Title

Multibeam sonar observations of near-surface bubbles during a storm

Abstract

In October 2006, a reson SeaBat 7125 multibeam sonar (400 kHz) mounted on the drop keel of the R/V Hugh Sharp was used to collect acoustic backscatter from bubbles generated by breaking wind‐waves in the Gulf of Maine. The multibeam sonar has a very high spatial resolution, with 256 1.0×0.5 deg beams. The data of interest here were collected as the shipreturned to port because of bad weather (sustained 15 m/s wind speed), traveling through the plumes of breaking waves. Data were collected at a ping rate that varied between 5–10 pings/s. These observations show frequent breaking wave bubble plumes extending up to 12 m deep. The data also show that preferential concentrations of bubbles (clusters) were often present.Correlation functions (e.g., the pair correlation) describing the bubble clustering have been extracted from this data, and their affect on acoustic propagation characteristics (sound speed, attenuation) will be presented. [Work supported by ONR Ocean Acoustics.]

Publication Date

2007

Journal or Conference Title

Journal of the Acoustical Society of America

Volume

122, Issue 5

Pages

2948

Publisher

Acoustical Society of America

Digital Object Identifier (DOI)

10.1121/1.2942502

Document Type

Journal Article