Atmospheric acoustics

목차 (Table of Contents)

• CONTENTS
• Preface = vi
• Foreword = vii
• 1 Introduction = 1
• 1.1 Scope of the discipline and historical review = 1
• 1.2 Structure and acoustic properties of the atmosphere = 5
• 1.2.1 Stratification structure of the atmosphere = 5
• 1.2.2 Turbulence structure of the atmosphere = 7
• 1.2.3 The acoustic properties of the atmosphere = 9
• 1.3 Thermodynamic relationships in the atmosphere = 12
• 1.3.1 Equation of state and adiabatic equation = 12
• 1.3.2 Barometric equation and scale height, isothermal atmosphere and atmosphere with constant temperature gradient = 13
• 1.3.3 Potential temperature and Vaisala-Brunt frequency = 15
• 1.4 Fundamental relations of atmospheric dynamics = 17
• 1.4.1 Equation of motion = 17
• 1.4.2 Equation of continuity, equation of state, tensor presentation = 18
• 1.4.3 Conservation laws = 19
• 1.4.4 Geopotential altitude and Coriolis force = 21
• 1.5 Types of atmospheric waves = 22
• 2 Basic Concepts and Processing Methods = 28
• 2.1 Wave equation in homogeneous atmosphere = 28
• 2.1.1 Derivation of the wave equation = 28
• 2.1.2 Velocity potential (acoustic potential) and wave equation including quantities of second order = 29
• 2.1.3 Helmholtz equation = 30
• 2.2 Energy relations in acoustic waves = 31
• 2.2.1 Energy and energy flow density in acoustic waves = 31
• 2.2.2 Momentum in acoustic waves and time-averaged values of acoustic pressure = 33
• 2.2.3 Lagrange density in acoustic waves = 35
• 2.3 Wave equation in inhomogeneous atmosphere = 37
• 2.3.1 Wave equation and solution-defining conditions = 37
• 2.3.2 Review of the existing solutions = 39
• 2.4 WKB approximation = 42
• 2.4.1 General remarks = 42
• 2.4.2 Airy functions = 43
• 2.4.3 The wave field in the presence of a turning point = 45
• 2.5 Normal mode solutions = 47
• 2.5.1 Image of virtual sources = 48
• 2.5.2 Integral representation of the field = 49
• 2.5.3 Normal modes = 51
• 2.5.4 Cases of arbitrary boundaries = 53
• 2.6 Basic concepts of geometrical (ray) acoustics = 54
• 2.6.1 Wave fronts, rays and eikonal = 54
• 2.6.2 Ray-tracing equations = 56
• 2.6.3 Fermat's principle = 57
• 3 Sound Propagation in Atmosphere - Refraction and Reflection = 60
• 3.1 Sound propagation in quiescent homogeneous media = 61
• 3.1.1 Parametric description of wave fronts = 61
• 3.1.2 Variation of principal radii of curvature along a ray = 62
• 3.1.3 Caustic surface = 63
• 3.2 Sound refraction in stratified in homogeneous media = 64
• 3.2.1 Refraction caused by sound-speed gradients = 64
• 3.2.2 Refraction caused by windspeed gradients = 66
• 3.3 Acoustic rays in the atmosphere = 68
• 3.3.1 Ray integrals = 68
• 3.3.2 Rays in waveguides = 69
• 3.3.3 "Abnormal" propagation = 70
• 3.4 Amplitude variations in quiescent media = 73
• 3.4.1 Wave amplitude in quiescent and homogeneous media = 73
• 3.4.2 Energy conservation along rays : extension to slowly-varying media = 76
• 3.5 Amplitude variations in moving media = 77
• 3.5.1 Wave equation in moving media = 77
• 3.5.2 Conservation of wave action quantities = 78
• 3.6 Sound wave reflection from the interface between two media = 81
• 3.6.1 Reflection of plane waves from rigid boundaries = 82
• 3.6.2 Reflection of plane waves at planes with finite specific acoustic impedances = 83
• 3.6.3 Locally-reacting surfaces = 84
• 3.6.4 Sound field above reflecting surfaces = 85
• 3.7 Effects of ground surfaces = 86
• 3.7.1 Expressions of sound fields above porous half-space media = 87
• 3.7.2 Ground wave and surface wave = 88
• 3.7.3 Four-parameter semi-empirical expression for calculating ground impedances = 89
• 3.7.4 Excess attenuation due to the ground surfaces = 92
• 3.7.5 Effects of topography = 92
• 4 Sound Scattering and Diffraction in Atmosphere = 97
• 4.1 Basic concepts of scattering = 98
• 4.1.1 Scattering of fixed rigid object = 98
• 4.1.2 Scattering cross section = 100
• 4.2 Scattering due to non-homogeneity = 101
• 4.2.1 Differential equation for scattering = 101
• 4.2.2 Integral equation for scattering = 102
• 4.2.3 Asymptotic expression for scattered waves = 102
• 4.2.4 Born approximation = 103
• 4.3 Interactions between atmospheric turbulences and acoustic waves = 105
• 4.3.1 Separating acoustic waves from turbulence = 105
• 4.3.2 Wave equation in turbulent atmosphere = 106
• 4.3.3 Interaction mechanisms between turbulence and acoustic waves = 110
• 4.4 Sound scattering in turbulent atmosphere = 115
• 4.4.1 Scattering cross section = 115
• 4.4.2 Power ratio = 116
• 4.4.3 Power spectra = 118
• 4.5 Sound diffraction in quiescent atmosphere = 120
• 4.5.1 Point source above a locally-reacting surface = 121
• 4.5.2 Sound field expressions in the shadow zone = 123
• 4.5.3 Series expansion of diffraction formula = 124
• 4.5.4 Creeping wave = 126
• 4.5.5 Geometric-acoustical interpretation of creeping waves = 128
• 4.6 Sound diffraction in moving atmosphere = 130
• 4.6.1 Fundamental equations and formal solutions = 130
• 4.6.2 Normal mode expansions = 132
• 4.6.3 Asymptotic expressions for the eigen-values = 133
• 4.6.4 Asymptotic expressions of the eigen-functions = 135
• 4.6.5 Approximated expressions for the diffraction field = 138
• 4.6.6 Analyses and conclusions = 141
• 5 Sound Absorption in Atmosphere = 145
• 5.1 Classical absorption = 146
• 5.1.1 Equation of motion for viscous fluid - Navier-Stokes equation = 146
• 5.1.2 Equation of heat-conduction = 148
• 5.1.3 Energy relationships of acoustic waves in viscous and heat-conducting fluids = 149
• 5.1.4 Sound absorption coefficient in viscous and heat-conducting fluids = 151
• 5.1.5 Practical classical sound absorption coefficient = 152
• 5.1.6 Wave modes in viscous and heat-conducting media = 153
• 5.2 Molecular rotational relaxation absorption = 157
• 5.2.1 Absorption mechanism for modes of the internal degrees of freedom = 157
• 5.2.2 Rotational relaxation contributions = 158
• 5.2.3 Collision reaction rate = 159
• 5.2.4 Absorption coefficient due to rotational relaxation = 160
• 5.3 Molecular vibrational relaxation absorption = 161
• 5.3.1 The exchange rate in mole numbers for vibration excited molecules = 161
• 5.3.2 Dynamic adiabatic compression modulus = 164
• 5.3.3 Vibration relaxation sound absorption coefficient = 165
• 5.3.4 Vibration relaxation frequencies for oxygen and nitrogen = 167
• 5.3.5 Mole fraction (molecular concentration) of water vapor = 168
• 5.4 Total absorption coefficient and additional absorption = 170
• 5.4.1 Total absorption coefficient = 170
• 5.4.2 Additional sound absorption = 171
• 5.5 Sound absorption in fog and suspended particles = 173
• 5.5.1 Historical review = 173
• 5.5.2 Basic analyses : mass transfer process = 175
• 5.5.3 Further analyses = 177
• 6 Effects from Gravity Field and Earth's Rotation = 181
• 6.1 Wave system in quiescent atmosphere = 182
• 6.1.1 Fundamental equations and frequency dispersion equation = 182
• 6.1.2 Internal waves = 184
• 6.1.3 Phase velocity and group velocity = 186
• 6.2 Waves in moving inhomogeneous atmosphere = 188
• 6.2.1 Fundamental equations and the processing procedures = 188
• 6.2.2 Transition to isothermal atmosphere, slowly-varying atmosphere = 190
• 6.2.3 Velocity divergence equation = 192
• 6.2.4 Energy density and Lagrange density = 193
• 6.3 Polarization relations = 195
• 6.3.1 Phase relations between perturbed quantities = 195
• 6.3.2 Air-parcel orbits = 198
• 6.3.3 Complex polarization terms = 199
• 6.4 Rossby waves = 200
• 6.4.1 Geostrophic wind = 200
• 6.4.2 Formation of Rossby wave = 201
• 6.4.3 Properties of Rossby wave = 203
• 6.5 External waves = 205
• 6.5.1 Characteristic surface waves = 205
• 6.5.2 Comparison with internal waves = 208
• 6.5.3 Boundary waves = 210
• 6.6 Atmospheric tides = 212
• 6.6.1 Outlines = 212
• 6.6.2 Theory = 214
• 7 Computational Atmospheric Acoustics = 220
• 7.1 Fast field program(FFP) = 221
• 7.1.1 Helmholtz equation, axial symmetric approximation = 222
• 7.1.2 Solutions of the Helmholtz equation = 226
• 7.1.3 Field at the receiver = 228
• 7.1.4 Improvements to the accuracy of numerical evaluations = 231
• 7.1.5 FFP solutions in homogeneous atmosphere in two dimensions = 231
• 7.2 Parabolic equation(PE) methodⅠ : Crank-Nicholson parabolic equation(CNPE) method = 233
• 7.2.1 Derivation of narrow-angle PE and wide-angle PE = 235
• 7.2.2 Finite-difference solutions of narrow-angle PE and wide-angle PE = 237
• 7.2.3 Effects of density profile = 240
• 7.2.4 Finite-element solutions = 241
• 7.3 Parabolic equation(PE) methodⅡ : Green function parabolic equation(GFPE) method = 242
• 7.3.1 Unbounded non-refracting atmosphere = 242
• 7.3.2 Refracting atmosphere = 246
• 7.3.3 Three-dimensional GFPE method = 247
• 7.4 Ray tracing = 251
• 7.4.1 Ray equations = 251
• 7.4.2 Concrete example for numerical integration - ray tracing for the infrasonic waves generated by typhoon = 255
• 7.4A : Ray theory for an absorbing atmosphere = 257
• 7.4A.1 The generalized dispersion equation = 258
• 7.4A.2 The generalized Hamilton equation = 261
• 7.4A.3 The generalized ray equations and fermat's principle = 263
• 7.5 Gaussian beam(GB) approach = 266
• 8 Acoustic Remote Sensing for the Atmosphere = 271
• Part One : Acoustic remote sensing for the lower atmosphere(troposphere) = 272
• 8Ⅰ.1 Probing system = 272
• 8Ⅰ.2 The physical foundations of acoustic sounding = 277
• 8Ⅰ.3 Outputs of the acoustic sounder = 285
• 8Ⅰ.4 Systematical algorithm for acquiring wind profiles from SODAR = 290
• 8Ⅰ.5 Passive remote sensing = 296
• Part Two : Acoustic remote sensing for the upper atmosphere = 297
• 8Ⅱ.1 Physical foundations of acoustic remote sensing for upper atmosphere = 298
• 8Ⅱ.2 Detecting systems for remote sensing = 300
• 8Ⅱ.3 Recognition of waves in the atmosphere = 303
• 8Ⅱ.4 Passive remote sensing of infrasonic waves existing objectively in atmosphere = 305
• 9 Non-linear Atmospheric Acoustics = 309
• 9.1 Non-linear effects in sound propagation = 309
• 9.1.1 Plane waves in homogeneous media = 309
• 9.1.2 Synopsis of shock waves = 312
• 9.1.3 Generation of harmonic waves = 313
• 9.1.4 Nonlinear dissipative waves, Burger's equation = 316
• 9.1.5 Nonlinear waves propagating in inhomogeneous media = 318
• 9.2 Sonic boom = 319
• 9.2.1 Fundamental theory of sonic boom = 320
• 9.2.2 Focus of sonic boom = 324
• 9.2.3 Thickness of shock wave = 325
• 9.2.4 Simulating programs of sonic boom = 325
• 9.3 Recent researches for sound waves in atmospheric turbulence = 326
• 9.3.1 Influences from intermittence = 327
• 9.3.2 Influences from anisotropy in small-sized turbulence = 328
• 9.3.3 Influence from quasi-periodic coherent structure of atmosphere boundary layer(ABL) on low-frequency power spectra of back-wave signals = 330
• 9.3.4 Influences from coherent structure on the propagation of pulses in ABL = 330
• 9.3.5 Sound scattering from anisotropy structure in mid-atmosphere = 331
• 9.3.6 Influences from turbulence on non-linear waves = 332
• 9.4 Atmospheric solitary waves = 334
• 9.4.1 Fundamental equations for atmospheric solitary waves = 334
• 9.4.2 Detection of atmospheric solitary waves = 338
• 10 Sound Sources in Atmosphere = 341
• 10.1 Fundamental sound sources = 341
• 10.1.1 Monopole sources = 341
• 10.1.2 Dipole source = 342
• 10.1.3 Quadrupole sources = 344
• 10.1.4 Piston sources = 344
• 10.1.5 Fluid sources = 345
• 10.2 Natural sound sources = 346
• 10.2.1 Ocean waves = 346
• 10.2.2 Heavy objects falling down into water = 352
• 10.2.3 Violent firing = 354
• 10.2.4 Strong wind = 357
• 10.2.5 Earthquake = 359
• 10.2.6 Volcano eruption and meteorite fall = 360
• 10.2.7 Aurora = 360
• 10.2.8 Others = 362
• 10.3 Artificial sound sources = 362
• 10.3.1 Airplanes = 362
• 10.3.2 Rockets = 362
• 10.3.3 Explosions in upper atmosphere = 363
• 10.3.4 Nuclear tests in atmosphere = 363
• 10.3.5 Explosion of U.S. space shuttle "Challenger" = 364
• References = 365