Gas bubbles are ubiquitous in the ocean and play a role in a variety of important processes including the the transfer of gas and momentum between the atmosphere and the sea, the transport of surfactants in the upper ocean, the generation of seeds for rain, and the transport of methane and other gases from the seabed toward the ocean surface.
Acoustically, individual gas bubbles in fluids can be modeled as simple harmonic oscillators. Their behavior near resonance makes them particularly strong acoustic targets for their size, and makes acoustic remote sensing a useful strategy for assessing their presence, their quantity, and their evolution over time. In this talk we will explore bubbles in the ocean, discuss some of the acoustic techniques we commonly use for investigating bubbles, and look ahead toward more sophisticated broadband echosounding techniques for quantifying bubbles (e.g., their size and quantity) in the ocean.