2019_programme: EXCITATION AND PROPAGATION OF WHISPERING GALLERY WAVES IN THE VICINITY OF CURVILINEAR ISOBATHS IN SHALLOW WATER

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  • Session: 17. Modeling techniques for underwater acoustic scattering and propagation
    Organiser(s): Gunderson Aaron, Isakson Marcia
  • Lecture: EXCITATION AND PROPAGATION OF WHISPERING GALLERY WAVES IN THE VICINITY OF CURVILINEAR ISOBATHS IN SHALLOW WATER [invited]
    Paper ID: 782
    Author(s): Katsnelson Boris, Petrov Pavel
    Presenter: Katsnelson Boris
    Presentation type: oral
    Abstract: In this paper sound signals propagation in a shallow-water area with bowl-like bottom relief which can be part of an underwater canyon, a bay, a lagoon or a lake is studied. Such area is characterized by curvilinear (in particular circular) isobaths with the depth increasing towards their center of curvature (inner part of the bowl). Manifestation of horizontal refraction in this case consists in the existence of whispering gallery waves (WGWs) localized in some vicinity of isobaths. Main attention is paid to conditions and criteria of excitation of such waves by a point source and specific features of their propagation. It is shown that WGWs can be excited by a source localized both inside the area with bowl-like bathymetry and in its exterior. The latter case can take place due to the “tunneling” of sound wave to the inner part of the bowl from the exterior. Efficiency of the tunneling is estimated for realistic waveguide models. The amplitude of excited WGWs depends on the sound frequency, on the position of the source and parameters of the waveguide, in particular, on the curvature radius of isobaths. Modal structure of whispering gallery beam is analyzed both in an analytical form and using numerical modeling within the framework of Parabolic Equation approach. The respective azimuthal wavenumbers and radial mode functions are computed. Dispersion of such waves is also investigated, and the possibility of their experimental observation is discussed.\n\n
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  • Corresponding author: Prof Katsnelson Boris
    Affiliation: University of Haifa
    Country: Israel
    e-mail:

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