Scientists have long been fascinated by the immense power of ocean currents and their profound influence on Earth’s climate system. Yet, despite decades of research, some of the most intricate small-scale movements in the ocean—submesoscale eddies—have remained elusive, hidden in the vast complexity of marine dynamics. Now, thanks to groundbreaking work led by Dr. Jinbo Wang of Texas A&M University, aided by next-generation satellite technology, researchers are unveiling these oceanic whirlpools with unprecedented clarity. Using data from the Surface Water and Ocean Topography (SWOT) satellite, this discovery marks a pivotal leap in understanding the ocean’s role in driving global climate patterns.
The SWOT satellite, an ambitious joint venture between NASA and the French space agency CNES, has revolutionized oceanography by delivering high-resolution observations of sea surface height variations at a global scale. Equipped with a Ka-band radar interferometer, SWOT measures changes with millimeter precision, enabling scientists to observe subtle eddy structures on the ocean’s surface that were previously undetectable. These capabilities have opened new windows into submesoscale dynamics—features that span anywhere from a few kilometers to 100 kilometers across—bringing to light ocean processes that fundamentally influence heat distribution, nutrient transport, and atmospheric interaction.
Submesoscale eddies are small but mighty whirlpools in the ocean that operate similarly to the vortices one might see swirling behind a rock in a river. However, their scale and energy yield are immense in comparison, making them crucial drivers of material and energy exchange within marine ecosystems. Despite their significance, these eddies have for years been a blind spot in climate and oceanographic research, partly due to limitations in spatial resolution of conventional observational platforms. With SWOT’s detailed altimetry, Wang’s team has now quantified that these features are not only present worldwide but also far more dynamic and energetic than formerly estimated.
Prior to this breakthrough, the oceanographic community primarily focused on larger mesoscale eddies—those often spanning hundreds of kilometers and visible via satellite radar altimetry since the 1990s. Mesoscale currents shape large-scale circulations and have well-studied impacts on climate and biogeochemical cycles. However, the turbulent, smaller submesoscale eddies were difficult to measure systematically. Their fast evolution and smaller size posed substantial measurement challenges, limiting precise modeling and understanding of their influence on vertical mixing and heat transport—critical factors in modulating ocean-atmosphere interactions.
Dr. Wang’s journey to leading this discovery spans over a decade, beginning during his tenure at NASA’s Jet Propulsion Laboratory (JPL), where foundational work on satellite ocean altimetry and radar interferometry was developed. His move to Texas A&M University has further solidified the institution’s position at the forefront of satellite oceanography, blending expertise in remote sensing and climate science. Collaborating closely with international partners, including CNES and Caltech, Wang’s team capitalized on SWOT data to break new ground in observing the ocean’s submesoscale processes, an achievement decades in the making.
The enhanced sensitivity of the SWOT satellite surpassed engineering expectations dramatically. Initial doubts existed over whether the satellite would detect the minuscule fluctuations in sea surface height caused by submesoscale eddies due to their subtle signals amid oceanic noise. Yet, the instrument outperformed those projections by a factor of four, providing cleaner and more detailed data than anticipated. This unexpected gain in performance has allowed the scientific team to track spiral-shaped eddies and long internal solitary waves that propagate along the ocean interior, phenomena that play substantial roles in energy transfer across vertical ocean layers.
These newly detected submesoscale eddies are instrumental in stirring the ocean, facilitating the mixing of warm and cold water masses over short spatial and temporal scales. This vertical and lateral exchange critically impacts the ocean’s stratification and nutrient distributions, which in turn influence marine ecosystems such as plankton blooms—the foundation of the marine food web. Moreover, through their effects on heat transfer to the atmosphere, these eddies indirectly modulate weather patterns, including the formation, path, and intensity of hurricanes and phenomena such as El Niño-Southern Oscillation events.
The implications of this work extend beyond pure oceanographic interest. These findings offer vital insights for improving numerical climate models, which have historically struggled to incorporate submesoscale dynamics effectively due to limited empirical data. Enhanced model resolution and accuracy will result in better predictions of ocean circulation, climate variability, and extreme weather events, ultimately benefiting global climate resilience strategies and policymaking.
One of the hallmarks of the SWOT mission is its international character and long-term vision. The mission reflects over twenty years of collaborative efforts among global space agencies and scientific institutions, embodying a testament to persistent innovation and teamwork. Dr. Shari Yvon-Lewis, head of the Texas A&M Oceanography Department, highlights the continuity and dedication of many scientists, some of whom retired after contributing to the satellite’s design and capabilities, yet whose foundational work laid the groundwork for today’s breakthroughs.
Texas A&M University’s commitment to fostering expertise in satellite remote sensing and ocean physics was reinforced through hiring leading scientists like Dr. Wang. In addition to advancing SWOT-related research, Wang chairs a NASA Ocean Artificial Intelligence working group that leverages machine learning techniques to enhance the interpretation of existing and future satellite datasets. This integration of AI with satellite oceanography signals a transformative approach to deciphering vast data streams and optimizing the design of upcoming space missions.
Published in the April 16, 2025 issue of Nature, the study titled “Wide-swath satellite altimetry unveils global submesoscale ocean dynamics” has garnered significant attention within the scientific community. Its findings challenge traditional notions of ocean current dynamics and highlight the imperative to reexamine ocean-climate interactions on finer spatial and temporal scales. This research exemplifies a new era of ocean observation—one that promises unprecedented understanding of Earth’s climate engine.
Looking ahead, Dr. Wang emphasizes that this milestone represents only the beginning of a broader scientific journey. Equipped with innovative satellite instruments complemented by computational advancements, researchers are poised to explore the ocean’s “hidden” processes in far greater detail. The continual unveiling of small-scale ocean dynamics will lead to paradigm shifts in climate science and marine ecology, bringing to light the intricate dance of forces shaping the world’s oceans—and, consequently, the global climate.
In conclusion, the successful deployment and operation of the SWOT satellite, combined with international collaboration and cutting-edge research led by Dr. Jinbo Wang, have opened a new frontier in oceanography. By uncovering the power and prevalence of submesoscale ocean currents, this work challenges previous assumptions and enhances our capacity to predict and respond to climate change impacts. It is a testament to the strength of innovative technology and interdisciplinary science in solving some of the planet’s most complex environmental challenges.
Subject of Research: Submesoscale ocean dynamics and satellite altimetry observation of ocean eddies
Article Title: Wide-swath satellite altimetry unveils global submesoscale ocean dynamics
News Publication Date: 16-Apr-2025
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- DOI: 10.1038/s41586-025-08722-8 (Nature)
Image Credits: NASA/JPL/SWOT
Keywords: Ocean currents, Ocean physics, Ocean circulation, Ocean temperature, Ocean waves, Ocean warming, Oceanography, Climatology, Earth systems science, Climate change, Climate systems, Earth climate, Climate stability, Climate data
