Parameterisation of Turbulent Transport in the Atmosphere
Parameterisation of Turbulent Transport in the Atmosphere
复制标题
大气中湍流传输的参数化
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
P. Gross
中科院分区：
文献类型：
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作者：
M. Raschendorfer;C. Simmer;P. Gross
描述大气状态的热流体动力学方程组只能在离散的空间和时间间隔内数值求解。因此，方程必须在这些间隔上取平均值。对方程求平均可得到协方差积，它代表次网格尺度（湍流）对平均大气流的贡献。由于这些协方差产品添加了额外的未知数，导致封闭问题，因此必须使用已知量对它们进行参数化。在湍流输运理论的基础上描述了参数化的一般概念。在这种情况下，两个湍流参数化方案的Lokal-Modell（LM），目前中尺度有限区域天气预报模式的德国气象局（DWD），进行了更详细的讨论。在模拟的大气状态，从这些计划的差异显示在一个案例研究。
The thermo-hydrodynamic equations describing the state of the atmosphere can only be solved numerically with discrete space and time intervals. Therefore the equations have to be averaged over these intervals. Averaging the equations results in covariance products which represent the sub-grid scale (turbulence) contributions to the mean atmospheric flow. Since these covariance products add additional unknowns leading to a closure problem, they have to be parameterised by use of known quantities. The general concept of parameterisation is described on the basis of turbulent transport theory. In this context the two turbulence parameterisation schemes of the Lokal-Modell (LM), the current meso-scale limited area weather forecast model of the German Weather Service (DWD), are discussed in more detail. Differences in the simulated atmospheric states resulting from these schemes are shown in a case study.