Newswise — The marginal ice zone marks the boundary between open ocean and sea-ice cover and represents one of the most dynamic environments in polar oceans. Ocean eddies generated near ice edges influence sea-ice transport, mixing processes, and energy exchange between the ocean and atmosphere. These rotating structures can redistribute floating sea ice, modify heat transport, and affect regional ecosystems and climate feedback mechanisms. However, direct observations of eddy evolution remain limited because of harsh polar conditions and sparse in-situ measurements. Satellite synthetic aperture radar (SAR) has become an important tool for detecting eddies through sea-ice patterns, yet most previous studies mainly analyzed spatial distributions rather than the dynamic evolution of individual eddies. Because of these challenges, deeper investigation of the spatiotemporal evolution of ice-edge eddies is required.

Researchers from the Aerospace Information Research Institute of the Chinese Academy of Sciences reported a new framework for analyzing the evolution of ice-edge eddies using sequential SAR satellite imagery. Their findings were published (DOI: 10.34133/remotesensing.1031) on March 2, 2026, in the journal Journal of Remote Sensing. The study focuses on an eddy observed in the Fram Strait, a key passage connecting the Arctic Ocean and the North Atlantic. By integrating sea-ice motion tracking with hydrodynamic vortex modeling, the researchers quantified key physical characteristics of the eddy, including rotational velocity, circulation strength, and radius, providing new insight into polar ocean dynamics.

The study introduces a dynamical parameter inversion framework capable of reconstructing the structure and temporal evolution of ice-edge eddies. Using sequential SAR images, the researchers tracked the displacement of floating sea ice to derive high-resolution surface current fields. These currents were then analyzed using a vortex-based hydrodynamic model to estimate key parameters such as suction intensity, angular velocity, and circulation strength.

Applying the framework to an Arctic eddy revealed a complete life cycle lasting about 22 days. During the early stage, the eddy gradually intensified as both its radius and circulation strength increased. The vortex reached a mature phase when its structure became most coherent and energetic. Afterward, the eddy weakened and gradually dissipated. The results demonstrate how polar ocean eddies evolve dynamically and provide quantitative evidence of their growth, maturity, and decay processes. The research focused on the Fram Strait, where complex interactions between the southward-flowing East Greenland Current and the northward-flowing West Svalbard Current frequently generate ocean eddies. Researchers analyzed time-series SAR images collected by the Sentinel-1A and Sentinel-1B satellites, which provide high-resolution radar observations capable of monitoring sea-ice patterns regardless of cloud cover or lighting conditions. To reconstruct eddy dynamics, the team first tracked the displacement of floating sea ice between consecutive SAR images separated by roughly 50 minutes, allowing them to retrieve the horizontal surface current field associated with the eddy. The retrieved currents were then processed using singular value decomposition to isolate the dominant rotational component while suppressing background currents and noise.

Next, the Burgers–Rott vortex model—derived from the Navier–Stokes equations—was applied to invert the dynamical parameters describing the eddy. Analysis showed that the eddy radius expanded from roughly 28 km to over 35 km, while circulation strength peaked at about 4.5 × 10⁴ m²/s. The reconstructed current fields closely matched satellite-derived observations, confirming the reliability of the proposed method for capturing real ocean dynamics.

The researchers emphasized that ice-edge eddies are crucial components of polar ocean circulation. “These eddies strongly influence sea-ice redistribution and ocean mixing in Arctic waters,” the team explained. By enabling continuous monitoring of eddy evolution using satellite radar imagery, the new framework provides a valuable observational tool for studying ocean–ice interactions and improving understanding of polar climate dynamics.

The framework integrates satellite remote sensing with physical modeling techniques. Sequential SAR images were first preprocessed through radiometric calibration, filtering, and image registration. The displacement of floating sea ice between image pairs was calculated using a maximum cross-correlation method to retrieve horizontal current vectors. Singular value decomposition was then applied to isolate the dominant eddy structure from the current field. Finally, a Burgers–Rott vortex model combined with a Levenberg–Marquardt optimization algorithm was used to invert the eddy’s key dynamical parameters, enabling quantitative analysis of its evolution.

The proposed approach opens new opportunities for monitoring ocean dynamics in polar environments using satellite observations. As high-resolution SAR datasets continue to expand, researchers will be able to track multiple eddies simultaneously and analyze their interactions with sea ice, ocean currents, and atmospheric forcing. Such insights could improve numerical models of Arctic circulation and enhance understanding of how polar oceans respond to climate change. In the future, combining satellite observations with oceanographic models and in-situ measurements may provide a more comprehensive picture of Arctic marine processes and their global impacts.

###

References

DOI

10.34133/remotesensing.1031

Original Souce URL

https://doi.org/10.34133/remotesensing.1031

Funding information

This work was supported by the National Natural Science Foundation of China (grant number 62231024).

About Journal of Remote Sensing

The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.

Newswise — Imagine descending nearly a mile and a half into a watery abyss, watching the sunlight disappear as the world around you turns completely black. Then suddenly, you find yourself surrounded by a shower of brilliant, bioluminescent fireworks.

This is just the beginning of an ocean expedition into the realm of deep-sea hydrothermal vents — alien ecosystems teeming with life we have yet to fully understand. Here, a place where the sunlight never reaches, crabs, rays and fish thrive even under the extreme hydrostatic pressure.

A team of intrepid researchers from Arizona State University embarked on a recent journey to these hidden depths to learn more about nitrogen cycling and the microbial life thriving in these extreme conditions. These microscopic organisms play a vital role in the ocean’s delicate chemistry.

“I think the deep sea is one of the final frontiers of exploration on Earth,” said Carolynn Harris, a postdoctoral researcher in ASU’s School of Earth and Space Exploration. “We know more about the surface of the moon than we know about the bottom of the ocean on our own planet.”

Sheryl Murdock, a postdoctoral research scholar with ASU’s School of Ocean Futures, part of the Julie Ann Wrigley Global Futures Laboratory, led the expedition along with Elizabeth Trembath-Reichert, an associate professor with the School of Earth and Space Exploration. Six ASU students and staff participated, working on everything from taking samples and planning the next day’s dive, to testing equipment and leading the team’s experiments and school outreach.

Murdock and her research team are working to understand exactly what the smallest inhabitants of the ocean are contributing to ocean chemistry. While microbes are tiny, they have a tremendous impact, and Murdock says they’re not something that gets thought about often when it comes to protecting and managing the ocean.

“Nobody’s going to buy the ‘save the microbes’ bumper sticker,” Murdock said. “We need the public to know that the way the chemistry of the ocean stays in balance has loads to do with microbes and how they cycle nitrogen and other chemical elements. And by understanding what microbes contribute, we can learn how that plays into the wider ocean chemistry and, importantly, ocean health.”

One way the researchers learn more is by taking samples of microbes that thrive under deep-sea pressure — gathered from water and sediment samples. But this team is trying something that has never been done before.

“We are working to understand the microbes living in tubeworm communities by sampling the fluids and then bringing the water back onto the ship, running incubations, and looking at how those microbes use different sources of nitrogen,” Murdock said. “What’s novel about this is bringing them to the surface but keeping them under seafloor pressure and running experiments at that high pressure.”

This process is difficult at best. The team must travel far out to sea on a ship called the R/V Atlantis — a U.S. Navy-owned research vessel operated by the Woods Hole Oceanographic Institution. This ship is designed specifically to launch Alvin, a specialized “human occupied vehicle,” or HOV, used by researchers to explore the deep sea.

Once the team reached its final destination in the Pacific northwest — a spreading center between tectonic plates called the Juan de Fuca Ridge — the team performed multiple dives in the submersible, as weather conditions allowed.

Their innovative approach to collecting water, sediment and microbial samples — bringing them to the surface under the same pressure — is expected to bring new insights to our understanding of ocean chemistry, what roles microbes play on the seafloor, and how they contribute to ecosystem health and function.

Ship to shore: Bringing deep-sea exploration to the classroom

Beyond the scientific breakthroughs, the expedition sparked a wave of inspiration among hundreds of students back on land. The cruise carried a dedicated outreach team — responsible for a ship-to-shore “virtual field trip” program that brought live video, interviews and demonstrations into classrooms thousands of miles away.

Will Carter, an outreach coordinator with the ASU Bermuda Institute of Ocean Sciences, or BIOS, helped build the pipeline.

“We had a full Zoom setup,” Carter said, describing a dizzying array of gear: a handheld gimbal and iPhone for roaming footage, a 360 conference camera to show a room, and microphones that had to survive both wind and poor bandwidth. “You can imagine with all of these different tech elements, especially being on a ship where there’s limited Wi-Fi, it took a long time to really set up and master.”

Carter, who has a background in biology and media studies, edited dive footage each night and crafted short, punchy videos for the next day’s calls. Their goal was modest at first — reach a few hundred students — but the appetite for real-time science grew fast.

For students at Osborne Middle School in Phoenix, the experience wasn’t a distant slideshow. Science teacher Jim Hess watched his seventh and eighth graders press toward the screen, leaning in to see hydrothermal chimneys and hear Alvin crew explain life in a tin can at the bottom of the world.

“They decorated Styrofoam cups before the team left to go to the boat,” Hess said. The cups were taken down on the outside of the submersible; at 2,300 meters (more than six Empire State Buildings) deep, the air is crushed out of the foam. “Your regular six-inch Styrofoam cup shrinks down to about the size of your thumb,” he told students. The cups were returned as tiny souvenirs — a reminder that sometimes science is a tactile thrill as much as it is data.

Middle schoolers asked the questions adults skip. 

“How do you use the bathroom?” one asked. And the answer — “you try to go before, and if not, then you go on this little red bedpan” — produced exactly the reaction the outreach team wanted: awe and laughter, followed by curiosity. 

“Those middle school questions,” Carter said, “are perfect.”

From the beginning, the ship-to-shore goal was simple but ambitious: bring real impact and working science directly to students in real time, as discovery is unfolding live.

“We knew to get this over the goal line, it couldn’t just be creating a curriculum module,” said Kaitlin Noyes, director of education and community engagement at ASU BIOS. “It needed to be something bigger.” 

That “something bigger” became a series of live broadcasts from the research vessel and the submersible using special communications tools, connecting students from third grade through college — and even professional educators — to science, as it was happening at sea.

Over the course of the two-week expedition, they hosted 29 live shows and reached 857 participants.

“A lot of these kids have never had interaction with anything outside of their immediate area,” Hess said. “They hear about ASU, but they don’t really know what that means. This shows them the world is bigger — and that they can be part of it.”

From under the sea to under the microscope

Back on deck, the science had its own setbacks: rough weather grounded dives, forcing the team to compress their goals into fewer opportunities. Harris described how team dynamics became essential in cramped, chilly, sometimes seasick conditions.

“Anytime you take a group of people and put them in a confined, isolated situation, the group dynamics are so important,” she said. “We had a quarter fewer dives than we had hoped, but we still accomplished all of our major science objectives.”

Now the team’s samples — including water, sediments and microbes — will be analyzed. The next phase will take time and precision: sequencing DNA from microbes, measuring nitrogen species and piecing together how these unseen organisms move nutrients through a world without sunlight.

As the team measures the samples over the next several months, the researchers share a message: The deep sea is not a desolate wasteland but a vibrant ecosystem facing unprecedented threats due to climate impacts, overfishing and bottom-trawling, pollution and potential deep-sea mining.

“Industrialization of the deep sea is really knocking at the door,” Murdock said. “Our research is but one important step to reaching a better understanding of how our ocean works, and by doing that, we hope to contribute to strategies that ensure future ocean health.”

Robert Nelson and Christopher Reddy recognized for pioneering use of GCxGC to track and understand marine pollution

Newswise — Woods Hole, Mass. (February 20, 2026) — Two chemical oceanographers from the Woods Hole Oceanographic Institution (WHOI) are being awarded the 2026 Lifetime Scientific Achievement Award by the International Symposium on Comprehensive Multidimensional Chromatography.

Robert Nelson and Christopher Reddy, both in the Department of Marine Chemistry and Geochemistry, are being recognized for more than 15 years of continuous, high-impact contributions in the field of comprehensive two-dimensional gas chromatography, commonly known as GCxGC

GCxGC is an advanced analytical technique that separates and identifies highly complex mixtures of chemicals with exceptional detail.

With more than 60 years of combined experience, Nelson and Reddy have pioneered the use of this method to analyze pollutants in the ocean, revolutionizing the field of oil-spill forensics. Their work has advanced scientific understanding and informed response strategies for some of the most significant oil spills in recent history, including the 2010 Deepwater Horizon disaster, as well as spills in San Francisco, Massachusetts, Florida, Texas, and California, and internationally in Brazil, Sri Lanka, Mauritius, Korea, and Japan.

“As an oceanographer, I am particularly proud that this award is selected by, and presented to, analytical chemists—a field dedicated to advancing how chemicals are measured,” Reddy said. “It is a tremendous honor to have our work recognized by this community.”

“What is especially meaningful to me is that Chris and I worked so closely together—often on site collecting samples on boats and beaches, analyzing them, and writing about the results,” Nelson added. “This award reflects not just our technical work, but a long-term partnership forged in the field and in the lab.”

The Lifetime Scientific Achievement Award for GCxGC Research is one of the highest honors bestowed by the GCxGC community, recognizing sustained innovation and impact in analytical chemistry and separation science. Nelson and Reddy will receive the award at the 44th International Symposium on Capillary Chromatography & 21st GCxGC Symposium in Riva del Garda, Italy, this spring.

About Woods Hole Oceanographic Institution

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility.

Newswise — Woods Hole, Mass. (February 4, 2026) – Alan Seltzer, an affiliated scientist at Woods Hole Oceanographic Institution (WHOI), assistant professor at University College Dublin, and former WHOI postdoctoral scholar, has been named the 2026 recipient of the F.G. Houtermans Award by the European Association of Geochemistry (EAG). The award is among the highest international honors recognizing early-career scientists in geochemistry.

Seltzer is being recognized for pioneering the use of dissolved gas isotopes to quantify physical and biogeochemical processes across the Earth system, including exploring the sensitivity of groundwater systems to climate and the dynamics of atmosphere-ocean gas exchange. Much of the work cited by the award committee was conducted at WHOI, where Seltzer was a postdoctoral scholar from 2019 to 2021 and later a member of the scientific staff in the Marine Chemistry and Geochemistry Department, where he established a gas isotope tracer laboratory and developed several new analytical techniques.

His research helped open new pathways for using noble gas and nitrogen isotopes to investigate groundwater, seawater, air, and volcanic gases. Seltzer also helped extend high-precision noble gas isotope techniques to volcanic systems in collaboration with WHOI associate scientist Peter Barry to better understand the origins and transport pathways of volatiles from Earth’s deep interior. He also expanded oceanic applications of noble gas tracers for air-sea interaction and glacial meltwater circulation with WHOI scientists Bill Jenkins and Roo Nicholson, and more recently advanced high-precision tools for quantifying nitrogen cycling in aquatic environments in collaboration with MIT-WHOI Joint Program student Katelyn McPaul and WHOI associate scientist Scott Wankel.

“It is an honor to be recognized with the F.G. Houtermans Award,” Seltzer said. “WHOI has a special culture in which collaboration and high-risk science are celebrated, and without the encouragement and freedom at WHOI to take risks, push analytical limits, and fail a lot along the way, much of my work would not have been possible. I’m deeply grateful for all the support I’ve received from the WHOI community over my career so far.”

Seltzer’s selection continues a notable streak for WHOI’s Marine Chemistry and Geochemistry Department. Former WHOI postdoctoral scholar David Bekaert received the Houtermans Award in 2025, marking back-to-back years in which the honor has gone to WHOI-trained scientists—a rare distinction that highlights the strength and impact of the Institution’s postdoctoral program.

The 2026 F.G. Houtermans Award will be formally presented at the Goldschmidt Conference in July.

About Woods Hole Oceanographic Institution

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge and possibility.