A cutting-edge satellite reveals an oceanic whirlpool by the northeast of Mallorca

The SWOT satellite demonstrates its ability to observe key oceanic structures that until now had escaped conventional altimetry.

The research focuses on an eddy located northwest of Mallorca, a key region for the dynamics of the Balearic Sea, and highlights the ability of this new mission to detect and measure small-scale structures that were difficult to characterize with previous satellites.

The study was carried out during the initial commissioning phase of the SWOT mission, launched in December 2022. During this period, scientists conducted an experiment in the western Mediterranean combining satellite data with direct ocean measurements, using underwater gliders, drifting buoys, and current sensors.

The measurements confirmed the presence of an anticyclonic eddy with a radius of about 25 kilometers, located beneath the surface layer of the sea. Inside it, currents of up to 30 centimeters per second were detected at depths greater than 150 meters, a clear signal that this is a dynamic and intense structure, but one that was difficult to identify with previous systems.

The data obtained successfully reproduced with high fidelity both the small variations in sea level and the currents associated with this eddy. Compared to conventional satellites, the error margin in sea level estimation was reduced by around 24%, and the calculation of current velocity improved by between 30% and 35%.

This improvement is due to the mission’s spatial resolution being up to ten times higher than that of previous satellites, allowing the detection of medium- and small-sized marine structures that previously appeared blurred. This is especially relevant in regions such as the Mediterranean, where these eddies are relatively small but frequent.

According to the researchers, these advances will improve understanding of the role played by eddies in ocean circulation and in the exchange of heat, water, and nutrients, processes that are fundamental for understanding climate and marine ecosystems.

The study places the Balearic Sea and Mallorca at the center of cutting-edge scientific research on an international scale and confirms that the SWOT satellite represents a qualitative leap in ocean observation, with applications and benefits that extend far beyond the Mediterranean.