Rayleigh–Benard thermal convection in a doubly periodic channel with rigid walls is studied using the LES-model as an analogue of multiscale atmospheric turbulence from the viewpoint of reproduction of spectral properties. A large ratio of the horizontal size to the vertical one ensures the existence of quasi-two-dimensional large-scale flow components, and a computational grid of several tens of millions nodes allows us to reproduce explicitly the dynamics of the small-scale three-dimensional turbulent component. The decomposition of the turbulent flow into the barotropic and baroclinic components allows us to propose the transformation scheme for kinetic energy in the studied system, which explains some spectral properties of the observed atmospheric turbulence.

Ключевые слова: Turbulence, convection, spectra, barotropic and baroclinic components