Unified theory for surface layers in atmospheric convective and stably stratified turbulence

I. Rogachevskii, N. Kleeorin, S. Zilitinkevich

Research output: Working paper/PreprintPreprint

9 Downloads (Pure)

Abstract

The Energy- and Flux Budget (EFB) turbulence closure theory for the atmospheric surface layers in convective and stably stratified turbulence has been developed using budget equations for turbulent energies and fluxes in the Boussinesq approximation. In the lower part of the surface layer in the atmospheric convective boundary layer (CBL), the rate of turbulence production of the turbulent kinetic energy (TKE) caused by the mean-flow surface shear and the shear of self-organised coherent structures is much larger than that caused by the buoyancy, which results in three-dimensional turbulence of very complex nature. In the upper part of the surface layer, the rate of turbulence production of TKE due to the shear is much smaller than that caused by the buoyancy, which causes unusual strongly anisotropic buoyancy-driven turbulence. Considering the applications of the obtained results to the atmospheric convective and stably stratified boundary-layer turbulence, the theoretical relationships potentially useful in modelling applications have been derived. In particular, the developed unified theory for the surface layers in turbulent convection and stably stratified turbulence allows us to determine the vertical profiles for all turbulent characteristics, including TKE, the intensity of turbulent potential temperature fluctuations, the vertical turbulent fluxes of momentum and buoyancy (proportional to potential temperature), the integral turbulence scale, the turbulent anisotropy, the turbulent Prandtl number and the flux Richardson number. This theory also yields the profiles of the mean velocity and mean potential temperature.
Original languageEnglish
StatePublished - 1 Dec 2021

Keywords

  • Physics - Atmospheric and Oceanic Physics
  • Physics - Fluid Dynamics
  • Physics - Geophysics

Fingerprint

Dive into the research topics of 'Unified theory for surface layers in atmospheric convective and stably stratified turbulence'. Together they form a unique fingerprint.

Cite this