Measurement of boundary layer structure parameter profiles by acoustic sounding and comparison with direct measurements

Abstract

Acoustic sounder derived profiles of the atmospheric velocity and temperature structure parameters, Cv2 and CT2, are presented. the former is obtained using a novel bistatic acoustic sounder comprising a fan beam transmitter and a vertically directed receiver. Simultaneous profiles of the temperature structure parameter are obtained using a conventional monostatic sounder. Time histories of these quantities at two heights in the boundary layer are given and are compared with in‐situ measurements. the results indicate significant anisotropy in the temperature field at scales greater than a few metres and emphasize the care required when comparing directly measured and acoustically estimated turbulence quantities. the significance of anisotropy in the assessment of excess attenuation is also discussed.

On the Evaluation of the Proportionality Coefficient between the Turbulence Temperature Spectrum and Structure Parameter

“…in the Wyngaard et al (1971) form, Eq. (11), has been widely used in structure-parameter calculations (e.g., Kaimal 1973;Asimakopoulos et al 1976;Wyngaard and LeMone 1980;Moulsley et al 1981;Kohsiek 1982;Cuijpers and Kohsiek 1989;Beland 1993;Green et al 1994;Muschinski et al 2001Muschinski et al , 2004Cheinet and Siebesma 2009;Wilson and Fedorovich 2012;Maronga et al 2013;Maronga 2014;Maronga et al 2014;Gibbs et al 2016). The error reported here may affect conclusions regarding the validity of this relationship as compared with observational and numerical data.…”

Structure Functions and Structure Parameters of Velocity Fluctuations in Numerically Simulated Atmospheric Convective Boundary Layer Flows

“…In these seminal works, Kolmogorov established fundamental properties of turbulence dynamics and energy transfer across turbulent scales through the use of velocity structure functions. The structure functions and associated structure parameters for velocity are important for assessing boundary layer mixing (Moulsley et al 1981), turbulence intermittency (Gaudin et al 1998), and acoustic wave scattering (Little 1969).…”