Long-Lived Bubbles and Their Impact on Underwater Acoustic Communication.

The impact of bubbles on underwater acoustic communication has mostly been studied in environments with strong winds (> 12 m/s), and it has been found that the main impact is the strong attenuation due to dense bubble clouds. Without continuous replenishment during high winds, these dense bubble clouds dissipate rapidly in a few minutes, along with the strong attenuation. We find that after the dense bubble clouds dissipate, they leave behind a diffused bubble cloud with very small bubbles. The lifetime of this diffused bubble cloud is much longer than that of the dense bubble cloud. The attenuation due to these residual bubbles is small, but they result in an increase in channel variability due to their random motion. Furthermore, because they can be transported by currents to distant locations, we argue that these bubbles have a more persistent impact in many environments, including ones where winds are not very strong, but there are other sources of bubbles (e.g., shipping channels). We give a statistical characterization of the propagation through these bubbles, and show the impact on acoustic communications with experimental data. [ABSTRACT FROM AUTHOR]