Field measurements and modeling of attenuation from near-surface bubbles for frequencies 1-20 kHz.
Measurements of excess attenuation from near-surface bubbles from the Shallow Water '06 experiment are reported. These are transmission measurements made over the frequency range 1-20 kHz, and they demonstrate a frequency, grazing angle, and wind speed dependence in attenuation. Data modeling points to bubble void fractions of order 10(-6) in effect for wind speeds 10-13 m/s. Simultaneous measures of wind speed made within 1.5 and 11 km of the open water experimental location differed by 2 m/s in their respective 30 min average; this has cautionary implications for empirical models for bubble attenuation that are a strong function of wind speed.
Dahl
Peter H
PH
Choi
Jee Woong
JW
Williams
Neil J
NJ
Graber
Hans C
HC
D000162:Acoustics; D008962:Models, Theoretical; D009038:Motion; D009792:Oceans and Seas; D011825:Radar; D013016:Sound; D013499:Surface Properties; D013997:Time Factors; D014919:Wind