Ocean Ambient Noise

by Carey, William M.; Evans, Richard B.

• ISBN13: 9781441978318
• ISBN10: 1441978313
• Format: Hardcover
• Copyright: 2011-04-06
• Publisher: Springer Verlag

Summary

This monograph develops the theory of noise mechanisms and measurements, and describes general noise characteristics and computational methods. The vast ambient noise literature is concisely summarized using theory combined with key representative results.The air sea boundary interaction zone is described in terms of nondimensional variables requisite for future experiments. Noise field coherency, rare directional measurements, and unique basin scale computations and methods are presented. The use of satellite measurements in these basin scale models is demonstrated. A series of appendices provides in-depth mathematical treatments which will be of interest to graduate students and active researchers.

Table of Contents

Introduction	p. 1
References and Suggested Readings	p. 7
Ambient Noise Reviews and Proceedings	p. 8
The Air-Sea Boundary Interaction Zone	p. 11
The Marine Boundary Layer	p. 12
The Viscous Sublayer	p. 14
Mechanical Turbulence	p. 14
The Effect of Buoyancy	p. 16
The Influence of Heat Transport	p. 17
The Monin-Obukhov Length	p. 17
The Combined Influence of Mass, Momentum, and Heat Transport	p. 18
The Roughness Scale and Motion of the Surface	p. 20
A Summary of the Wind Stress Coefficient and Critical Friction Velocity	p. 21
Friction Velocity and Breaking Waves	p. 22
The Whitecap Index	p. 27
References and Suggested Readings	p. 29
Fundamental Mechanisms	p. 31
The Inhomogeneous Wave Equation and Sources of Sound	p. 31
The Point Source Solution, Green's Function	p. 33
Solutions to the Inhomogeneous Equation	p. 34
The Sea Surface	p. 37
The Source Integrals	p. 38
References and Suggested Readings	p. 42
The Measurement of Oceanic Ambient Noise	p. 45
Introduction	p. 45
Noise Measurement	p. 46
The Autocorrelation Function, ¿p(¿)	p. 48
The Power Spectral Density	p. 48
Some Simple Statistical Concepts	p. 50
Phenomenological Observations	p. 52
lnfrasonic Noise	p. 54
The Sonic Region	p. 56
The Wind Speed Dependency at Frequencies Less Than 500 Hz	p. 62
Mid- to High-Frequency Wind Speed Dependence	p. 66
Low-Frequency Noise Characteristics	p. 68
Directionality	p. 69
Low-Frequency Directional Noise Characteristics	p. 69
Beam Noise Levels and Horizontal Directionality	p. 70
Vertical Noise Directionality	p. 74
Rain Noise	p. 78
Arctic Ambient Noise	p. 85
Arctic Ambient Noise over the 10 Hz to 1 kHz Band	p. 85
Low-Frequency Arctic Ambient Noise	p. 89
References and Suggested Readings	p. 93
Numerical Modeling of Ambient Noise	p. 99
Introduction	p. 99
Ambient Noise Modeling	p. 100
The Noise Field	p. 102
Plane Wave Response	p. 104
Ambient Noise Computation	p. 107
Parabolic Equation Field Computations	p. 109
Field Interpolation	p. 111
Noise Realizations	p. 112
Environmental Considerations	p. 113
Noise Source Levels	p. 113
Wind Source Levels	p. 114
Shipping Source Levels	p. 115
Ambient Noise Examples	p. 116
UniformNoise	p. 118
Wind Noise	p. 120
Shipping Noise	p. 122
Summary of Examples	p. 124
Summary	p. 124
References and Suggested Readings	p. 126
Research Issues and Applications of Oceanic Noise	p. 129
Summary	p. 129
Noise Mechanisms	p. 131
Hydromechanical Sources of Sound	p. 132
Geoacoustic Uncertainty	p. 133
Correlation Issues	p. 135
Computational Issues	p. 136
References and Suggested Readings	p. 136
Solutions to the Inhomogeneous Wave Equation	p. 141
Derivation of the Inhomogeneous Wave Equation	p. 141
The Retarded Green's Function Solution	p. 144
References and Suggested Readings	p. 147
Solution to the Inhomogeneous Wave Equation	p. 148
References and Suggested Readings	p. 149
The Inhomogeneous Wave Equation with a Surface Boundary Condition: Derivation of the Source Integrals	p. 151
The General Solution	p. 151
The Initial Conditions and Surface Boundary Conditions	p. 151
The Surface Integrals	p. 152
The Volume Integral Over the Source Region	p. 153
The Source Integrals	p. 155
References and Suggested Readings	p. 157
Standard Definitions	p. 159
Harmonic Sound	p. 160
Transient Sounds	p. 161
Energy Flux Source Level	p. 162
Spectral Density of a Transient	p. 162
The Impulse	p. 163
Steady Sounds	p. 163
The Autocorrelation Function	p. 164
The Power Spectral Density	p. 164
Summary	p. 166
A Brief Note on Parseval's Theorem	p. 166
An Engineer's Proof of the Energy Theorem	p. 168
Selected References	p. 170
Applicable Standards	p. 170
A Review of the Sonic Properties of Bubbly Liquids	p. 171
The Mallock-Wood Approach	p. 171
An Extension to Include Bubble Dynamics	p. 175
References and Suggested Readings	p. 181
Radiation and Scattering from Compact Bubble Clouds	p. 185
References and Suggested Readings	p. 191
The Radiation from a Pulsating Sphere	p. 193
The Monopole	p. 195
The Finite-Size Sphere	p. 196
The Bubble as a Monopole Source of Sound	p. 197
The Transient Response of a Bubble	p. 199
References and Suggested Readings	p. 202
Thermal Noise	p. 203
The Modal Density	p. 203
The Modal Energy Density	p. 205
References and Suggested Readings	p. 208
The Lloyd Mirror	p. 209
References and Suggested Readings	p. 216
Sounds from Drop Impacts	p. 217
References and Suggested Readings	p. 219
Source Levels for Wind-Driven Noise	p. 221
References and Suggested Readings	p. 227
Modal Noise Cross-Correlation Matrix	p. 229
References and Suggested Readings	p. 232
Nomenclature	p. 233
Roman Letters	p. 233
Greek Letters	p. 236
Mathematical Operators	p. 237
Abbreviations	p. 237
Bibliography	p. 241
Index	p. 257
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