Extended Duration Expendable microFloats for Dense Upper Ocean and Coastal Sampling

Many upper-ocean and coastal processes occur at small scales and evolve over short time frames of minutes to days. To measure these, scientists employ a variety of technologies including profiling floats, gliders, autonomous underwater vehicles (AUVs), and ship-based surveys. Each has its advantages and disadvantages but for physical processes present in coastal and upper-ocean water, floats that are small, low-cost, and easy to deploy at shallow depths are ideal. The investigators will develop a short endurance, expendable microFloat optimized for shallow ocean environments. Understanding these processes is important because they physically transfer large amounts of heat, carbon, and nutrients which can help predict short-term changes in weather and longer-term patterns of environmental change. The investigators will provide hands-on engineering experience to undergraduate students, training them at the interface of ocean engineering and fundamental science. The project will support also an early-career investigator. Upper-ocean and coastal processes, such as submesoscale fronts, internal waves, and river plumes, span meter to kilometer scales and evolve over minutes to days. Resolving these dynamics requires dense, sustained measurements that conventional profiling floats often cannot provide due to cost, depth-rating, and endurance limits. The investigators will develop a next-generation, month-endurance expendable microFloat optimized for shallow (≤300 m) energetic environments. The platform will integrate a low-power microcontroller, energy-aware firmware, improved buoyancy-engine control, and Iridium telemetry to enable persistent pro-filing and flexible Lagrangian sampling modes. The work advances autonomous ocean observing by enabling sustained, high-resolution sampling of rapidly evolving upper-ocean and coastal processes that are poorly resolved by existing platforms. The extended-duration microFloat will fill an observational gap between short-duration drifters and deep-rated Argo-style floats. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.