Lidar Studies of Wave Structures and Wind Turbulence in the Stable Atmospheric Boundary Layer

Abstract

The study of internal gravity waves (IGWs) generated in the atmospheric boundary layer (ABL) under stable temperature stratification and the mechanisms of interaction between IGWs and wind turbulence is important for understanding dynamic processes in the atmosphere and improving algorithms for ABL numerical modeling and weather forecasts. This work is devoted to the study of wave structures and turbulence in a stable ABL with the use of the data of our experiments conducted in 2023. In these experiments, two pulsed coherent Doppler lidars (PCDLs) horizontally spaced 3250 m apart were simultaneously involved. The analysis of the experimental results has shown that from the measurements of two PCDLs it is possible to determine the time shift of the moments at which the leading edge of an atmospheric wave passes through the lidar locations; using this shift, one can determine the propagation velocity of the atmospheric wave. For the first time in our lidar experiments, the case of atmospheric wave propagation in the layer at heights from 200 m to 1 km with a maximum amplitude of quasi-harmonic oscillations of the vertical component of the wind velocity vector of about 4 m/s (at a height of 400 m) has been revealed. It has been found that due to the transfer of energy from an atmospheric wave to small-scale wind fluctuations, it is possible to increase the turbulent energy dissipation rate by four orders of magnitude in just a few tens of minutes.