Modelling the arctic convective boundary-layer with different turbulence parameterizations
Modelling the arctic convective boundary-layer with different turbulence parameterizations
复制标题
使用不同的湍流参数化对北极对流边界层进行建模
DOI：
10.1007/bf00120077
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发表时间：
1996
影响因子：
4.3
通讯作者：
K. Heinke Schl�nzen
中科院分区：
文献类型：
--
作者：
Christof L�pkes;K. Heinke Schl�nzen
利用非静力和滞弹性中尺度模式中不同的次网格尺度通量参数化，研究它们对模拟北极冷空气爆发的影响。应用了一个局部闭包、一个剖面闭包和两个非局部闭包格式，包括一个基于其它非局部闭包的改进格式。它占连续的亚网格尺度通量在表层的顶部和一个连续的普朗特数相对于分层。在中性层结的限制，改进的方案给出了类似于其他参数化的涡扩散系数，而对于强不稳定层结，它们变得更大，从而湍流传输更有效。它示出的模式结果与观测的比较，简单的非局部封闭方案的应用结果在一个更真实的模拟对流边界层比一个本地或剖面封闭方案。改进是由于非本地制定的涡流扩散系数和列入热传输，这是独立的局部梯度（反梯度运输）。
Different parameterizations of subgrid-scale fluxes are utilized in a nonhydrostatic and anelastic mesoscale model to study their influence on simulated Arctic cold air outbreaks. A local closure, a profile closure and two nonlocal closure schemes are applied, including an improved scheme, which is based on other nonlocal closures. It accounts for continuous subgrid-scale fluxes at the top of the surface layer and a continuous Prandtl number with respect to stratification. In the limit of neutral stratification the improved scheme gives eddy diffusivities similar to other parameterizations, whereas for strong unstable stratifications they become much larger and thus turbulent transports are more efficient. It is shown by comparison of model results with observations that the application of simple nonlocal closure schemes results in a more realistic simulation of a convective boundary layer than that of a local or a profile closure scheme. Improvements are due to the nonlocal formulation of the eddy diffusivities and to the inclusion of heat transport, which is independent of local gradients (countergradient transport).