VORTEX-DYNAMO MECHANISM OF GENERATION OF LARGE-SCALE STRUCTURES IN DIFFERENTIALLY ROTATING FLUIDS

Generation of large-scale structures by three-dimensional small-scale turbulence in a differential rotating incompressible fluid is studied in the framework of a two-scale direct interaction approximation. It i s shown that the turbulent helicity and rotation inhomogeneity may mai ntain a large-scale regular vortex structure in a mean flow. Correspon ding values of the Reynolds stress and the vortex-motive force are cal culated. The constructed general theorry is applied to the problem of the generation of two-dimensional Rossby waves in turbulent atmosphere s. The self-organization instability of Rossby waves is shown to be po ssible, and its threshold is defined. Obtained results are discussed i n the context of their application to theoretical studies of large-sca le vortices in rotating space systems.