Ocean waters are getting greener at the poles and bluer toward the equator, according to an analysis of satellite data published in Science on June 19. The change reflects shifting concentrations of a green pigment called chlorophyll made by phytoplankton, photosynthetic marine organisms at the base of the ocean food chain. If the trend continues, marine food webs could be affected, with potential repercussions for global fisheries. 

“In the ocean, what we see based on satellite measurements is that the tropics and the subtropics are generally losing chlorophyll, whereas the polar regions — the high-latitude regions — are greening,” says first author Haipeng Zhao, a postdoctoral researcher at Georgia Tech working with Susan Lozier, dean of the College of Sciences and Betsy Middleton and John Sutherland Chair at Georgia Tech and Nicolas Cassar, the Lee Hill Snowdon Bass Chair at Duke University’s Nicholas School of the Environment.

Since the 1990s, many studies have documented enhanced greening on land, where global average leaf cover is increasing due to rising temperatures and other factors. But documenting photosynthesis across the ocean has been more difficult, according to the team. Although satellite images can provide data on chlorophyll production at the ocean’s surface, the picture is incomplete. 

The study analyzed satellite data collected from 2003 to 2022 by a NASA instrument that combs the entire Earth every two days, measuring light wavelength. The researchers were looking for changes in chlorophyll concentration, a proxy for phytoplankton biomass. For consistency, they focused on the open ocean and excluded data from coastal waters. 

“There are more suspended sediments in coastal waters, so optical properties are different than in the open ocean,” Zhao explains.  

The satellite data revealed broad trends in color, indicating that chlorophyll is decreasing in subtropical and tropical regions and increasing toward the poles. Building on that finding, the team examined how chlorophyll concentration is changing at specific latitudes. To work around background noise and gaps in data, they had to get creative. 

“We borrowed concepts from economics called the Lorenz curve and the Gini index, which together show how wealth is distributed in a society. So, we thought, let’s apply these to see whether the proportion of the ocean that holds the most chlorophyll has changed over time,” Cassar says.

They found similar but opposing trends in chlorophyll concentration over the two-decade period. Green areas became greener, particularly in the northern hemisphere, while blue regions got even bluer. 

“It’s like rich people getting richer and the poor getting poorer,” Zhao says.

Next, the team examined how the patterns they observed were affected by several variables, including sea surface temperature, wind speed, light availability and mixed layer depth — a measure that reflects mixing in the ocean’s top layer by wind, waves and surface currents. Warming seas correlated with changes in chlorophyll concentration, but the other variables showed no significant associations.

The authors cautioned that their findings cannot be attributed to climate change. 

“The study period was too short to rule out the influence of recurring climate phenomena such as El Niño,” Lozier says. “Having measurements for the next several decades will be important for determining influences beyond climate oscillations.” 

If poleward shifts in phytoplankton continue, however, they could affect the global carbon cycle. During photosynthesis, phytoplankton act like sponges, soaking up carbon dioxide from the atmosphere. When these organisms die and sink to the ocean bottom, carbon goes down with them. The location and depth of that stored carbon can influence climate warming.

“If carbon sinks deeper or in places where water doesn’t resurface for a long time, it stays stored much longer. In contrast, shallow carbon can return to the atmosphere more quickly, reducing the effect of phytoplankton on carbon storage,” Cassar says. 

Additionally, a persistent decline in phytoplankton in equatorial regions could alter fisheries that many low- and middle-income nations, such as those in the Pacific Islands, rely on for food and economic development — especially if that decline carries over to coastal regions, according to the authors.

“Phytoplankton are at the base of the marine food chain. If they are reduced, then the upper levels of the food chain could also be impacted, which could mean a potential redistribution of fisheries,” Cassar says. 

Funding: National Science Foundation and NASA.

Citation: “Greener green and bluer blue: Ocean poleward greening over the past two decades,” Zhao H., Manizza M., Lozier S.M. and Cassar N. Science, June 19, 2025, DOI: 10.1126/science.adr9715 

This story by Julie Leibach is shared with the Duke University Nicholas School of the Environment newsroom.

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The Institute for Matter and Systems (IMS) at Georgia Tech has announced the Spring 2025 Core Facility Seed Grant recipients. The primary purpose of this program is to give graduate students in diverse disciplines working on original and unfunded research in micro- and nanoscale science and engineering the opportunity to access the most advanced academic cleanroom space in the Southeast. In addition to using the labs' state-of-the-art fabrication, lithography, and characterization tools, the awardees will have the opportunity to gain proficiency in cleanroom and tool methodology and access the consultation services provided by research staff members in IMS. Seed Grant awardees are also provided travel support to present their research at a scientific conference.

In addition to student research skill development, this biannual grant program gives faculty with novel research topics the ability to develop preliminary data to pursue follow-up funding sources. The Core Facility Seed Grant program is supported in part by the Southeastern Nanotechnology Infrastructure Corridor (SENIC), a member of the National Science Foundation’s National Nanotechnology Coordinated Infrastructure (NNCI).

The five winning projects in this round were awarded IMS cleanroom and lab access time to be used over the next year. 

The Spring 2025 IMS Core Facility Seed Grant recipients are:

Stretchable Power Sources for Vertically Integrated Bioelectronics
PI: Antonio Facchetti
Student: Sakshi Sharma
School of Materials Science and Engineering

Next-generation 3D Solid-state Neutron Detectors for Nuclear Nonproliferation
PI: Anna Erickson
Student: David Straub
George W. Woodruff School of Mechanical Engineering

Programmable Microchip-based Cytotoxicity Assay for Real-Time Immune Cell Profiling
PI: Fatih Sarioglu
Student: Ahmadreza Rostamzadeh
School of Electrical and Computer Engineering

Experimental Study of Neutron-induced Radiation Damage in Lunar Materials with Key Implications for the Future of Lunar Geochronology
PI: Karl Lang
Student: Shreya Mukherjee
School of Earth and Atmospheric Sciences

Enhanced Dielectrophoretic Enrichment and Removal of Microplastics from Drinking Water via Engineered Nonuniform Electric Fields on Microfluidic Chips
PI: Xing Xie
Student: Shuai Wang
School of Civil and Environmental Engineering

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When NASA’s PRIME-1 Mission landed on the moon in March, an Intuitive Machine’s lander named Athena ended up on its side. The faulty landing meant the instruments couldn’t drill into the moon to measure water and other resources, as intended. But the mission wasn’t a total loss: PRIME-1’s The Regolith Ice Drill for Exploring New Terrain (TRIDENT) and Mass Spectrometer Observing Lunar Operations (MSOLO) could still operate and gather some data. The mission, led by Georgia Tech alumni who collaborated with Georgia Tech faculty, is already pivotal to future NASA missions.

PRIME-1, or Polar Resources Ice Mining Experiment-1, is a combination tool of two instruments: TRIDENT and MSOLO. PRIME-1’s objective is to help scientists determine resources available on the moon, with the eventual goal of sending humans to live there. TRIDENT is a space-rated drill designed and built by Honeybee Robotics that can extract lunar soil up to 3 feet deep. MSOLO is a mass spectrometer that can analyze TRIDENT’s soil samples for water and other critical volatiles. Together, this data can show how viable living on and mining from the moon could be.

Two Georgia Tech alumna, Jackie Williams Quinn and Janine E.  Captain, led the PRIME-1 team for NASA. They had help with computer modeling of PRIME-1’s mass spectrometer data from Georgia Tech’s Regents’ Professor Thom Orlando and Senior Research Scientist Brant Jones in the School of Chemistry and Biochemistry. 

Georgia Tech to the Moon

Georgia Tech’s expertise influenced all areas of developing PRIME-1, but perhaps their biggest contribution was the collaboration across disciplines. 

Quinn, a civil engineering graduate, wrote the initial proposal. She also managed TRIDENT’s development, through a contract with Honeybee Robotics, ensuring it was also built to operate in the harsh lunar environment (a process known as ruggedizing). The team worked with Honeybee’s Jameil Bailey, fellow Tech alumnus.

Captain, the MSOLO principal investigator and chemistry Ph.D. graduate, never planned to work at NASA. But her advisor, Orlando, got her interested. 

“What drew me to NASA’s In-Situ Resource Utilization team is that I could apply the instrumentation techniques that I learned in my Ph.D.  to measuring vital things like oxygen on the moon,” Captain said. 

Ruggedization Redux

When it was confirmed in 2008 the moon had water, NASA wondered if humans could one day live there. Having a functional mass spectrometer on the moon was paramount to determining where the water was and how much of it existed. Captain’s team modified a commercial mass spectrometer and tested it in a harsh environment comparable to the moon: Hawaii’s dormant shield volcano, Mauna Kea. Once they demonstrated the mission operation in this environment, they worked to ruggedize an existing one manufactured by instrumentation company INFICON. The team worked with INFICON and through lab tests, they showed that all components of the mass spectrometer functioned in a lunar vacuum environment.  

In Orlando’s lab, his team experimented with lunar material to determine how water interacts with lunar soil. From there, they created a theoretical model that simulated how much water they might find from what PRIME-1 sampled.  

“To create the model, we used the data of how water sticks to the lunar surface — from controlled experiments carried out in our ultra-high vacuum chambers at Georgia Tech,” Orlando said. “We approached the problem from a surface physics point of view in these lab experiments, but then in our model, we were able to connect to the actual mission activity.”

Once PRIME-1 hardware validation testing was finished, NASA was ready to launch.  That’s when things got hairy.

“We don't fully understand everything that happened during the landing, but the fact that PRIME-1 was fully functional is pretty amazing,” Captain said. “We got the data. It was so cool to know that all this work we did was worth it.” 

Moon Milestones

Although they didn’t get the chance to drill into the moon as planned, they can still analyze the data PRIME-1 pulled from the lunar atmosphere. This data includes how the spacecraft may have contaminated the local atmosphere.

“PRIME-1 was the only instrument that got to fully run and check out everything because when the lander fell over, the instrument was on top,” Quinn noted. “They were able to extend the drill all the way out a meter. It was drilling into empty space, but we were able to show that the drill got the signal from Earth, fully extended, and was able to auger and percuss. We were also able to fully operate MSOLO and gather data on gases coming off the lander in its final resting orientation.” 

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As the second-leading cause of cancer death in the U.S., colorectal cancer is rising in the number of cases in younger adults. To combat this and offer a less-invasive alternative to a colonoscopy, Wallace H. Coulter Department of Biomedical Engineering Assistant Professor Leslie Chan and her lab has been awarded a grant to develop an innovative diagnostic to detect colorectal cancer through a simple breath test. Read more.

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In a unanimous vote on June 2, the Atlanta City Council approved a significant ordinance requiring all new and replacement roofs to be built with light-colored, reflective materials, commonly known as “cool roofs.” The ordinance, set to take effect in one year, is part of a growing effort to reduce the city’s vulnerability to extreme heat.

Georgia Tech researchers say the new policy marks a major step forward in climate adaptation, especially for heat-vulnerable communities, and could help position Atlanta as a national leader in urban resilience.

How Cool Roofs Can Help Hotlanta 

”On any given summer afternoon, temperatures in Atlanta’s intown neighborhoods can be as much as 15 degrees Fahrenheit higher than in the city’s most forested areas,” said Brian Stone, professor in the School of City and Regional Planning and associate director of Georgia Tech’s Center for Urban Resilience and Analytics.

That spike is partly due to the urban heat island effect — a phenomenon driven by heat-trapping materials like concrete, asphalt, and dark rooftops, combined with the loss of trees and natural landscapes. The impacts are not just uncomfortable — they’re dangerous. Extreme heat is now one of the deadliest forms of weather in the U.S., with disproportionate effects on low-income communities, elderly residents, and those without access to air conditioning.

According to Patrick Kastner, assistant professor in the School of Architecture, rooftops are key contributors. “A major driver [of heat buildup] is dark, heat-absorbing material that stores solar energy during the day and then re-radiates it at night. If you look at a satellite image, for most of the day rooftops have more exposure to the sun than building facades — so the material choice there matters a lot.”

The Power of Reflective Roofs — and Trees

Stone and his students conducted modeling that found that widespread adoption of cool roofs across Atlanta could lower summer afternoon temperatures by more than 2 degrees Fahrenheit in many neighborhoods. That’s comparable to findings in other global cities like London, where cool roofs have reduced average temperatures by up to 2 degrees Celsius (3.6 F).

But cool roofs are only one part of a broader urban cooling strategy. In the same study, Stone’s team showed that planting trees in just half of Atlanta’s available planting zones could yield an even more dramatic effect, reducing temperatures by 4 F or more in some areas.

“Cool roofs are highly effective, but pairing them with increased urban tree cover would multiply the benefits, especially for neighborhoods currently lacking shade,” Stone said.

Equity and Energy Impacts

Atlanta’s ordinance requires cool roofing materials on new commercial construction and when existing commercial roofs are replaced. While that may sound like a technical design tweak, Stone emphasized its equity implications.

“Residents in South and West Atlanta, where tree canopy is sparse, and energy costs take up a larger share of household income, stand to gain the most,” Stone said. “When a cool roof is installed as part of a required roof replacement, those households will see meaningful reductions in cooling costs month after month.”

Kastner added that cool roofs could ease pressure on the electrical grid, lowering peak energy demand required for cooling during extreme heat and possibly reduce the risk of outages.

Durability, Maintenance, and Design Trade-offs

Stone noted that cool roofs tend to extend the life of roofing materials by limiting thermal degradation. However, he and Kastner also flagged some trade-offs.

For example, highly reflective coatings can create glare, especially on sloped roofs near neighboring buildings. The ordinance accounts for this by setting different standards for flat and pitched roofs. Maintenance is another consideration: over time, reflective coatings may degrade or become dirty, requiring periodic cleaning to maintain performance.

“Aesthetics and material compatibility may also challenge adoption when it comes to historic buildings or for roofs already outfitted with solar panels,” Kastner said. “But advancements in roofing technology, including high-performance materials that aren’t plain white, offer more flexible options than ever before.”

A Cool Roof Policy With National Impact

While cities like New York and Chicago have implemented cool roof programs for over a decade, Atlanta’s proposed ordinance is one of the most comprehensive in the country — applying to all roof types, not just flat industrial ones.

“Atlanta is steadily emerging as one of the most climate-resilient cities in the U.S.,” said Stone, pointing to the city’s urban forest and growing network of floodable parks as complementary resilience strategies. “Adding a best-in-class cool roofing ordinance to that portfolio is a bold step forward.”

And it could spark innovation across the region.

“Georgia Tech is uniquely positioned to help advance climate-resilient design,” Kastner said. “From research on advanced coatings to urban planning tools that target the most heat-vulnerable areas, we’re bringing science and policy together to shape cooler, healthier cities.”

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As the planet warms, changing weather patterns are only one effect. Warming air is often more toxic, leading to asthma and even heart attacks. A better understanding of these air quality changes can help society mitigate their consequences. Georgia Tech researchers are innovating ways to study air quality — beginning with prehistoric insights and zooming all the way to satellites in our orbit.

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Electing to have invasive brain surgery isn’t something most people have done. Ian Burkhart isn’t most people.

“When I finished rehabilitation, my doctors and therapist and, most importantly, the insurance company said, ‘For someone with your condition, we feel like you've made all the improvement that you will, have a nice life,’” said Burkhart, who was left with limited feeling and mobility below the neck after a 2010 diving accident injured his spinal cord. “That didn't sit well with me.” 

Hoping even a fraction of hand mobility would increase his independence, Burkhart turned to a clinical research trial on a brain-computer interface (BCI) designed to detect movement signals in the brain and send them to a computer to stimulate the arm muscles, bypassing the spinal cord in the hopes of restoring movement.

“I had had four and a half years of never thinking my hand was going to move again,” he recalled. When testing to see if he qualified for the study, researchers stimulated his hand muscles. “I saw my hand move, and that was all I needed to know — I was ready to risk it all for something that may or may not work.” 

Burkhart’s story is one of many that reveal the deeply personal side of neurotechnology research. Centering lived experiences like his is central to the mission of the Institute for Neuroscience, Neurotechnology, and Society (INNS), a new Interdisciplinary Research Institute launching this July at Georgia Tech.

“If we want to build neurotechnology that truly serves people, their voices should be part of the scientific process from the very beginning,” said Chris Rozell, a professor in the School of Electrical and Computer Engineering and one of the many researchers at Georgia Tech working to understand and advance BCIs. “Hearing from individuals who live with these devices helps guide more ethical, inclusive, and effective research. The entire field benefits from inclusive conversations like these.” 

Life With a Brain Implant

Burkhart and three others recently shared their stories live on the Ferst Center stage at “Wired Lives: Personal Stories of Brain-Computer Interfaces, an event organized by Georgia Tech’s Neuro Next Initiative. Their stories gave over 200 attendees a rare, honest glimpse into the realities of neurological conditions and the path to brain-computer interface research.

“I was at a crossroads in my life at 47 years old,” said Brandan Mehaffie, who told his story of living with early-onset Parkinson’s disease. “I was trying to figure out, do I continue with the status quo and watch my career dwindle into nothing? Watch my life with my family, my kids, not being able to go on hikes or family vacations?” 

Mehaffie eventually qualified for deep brain stimulation (DBS) treatment, a procedure where a pacemaker-like device is implanted into the brain to provide electrical stimulation. “It changed my life for the better in ways that I can't even tell you.”

When former U.S. Air Force Sgt. Jennifer Walden’s doctor told her about a clinical trial testing DBS as an epilepsy treatment, she jumped at the chance. “The 48 hours after those seizures are 48 hours where you don't want to live anymore.” Walden explained that her response to medication had dwindled after years of traditional treatment, increasing the frequency and severity of her seizures. “I feared suicide. It's something I didn't want to do, but if something happened in those 48 hours to end my life, I didn't care,” she said.

“I am now probably 99% seizure-free,” she beamed as she recalled her response to DBS on stage. “I don't know how I got so lucky in life, but I don't take it for granted.”

Common themes in their stories were resilience, hope, and a deep desire to give back.

“When I joined the study, it had no physical benefit to me, but that's not why I joined it,” said Scott Imbrie, who experienced a major spinal cord injury and participates in a clinical BCI study at the University of Chicago. “I decided to have invasive brain surgery and have electrodes implanted on my brain to help other people.”

A New Approach to Interdisciplinary Research

Timed alongside the InterfaceNeuro conference at Georgia Tech, the gathering offered a rare opportunity for scientists, engineers, and clinicians to engage directly with the lived experiences of individuals using brain-computer interfaces — a perspective often missing from traditional research settings.

“It makes you think about how we ethically conduct research and how we recruit and interface with patients,” said Eric Cole, a postdoctoral researcher at Emory University, who was reminded that many patients participating in BCI research have been on a long, difficult journey before interacting with researchers. “We should remember to take their experiences seriously and respect them. They're giving up something for research — that part we should always remember.”

“Wired Lives” was one in a series of events highlighting the lived experience of individuals with neurological conditions organized by the Neuro Next Initiative, which has served as the precursor to INNS.

“A core mission of INNS is to consider how neuroscience and neurotechnology impact people’s lives,” said Jennifer Singh, associate professor in the School of History and Sociology, a member of NNI’s executive committee, and a co-organizer of the event. “Their stories matter when it comes to the types of science and technology we pursue and how they benefit the human condition. Many scientists and engineers may never encounter people living with neurological conditions outside of events like this. That will be a priority for INNS — to bring the expertise of lived experiences to the research process.”

Ian Burkhart’s lived experience reminded the audience that not every clinical trial has a happy ending. His BCI was ultimately removed after seven years as research funding ran short, taking his newly improved hand mobility with it. Despite this, Burkhart remained positive.

“I'm so glad I was able to take that risk and have that voluntary brain surgery and participate in this type of research because it's defined my life.” Burkhart went on to found the BCI Pioneers Coalition and his own nonprofit because of his research participation. “It gave me a lot of hope for the future, and a lot of hope that these types of devices are going to be able to help people and improve their quality of life.”

This event was produced in partnership with The Story Collider and made possible through support from Blackrock Neurotech and Medtronic.

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An algorithmic breakthrough from School of Interactive Computing researchers that earned a Meta partnershipdrew more attention at the IEEE International Conference on Robotics and Automation (ICRA).

Meta announced in February its partnership with the labs of professors Danfei Xu and Judy Hoffman on a novel computer vision-based algorithm called EgoMimic. It enables robots to learn new skills by imitating human tasks from first-person video footage captured by Meta’s Aria smart glasses. 

Xu’s Robot Learning and Reasoning Lab (RL2) displayed EgoMimic in action at ICRA May 19-23 at the World Congress Center in Atlanta.

Lawrence Zhu, Pranav Kuppili, and Patcharapong “Elmo” Aphiwetsa — students from Xu’s lab — used Egomimic to compete in a robot teleoperation contest at ICRA. The team finished second in the event titled What Bimanual Teleoperation and Learning from Demonstration Can Do Today, earning a $10,000 cash prize.

Teams were challenged to perform tasks by remotely controlling a robot gripper. The robot had to fold a tablecloth, open a vacuum-sealed container, place an object into the container, and then reseal it in succession without any errors.

Teams completed the tasks as many times as possible in 30 minutes, earning points for each successful attempt.

The competition also offered different challenge levels that increased the points awarded. Teams could directly operate the robot with a full workstation view and receive one point for each task completion. Or, as the RL2 team chose, teams could opt for the second challenge level.

The second level required an operator to control the task with no view of the workstation except for what was provided to through a video feed. The RL2 team completed the task seven times and received double points for the challenge level.

The third challenge level required teams to operate remotely from another location. At this level, teams could earn four times the number of points for each successful task completed. The fourth level challenged teams to deploy an algorithm for task performance and awarded eight points for each completion.

Using two of Meta’s Quest wireless controllers, Zhu controlled the robot under the direction of Aphiwetsa, while Kuppili monitored the coding from his laptop.

“It’s physically difficult to teleoperate for half an hour,” Zhu said. “My hands were shaking from holding the controllers in the air for that long.”

Being in constant communication with Aphiwetsa helped him stay focused throughout the contest.

“I helped him strategize the teleoperation and noticed he could skip some of the steps in the folding,” Aphiwetsa said. “There were many ways to do it, so I just told him what he could fix and how to do it faster.”

Zhu said he and his team had intended to tackle the fourth challenge level with the EgoMimic algorithm. However, due to unexpected time constraints, they decided to switch to the second level the day before the competition due to unexpected time constraints. 

“I think we realized the day before the competition training the robot on our model would take a huge amount of time,” Zhu said. “We decided to go for the teleoperation and started practicing.”

He said the team wants to tackle the highest challenge level and use a training model for next year’s ICRA competition in Vienna, Austria.

ICRA is the world’s largest robotics conference, and Atlanta hosted the event for the third time in its history, drawing a record-breaking attendance of over 7,000.