SWOT Satellite Data Forces Revision of Ocean Wave Physics Models

The deployment of the Surface Water and Ocean Topography (SWOT) satellite has provided oceanographers with high-resolution data on oceanic storm mechanics, leading to a necessary revision of long-standing physical models. For years, exceptionally large wave formations in the open ocean, particularly in the North Pacific, existed largely as anecdotal reports until the precise data acquisition capabilities of SWOT became operational.

This critical observational period focused on a major meteorological event in late 2024, when a storm designated Eddie intensely agitated the Pacific, serving as a large-scale laboratory for the international team managing the mission. SWOT, a collaboration between NASA and the French Centre National d'Études Spatiales (CNES), was launched on December 16, 2022, with contributions also from the Canadian Space Agency and the UK Space Agency. Data streamed from the orbiting sensors confirmed wave heights reaching as high as 35 meters in the open ocean during December 2024, formations comparable in height to a ten-story structure.

The satellite achieves this detail using radar interferometry to map the water surface topography in three dimensions. A comprehensive study detailing these observations was published in September 2025 in the Proceedings of the National Academy of Sciences (PNAS). Research led by Fabrice Ardhuin of the French Institute for Ocean Exploitation (IFREMER) suggests a fundamental inadequacy in current theoretical understanding, as empirical models had systematically overestimated the energy dissipation rate of the longest waves by a factor of twenty.

This finding indicates a mechanism where energy concentrates into a smaller number of dominant, colossal waves. Storm Eddie served as the primary case study, illustrating the newly observed, far-reaching power of these waves, which propagated southward across the Drake Passage and reached the tropical Atlantic in early 2025, covering nearly 24,000 kilometers while retaining substantial kinetic energy. While these powerful swells created notable surfing conditions, the underlying data carries a more serious implication: these energetic waves significantly elevate the potential for coastal erosion and flooding far from the generating storm's epicenter.

This recalibration of wave physics, driven by the SWOT mission, prompts a re-evaluation of maritime safety protocols and coastal defense planning worldwide. The ability to accurately model the propagation of extreme wave energy across entire ocean basins represents a significant advancement in geophysical forecasting, moving beyond previous limitations imposed by sparser measurements.