Estimation of the height of turbulent mixing layer from data of Doppler lidar measurements using conical scanning by a probe beam

Abstract

Abstract. A method is proposed for determining the height of the turbulent mixing layer on the basis of the vertical profiles of the dissipation rate of turbulent energy, which is estimated from lidar measurements of the radial wind velocity using conical scanning by a probe beam around the vertical axis. The accuracy of the proposed method is discussed in detail. It is shown that for the estimation of the mixing layer height (MLH) with the acceptable relative error not exceeding 20 %, the signal-to-noise ratio should be no less than −16 dB, when the relative error of lidar estimation of the dissipation rate does not exceed 30 %. The method was tested in an experiment in which the wind velocity turbulence was estimated in smog conditions due to forest fires in Siberia in 2019. The results of the experiment reveal that the relative error of determination of the MLH time series obtained by this method does not exceed 10 % in the period of turbulence development. The estimates of the turbulent mixing layer height by the proposed method are in good agreement with the MLH estimated from the distributions of the variance of radial velocity and the Richardson number in height and time.

On the estimation of boundary layer heights: a machine learning approach

“…Ground-based lidar systems, such as the Raman lidars (Turner et al, 2014), ceilometer, micro-pulse lidar (Campbell et al, 2002), atmospheric emitted radiance interferometer (Knuteson et al, 2004;Sawyer and Li, 2013), Doppler lidar (Tucker et al, 2009;Berg et al, 2017;Bonin et al, 2018;Vakkari et al, 2015;Banakh et al, 2021), and high-spectralresolution lidar, have been commonly used to provide PBL height estimates (Quan et al, 2013;McNicholas and Turner, 2014). For elastic lidar systems such as the micro-pulse lidar, z i is estimated by locating the height where the rangecorrected signal-to-noise ratio (SNR) or attenuated backscatter profile experiences a strong decrease with height (Emeis et al, 2008).…”

“…Also, this method fails under stable nocturnal conditions due to weak turbulence and the fact that the lowest gate of the lidar is often above the depth of the nocturnal z i . Horizontal velocity variance and dissipation rate profiles from a Doppler lidar can be used to estimate z i in nocturnal conditions (Vakkari et al, 2015;Banakh et al, 2021). Alternatively, one can estimate the PBL height based on wind shear and turbulence kinetic energy (TKE), but there has been lim-ited research on this topic (Brost and Wyngaard, 1978;Teixeira and Cheinet, 2004;LeMone et al, 2018).…”