Estimating intermittency exponent in neutrally stratified atmospheric surface layer flows: A robust framework based on magnitude cumulant and surrogate analyses
نویسندگان
چکیده
This study proposes a novel framework based on magnitude cumulant and surrogate analyses to reliably detect the presence of intermittency and estimate the intermittency coefficient from short-length coarse-resolution turbulent time series. Intermittency coefficients estimated from a large number of neutrally stratified atmospheric surface layer turbulent series from various field campaigns are shown to remarkably concur with well-known laboratory experimental results. In addition, surrogate-based hypothesis testing significantly reduces the likelihood of detecting a spurious nonzero intermittency coefficient from nonintermittent series. The discriminatory power of the proposed framework is promising for addressing the unresolved question of how atmospheric stability affects the intermittency properties of boundary layer turbulence. © 2007 American Institute of Physics. DOI: 10.1063/1.2786001
منابع مشابه
Estimating Global and Local Scaling Exponents in Turbulent Flows using Wavelet Transformations
High frequency longitudinal velocity (u) measurements were performed in the atmospheric boundary layer to investigate the inertial subrange structure of turbulence. Global and local scaling exponent distributions and other statistical properties were derived using continuous (CWT ) and critically sampled orthonormal (OWT ) wavelet transformations. These statistical measures were contrasted to s...
متن کاملOn the effects of surrogacy of energy dissipation in determining the intermittency exponent in fully developed turbulence
– The two-point correlation function of the energy dissipation, obtained from a one-point time record of an atmospheric boundary layer, reveals a rigorous power law scaling with intermittency exponent μ ≈ 0.20 over almost the entire inertial range of scales. However, for the related integral moment, the power law scaling is restricted to the upper part of the inertial range only. This observati...
متن کاملQuantifying the Effects of Atmospheric Stability on the Multifractal Spectrum of Turbulence
Over the past decade, several studies suggested possible analogy between price dynamics in the foreign exchange market and atmospheric turbulent flows. Such analogies suggest that applications in business and industry can directly benefit from detailed quantification of the scale-hierarchy existing in fully developed turbulent flows. Numerous studies have already demonstrated the multifractal p...
متن کاملStochastic analysis of neutrally stratified cirrus layer
Two cirrus cloud systems observed during the winter of 2001 at the Southern Great Plains site of the Atmospheric Radiation Measurements program in Oklahoma, USA are studied because of the distinct neutrally stratified layers formed within the clouds. Observations are obtained with 35GHz millimeter-wave radar and backscattering cross-section ZðtÞ signals within radar-reflectivity restricted subl...
متن کاملIntermittency exponent of the turbulent energy cascade.
We consider the turbulent energy dissipation from one-dimensional records in experiments using air and gaseous helium at cryogenic temperatures, and obtain the intermittency exponent via the two-point correlation function of the energy dissipation. The air data are obtained in a number of flows in a wind tunnel and the atmospheric boundary layer at a height of about 35 m above the ground. The h...
متن کامل