles in the snow.