Scaling, Anisotropy, and Complexity in Near-Surface Atmospheric Turbulence
Scaling, Anisotropy, and Complexity in Near-Surface Atmospheric Turbulence
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DOI：
10.1029/2018jd029383
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发表时间：
2019-02-16
影响因子：
4.4
通讯作者：
Rotach, Mathias W.
中科院分区：
文献类型：
--
作者：
Stiperski, Ivana;Calaf, Marc;Rotach, Mathias W.
到目前为止，一个统一的相似性缩放的发展失败了复杂的表面，缩放研究表明，从经验公式开发的平坦和水平均匀的地形，以及不同的复杂地形数据集之间的大偏差大偏差。然而，最近的一项研究表明，湍流各向异性的平坦和水平均匀的地形，分离的数据，根据各向异性的限制状态（各向同性，两个组件的轴对称和一个组件的湍流），提高近地表缩放。在本文中，我们探讨这一发现是否可以扩展到湍流倾斜和水平异质表面的近地表缩放12个不同的数据集，地形范围从平坦到多山。虽然这些数据集显示大的偏差缩放时，所有的各向异性类型一起检查，根据各向异性的极限状态的分离显着提高了崩溃的数据到共同的缩放关系，表明一个统一的框架湍流缩放的可能性。湍流复杂性的措施的开发，和故障的缩放和复杂地形上遇到的湍流复杂性背后的物理机制的原因被确定，并示出有关的距离各向同性状态，在山区地形的高度方向剪切的患病率，和各向同性的惯性子范围的偏差。
The development of a unified similarity scaling has so far failed over complex surfaces, as scaling studies show large deviations from the empirical formulations developed over flat and horizontally homogeneous terrain as well as large deviations between the different complex terrain data sets. However, a recent study of turbulence anisotropy for flat and horizontally homogeneous terrain has shown that separating the data according to the limiting states of anisotropy (isotropic, two-component axisymmetric and one-component turbulence) improves near-surface scaling. In this paper we explore whether this finding can be extended to turbulence over inclined and horizontally heterogeneous surfaces by examining near-surface scaling for 12 different data sets obtained over terrain ranging from flat to mountainous. Although these data sets show large deviations in scaling when all anisotropy types are examined together, the separation according to the limiting states of anisotropy significantly improves the collapse of data onto common scaling relations, indicating the possibility of a unified framework for turbulence scaling. A measure of turbulence complexity is developed, and the causes for the breakdown of scaling and the physical mechanisms behind the turbulence complexity encountered over complex terrain are identified and shown to be related to the distance to the isotropic state, prevalence of directional shear with height in mountainous terrain, and the deviations from isotropy in the inertial subrange.