Nonlinear dynamics of the upper ocean
Nonlinear dynamics of the upper ocean belongs to the research lines rapidly developed at the IAP RAS from the first years of its activities. The achieved progress was essentially provided by fundamental results on the general theory of nonlinear waves obtained first at the RRI and then at the IAP RAS by V. I. Talanov, L. A. Ostrovsky, E. N. Pelinovsky, and their numerous disciples. Universe methods of the theory of nonlinear oscillations and waves developed at the Nizhny Novgorod School of Radiophysics proved to be efficient for describing wave motions in the ocean in various ranges from small-scale capillary ripples (of wavelength several millimeters) to tsunami waves (of wavelength several ten kilometers). The elaboration of physical and numerical models of wave phenomena in the ocean was always based on the own powerful experimental base that includes unique setups and measuring complexes for laboratory and field experiments.
It is well known that waves of different nature and with various dispersion and nonlinear properties can propagate in the ocean. By tradition, the most important subjects of research are surface waves of various spatial scales (wind, capillary, and tsunami waves) on the ocean surface and internal waves (typical of the ocean as a vertically stratified medium). An essential role in the upper ocean dynamics is also played by the interaction between internal and surface waves, underwater currents, and turbulence. These studies are of considerable importance both from the fundamental point of view and as a scientific basis for developing methods of remote diagnostics of the ocean and advanced engineering facilities of diagnostics, primarily, radar and optical ones. Many results on this interrelated topic obtained at the IAP RAS have gained wide recognition in the world community.