Lidar studies of wave structures and wind turbulence in the stable atmospheric boundary layer
I.N. Smalikho, V.A. Banakh, A.V. Falits, A.M. Sherstobitov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: coherent Doppler lidar, wind turbulence, internal gravity wave, spectral density, 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 of IGW with wind turbulence are important for understanding the dynamic processes in the atmosphere and improving the algorithms of ABL numerical modeling and weather forecasts. This work is devoted to the study of wave structures and turbulence in stable ABL using the data of our experiments conducted in 2023. In these experiments, two pulsed coherent Doppler lidars (PCDL) horizontally spaced 3250 m apart were simultaneously used. 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 of passage of the leading edge of an atmospheric wave through the lidar locations, which is used to 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 altitudes from 200 m to 1 km with a maximum amplitude of quasi-harmonic oscillations of the vertical component of the wind speed vector of about 4 m/s (at an altitude of 400 m) was revealed. It is established 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.
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