TY - UNPB

T1 - Unified theory for surface layers in atmospheric convective and stably stratified turbulence

AU - Rogachevskii, I.

AU - Kleeorin, N.

AU - Zilitinkevich, S.

PY - 2021/12/28

Y1 - 2021/12/28

N2 - 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 stablystratified 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.

AB - 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 stablystratified 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.

KW - Physics - Atmospheric and Oceanic Physics

KW - Physics - Fluid Dynamics

KW - Physics - Geophysics

U2 - 10.48550/arXiv.2112.14121

DO - 10.48550/arXiv.2112.14121

M3 - Preprint

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

ER -