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NASA’s SWOT Satellite Uncovers Outsized Role of Tiny Ocean Currents in Shaping Marine Ecosystems

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NASA’s SWOT Satellite Sheds Light on Hidden Ocean Currents That Influence Global Climate and Marine Life

The smallest of ocean waves and currents, long overlooked by traditional observation methods, are now emerging as key players in shaping the Earth’s climate and marine ecosystems. Thanks to high-resolution imaging from NASA’s SWOT (Surface Water and Ocean Topography) satellite—developed in partnership with the French space agency CNES—scientists are getting an unprecedented view of submesoscale ocean activity. These features, spanning just a mile or so, are instrumental in transferring carbon, heat, and nutrients throughout ocean layers, highlighting the hidden complexity and power of the world’s marine systems.

In recent studies led by NASA’s Jet Propulsion Laboratory (JPL), SWOT has demonstrated its ability to map vertical ocean currents in detail. Previously, such currents fell into a frustrating observational blind spot: too small for satellites to detect, yet too vast for direct ship-based instruments to monitor. With SWOT, researchers can now see how these vertical circulations move water—and the energy and materials within it—from deep ocean layers to the surface, impacting everything from temperature regulation to nutrient cycles. For instance, the satellite tracked a swirling submesoscale eddy in the Kuroshio Current and detected vertical movements of up to 14 meters per day.

These vertical exchanges play a crucial role in ecosystem health and climate processes. “Vertical currents can bring heat from deep layers to the surface, warming the atmosphere,” said oceanographer Matthew Archer. In another case, SWOT identified an internal solitary wave in the Andaman Sea that carried twice the energy of a typical internal tide. Using sea surface height data, the satellite helps researchers infer not only the slope of waves but also the fluid pressure, which ultimately reveals the strength and influence of oceanic motion. “Force is the fundamental quantity driving fluid motion,” added coauthor Jinbo Wang from Texas A&M University.

Beyond observation, the SWOT mission is reshaping the way scientists model the ocean. Lee Fu, a senior researcher at JPL, emphasized that ocean simulation tools must now adapt to account for these newly visible small-scale processes. NASA has already begun integrating SWOT data into its ECCO ocean model to improve accuracy in climate forecasting. As SWOT continues to provide continuous, detailed measurements of ocean topography, it promises to deepen our understanding of how fine-scale ocean mechanics influence broader environmental changes and climate dynamics.

SWOT Satellite Captures Seismic Tsunami Event in Greenland’s Dickson Fjord

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In September 2023, the Surface Water and Ocean Topography (SWOT) satellite, a collaborative mission between NASA and France’s Centre National d’Études Spatiales (CNES), recorded an extraordinary seismic tsunami event in Greenland’s Dickson Fjord. This unprecedented event, caused by a massive rockslide, led to a nine-day sequence of waves reverberating throughout the fjord. The event is notable for being one of the few instances where satellite technology captured such a prolonged natural phenomenon with remarkable precision, providing valuable data that could aid in understanding similar events in the future.

The rockslide, which unleashed over 25 million cubic meters of rock and ice into the fjord, displaced vast amounts of water, creating a series of massive waves. These waves, which oscillated between the fjord’s steep walls every 90 seconds, continued for nearly a week, making this a rare and unique event. According to NASA’s Jet Propulsion Laboratory scientist Josh Willis, SWOT’s advanced technology allowed researchers to observe the wave contours in unprecedented detail. The wave height variation between the northern and southern sides of the fjord, with water levels rising by as much as 1.2 meters, demonstrated the immense force of the rockslide’s impact.

What makes SWOT’s detection particularly groundbreaking is its use of cutting-edge radar technology. Orbiting approximately 900 kilometers above Earth, the satellite employs a Ka-band Radar Interferometer (KaRIn) to measure water surface heights with exceptional accuracy. This technology proved crucial in capturing the dynamic effects of the tsunami in the remote, narrow fjord, where conventional altimeters with larger measurement footprints would have struggled. The satellite’s precision allowed scientists to observe the tsunami’s full duration and track its rhythmic movement, which was not possible with previous methods.

SWOT’s ability to detect and monitor such an event emphasizes the growing importance of advanced satellite technology in global hazard monitoring. According to Nadya Vinogradova Shiffer, a NASA scientist, SWOT’s precise measurements could significantly improve preparedness for natural disasters by providing real-time data that enhances risk assessment and management. This event highlights the satellite’s potential to monitor not just oceanic phenomena but also smaller, more localized natural events, contributing to a broader understanding of Earth’s dynamic systems and aiding in disaster risk reduction.