Air-deployed microFloats for profiling the ocean submesoscale: a systems-level design approach and demonstration
PI: Trevor Harrison, University of Washington Applied Physics Laboratory
Partners: MarineSitu
The scientific community’s growing interest in how subsurface dynamics contribute to submesoscale processes highlights the difficulty in resolving these small scales due to the lack of low-cost vehicles that can be deployed in large numbers. We will fill this need for a shallow inexpensive air-deployable profiling float by undertaking a holistic design process: combining highly experienced engineers, users, and scientists to design a vehicle that not only meets the engineering constraints (cost, technical specs, and production), but that also reduces the real-world limitations of using profiling floats designed for the Argo mission. In particular, the new design will aim to minimize effort from expert engineers or scientists on a per-float basis in three areas: pre-deployment preparation, piloting and control, and data processing and dissemination.
The design effort will work from two existing and proven systems, the microFloat and the microSWIFT, that together meet many of the desired performance specs. Informed by these platforms, we will develop a new inexpensive air-deployable microFloat design that enables deployments at scales of 1000 floats. In developing the new design, the critical subsystems we will evaluate and refine are air deployability, buoyancy engine performance, satellite communications, sensor choices – including a novel conductivity sensor concept, energy budget, float controls, and downstream data processing. Design choices will be evaluated for their overall impact on operations – from fabrication and assembly, to initial deployment setup, to post-deployment logistics – to avoid “hidden costs” that can severely hinder deployments at large scales and minimize the total cost per profile. As a first step toward refining air deployment, we will build a parachute system for the existing microFloat and use local tests in Puget Sound to inform our float design.
Throughout the design process, we will incorporate expert system-level input by bringing together a highly experienced team including: design engineers who have developed dozens of vehicles; production and field engineers who make custom and commercial vehicles perform reliably in the field; a company that produces underwater monitoring products with simple and automated software and data management; and scientists who plan and carry out deployments to advance our awareness and understanding of the ocean.