Unsteady regimes of internal gravity wave generation in the ocean

Abstract

The problem of mathematical modeling of internal gravity wave fields generated by an unsteady perturbation source moving in the stratified ocean of finite depth is considered. Integral forms of the solution are obtained in the linear approximation for a separate wave mode, and it is shown that, at certain generation parameters, the wave pattern of excited internal wave fields represents systems of hybrid wave perturbations which simultaneously have the properties of two waves of the following two types: annular-like (transverse) and wedge-like (longitudinal). The results of numerical simulations describing the basic specific features of the phase structures and wave patterns of the excited fields depending on the generation parameters are presented and discussed. KEYWORDS: Internal gravity waves; moving source; stratified ocean; wave patterns; phase structure.Citation: Bulatov, V. V. and Yu. V. Vladimirov (2018), Unsteady regimes of internal gravity wave generation in the ocean, Russ.

Far fields of internal gravity waves from a source moving in the ocean with an arbitrary buoyancy frequency distribution

“…The source is moving in the ocean of a finite depth with an arbitrary stratification. Indeed, at large distances, the real sources of perturbations (moving typhoon) allow a physically justified approximation by a system of localized point sources taken with certain weights [Bulatov and Vladimirov, 2018;Furuichi et al, 2008;Gill, 1984;Kang and Fringer, 2010;Lecoanet et al, 2015]. The use of real hydrology allows us to take into account the specific characteristics of wave dynamics with regard to the variability of the marine environment density observed in the field measurements of internal waves in the ocean.…”

Generation of Internal Gravity Waves Far from Moving Non-Local Source

“…One of the mechanisms for the generation of internal gravity waves may be wave fields excitation caused by, for example, a movement of the solid bodies, the turbulent spots, the water lenses and the other non-wave formations with abnormal characteristics [5][6][7]. Of the solutions to the problem of the generation of internal gravity waves-for example, the stream of the stratified fluid, which is flowing past some non-local obstacle-the most widespread are the following two methods [20,21,[25][26][27]. The first method considers the numerical solution of the linearized system of the hydrodynamics equations of describing the internal waves, a shortcoming of which may be the limitation of the field of integration of the space, in which there is a possibility to have the numerical solution to the problem.…”