MELOA: New low-cost, low-power drifters to improve sea observation and monitoring systems in coastal and oceanic areas

The device has been developed as an improvement on the WAVY device, conceived by the Faculty of Engineering at the University of Porto, which was used to measure surface circulation forced by wave breaking, including the detailed structure of rip currents and littoral drift. The philosophy behind the WAVY device has been essentially respected: a small-sized sphere with enough space to house the power source, GPS receiver, communication modules, antennas, sensors, and data processor; optimised buoyancy to prevent the device’s trajectory from responding to wind instead of currents, while providing the right exposure of the antennas to ensure GPS signal acquisition at the required speed and reliable near real-time communications.

Given the low influence of wind on the movement of drifting devices, these devices offer an effective and cost-efficient way to monitor surface currents and dynamic surface characteristics anywhere in the global ocean. By equipping the devices with thermistors (a type of resistor that varies with temperature) at two different levels, it becomes possible to monitor the "near-surface temperature" and vertical temperature gradients near the surface.

These in situ measurements are invaluable for the calibration/validation of current surface oceanographic models and satellite-derived sea data. This is the case for the GEOSS and Copernicus programs, which study surface currents and sea temperatures through satellite measurements and require in situ data to validate their results.

The MELOA project is developed under the Horizon 2020 program and aims to improve current ocean observation and monitoring systems. The consortium is made up of nine other partners, has lasted 4 and a half years, and has a total budget of 4.7 million euros.