Remote determination of turbulence parameters of a stratified atmospheric boundary layer
V.A. Banakh, I.N. Smalikho, E.V. Gordeev, A.A. Sukharev, A.V. Falits
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: structural constant of temperature fluctuations, dissipation rate of turbulence kinetic energy, turbulent Prandtl number, gradient Richardson number, fluctuations of the refractive index
Abstract
The results of experiments on determining the turbulence parameters of a stratified atmospheric boundary layer using remote sensing are presented. The height-time distributions and vertical profiles of the dissipation rate of kinetic energy of turbulence and the structural constant of turbulent fluctuations of temperature obtained from measurements of radial velocity with a coherent wind lidar and temperature with a microwave radiometer are compared with altitude variations in the parameters characterizing atmospheric stability. It is shown that the dissipation rate, which determines the intensity of wind turbulence, decreases in the boundary layer with altitude for all types of thermal stratification. The intensity of turbulent fluctuations of temperature depends to a greater extent on altitude variations in thermodynamic conditions in the atmosphere. If the thermal instability of the atmosphere at higher altitudes exceeds that in lower layers, then the structural constant of temperature fluctuations can not decrease but increase with altitude. In accordance with the altitude variation in the structural constant of temperature, the values of the structural constant of turbulent pulsations of the refractive index can also increase with altitude and differ from those predicted on the basis of known models.
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