Monitoring Air-Sea Exchange Processes Using the High Frequency Ambient Sound Field

Abstract

The ambient sound field contains information about the processes generating the sound and the intervening media modifying the sound. This research seeks to demonstrate measurement of useful ocean surface processes using passive measurements of the high frequency underwater ambient sound field. This will allow passive monitoring of environmental conditions from simple and robust sensors, namely hydrophones. In turn, given environmental weather conditions, predictive Naval ocean ambient noise models will be improved. This technique introduces no acoustic disturbance to the environment, and is hence covert and poses no potential harm to marine mammals or other forms of life in the ocean. The frequency range of interest is roughly 200 Hz to 50 kHz. In this frequency range, the dominant sources of sound are breaking wind waves and precipitation. The sound generated by these phenomena can be subsequently modified by ambient bubbles. Breaking waves, precipitation and bubbles are an important part of the exchange of momentum, heat, water and gas between the ocean and the atmosphere. Coupled air-sea models are currently the weakest of the numerical models needed to analyze and forecast environmental (weather) conditions. Modelers have identified the need for data, especially of wind and rain, to develop and verify these models. Acoustical inversion of the sound field should be able to provide these data, even in remote and difficult regions where more conventional measurements are unavailable.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1999
Accession Number
ADA629692

Entities

People

  • Jeffrey Aaron Nystuen

Organizations

  • University of Washington

Tags

Communities of Interest

  • Sensors
  • Space

DTIC Thesaurus Topics

  • Acoustic Detection
  • Acoustic Measurement
  • Acoustics
  • Ambient Noise
  • Data Sets
  • Detection
  • Detectors
  • Drops
  • Frequency
  • Measurement
  • Monitoring
  • Oceans
  • Pacific Ocean
  • Physics Laboratories
  • Rain Gages
  • South China Sea
  • Underwater Sound

Fields of Study

  • Environmental science

Readers

  • Acoustics.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Strategic Security Studies