Wave breaking represents one of the most interesting and challenging problems for fluid mechanics and physical oceanography. Over the last 15 years our understanding has undergone a dramatic leap forward, and wave breaking has emerged as a process whose physics is clarified and quantified. Ocean wave breaking plays the primary role in the air-sea exchange of momentum, mass and heat, and it is of significant importance for ocean remote sensing, coastal and ocean engineering, navigation and other practical applications. This book outlines the state of the art in our understanding of wave breaking and presents the main outstanding problems. It is a valuable resource for anyone interested in this topic: researchers, modellers, forecasters, engineers and graduate students in physical oceanography, meteorology and ocean engineering.
Author(s): Alexander V Babanin
Publisher: Cambridge University Press
Year: 2011
Language: English
Pages: 480
City: Cambridge
Tags: Науки о Земле;Океанология (океанография);
Cover......Page 1
BREAKING AND DISSIPATION OF OCEAN SURFACE WAVES......Page 3
Title......Page 5
Copyright......Page 6
Preface......Page 9
1 Introduction......Page 17
1.1 Wave breaking: the process that controls wave energy dissipation......Page 18
1.2 Concept of wave breaking......Page 20
2 Definitions for wave breaking......Page 28
2.1 Breaking onset......Page 29
2.2 Breaking in progress......Page 30
2.3 Residual breaking......Page 34
2.4 Classification of wave-breaking phases......Page 35
2.5 Breaking probability (frequency of occurrence)......Page 38
2.6 Dispersion relationship......Page 43
2.7 Breaking severity......Page 44
2.8 Types of breaking waves: plunging, spilling and micro-breaking......Page 56
2.9 Criteria for breaking onset......Page 58
2.10 Radiative transfer equation......Page 63
3 Detection and measurement of wave breaking......Page 65
3.1 Early observations of wave breaking, and measurements of whitecap coverage of ocean surface......Page 66
3.2 Traditional means (visual observations)......Page 75
3.3 Contact measurements......Page 79
3.4 Laboratory measurements in deterministic wave fields......Page 85
3.5 Acoustic methods......Page 90
3.6 Remote sensing (radar, optical and infrared techniques)......Page 109
3.7 Analytical methods of detecting breaking events in surface elevation records......Page 114
3.8 Statistical methods for quantifying breaking probability and dissipation......Page 128
4 Fully nonlinear analytical theories for surface waves and numerical simulations of wave breaking......Page 134
4.1 Free surface at the wave breaking......Page 136
4.1.1 Simulating the evolution of nonlinear waves to breaking......Page 140
4.1.2 Simulation of the breaking onset......Page 150
4.1.3 Influence of wind and initial steepness......Page 152
4.2 Lagrangian nonlinear models......Page 155
5 Wave-breaking probability......Page 158
5.1 Initially monochromatic waves......Page 159
5.1.1 Evolution of nonlinear waves to breaking......Page 164
5.1.2 Measurement of the breaking onset; limiting steepness at breaking......Page 166
5.1.3 Laboratory investigation of wind influence......Page 177
5.1.4 Distance to the breaking......Page 181
5.2 Wave-breaking threshold......Page 184
5.3 Spectral waves......Page 191
5.3.1 Breaking probability of dominant waves......Page 192
5.3.2 Breaking probability of small-scale waves......Page 198
5.3.3 Breaking in directional wave fields......Page 215
5.3.4 Wind-forcing effects, and breaking threshold in terms of wind speed......Page 223
6 Wave-breaking severity......Page 235
6.1 Loss of energy by an initially monochromatic steep wave......Page 236
6.2 Dependence of the breaking severity on wave field spectral properties......Page 243
7 Energy dissipation across the wave spectrum......Page 248
7.1 Theories of breaking dissipation......Page 249
7.1.1 Probability, quasi-saturated and whitecap models......Page 250
7.1.2 Kinetic-dynamic model......Page 253
7.2 Simulating the wave dissipation in phase-resolvent models......Page 254
7.3 Measurements of the wave dissipation of spectral waves......Page 262
7.3.1 Laboratory measurements......Page 263
7.3.2 Difference in the spectral distribution of dissipation due to different types of breaking mechanisms......Page 266
7.3.3 Field measurements......Page 268
7.3.4 Cumulative effect......Page 279
7.3.5 Whitecapping dissipation at extreme wind forcing......Page 281
7.3.6 Directional distribution of the whitecapping dissipation......Page 285
7.4 Whitecapping dissipation functions in spectral models for wave forecasting......Page 288
7.5 Non-breaking spectral dissipation......Page 311
8 Non-dissipative effects of breaking on the wave field......Page 338
8.1 Spectral peak downshift due to wave breaking......Page 339
8.2 Role of wave breaking in maintaining the level of the spectrum tail......Page 343
8.3 Wind-input enhancement due to wave breaking......Page 349
9.1 Atmospheric boundary layer......Page 366
9.1.1 Sea-drag dependence on wave breaking......Page 368
9.1.2 Generation of spray......Page 376
9.1.3 Boundary layer at extreme breaking......Page 387
9.2 Upper-ocean mixing......Page 391
9.2.1 Transfer of energy and momentum from the wind to the ocean......Page 392
9.2.2 Generation of turbulence......Page 400
9.2.3 Injecting the bubbles; gas exchange across the surface......Page 412
10 Conclusions. What else do we need to know about wave breaking?......Page 421
References......Page 11
Index......Page 442
