Environmentally Adaptive Deployment of Lagrangian Instrumentation Using a Submerged Autonomous Launch Platform (SALP)

Satellite-tracked surface drifters, acoustically tracked subsurface floats, and actively ballasted profiling floats provide an effective and efficient means of describing the ocean environment over a wide range of spatial and temporal scales. Many coastal and blue-water process studies require the repetitive deployment of such instrumentation over periods of days to years. At best, reliance on ships and/or aircraft for serial instrument deployment can be expensive and logistically difficult. At worst, such deployments may be impossible in remote locations, areas of unfavorable weather, or seasonal ice cover or in response to transient or episodic phenomena such as spawning events or severe storms. The submerged autonomous launch platform (SALP) enables serial deployment of an arbitrary mixture of drifting instrumentation (surface drifters, subsurface floats, profiling floats) from depths as great as 2,000 m on a standard oceanographic mooring. A single SALP magazine allows up to 16 floats to be deployed automatically according to a user-defined schedule, interactively by real-time acoustic remote control or adaptively in response to observed environmental conditions. Here, the authors describe the design and implementation of the SALP prototype and evaluate its performance during extended field trials in the Atlantic Ocean near Bermuda. During these trials, moored subsurface measurements of temperature, pressure, and velocity were autonomously processed by the SALP and used to preferentially deploy novel glass-encapsulated GPS/Argos surface drifters within mid-ocean mesoscale anticyclones.