Reverberation Level Modeling via Coupled Mode Approach in Shallow-Water Sound Channel with Internal Solitary Waves

2018 ◽  
Vol 27 (04) ◽  
pp. 1850045 ◽  
Author(s):  
Jungyong Park ◽  
Haesang Yang ◽  
Woojae Seong ◽  
Youngmin Choo
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Underwater Sound ◽  
Sound Channel ◽  
Trapped Mode ◽  
Coupled Mode ◽  
Shallow Water Environment ◽  
Mode Method ◽  
Abnormal Increase ◽  
Mode Energy

Reverberation level (RL) is modeled in a shallow water environment with an underwater sound channel and internal solitary wave (ISW) using the coupled mode method. Numerical RL result based on one-way coupled mode shows an abnormal increase when a source is located near the channel axis and the ISW is located far from the source. The abnormal increase is analyzed by using a two-mode approach (assuming a trapped mode and a bottom interacting mode). The two-mode approach explains the relation between the RL increase and the ISW location explicitly: the ISW transfers trapped mode energy to bottom interacting mode energy, and its increasing rate is a function of its modal attenuation and ISW location from the source. The sensitivity test according to several ISW parameters is also performed.

scholarly journals Underwater Sound Propagation Modeling in a Complex Shallow Water Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Tiago C. A. Oliveira ◽  
Ying-Tsong Lin ◽  
Michael B. Porter
Keyword(s):  
Shallow Water ◽  
Normal Mode ◽  
Sound Propagation ◽  
Long Island ◽  
Water Environment ◽  
Long Island Sound ◽  
Underwater Sound ◽  
Shallow Water Environment ◽  
3D Effects ◽  
Island Sound

Three-dimensional (3D) effects can profoundly influence underwater sound propagation in shallow-water environments, hence, affecting the underwater soundscape. Various geological features and coastal oceanographic processes can cause horizontal reflection, refraction, and diffraction of underwater sound. In this work, the ability of a parabolic equation (PE) model to simulate sound propagation in the extremely complicated shallow water environment of Long Island Sound (United States east coast) is investigated. First, the 2D and 3D versions of the PE model are compared with state-of-the-art normal mode and beam tracing models for two idealized cases representing the local environment in the Sound: (i) a 2D 50-m flat bottom and (ii) a 3D shallow water wedge. After that, the PE model is utilized to model sound propagation in three realistic local scenarios in the Sound. Frequencies of 500 and 1500 Hz are considered in all the simulations. In general, transmission loss (TL) results provided by the PE, normal mode and beam tracing models tend to agree with each other. Differences found emerge with (1) increasing the bathymetry complexity, (2) expanding the propagation range, and (3) approaching the limits of model applicability. The TL results from 3D PE simulations indicate that sound propagating along sand bars can experience significant 3D effects. Indeed, for the complex shallow bathymetry found in some areas of Long Island Sound, it is challenging for the models to track the interference effects in the sound pattern. Results emphasize that when choosing an underwater sound propagation model for practical applications in a complex shallow-water environment, a compromise will be made between the numerical model accuracy, computational time, and validity.

Hawaii Experimental Acoustics Range for Shallow Water Applications

2011 ◽  
Vol 45 (3) ◽  
pp. 69-76 ◽  
Author(s):  
Tom Fedenczuk ◽  
Eva-Marie Nosal
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Shallow Water Acoustics ◽  
Central Node ◽  
Long Baseline ◽  
Wide Range ◽  
Shallow Water Environment ◽  
Near Shore ◽  
Monitoring And Surveillance ◽  
Passive Acoustic

AbstractShallow water acoustics provide a means for monitoring and surveillance of near-shore environments. This paper describes the current and future capabilities of the low- to high-frequency Hawaii Experimental Acoustics Range (HEAR) that was designed to facilitate a wide range of different shallow water acoustics experiments and allow researchers from various institutions to test various array components and configurations. HEAR is a portable facility that consists of multiple hydrophones (12‐16) cabled independently to a common central node. The design allows for variable array configurations and deployments in three modes: experimental (off boats and piers), autonomous, and cabled. An application of HEAR is illustrated by the results from a deployment at Makai Research Pier, Oahu, Hawaii. In this deployment, HEAR was configured as a long-baseline range of two volumetric subarrays to study passive acoustic tracking capabilities in a shallow water environment.

scholarly journals Analysis of wind-driven ambient noise in a shallow water environment with a sandy seabed

2008 ◽  
Vol 124 (3) ◽  
pp. EL157-EL162 ◽  
Author(s):  
D. P. Knobles ◽  
S. M. Joshi ◽  
R. D. Gaul ◽  
H. C. Graber ◽  
N. J. Williams
Keyword(s):  
Shallow Water ◽  
Ambient Noise ◽  
Water Environment ◽  
Shallow Water Environment

Aldebarania arenitea, a new genus and species of Astropectinidae (Asteroidea; Echinodermata) from the Maastrichtian (Upper Cretaceous) Peedee Formation of North Carolina

1995 ◽  
Vol 69 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Daniel B. Blake ◽  
Keith Sturgeon
Keyword(s):  
North Carolina ◽  
Shallow Water ◽  
Phylogenetic Relationships ◽  
Upper Cretaceous ◽  
New Genus ◽  
Water Environment ◽  
New Genus And Species ◽  
Marine Fauna ◽  
Shallow Water Environment

Aldebarania arenitea (Astropectinidae; Asteroidea; Echinodermata) is described from the Rocky Point Member of the Maastrichtian (Upper Cretaceous) Peedee Formation of North Carolina. A turbulent, shallow-water environment is suggested by sedimentary features, a diverse marine fauna, and the morphology of Aldebarania. Aldebarania appears to be a partial ecological equivalent of living Astropecten and Luidia; however, phylogenetic relationships within the Astropectinidae are unstudied and the origin of similarities is unknown.

Trilobites from the Ordovician Shihtzupu Formation, Zunyi, Guizhou Province, China

1984 ◽  
Vol 75 (1) ◽  
pp. 13-36 ◽  
Author(s):  
Zhiyi Zhou ◽  
Gongzheng Yin ◽  
Ronald P. Tripp
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Guizhou Province ◽  
Type Section ◽  
Shallow Water Environment ◽  
First Time

ABSTRACTTwenty-seven species assigned to 20 genera of trilobites are described from Feilaishi in Guizhou Province, the type section of the Shihtzupu Formation in S W China. They occur in association with a sparse graptolite fauna including Glyptograptus teretiusculus. Eleven taxa are recorded here for the first time. Much new morphological information is provided regarding previously known species and 3 lectotypes are selected. The trilobites are largely endemic and indicate a quiet and comparatively shallow water environment

scholarly journals Passenger ship source level determination in shallow water environment

2016 ◽  
Author(s):  
Mirko Mustonen ◽  
Aleksander Klauson ◽  
Janek Laanearu ◽  
Madis Ratassepp ◽  
Thomas Folegot ◽  
...  
Keyword(s):  
Shallow Water ◽  
Water Environment ◽  
Passenger Ship ◽  
Shallow Water Environment ◽  
Source Level

scholarly journals Wave Equation Datuming Applied to Seismic Data in Shallow Water Environment and Post-Critical Water Bottom Reflection

Energies ◽  
2017 ◽  
Vol 10 (9) ◽  
pp. 1414 ◽  
Author(s):  
Umberta Tinivella ◽  
Michela Giustiniani ◽  
Ivan Vargas-Cordero
Keyword(s):  
Wave Equation ◽  
Shallow Water ◽  
Seismic Data ◽  
Water Environment ◽  
Shallow Water Environment ◽  
Water Bottom
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