Theory and observation of anisotropic and episodic internal wave effects on 100-400 Hz sound
Duda, Timothy F.
MetadataShow full item record
KeywordInternal waves; Nonlinear internal waves; Internal tides; Coherence; Shallow-water acoustics
Propagation of sound through shallow-water internal waves of various types is discussed. The anisotropy of the waves imparts an anisotropy to their effects on sound. The internal waves are of two types: Long-wavelength internal tides and short-wavelength high-frequency waves. On the continental shelf both types of waves tend to move shoreward from deep water (i.e. have anisotropic motion and anisotropic correlation scales). The internal tides are less predictable than the surface tides that generate them. The short-wavelength nonlinear internal waves are also somewhat unpredictable, and also have anisotropic correlation scales, having crests of tens of kilometres in length but wavelengths of order 300 to 1000 m. Coupled-mode propagation dominates across-shelf sound propagation, which in the direction of short internal wave correlation scale. Refracted-mode propagation dominates along-shelf propagation. Data from two sea exercises illustrate the character of the waves and their effects on sound.
Underwater Acoustic Measurements (UAM) 4th International Conference and Exhibition on "Underwater Acoustic Measurements: Technologies & Results." 20-24 June 2011, Kos, Greece
Showing items related by title, author, creator and subject.
Acoustic travel time perturbations due to an internal tide and internal wave field in the Barents Sea Ray, Douglas S. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-08)Travel time perturbations of adiabatic normal modes due to an internal tide and internal mode field in the Barents Sea are examined. A formalism for the travel time perturbation due to a change in sound speed is presented. ...
Internal tide and nonlinear internal wave behavior at the continental slope in the northern south China Sea Duda, Timothy F.; Lynch, James F.; Irish, James D.; Beardsley, Robert C.; Ramp, Steven R.; Chiu, Ching-Sang; Tang, Tswen Yung; Yang, Yiing-Jang (IEEE, 2004-10)A field program to measure acoustic propagation characteristics and physical oceanography was undertaken in April and May 2001 in the northern South China Sea. Fluctuating ocean properties were measured with 21 moorings ...
A science plan for a collaborative international research program on the coupled North Atlantic-Arctic system, a report of a Planning Workshop for an International Research Program on the Coupled North Atlantic-Arctic System developed from a workshop held in Arlington, VA 14-16 April 2014 Hofmann, Eileen E.; St. John, Mike; Benway, Heather M. (Ocean Carbon & Biogeochemistry Program, 2015)This North Atlantic-Arctic science plan is derived from an international workshop held in April 2014 with support from the National Science Foundation Division of Ocean Sciences and the European Union (EU). The workshop ...