An empirical model for wind-generated ocean noise

Abstract

An empirical model for wind-generated underwater noise is presented that was developed using an extensive dataset of acoustic field recordings and a global wind model. These data encompass more than one hundred years of recording-time and capture high wind events, and were collected both on shallow continental shelves and in open ocean deep-water settings. The model aims to explicitly separate noise generated by wind-related sources from noise produced by anthropogenic sources. Two key wind-related sound-generating mechanisms considered are: surface wave and turbulence interactions, and bubble and bubble cloud oscillations. The model for wind-generated noise shows small frequency dependence (5 dB/decade) at low frequencies (10–100 Hz), and larger frequency dependence (∼15 dB/decade) at higher frequencies (400 Hz–20 kHz). The relationship between noise level and wind speed is linear for low wind speeds (<3.3 m/s) and increases to a higher power law (two or three) at higher wind speeds, suggesting a transition between surface wave/turbulence and bubble source mechanisms. At the highest wind speeds (>15 m/s), noise levels begin to decrease at high frequencies (>10 kHz), likely due to interaction between bubbles and screening of noise radiation in the presence of high-density bubble clouds.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 01, 2021
Source ID
10.1121/10.0005430

Entities

People

  • John A Hildebrand
  • Kaitlin E Frasier
  • Sean M. Wiggins
  • Simone Baumann-Pickering

Organizations

  • Office of Naval Research
  • University of California, San Diego

Tags

Fields of Study

  • Environmental science

Readers

  • Acoustics.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers