Satellites recorded the biggest ocean swells ever seen from area, highlighting how huge waves can act as storm “messengers,” carrying a storm’s energy throughout whole oceans.
Observations from the Surface Water and Ocean Topography (SWOT) mission allowed scientists to trace waves born from highly effective storms. These waves, pushed by wind, generate swells that carry harmful vitality to faraway shores — even when the storm itself by no means makes landfall.
Using SWOT’s wide-swath imaging with radar altimetry information from Earth-observing satellites together with SARAL, Jason-3, Copernicus Sentinel-3A and -3B, Copernicus Sentinel-6 Michael Freilich, CryoSat and CFOSAT, researchers had been in a position to create a global picture of how storm waves move, merge and evolve as they spread outward across the planet, according to a statement from the European Space Agency (ESA).
One storm specifically — Storm Eddie, which shaped over the North Pacific in December 2024 — served as a pure laboratory for the research. During the height of the storm, satellites noticed open-ocean waves reaching practically 65 toes (20 meters), or roughly the peak of the Arc de Triomphe in Paris. Those are the best ever measured from area.
Over the next two weeks, these swells traveled greater than 15,000 miles (24,000 kilometers), crossing the Drake Passage and coming into the tropical Atlantic. Although the storm by no means made landfall, its waves reached distant coasts with shocking power, highly effective sufficient in some circumstances to trigger erosion and flooding.
Therefore, the ocean floor acts as a “messenger,” the researchers mentioned. By measuring the time between crests of enormous swells, also referred to as wave interval, researchers are in a position to estimate a storm’s measurement and energy. For instance, a 20-second interval means a big wave arrives each 20 seconds.
The research additionally revealed that shorter, high-energy storm waves — not simply lengthy, sluggish swells — carry a lot of the ocean’s transported vitality, difficult long-held assumptions about how wave energy is distributed. That perception will assist scientists refine international wave fashions and higher defend coastal communities from associated hazards.
Their findings had been published Sept. 16 within the journal Proceedings of the National Academy of Sciences.