Interaction of hydrodynamic turbulence with stratified flows and internal waves: The role of turbulent diffusion and density fluctuations

An outline of studies of the interaction of small-scale turbulence with stratified turbulent flows and internal waves (IW) is presented. They include elements of general theory of such flows, internal waves’ damping on small-scale turbulence, and support and amplification of turbulence by shear flows and internal waves. It is shown that perturbation of turbulent exchange parameters (such as the diffusion coefficient) results in significant wave damping in a long-wave range. On the other hand, density fluctuations or, equivalently, variation of potential energy of turbulence due to stratification allow the shear flows and waves to support turbulence at any Richardson numbers, with no finite threshold. Publications of different years outlined here include analytical and numerical modeling, as well as applications to the available data of measurements in the upper layer of the ocean in different geographic sites.