Measurements of wind turbulence parameters by a conically scanning coherent Doppler lidar in the atmospheric boundary layer

Abstract

Abstract. The method and results of lidar studies of spatiotemporal variability of wind turbulence in the atmospheric boundary layer are reported. The measurements were conducted by a Stream Line pulsed coherent Doppler lidar (PCDL) with the use of conical scanning by a probing beam around the vertical axis. Lidar data are used to estimate the kinetic energy of turbulence, turbulent energy dissipation rate, integral scale of turbulence, and momentum fluxes. The dissipation rate was determined from the azimuth structure function of radial velocity within the inertial subrange of turbulence. When estimating the kinetic energy of turbulence from lidar data, we took into account the averaging of radial velocity over the sensing volume. The integral scale of turbulence was determined on the assumption that the structure of random irregularities of the wind field is described by the von Kármán model. The domain of applicability of the used method and the accuracy of the estimation of turbulence parameters were determined. Turbulence parameters estimated from Stream Line lidar measurement data and from data of a sonic anemometer were compared.

Estimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaign

“…The median error is higher during stable conditions (average: MAE = 51 %) compared to unstable conditions (average: MAE = 29 %), as expected and as observed in other studies (Smalikho and Banakh, 2017).…”

Response to Anonymous Referee #1

“…As expected, the larger eddies which characterize unstable conditions determine the need for a longer timescale to capture the influence of all the scales included in the inertial subrange, while for stable conditions a shorter timescale is more appropriate. The median error is higher during stable conditions (average: MAE = 51 %) compared to unstable conditions (average: MAE = 29 %), as expected and as observed in other studies (Smalikho and Banakh, 2017).…”

“…Turbulence within the atmospheric boundary layer is critically important to transfer heat, momentum and moisture between the surface and the upper atmosphere (Sobel and Neelin, 2006). Hence, global and regional models need an accurate representation of turbulence to produce precise atmospheric predictions of winds, temperature and moisture in the boundary layer.…”

Wind in Complex Terrain—Lidar Measurements for Evaluation of CFD Simulations

“…An analysis was carried out to determine how the correlation of the Lidar and sonic anemometer data was affected by filtration of SNR values. Although recent studies [6,13] have shown that the spatial averaging effects of the Lidar can be corrected to some extent, none of these methods were applied. The aim of this study was to verify that the Lidar is sufficiently accurate to validate numerical models in complex terrain.…”