Acoustical Probing for Microbubbles at Sea
Abstract
Free gas bubbles have been indicted for many physical processes at sea including: scavenging detritus and chemicals from the ocean volume; generating droplets whose salts affect thunderstorm activity over the sea; providing cavitation nuclei; producing sound scatter and sound attenuation. It is the latter two phenomena that make acoustic measurements the most promising pathway for conducting a census of bubble populations. In particular, the very large scattering and extinction cross sections of a bubble at resonance, and the dispersion of sound speed in bubbly water, have made it possible to recently obtain marine bubble populations as a function of radius from 20 to 300 microns at depths to 15 metres. The growing knowledge of bubble numbers and behaviour will, in turn, permit more accurate predictions of sound propagation and fluctuations, particularly near the sea surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- AD1114366
Entities
People
- Herman Medwin