Abstract

We discuss energy and flux budget (EFB) analysis for stably stratified and convective atmospheric turbulence. The EFB analysis shows that that high-Reynolds-number stably stratified turbulence is maintained by shear in any stratification, and the “critical Richardson number,” treated many years as a threshold between the turbulent and laminar regimes, actually separates two turbulent regimes, namely, the strong turbulence typical of atmospheric boundary layers and the weak three-dimensional turbulence typical of the free atmosphere and characterized by a strong decrease in the heat transfer in comparison to the momentum transfer. Large-scale internal gravity waves result in additional vertical turbulent flux of momentum and additional productions of the densities of the turbulent kinetic and potential energies and turbulent flux of potential temperature. We also discuss application of the EFB analysis to convective atmospheric turbulence, which allows to describe the surface layer (unstably stratified and dominated by small-scale turbulence of very complex nature) as well as the convective boundary layer core (dominated by the energy-, momentum-, and mass-transport of semi-organized large-scale structures with a small contribution from small-scale turbulence produced by local structural shears).