Winds, waves, and bubbles at the air-sea boundary

Subsurface bubbles are now recognized as a dominant acoustic scattering and reverberation mechanism in the upper ocean. A better understanding of the complex mechanisms responsible for subsurface bubbles should lead to an improved prediction capability for underwater sonar. The Applied Physics Laboratory recently conducted a unique experiment to investigate which air-sea descriptors are most important for subsurface bubbles and acoustic scatter. Initial analyses indicate that wind-history variables provide better predictors of subsurface bubble-cloud development than do wave-breaking estimates. The results suggest that a close coupling exists between the wind field and the upper-ocean mixing processes, such as Langmuir circulation, that distribute and organize the bubble populations