Relationship between wave states and deep bubble plume formation in the open ocean

Bubbles formed from breaking waves contribute to gaseous exchange of oxygen and carbon dioxide at the air-sea interface. Recent developments in acoustic sensing of bubbles and autonomous underwater platforms have enabled measurements of bubble plumes formed from wave-breaking events, including their penetration depth, interaction with ocean currents and turbulent fluctuations, as well as their lifetimes. However, the relationship between bubble plume characteristics and upper ocean wind and wave states is still incomplete, particularly in high wind and wave conditions and in conditions where strong surface cooling is present. Here we present observational results from the Bubble Exchange in the Labrador Sea (BELS) experiment conducted in December 2023, where Surface Wave Instrument Float with Tracking (SWIFT) buoys deployed measure wind and wave conditions, current velocities below the surface, as well as bubble signals obtained from downward-looking acoustic Doppler current profilers (ADCPs). We find that at conditions of high winds, large significant wave heights, and frequent wave-breaking, bubble depths tend to scale with the local significant wave heights; with greater depth penetration possible at calmer sea states possibly from bubble-turbulence interaction or convective circulations.