Sea Surface Sound: Natural Mechanisms of Surface Generated Noise in the Ocean

ISBN-13: 9789401078566 / Angielski / Miękka / 2011 / 652 str.

B. R. Kerman

Opis

In its relentless pursuit of further knowledge, science tends to compartmentalize. Over the years the pursuit of What might be called geophysical acoustics of the sea-surface has languished. This has occured even through there are well-developed and active research programs in underwater acoustics, ocean hydrodynamics, cloud and precipitation physics, and ice mechanics - to name a few - as well as a history of engineering expertise built on these scientific fields. It remained to create a convergence, a dialogue across disciplines, of mutual benefit. The central theme of the Lerici workshop, perhaps overly simplified, was 'What are the mechanisms causing ambient noise at the upper surface of the ocean?' What could hydrodynamicists contribute to a better understanding of breaking wave dynamics, bubble production, ocean wave dynamics, or near-surface turbulence for the benefit of the underwater acoustics community? What further insights could fluid dynamicists gain by including acoustic measurements in their repertoire of instrumentation? While every attendee will have his or her percep tions of details, it was universally agreed that a valuable step had been taken to bring together two mature disciplines and that significant co-operative studies would undoubtedly follow. The scope of the workshop was enlarged beyond its original intent to also include the question of ice-noise generation. The success of this decision can be seen in high quality of the presentations. the contribution of its disciples in the other workshop discussions and the heightened awareness and interest of we other novices.

Recenzje

`The papers collected in Sea-surface Sound are a landmark in its field, and will keenly interest marine acousticians and seismologists having primarily theoretical and numerical modeling interests, but will also be valuable for seismic and sonar survey planners interested in reducing ambient noise effects for specific environments.'
Pageoph, 135 (1) 1991

Spis treści

Ocean Wave Dynamics.- Mechanisms of Wave Breaking in Deep Water.- Equilibrium Range Characteristics of Breaking Waves.- Experiments on Breaking Waves.- Wind Waves as a Coupling Process Between Air and Water Turbulent Boundary Layers.- On the Mechanics of Spilling Zones of Quasi-Steady Breaking Waves.- An Estimate of Wave Breaking Probability for Deep Water Waves..- Whitecap Coverage as a Remotely Monitorable Indication of the Rate of Bubble Injection into the Oceanic Mixed Layer.- Wave and Bubble Characteristics in the Surf Zone.- LDA as a New Tool to Detect Air-Sea Interaction Mechanisms.- Feasibility Study of At-Sea Measurement of Ocean-Air Interface Parameters Needed to Evaluate Ocean Surface Generated Noise.- Bubble Dynamics and Observations.- Bubble Noise Creation Mechanisms.- Bubble Dynamics in Oceanic Ambient Noise.- The Horizontal Structure and Distribution of Bubble Clouds.- On the Distribution of Bubbles Near the Ocean Surface.- Study of Micro-Bubbles in the North Sea.- Optical Microbubble Measurements in the North Sea.- Acoustical Estimates of Subsurface Bubble Densities in the Open Ocean and Coastal Waters..- Acoustic Measurements of Bubble Densities at 15–50 kHz.- Propagation Effects.- Propagation Effects Associated with Ambient Noise.- Low Frequency Wind Generated Ambient Noise in Shallow Water.- The Effect of Propagation Conditions on Wind-Generated Noise at Real Shallow Water Sites.- Simultaneous Measurements of Surface Generated Noise and Attenuation at the Fixed Acoustic Shallow Water Range “NORDSEE”.- Wind and Wave Noise.- Mechanisms of Sound Generation at the Ocean Surface.- Ambient Noise Radiation by “Soliton” Surface Waves.- Ocean Noise Spectrum Below 10 hz - Mechanisms and Measurements.- Low Frequency Ocean Ambient Noise: Measurements and Theory.- Estimation of Source Characteristics from Underwater Noisefield Measurements.- Noise Generated by Motion of the Sea Surface - Theory and Measurement.- Observations of High Frequency Ambient Sound Generated by Wind.- On the Spectra of Wind Generated Sound in the Ocean.- Physical Mechanisms of Noise Generation by Breaking Waves - a Laboratory Study.- Audio Signature of a Laboratory Breaking Wave.- Noise Generation by Bubbles Formed in Breaking Waves.- Rain Noise.- Acoustic Emissions Associated with Drop Impacts.- The Sound Generated by Precipitation Striking the Ocean Surface.- Studies of Mechanisms Influencing Rain Noise.- Ice Noise.- Speculations on the Origin of Low Frequency Arctic Ocean Noise.- Observation of the Sound Radiated by Individual Ice Fracturing Events.- The Correlation of Mid-Frequency Pack Ice Noise with Environmental Parameters.- High Frequency Ambient Sound in the Arctic.- Arctic Ocean Noise Generation Due to Pack Ice Kinematics and Heat Fluxes.- Acoustic Ambient Noise in the Arctic Ocean Below the Marginal Ice Zone.- Ice Eddy Ambient Noise.- Panel Discussion Reports.- Breaking Waves.- Study of the Distribution of Bubbles and Turbulence In and Near a Breaking Wave.- Sources of Sound at the Ocean Surface; Bubbles and Other Noise.- Wave and Turbulence Noise.- Precipitation Noise.- Ice Noise.