The relation of density and temperature fluctuations to the kinetic energy of turbulence in the atmospheric boundary layer
V.P. Yushkov
Lomonosov Moscow State University, Moscow, Russia
Keywords: turbulence, adiabatic fluctuations, available energy, dissipation rate of sound speed fluctuations
Abstract
The development of the turbulence theory should be aimed at studying not only incompressible vortices but also the adiabatic component, first of all, pressure and density fluctuations. The intensity of the pressure fluctuations is compared with fluctuations of the potentially available energy of Lagrangian particles. An equation linking the smoothing of entropy fluctuations with the rate of generation of adiabatic fluctuations is proposed. The rate constant of entropy fluctuation smoothing is estimated from measurements in the atmospheric boundary layer. This constant allows us to relate the integral spatial scale of turbulent vortices to the standard deviation of the sound speed fluctuations in the atmospheric boundary layer. Estimates of the adiabatic noise amplitude in the turbulent medium are constructed and the relation between its energy, and the correlation time of the vortex velocity fluctuations is shown.
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