Temporal sound field fluctuations in the presence of internal solitary waves in shallow water

Katsnelson, Boris; Григорьев, В. А.; Badiey, Mohsen; Lynch, James F.

doi:10.1121/1.3151719

Cited by 22 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The refraction can cause sound convergence within internal-wave ducts or divergence from antiducts (Katsnelson and Pereselkov, 2000;Badiey et al 2005: Frank et al, 2005, and fluctuating sound radiation from terminating ducts (Lin et al, 2009). Further effects observed as a result of horizontal refraction are sharp intensity fluctuations and frequency-dependent fluctuations (Badiey et al, 2007;Katsnelson et al, 2008;Katsnelson et al, 2009;Badiey et al, 2011), plus rapidly varying modal arrivals, including nulling of modes that would be prominent in the absence of the waves (Lin et al, 2009). Both the across-wave and along-wave situations cause rapid changes in the nature of received acoustic signals.…”

Section: B Prior Workmentioning

confidence: 99%

Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity

Duda

Collis

Lin

et al. 2012

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

Sound at 85 to 450 Hz propagating in approximately 80-m depth water from fixed sources to a joint horizontal/vertical line array (HLA/VLA) is analyzed. The data are from a continental shelf area east of Delaware Bay (USA) populated with tidally generated long-and short-wavelength internal waves. Sound paths are 19 km in the along-shore (along internal-wave crest) direction and 30 km in the cross-shore direction. Spatial statistics of HLA arrivals are computed as functions of beam steering angle and time. These include array gain, horizontally lagged spatial correlation function, and coherent beam power. These quantities vary widely in magnitude, and vary over a broad range of time scales. For example, correlation scale can change rapidly from forty to five wavelengths, and correlation-scale behavior is anisotropic. In addition, the vertical array can be used to predict correlation expected for adiabatic propagation with cylindrical symmetry, forming a benchmark. Observed variations are in concert with internal-wave activity. Temporal variations of three coherence measures, horizontal correlation length, array gain, and ratio of actual correlation length to predicted adiabatic-mode correlation length, are very strong, varying by almost a factor of ten as internal waves pass.

show abstract

Section: B Prior Workmentioning

confidence: 99%

Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity

Duda

Collis

Lin

et al. 2012

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

show abstract

“…These internal waves are the precursors of many high-frequency nonlinear internal waves on the shelf that are known to have noticeable time-dependent effects on sound propagation [1][2][3]. Because the majority of the nonlinear waves travel towards the shore [4], three processes at the shelf edge are of interest: generation of long-wavelength internal waves at the shelf edge, conversion of these internal waves to shelf waves, and conversion of incident deep-water waves to shelf waves.…”

Section: Introductionmentioning

confidence: 99%

Studies of internal tide generation at a slope with nonlinear and linearized simulations: Dynamics and implications for ocean acoustics

2012

View full text Add to dashboard Cite

Under the framework of a project to model submesoscale processes in support of underwater acoustic predictions, flow fields within an across-shelf section of continental shelf and slope have been modeled with the Regional Ocean Modeling System (ROMS). The model has been run with several versions of ocean dynamics in order to deduce the effects of various dynamical processes. The findings are that momentum advection causes nonlinear effects to occur in the formation of internal tides (internal waves) from barotropic surface tides, not unexpectedly. The nonlinear nature of the process is quantified. This study differs from many prior computational studies of internal tide generation at sloping bathymetry by having a very high resolution, by having very low background eddy viscosity and diffusivity, and by admitting the majority of mixing through a turbulent mixing closure scheme. The initial new results shown here appear in the nonlinear simulations. Zones of nonlinear wave-wave interactions are mapped with bispectrum and bicoherence analysis. The net result of the nonlinearity and weak background eddy mixing is a broadband internal wave spectrum. Technical aspects of using information from internal tide generation models such as this to initialize coastal internal wave models for use with acoustic propagation models are discussed.

show abstract

“…Details of mode coupling mechanism for a similar case is shown in Ref. 7 and falls in the category of higher order effects. Other observable effects, for example, temporal fluctuations of intensity such as the intensity fringes seen in the data, are also higher order effects that need to be considered in more detail.…”

Section: à2mentioning

confidence: 99%

“…Except for mode 6, which is very weak compared to the rest of the modes, both components of these energies exist in various levels of intensity in each mode. 7 However, the ratio of the energies between the primary and secondary paths varies from mode to mode with the secondary path always smaller than the primary path energy. Since the goal here is only to establish the existence of the primary and secondary horizontal modal ray paths, and not the intermodal energy partitioning, we focus our attention on the mode that shows an almost equal energy ratio between these two, which is mode 4.…”

Section: Experimental Observationmentioning

confidence: 99%

Acoustic multipath arrivals in the horizontal plane due to approaching nonlinear internal waves

Badiey

Katsnelson

Lin

et al. 2011

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

Simultaneous measurements of acoustic wave transmissions and a nonlinear internal wave packet approaching an along-shelf acoustic path during the Shallow Water 2006 experiment are reported. The incoming internal wave packet acts as a moving frontal layer reflecting (or refracting) sound in the horizontal plane. Received acoustic signals are filtered into acoustic normal mode arrivals. It is shown that a horizontal multipath interference is produced. This has previously been called a horizontal Lloyd’s mirror. The interference between the direct path and the refracted path depends on the mode number and frequency of the acoustic signal. A mechanism for the multipath interference is shown. Preliminary modeling results of this dynamic interaction using vertical modes and horizontal parabolic equation models are in good agreement with the observed data.

show abstract

Temporal sound field fluctuations in the presence of internal solitary waves in shallow water

Cited by 22 publications

References 4 publications

Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity

Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity

Studies of internal tide generation at a slope with nonlinear and linearized simulations: Dynamics and implications for ocean acoustics

Acoustic multipath arrivals in the horizontal plane due to approaching nonlinear internal waves

Contact Info

Product

Resources

About