当前位置: X-MOL 学术Boundary-Layer Meteorol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Velocity and Temperature Dissimilarity in the Surface Layer Uncovered by the Telegraph Approximation
Boundary-Layer Meteorology ( IF 2.3 ) Pub Date : 2021-06-25 , DOI: 10.1007/s10546-021-00632-2
Kelly Y. Huang , Gabriel G. Katul , Marcus Hultmark

The physicist and mathematician Shang-Keng Ma once commented that “the simplest possible variable is one that can have two values. If there is only one value, no variation is possible." Guided by this dictum, the telegraphic approximation (TA) is applied to the streamwise velocity component and air temperature time series acquired in the first metre above the salt flats of Utah, USA. The TA technique removes amplitude variations and retains only zero-crossing behaviour in a turbulent series, thereby allowing for an isolated examination of the role of clustering in intermittency. By applying the TA technique, clustering properties are analyzed to uncover dissimilarity in temperature and velocity across unstable, near-neutral, and stable atmospheric stratification. The spectral exponents of the original and of the TA series are examined, with the inertial-subrange behaviour conforming to prior empirical relations and the energy-containing range exhibiting deviations. These two distinct scale regimes are observed in the standard deviations of the running density fluctuations of the TA series, delineating scaling behaviour between fine and large scales. In the fine scales, clustering is not appreciably affected by the stability regime and is higher than in the large scales. In the large scales, the temperature series exhibits stronger clustering with increasing stability, and higher clustering compared with the streamwise velocity component series under stable conditions. Amplitude variations are shown to mitigate intermittency in the small scales of velocity, but play only a minor role in intermittency for temperature. Last, the inter-pulse period probability distributions are explored and implications to self-organized criticality as models for TA turbulence are discussed.



中文翻译:

电报近似揭示的表层速度和温度差异

物理学家、数学家马尚铿曾评论说:“最简单的可能变量是一个可以有两个值的变量。如果只有一个值,则不可能发生变化。”在此格言的指导下,将电报近似 (TA) 应用于在美国犹他州盐滩上方第一米处获得的流向速度分量和气温时间序列。 TA 技术消除了振幅变化并仅保留湍流序列中的过零行为,从而允许对间歇性聚类的作用进行隔离检查。通过应用 TA 技术,分析聚类属性以发现温度和速度的不同不稳定、近中性和稳定的大气分层。检查原始和 TA 系列的光谱指数,惯性子范围行为符合先前的经验关系,而包含能量的范围表现出偏差。在 TA 系列的运行密度波动的标准偏差中观察到这两种不同的尺度制度,描绘了细尺度和大尺度之间的尺度行为。在精细尺度中,聚类不受稳定性制度的影响明显,并且高于大尺度。在大尺度上,温度序列表现出更强的聚类,稳定性增加,与稳定条件下的流向速度分量序列相比,聚类程度更高。幅度变化被证明可以减轻小速度范围内的间歇性,但在温度的间歇性中只起次要作用。最后的,

更新日期:2021-06-25
down
wechat
bug