Laboratory Observations of the Target Strength of Non-Spherical Gas Bubbles in Water

TitleLaboratory Observations of the Target Strength of Non-Spherical Gas Bubbles in Water
Publication TypeJournal Article
Year2015
AuthorsWeber, TC, Pillsbury, L, Loranger, S
JournalThe Journal of the Acoustical Society of America
Volume137(4)
Pages2361-2361
Date PublishedApril 27
PublisherAcoustical Society of America

Naturally occurring methane bubbles in the ocean are often observed to have ellipsoidal or otherwise deformed shapes. Models of acoustic scattering from non-spherical gas bubbles suggest changes in resonance frequency and scattering strength relative to spherical gas bubbles with identical volumes. These changes potentially confound our ability to easily relate measurements of acoustic backscatter from gas bubbles to their size and quantity. To help quantify the magnitude of this effect, we have conducted a series of laboratory measurements of acoustic backscatter from non-spherical air bubbles rising from the bottom of a 6 m deep test tank. The acoustic measurements were made at frequencies between 10 kHz to 150 kHz, well above the frequency of bubble resonance (as is often the case for measurements of methane bubbles in shallow coastal environments). Laboratory measurements of bubbles with different sizes and deformations are compared with models for spherical bubbles with identical volumes.

DOI10.1121/1.4920577
Refereed DesignationRefereed