Ocean surface currents directly imaged from space

Nicolas Gilles Rascle , Aurelien Ponte, Frederic Nouguier, Renaud Binet, Dhruv Balwada, Fabrice Ardhuin, Bertrand Chapron, Erwin W. J. Bergsma, Fabrice Collard, Louis Marie, Rafael Almar

For more than four decades, satellite images of ocean temperature and colour have revealed jets, swirling eddies, and filaments. Yet the currents that shape these structures have never been directly imaged from space. This observational gap limits our understanding of the ocean's impact on climate and marine ecosystems, as these currents modulate exchanges between the coast and open ocean, vertical transport to the deep sea, and fluxes of heat, carbon, and nutrients.

Here we demonstrate the first direct satellite imaging of kilometre-scale surface currents using a tandem configuration of optical satellites that tracks surface wave propagation. This new capability shifts satellite observations beyond the predominantly geostrophic view of ocean circulation, revealing dynamics that have remained largely invisible to satellites - from intense coastal jets and equatorial flows to submesoscale motions just kilometres wide. Across these regimes, the elusive divergence of fronts and internal waves, thought to play a key role in upper-ocean vertical exchange, is concentrated at scales below 5 km, previously unresolved from space.

These reference measurements provide a new observational window into the multiscale physics of the upper ocean and its mediating role for the Earth’s climate system and marine life.