Turbulence Detection in the Atmospheric Boundary Layer Using Coherent Doppler Wind Lidar and Microwave Radiometer

Abstract

The refractive index structure constant (C2n) is a key parameter used in describing the influence of turbulence on laser transmissions in the atmosphere. Three different methods for estimating C2nwere analyzed in detail. A new method that uses a combination of these methods for continuous C2nprofiling with both high temporal and spatial resolution is proposed and demonstrated. Under the assumption of the Kolmogorov "2/3 law", the C2nprofile can be calculated by using the wind field and turbulent kinetic energy dissipation rate (TKEDR) measured by coherent Doppler wind lidar (CDWL) and other meteorological parameters derived from a microwave radiometer (MWR). In a horizontal experiment, a comparison between the results from our new method and measurements made by a large aperture scintillometer (LAS) is conducted. The correlation coefficient, mean error, and standard deviation between them in a sixday observation are 0.8073, 8.18 × 10−16m−2/3, and 1.27 × 10−15m−2/3, respectively. In the vertical direction, the continuous profiling results of C2nand other turbulence parameters with high resolution in the atmospheric boundary layer (ABL) are retrieved. In addition, the limitation and uncertainty of this method under different circumstances were analyzed, which shows that the relative error of C2n estimation normally does not exceed 30% under the convective boundary layer (CBL).