scholarly journals Spatial structure of ambient noise in shallow water

1993 ◽  
Vol 94 (3) ◽  
pp. 1825-1825
Author(s):  
Michael J. Buckingham
Keyword(s):  
Spatial Structure ◽  
Shallow Water ◽  
Ambient Noise

Analysis and Modeling of Ambient Noise in Shallow Water of Arabian Sea

2012 ◽  
Vol 2 (6) ◽  
pp. 271-272
Author(s):  
Sudhir Pal Singh Rawat ◽  
◽  
Dr. Arnab Das ◽  
Dr. H.G.Virani Dr. H.G.Virani ◽  
Dr. Y.K.Somayajulu Dr. Y.K.Somayajulu
Keyword(s):  
Shallow Water ◽  
Arabian Sea ◽  
Ambient Noise

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

A Two-Dimensional Dynamical Model for the Subseasonal Variability of the Asian Monsoon Anticyclone

2018 ◽  
Vol 75 (10) ◽  
pp. 3597-3612 ◽  
Author(s):  
Arata Amemiya ◽  
Kaoru Sato
Keyword(s):  
Spatial Structure ◽  
Shallow Water ◽  
Asian Monsoon ◽  
Dynamical Instability ◽  
Water Model ◽  
Boreal Summer ◽  
Shallow Water Model ◽  
Model Composite ◽  
Characteristic Structure ◽  
Subseasonal Variability

The Asian monsoon anticyclone, which develops in the upper troposphere and lower stratosphere during boreal summer, exhibits significant subseasonal variability with a characteristic spatial structure. The dynamics of this variability is investigated using a nonlinear β-plane shallow-water model. The equivalent depth is estimated using reanalysis data to relate the three-dimensional dynamics in isentropic coordinates to the shallow-water model. Composite analysis reveals the resemblance of the horizontal structures between the Montgomery streamfunction and thickness on the 360-K level. However, the coefficients of the linear regressions between those two variables are strongly dependent on latitude. The estimated equivalent depths of the northern region are more than 2 times greater than those of the southern region. This is attributable to the background thermal structure around the tropopause. Based on this, a latitude-dependent mean depth is incorporated into the shallow-water model to numerically investigate responses to a steady localized forcing in the subtropics. With the inclusion of the latitudinal dependence of the mean depth, the vortex shedding state is able to have a longitudinally confined structure, which differs from the conventional case of constant mean depth. The spatial structure of this numerical solution corresponds to the observed structure, in which low-PV air is largely confined to finite longitudes within the Asian monsoon anticyclone. This suggests the possible role of dynamical instability and the interaction with the subtropical jet in determining the characteristic structure of the Asian monsoon anticyclone.

Geo-acoustic Inversion Using Shallow Water Ambient Noise and Analysis of Uncertainty

2010 ◽  
Author(s):  
Jianheng Lin ◽  
Baoyou Yin ◽  
Xuejuan Yi ◽  
Jeffrey Simmen ◽  
Ellen S. Livingston ◽  
...  
Keyword(s):  
Shallow Water ◽  
Ambient Noise ◽  
Acoustic Inversion

Low Frequency Wind Generated Ambient Noise in Shallow Water

1988 ◽  
pp. 273-280
Author(s):  
Henrik Schmidt ◽  
Tuncay Akal ◽  
W. A. Kuperman
Keyword(s):  
Shallow Water ◽  
Ambient Noise ◽  
Low Frequency

scholarly journals A Prediction Method for Acoustic Intensity Vector Field of Elastic Structure in Shallow Water Waveguide

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Wenbo Wang ◽  
Desen Yang ◽  
Jie Shi
Keyword(s):  
Spatial Structure ◽  
Shallow Water ◽  
Transfer Functions ◽  
Source Parameters ◽  
Prediction Method ◽  
Sound Field ◽  
Elastic Structure ◽  
Superposition Method ◽  
Acoustic Intensity ◽  
Sound Energy

Compared with scalar sound field, vector sound field explained the spatial structure of sound field better since it not only presents the sound energy distribution but also describes the sound energy flow characteristics. Particularly, with more complicated interaction among different wavefronts, the vector sound field characteristics of an elastic structure in a shallow water waveguide are worthy of studying. However, there is no reliable prediction method for the vector sound field of an elastic structure with a high efficiency in a shallow water waveguide. To solve the problem, transfer functions in the waveguide have been modified with some approximations to apply for the vector sound field prediction of elastic structures in shallow water waveguides. The method is based on the combined wave superposition method (CWSM), which has been proved to be efficient for predicting scalar sound field. The rationality of the approximations is validated with simulations. Characteristics of the complex acoustic intensity, especially the vertical components are observed. The results show that, with constructive and destructive interferences in the depth direction, there could be quantities of crests and vortices in the spatial structure of time-dependent complex intensity, which manifest a unique dynamic characteristic of sound energy. With more complicated interactions among the wavefronts, a structure source could not be equivalent to a point source in most instances. The vector sound field characteristics of the two sources could be entirely different, even though the scalar sound field characteristics are similar. Meanwhile, source types, source parameters, ocean environment parameters, and geo parameters may have influence on the vector sound field characteristics, which could be explained with the normal mode theory.

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