An AutoNaut is a wave-propelled unmanned autonomous surface vessel designed to take meteorological and oceanographic measurements at the air-sea interface. The vehicle is fitted with solar panels to power the instrumentation, as well as a small propeller for thrust when there are no waves. UEA recently purchased a 5-metre AutoNaut, named Caravela. The focus of Caravela’s work during EUREC⁴A is to gather data to determine air-sea fluxes of heat and momentum. One advantage of using an AutoNaut for this work is that the disturbance to the ocean surface is much lower than using a ship, improving accuracy of measurements close to the ocean surface. In addition, Caravela is equipped to carry and release a Seaglider, such that vertical fluxes can be determined throughout the ocean boundary layer. These platforms provide the opportunity to collect data in remote and harsh environments at a fraction of the cost of ship-based fieldwork.

Seagliders are buoyancy-powered autonomous underwater vehicles that can profile to 1000 m depth every 4 h for up to 6 months. A Seaglider will repeatedly dive and climb to produce a profile of the upper ocean. During EUREC⁴A, we will deploy 3 Seagliders (1 from Caravela and 2 from the R/V Meteor). These Seagliders will observe how the surface fluxes measured by the AutoNaut affect the near-surface ocean properties and processes.