General effects of currents and sound-speed variations on short-range acoustic transmission in cyclonic eddies

Henrick, R. F.; Jacobson, M. J.; Siegmann, William L.

doi:10.1121/1.384471

Cited by 16 publications

(11 citation statements)

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“…20 Only small horizontal refraction was demonstrated theoretically for deepwater situations involving, for example, strong eddies and currents. 21,22 This paper contains three principal contributions. First, the dominant signals generated by the airgun source are broadband pulses below 100 Hz, with relatively less energy up to 180 Hz.…”

Section: Introductionmentioning

confidence: 99%

Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves

Frank

Badiey

Lynch

et al. 2005

The Journal of the Acoustical Society of America

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The 1995 SWARM experiment collected high quality environmental and acoustic data. One goal was to investigate nonlinear internal wave effects on acoustic signals. This study continues an investigation of broadband airgun data from the two southwest propagation tracks. One notable feature of the experiment is that a packet of nonlinear internal waves crossed these tracks at two different incidence angles. Observed variations for the lower angle track were modeled using two-dimensional parabolic equation calculations in a previous study. The higher incidence angle is close to critical for total internal reflection, suggesting that acoustic horizontal refraction occurs as nonlinear internal waves traverse this track. Three-dimensional adiabatic mode parabolic equation calculations reproduce principal features of observed acoustic intensity variations. The correspondence between data and simulation results provides strong evidence of the actual occurrence of horizontal refraction due to nonlinear internal waves.

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Section: Introductionmentioning

confidence: 99%

Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves

Frank

Badiey

Lynch

et al. 2005

The Journal of the Acoustical Society of America

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“…Previous studies have addressed the question of the impact of oceanic eddies on sound propagation, mostly for surface intensified eddies. Henrick et al (1980) [12] introduced an acoustic model that related sound speed variations to the eddy radii and rotation rates. Bong-Chae et al (2012) [13] investigated eddies in the East/Japan Sea near the Korean Peninsula.…”

Section: Introductionmentioning

confidence: 99%

Effect of Subsurface Mediterranean Water Eddies on Sound Propagation Using ROMS Output and the Bellhop Model

Bozroudi

Ciani

Mahdizadeh

et al. 2021

Water

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Ocean processes can locally modify the upper ocean density structure, leading to an attenuation or a deflection of sound signals. Among these phenomena, eddies cause significant changes in acoustic properties of the ocean; this suggests a possible characterization of eddies via acoustics. Here, we investigate the propagation of sound signals in the Northeastern Atlantic Ocean in the presence of eddies of Mediterranean Water (Meddies). Relying on a high-resolution simulation of the Atlantic Ocean in which Meddies were identified and using the Bellhop acoustic model, we investigated the differences in sound propagation in the presence and absence of Meddies. Meddies create sound channels in which the signals travel with large acoustic energy. The transmission loss decreases to 80 or 90 dB; more signals reach the synthetic receivers. Outside of these channels, the sound signals are deflected from their normal paths. Using receivers at different locations, the acoustic impact of different Meddies, or of the same Meddy at different stages of its life, are characterized in terms of angular distributions of times of arrivals and of energy at reception. Determining the influence of Meddies on acoustic wave characteristics at reception is the first step to inverting the acoustic signals received and retrieving the Meddy hydrological characteristics.

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“… Henrick et al [1977] presented a model of acoustically relevant sound speed perturbation and currents, relating these environmental effects to the parameters characterizing the eddy size and strength. With the model, the influences of the current and the sound speed variation on the travel time and the phase variation were examined [ Henrick et al , 1980]. These numerical studies were carried out in deep sea acoustical environments, which are different from the shallow waters, such as the ECS shelf area.…”

Section: Introductionmentioning

confidence: 99%

Acoustic transmission in the cold eddy in the southern East China Sea

et al. 2006

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An acoustic transmission experiment with the hydrological observation was carried out in the southern East China Sea (ECS) in summer 2003. The experiment site was located at a northwestern position of a cold eddy. The comb‐structure of multipath signals, a feature of the acoustic transmission in the typical shallow water with thermocline, is received by the receiver positioned in the mixed layer. The formation of the comb‐structure is explained with the normal modes in a depth‐mode‐number space, combined with modal group velocities (GVs). The cold eddy has influence on the mode patterns and the modal GVs, and the multipath structure of received signals.

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General effects of currents and sound-speed variations on short-range acoustic transmission in cyclonic eddies

Cited by 16 publications

References 0 publications

Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves

Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves

Effect of Subsurface Mediterranean Water Eddies on Sound Propagation Using ROMS Output and the Bellhop Model

Acoustic transmission in the cold eddy in the southern East China Sea

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