Breaking Waves, Bubbles, and Mixed Layer Turbulence at the Equator

During the recent DYNAMO experiment in the Indian Ocean, a novel "over-the-side" deployment of a phased-array Doppler sonar (PADS) was undertaken to image a vertical slice of waves, wave breaking, bubble injection, and the resulting turbulence and turbulent evolution. Results from this "test deployment" are related to the mixed layer depth as estimated from wire-walker profiles of temperature or density, and to the prevailing wind and wave conditions. Bubble plumes occasionally penetrate below 10m depth, nearly filling the diurnal mixed layer to the base, while more typically the bubbles are confined to just the upper 2-3 meters. Limitations due to motion correction and the very irregular transmission through the near-surface bubble clouds are discussed, and future plans in response to these challenges.