Lidar investigation of wind turbulence in the presence of low-level jet in the atmosphere
I.N. Smalikho, V.A. Banakh, A.V. Falits
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634055, Russia
Keywords: когерентный доплеровский лидар, ветровая турбулентность, низкоуровневое струйное течение, coherent Doppler lidar, wind turbulence, low-level jet
Abstract
The results of lidar investigation of wind turbulence in the presence of low-level jet (LLJ) in the atmospheric boundary layer are presented. From the measurements by Stream Line lidar at the Basic Experimental Complex of IAO SB RAS and on the coast of Lake Baikal, different turbulence parameters inside LLJ were estimated. It is ascertained that the turbulence is very weak in the central part of LLJ. In particular, the turbulence kinetic energy does not exceed 0.1 (m/s)2. The turbulent energy dissipation rate and turbulence integral scale within a jet stream were quantitatively estimated from lidar measurements with a relative error of no more than 12% for the first time. According to these measurements, a dissipation rate of about 10-5 m2/s3 is characteristic. From the lidar measurements on the coast of Lake Baikal, the turbulent energy dissipation rate in the lower part of a jet stream exceeds the corresponding value in the upper part of the LLJ by 1 to 2 orders of magnitude. In the central part of LLJ, the turbulence integral scale averages about 100 m, which is 2-3 times lower than the effective thickness of the jet stream.
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