EOS

Source: Global Biogeochemical Cycles

For years, oceanographers have puzzled over why algorithms were detecting mysteriously high levels of particulate inorganic carbon (PIC) in satellite imagery of remote Antarctic waters. In other areas, high PIC is a sign of massive blooms of single-celled phytoplankton known as coccolithophores, whose shiny calcium carbonate shells reflect light back to satellites. However, these polar waters have long been thought to be too cold for coccolithophores to thrive in.

The mystery is now solved, thanks to new ship-based measurements from Balch et al. They discovered an abundance of a different type of phytoplankton known as diatoms, whose reflective silica shells, or frustules, can mimic the reflectivity of PIC when found at very high concentrations. This reflectivity can lead satellite algorithms to misclassify these far southern waters as high-PIC areas.

Earlier ship-based observations from the same research team had already confirmed that PIC from coccolithophores is responsible for the Great Calcite Belt—a massive, seasonal, reflective ring of water encircling Antarctica in warmer waters to the north. Farther south, however, unusually bright areas around the continent remained unexplained, with hypothesized causes including loose ice, bubbles, or reflective glacial “flour” (eroded rock particles) released into the ocean.

The researchers sailed south from Hawaii into the less explored waters—known for their icebergs and rough seas—aboard R/V Roger Revelle. They measured PIC and silica levels, determined photosynthesis rates, conducted optical measurements, and observed microbes under microscopes. Together the data revealed that the high reflectivity of these remote areas is primarily caused by diatom frustules.

However, the researchers were also surprised to detect some coccolithophores in the polar waters, suggesting these phytoplankton can survive in seas colder than previously thought.

The findings could have key implications for Earth’s carbon cycle, as both coccolithophores and diatoms play major roles in the fixation of oceanic carbon. This work could also inform improvement of satellite algorithms to better distinguish between PIC and diatom frustules, the researchers suggest. (Global Biogeochemical Cycles, https://doi.org/10.1029/2024GB008457, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Mysteriously bright waters near Antarctica explained, Eos, 106, https://doi.org/10.1029/2025EO250337. Published on 12 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Quantifying the major elements of an earthquake energy budget is challenging. Seismologists can quantify the radiant energy that causes ground shaking, but they cannot quantify the other two major components: thermal dissipation and the energy that goes into creating new surface energy.

Since less than about 20% of an earthquake’s energy goes into radiation, approximately 80% of the budget is in question and represents a major unknown in earthquake physics. This is a significant limitation considering that the energy budget and the conversion of energy into various forms are one of the most powerful tools for describing natural phenomena in a robust and quantitative manner. The only way to resolve such lack of knowledge is by field-based and/or laboratory studies.

Using laboratory experiments, or “lab-quakes”, Ortega-Arroyo et al. [2025] quantify, for the first time, all three major components of the earthquake energy budget. Their findings open new opportunities for earthquake hazard assessment.

Citation: Ortega-Arroyo, D., O’Ghaffari, H., Peč, M., Gong, Z., Fu, R. R., Ohl, M., et al. (2025). “Lab-quakes”: Quantifying the complete energy budget of high-pressure laboratory failure. AGU Advances, 6, e2025AV001683. https://doi.org/10.1029/2025AV001683

—Alberto Montanari, Editor-in-Chief, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
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body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

An analysis of 20 years of health data in eight Amazonian countries, published today in Communications Earth and Environment, shows that protecting Indigenous-managed forests may help reduce various kinds of disease, including fire-related respiratory diseases and illnesses spread by animals. 

The results are further evidence of the importance of ensuring Indigenous communities have land sovereignty and the tools to maintain healthy forests, the paper’s authors said. 

“Ensuring Indigenous communities have strong rights over their lands is the best way to keep forests and their health benefits intact.”

“Protecting more forest areas under Indigenous people’s management could significantly reduce atmospheric pollutants and improve human health outcomes,” the authors wrote. 

Deforestation in the Amazon often occurs via clear-cutting, a practice by which nearly all trees and vegetation in an area are cut down, left to dry, and burned. Smoke and especially tiny particulate matter (PM2.5) from these fires makes those living in the Amazon sick with respiratory and cardiovascular illnesses: In the Brazilian Amazon, for example, deforestation fires were responsible for 2,906 premature deaths each year, on average, between 2002 and 2011.

Zoonotic and vector-borne diseases, such as Chagas disease, malaria, hantavirus, rickettsia, and spotted fevers also affect the estimated 2.7 million Indigenous people living in the Amazon. 

According to the researchers’ analysis of disease incidence and landscape in 1,733 Amazonian municipalities, Indigenous-managed forests seem to mitigate each form of disease (fire-related, zoonotic, and vector-borne) in some cases, depending on the characteristics of the surrounding land.

The decades of data revealed that Indigenous territories were able to mitigate the impacts of PM2.5 on fire-related diseases when those territories were part of municipalities with high forest cover. Indigenous territories also decreased the risk of zoonotic and vector-borne diseases when those territories covered more than 40% of the municipality. 

The effects were more pronounced when Indigenous territories were legally protected. The results may be explained by the fact that Indigenous territories have previously been linked to decreased deforestation (and therefore fewer clear-cutting fires) as well as decreased biodiversity loss, which previous research suggests may reduce the transmission of pathogens.

 
Related

•  Deforestation Threatens Public Health. Securing Indigenous Land Rights Can Help, Researchers Find
•  Well-Preserved Amazon Rainforest on Indigenous Lands Can Protect People from Diseases, Study Finds
•  Read the Paper: Indigenous Territories Can Safeguard Human Health Depending on the Landscape Structure and Legal Status
 

In municipalities with fragmented forests or low forest cover, though, Indigenous territory was less effective in mitigating disease risk. 

“Indigenous forests in the Amazon bring health benefits to millions,” said Paula Prist, a biologist at the International Union for Conservation of Nature and Natural Resources and coauthor of the new study, in a statement. “Ensuring Indigenous communities have strong rights over their lands is the best way to keep forests and their health benefits intact.”

In Brazil, about a third of Indigenous territories lack a formal legal title even though Brazilian law requires the government to provide one, according to Inside Climate News. 

This year’s Conference of the Parties, or COP30, an annual UN climate change conference, will be held in the Amazon rainforest in Belem, Brazil. There, deforestation and ecological health are expected to be major topics of discussion. 

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Oceans

Ripples are bedforms on sandy sea beds in coastal regions that form and react to waves and currents. The sediment dynamics of these features are complex but important for understanding how coastal morphology can change at this scale.

DeVoe et al. [2025] investigate how sand and water behave inside and above these ripples. They use advanced computer models that combine fluid (using a Large Eddy Simulation) and sediment behavior (using a Discrete Particle Model) to find out how forces and shear stresses vary over and within a moving bed using a new mathematical method. The numerical method does not need assumptions of the near-bed boundary layer as required by other models and is an important new contribution toward understanding coastal sediment transport.

Diagram showing the numerical model domain, including the coordinate system and relevant dimensions. The mobile bed contains six sand ripples with wavelength (λr) and height (ηr), comprised of spherical sediment particles with diameter (dp). Flow over the bed oscillates in direction to simulate the influence of surface waves. Credit: DeVoe et al. [2025], Figure 1a

Citation: DeVoe, S. R., Wengrove, M. E., Foster, D. L., & Hagan, D. S. (2025). Characterization of the spatiotemporal distribution of shear stress and bedload flux within a mobile, rippled bed. Journal of Geophysical Research: Oceans, 130, e2025JC022369. https://doi.org/10.1029/2025JC022369

—Ryan P. Mulligan, Editor, JGR: Oceans

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Society experiences climate change most viscerally through high-impact events such as storms, floods, and droughts. The effects of these events felt by communities vary in their geography, timing, and severity and do not necessarily correspond to statistical descriptions of the extremity of hazards dominantly used by institutional scientists. For example, a landfalling category 3 hurricane may not be statistically rare for the United States—or, on the whole, “extreme”—but it can still upend lives and livelihoods where its impacts are felt most.

Opportunities exist to contextualize extremes with respect to time, place, and severity and to connect global change science with societal experiences.

The statistical significance of environmental hazards is often what is relayed through conventional metrics and risk communication. But if the metrics and communications don’t reflect or resonate with people’s lived experiences and interests, they’re less likely to be useful in helping inform and safeguard communities.

We propose that methods of analyzing, translating, and communicating Earth system science and the associated risks of high-impact events other than those conventionally applied in research can provide more relevant information to communities navigating climate-related environmental hazards.

Opportunities exist to contextualize extremes with respect to time, place, and severity and to connect global change science with societal experiences. Scientists who understand and take these opportunities are also more likely to make connections that translate data and raw science into locally tangible and actionable information.

Statistically Significant Versus High Impact

Scientists often use statistical tools, such as the t test, to assess whether changes in a variable or a set of conditions are statistically significant—for instance, in the attribution of a specific extreme to climate change. Although this approach works well for analyzing high-frequency data (daily mean temperature measurements, say), it is less applicable for characterizing rare events.

t tests assume normally distributed data and quantify what is rare or extreme in relation to that distribution. Yet climatic extremes themselves, by their nature, do not conform to normal distributions, and their statistical significance is not well represented when measured in this way. Indeed, changes in some extreme environmental hazards, such as in the frequency and intensity of tornadoes, are hard to model statistically. Although high-impact events that are rare historically may be happening more often, longer records than are typically available are necessary to demonstrate that changes in these events are truly statistically significant.

We recommend moving away from standard statistical practices for communicating about hazards.

We have often observed anecdotally that changes in quantities irrelevant to impact (e.g., a 1-millimeter increase in flood depth) are often found to be statistically significant, whereas changes in high-impact quantities (e.g., a small increase in hurricane wind speed that leads to dramatically different outcomes for residential properties) are deemed not statistically significant. This inconsistency is hardly surprising considering the paucity of extreme event records and may lead to miscommunication between those generating and those using information about the significance (statistical or not) of an extreme.

The question, then, is whether—and in which situations—it is useful or meaningful to discuss the statistical significance of changing extreme environmental hazards in risk communication. We find that “statistically significant” and “high impact” tend to be conflated and presented interchangeably in environmental hazard risk communication, even though they have different meanings and potentially very different repercussions for those facing the hazards. For instance, a statistically significant rise in local sea levels may only become high impact when it starts to interact with the built environment.

We, and other scientists, thus recommend moving away from standard statistical practices for communicating about hazards in favor of using probabilistic analyses founded on physical reasoning, which consider the likelihood (and likely consequences) of hazard occurrences [e.g., Shepherd, 2021].

Accounting for Lived Experiences

Reducing an event to whether it is statistically rare also removes considerations of human impacts and lived experiences and potentially keeps impactful (but not statistically significant) environmental hazards from being included in scientific analyses. Further, characterizing the significance of an event in isolation, apart from the interconnected ecosystem in which it occurs, can disconnect its measured significance from on-the-ground realities. Such realities can include intersecting and compounding impacts from the immediate effects of an event, as well as, for example, ongoing environmental injustices or legacies of extractive industrial activities. These impacts may inflict shocks and stresses on communities and ecosystems that are completely obscured by conventional scientific analyses.

Typically, scientifically determined indicators and metrics, such as those focused on projected averages, do not account for the variability and subtle, yet critical, site-specific nuances of local community contexts within which environmental hazards and climate effects occur. In many Indigenous communities, for example, locally informed and relevant metrics, such as the percentage of food sourced locally and the health and quality of the food for subsistence livelihoods and food sovereignty, are often based on multigenerational and Traditional Knowledges connected to and in relationship with place. Similarly, place-based climate impact data are often seen as more useful, relevant, and grounded in people’s lived experiences than climate data themselves.

Convergence and Cocreation

Here we provide examples of where community-focused metrics and risk communications can be valuable, highlighting convergence science and cocreated research on hazards and financial risk management.

Convergence science transcends disciplinary boundaries and weaves together knowledge systems, tools, and ways of thinking and understanding to tackle key societal and scientific challenges. It can be understood as “an expression of radically affirming the deep relationality of life of the planet, of Mother Earth, of the affirmation that we are all related” [Rising Voices, Changing Coasts Hub, 2024]. This collaborative framework, involving codesign and cocreation with community partners, enhances development of meaningful climate data and metrics [Lazrus et al., 2025]. It also looks beyond prevailing climate science metrics such as temperature to better understand how climate impacts are actually felt in place by different groups.

Shrimp nets, like the one seen here near Bayou Pointe Au Chien in June 2024, are a traditional means of harvesting seafood on the Louisiana coast. Credit: Julie Maldonado

For example, traditional harvesters on the working coast of Louisiana give attention to the health and quality of the seafood harvest and to what extent traditional diets and livelihoods can be sustained [Maldonado, 2019]. Measuring environmental impacts on this place-based community’s ability to maintain traditional livelihoods and lifeways [Barger et al., 2025; The Rising Voices Center for Indigenous and Earth Sciences, 2020] requires using definitions, metrics, and baselines defined by the community.

Another example comes from the Bering Sea–Bering Strait–Chukchi Sea region. In recent decades, dramatically and rapidly changing conditions of sea ice (location, extent, thickness, ice free days, seasonal shifts), ocean temperatures, permafrost thaw, and weather have profoundly affected communities in this part of the Arctic. Changes in sea ice have affected the safety of hunting practices, limited access to prey such as Pacific walrus, and threatened traditional methods of processing and storing harvested food in many communities that have relied for millennia on marine resources for food, culture, and community health and well-being [e.g., Apassingok et al., 2024]. Sea ice reductions have also increased communities’ vulnerability to the impacts of wind, waves, and coastal erosion [e.g., Overeem et al., 2011].

As in many low-lying communities on the Alaska coast, infrastructure and homes in Kotzebue, seen here, are growing more vulnerable with changing environmental conditions. Credit: iStock.com/ChrisBoswell

Major food shortages can result from compounding conditions that may not be extreme by themselves, such as the seasonal location of ever-shrinking sea ice and changing oceanic currents and temperatures, as well as issues of federal and state governance. Seasonal weather conditions and individual weather events—such as the October 2024 storm that caused severe flooding and damage to infrastructure in several coastal Alaskan towns—have also played roles in the extreme impacts experienced in the Bering-Chukchi region, even when these events themselves were not considered statistically extreme in isolation.

Conventional metrics and communications focused on statistically significant extremity can fail to capture how changing conditions are truly affecting the region’s peoples.

Whereas conventional metrics and communications focused on statistically significant extremity can fail to capture how changing conditions are truly affecting the region’s peoples, community-informed indicators focused more on food availability or traditional practices, for example, can be far more beneficial for guiding local decisionmaking.

A third example considers hazard metrics useful for financial risk management. Academic research into high-impact weather events in a changing climate typically compares hazard characteristics—of severe thunderstorms or tropical cyclones, say—between current and future climate periods and assesses the change in characteristics between the two periods. The timing of these future periods, however, can be somewhat arbitrary (e.g., at the end of this century).

Such assessments do not consider values or objectives of risk management, such as remaining financially solvent throughout the period leading up to the analyzed future period. They also provide information about conditions during only a narrow time window far in the future, whereas a financially destabilizing event that occurs sooner may render assessments of the more distant future obsolete.

A more usable metric would consider unacceptable risks to a given management objective, such as protecting lives or property, and calculate the time horizons at which these risks are likely to be crossed [Rye et al., 2021]. Such a metric would be cocreated by researchers and risk managers to link the changing character of hazards with management objectives. Framing climate change–induced risk in this way would allow it to be quantifiable and trackable by risk managers.

A similar approach has been proposed in engineering design, whereby the structural reliability of built infrastructure over a given service life (say, 100 years) is calculated from the maximum risk of a hazard occurring in each year to minimize associated failures [Rootzén and Katz, 2013].

An All-Hands-on-Deck Approach

The examples above by no means describe the full range of communities affected by environmental hazards, but they highlight the shared need for hazard information that is contextualized for time, place, and use.

Careful codesign of community-based metrics can enhance the relevance, uptake, and influence of geoscience information in societal decisionmaking.

Careful codesign of community-based metrics can enhance the relevance, uptake, and influence of geoscience information in societal decisionmaking [Jagannathan et al., 2021]. No single approach or framework for codesign exists. Rather, effective approaches are deeply specific to context and culture. They involve iterative processes of participatory, colearning knowledge exchange that require time and emotional labor—as well as effective mediation and shared learning strategies—to build and maintain relationships, mutual trust, and shared agreements [Jagannathan et al., 2021].

Such work should not be viewed apart from fundamental climate and global change science. On the contrary, it requires the weaving together of expertise and knowledge from many participants, including community members, practitioners, and institutional scientists. Through convergent and integrative approaches to environmental hazards research and risk communication, we can better understand—and communities can better respond to—changes in metrics that matter.

References

Apassingok, M., et al. (2024), How does the changing marine environment affect hunters’ access to Pacific walruses?, Arct. Antarct. Alpine Res., 56(1), 2367632, https://doi.org/10.1080/15230430.2024.2367632.

Barger, S., et al. (2025), Lessons from place: Indigenous-led rematriation for strengthening climate adaptation and resilience, J. Geogr., 124(3), 73–82, https://doi.org/10.1080/00221341.2025.2512244.

Jagannathan, K., A. D. Jones, and I. Ray (2021), The making of a metric: Co-producing decision-relevant climate science, Bull. Am. Meteorol. Soc., 102(8), E1579–E1590, https://doi.org/10.1175/BAMS-D-19-0296.1.

Lazrus, H., et al. (2025), Tapestries of knowledge: Using convergence science to weave Indigenous science and wisdom with other scientific approaches to climate challenges, Bull. Am. Meteorol. Soc., 106, E1558–E1565, https://doi.org/10.1175/BAMS-D-24-0215.1.

Maldonado, J. (2019), Seeking Justice in an Energy Sacrifice Zone: Standing on Vanishing Land in Coastal Louisiana, Routledge, London, www.routledge.com/Seeking-Justice-in-an-Energy-Sacrifice-Zone-Standing-on-Vanishing-Land-in-Coastal-Louisiana/Maldonado/p/book/9781629584010.

Overeem, I., et al. (2011), Sea ice loss enhances wave action at the Arctic coast, Geophys. Res. Lett., 38, L17503, https://doi.org/10.1029/2011GL048681.

Rising Voices, Changing Coasts Hub (2024), Co-created Knowledge and Actions: Moving from the Theory of Convergence Research to Practice, Working Group Session at 2024 National Tribal and Indigenous Climate Conference, Inst. for Tribal Environ. Prof., Anchorage, Alaska, 11 September, sites.google.com/view/nticc2024/home_1.

Rootzén, H., and R. W. Katz (2013), Design life level: Quantifying risk in a changing climate, Water Resour. Res., 49(9), 5,964–5,972, https://doi.org/10.1002/wrcr.20425.

Rye, C. J., J. A. Boyd, and A. Mitchell (2021), Normative approach to risk management for insurers, Nat. Clim. Change, 11(6), 460–463, https://doi.org/10.1038/s41558-021-01031-8.

Shepherd, T. G. (2021), Bringing physical reasoning into statistical practice in climate-change science, Clim. Change, 169(1–2), 2, https://doi.org/10.1007/s10584-021-03226-6.

The Rising Voices Center for Indigenous and Earth Sciences (2020), Rising Voices Workshop report on food systems, Rising Voices Workshop 2020, n2t.net/ark:/85065/d7s75mqf.

Author Information

Mari R. Tye (maritye@ucar.edu) and Laura Landrum, National Science Foundation National Center for Atmospheric Research, Boulder, Colo.; Julie Maldonado, Livelihoods Knowledge Exchange Network, Winchester, Ky.; and Diamond Tachera and James M. Done, National Science Foundation National Center for Atmospheric Research, Boulder, Colo.

Citation: Tye, M. R., L. Landrum, J. Maldonado, D. Tachera, and J. M. Done (2025), Environmental hazard impact metrics that matter, Eos, 106, https://doi.org/10.1029/2025EO250335. Published on 11 September 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Community Science

When plastic waste enters waterways, it can endanger aquatic animals, damage habitats, and splinter into tiny pieces that may affect ecosystems for centuries to come.

One tool used to collect and study the trash found in bodies of water is the trash trap—an anchored floating device that funnels trash toward an enclosed collection area. Between 2021 and 2024, seven North Carolina Waterkeepers organizations installed 21 trash traps in streams around the state, periodically cleaning them out and collecting the contents. Lauer et al. analyzed the products of these cleanouts.

Staff and volunteers retrieved 150,750 pieces of litter from 368 cleanouts of the traps during the study period. They then organized the collected trash into different categories. Different organizations used different protocols, but the most common was developed by the Haw River Assembly (HRA) and the Duke University Environmental Law and Policy Clinic. The Duke/HRA protocol divided trash into six major groups (plastic film, hard plastic, foamed plastic, metal, glass, and “other”) and 33 subcategories, such as plastic bags, food wrappers, drink bottles, and polystyrene foam fragments (Styrofoam).

About 96% of trash categorized with the Duke/HRA protocol was plastic. Of this, 72.6%, or nearly 83,000 pieces, was Styrofoam fragments. This material was particularly tricky to catalog, the researchers noted, because it breaks down into tiny pieces that are difficult to retrieve.

More litter tended to accumulate in regions with higher populations and more development. Increased rainfall drove greater trash collection in about half the traps, because rain helps carry trash into rivers and streams. Similarly, traps located in areas with more impervious surfaces, such as streets and pavement, tended to accumulate more trash because these surfaces channel litter through storm drains and into nearby waterways.

The researchers note that trash traps do not collect all trash, and that cleanouts can be labor intensive, but they also highlight benefits of this type of data collection: It can help scientists understand local sources of litter, engage the public in community science, and provide a basis for targeted policies aimed at reducing plastic pollution. (Community Science, https://doi.org/10.1029/2024CSJ000122, 2025)

—Rebecca Owen (@beccapox.bsky.social), Science Writer

Citation: Owen, R. (2025), How North Carolina trash traps could help inform policy, Eos, 106, https://doi.org/10.1029/2025EO250283. Published on 11 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

A sample collected in July 2024 by NASA’s Perseverance Mars rover may be “the closest we’ve actually come to discovering ancient life on Mars,” according to Nicky Fox, the science head of NASA.

In a press conference today, NASA officials shared new results of an analysis of a sample named “Sapphire Canyon,” the 25th sample Perseverance collected from Mars. The analysis was published today in Nature. 

Perseverance has been looking for signs of life on the Red Planet since 2021, exploring the 28-mile-wide (45-kilometer-wide) Jezero Crater that, billions of years ago, repeatedly flooded with water. The crater’s past conditions mean it could have been a suitable habitat for microbial life. 

The rover collected Sapphire Canyon from a vein of sedimentary rock in a river valley called Neretva Vallis that is situated in the crater. The rock bore a distinct, leopard-print pattern visible to the naked eye. “We hadn’t seen anything like that before on Mars,” Fox said at the press conference. 

An image taken by Perseverance shows the leopard spot pattern that scientists believe could be a signature of ancient microbial life. NASA/JPL-Caltech/MSSS

Perseverance has collected 30 samples in total from Jezero Crater. Though none of the samples have been returned to Earth, scientists have been able to study them via Perseverance’s on-board instrumentation. “We basically threw the entire rover science payload at this rock,” said Katie Stack Morgan, a Perseverance project scientist at NASA’s Jet Propulsion Laboratory and coauthor of the new study. 

“When we see features like this in sediment on Earth, these minerals are often the byproduct of microbial metabolisms that are consuming organic matter.”

Scientists analyzed the sample’s leopard spots using the rover’s Scanning Habitable Environments with Raman & Luminescnece for Organics and Chemicals (SHERLOC) spectrometer and Planetary Instrument for X-ray Lithochemistry (PIXL) X-ray spectrometer. The analysis revealed the presence of organic matter in the mud that formed the rock, as well as the presence of iron-, phosphorus-, and sulfur-bearing minerals called vivianite and greigite in the leopard spots. 

The combination of minerals and the organic matter in the mud indicated the past occurrence of chemical reactions that could have been driven by ancient microorganisms, said Joel Hurowitz, a planetary scientist at Stony Brook University and lead author of the new study.

“What’s exciting about this combination of mud and organic matter that has reacted to produce these minerals and these textures, is that when we see features like this in sediment on Earth, these minerals are often the byproduct of microbial metabolisms that are consuming organic matter,” Hurowitz said. 

Hurowitz added that there are also abiotic processes that could have created the patterns detected in the rock, and that with Perseverance’s instrumentation it isn’t possible to rule out abiotic explanations. 

NASA, in partnership with the European Space Agency, has been planning to develop the Mars Sample Return mission to eventually return samples collected by Perseverance to Earth, allowing scientists to get their hands on the rocks.

But budget changes have left the future of Mars Sample Return uncertain: President Trump’s May budget proposal suggested a $6 billion cut to NASA funding, including a proposal to “terminate unaffordable missions such as the Mars Sample Return.” Congress has not yet passed final appropriations bills and could still decide to allocate funding to Mars Sample Return. 

 
Related

•  Read the New Paper: Redox-Driven Mineral and Organic Associations in Jezero Crater, Mars
•  Read More About the Perseverance Rover
•  This Rock May Hold Proof of Life on Mars
•  Get Involved: AGU Science Policy Action Center
 

Acting NASA Administrator Sean Duffy fielded multiple questions at the press conference about the future of Mars Sample Return. In his responses, he implied that human space exploration, a priority of NASA under Trump, could allow for the return of samples from Mars on a faster timescale with less expensive methods. That notion may be inconsistent with revised estimated costs of a fully robotic sample return mission compared with that of a human exploration mission to Mars.

“If we don’t have the resources for the right missions or the right people, I will go to the President, I’ll go to the Congress, I’ll ask for more money. But I feel pretty confident that with the money that we’ve been given in the President’s budget, we can accomplish our mission,” Duffy said.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Earth’s Future

Global climate models are software behemoths, often containing more than a million lines of code.

Inevitably, such complex models will contain mistakes, or “bugs.” But because model outputs are widely used to inform climate policy, it’s important that they generate trustworthy results.

Proske and Melsen set out to understand how climate modelers think about, identify, and address bugs. They interviewed 11 scientists and scientific programmers from the Max-Planck-Institut für Meteorologie who work on the ICON climate model.

When new code is developed for ICON, it’s screened and tested to catch bugs before being integrated into the model itself, the interviewees said.

After code is integrated, however, such testing usually stops. The code is assumed to be bug free until the model behaves weirdly or a programmer serendipitously discovers a bug while examining the code for other reasons. Even when the model crashes, it’s not necessarily a sign that a bug needs to be fixed because researchers are always making trade-offs between the speed and the stability of the model, and sometimes they simply push the model outside the bounds of what it can handle given those constraints.

Tracking down bugs and fixing them can be time-consuming, so even if the team suspects the presence of a bug, they sometimes estimate its impact to be minor enough that it doesn’t warrant correction. When the researchers do decide to fix a bug, many view the process as an extension of climate science: They generate hypotheses about how the bug might cause the model to behave, then test those hypotheses to discern the exact nature of the bug and how to address it.

The best way to avoid bugs is to test code thoroughly before it’s integrated into the full model, many interviewees said. Tools exist to facilitate testing, such as Buildbot and the GitLab development platform, and the scientists said such tools could be leveraged more fully in ICON’s development process. However, they also said there are inherent limits to how thoroughly researchers can test climate models because researchers don’t always know what a 100% accurate model output would look like. Thus, they do not have that basis to which they can compare actual model output.

Though the interviewees acknowledged that ICON is imperfect, they also considered it to be “good enough” to forecast weather or to answer research questions such as how increased atmospheric carbon will affect global temperatures. The authors write that although “the principle of ‘good enoughness’” is pragmatic and understandable, it could also lead to misunderstandings if users don’t appreciate a model’s limits. (Earth’s Future, https://doi.org/10.1029/2025EF006318, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2025), When is a climate model “good enough”?, Eos, 106, https://doi.org/10.1029/2025EO250332. Published on 10 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Source: GeoHealth

Recent heat waves in the United States underscore a growing public health threat: Extreme heat events are growing longer, hotter, and more frequent. Soaring temperatures raise the risk of various health problems, such as heat stroke and cardiovascular disease—particularly for older people, people with preexisting conditions, and people who work outdoors.

Understanding these risks, and how to handle them, requires epidemiological research on heat exposure in cities, where most U.S. residents live. However, scientific instruments for measuring urban temperatures are often located at airports, rather than in city centers, where temperatures are typically higher than in surrounding rural regions. Thus, these tools often do not adequately capture the so-called urban heat island effect.

A novel method for measuring heat exposure, created by Marquès and Messier, can pinpoint urban heat islands that previously went undetected. The researchers’ approach harnesses crowdsourced data from the thousands of personal weather stations already installed by residents seeking precise weather information.

The new method employs a statistical technique known as Bayesian hierarchical modeling, which helps account for uncertainty in the crowdsourced temperature data. To demonstrate its capabilities, the researchers applied the method to four urban areas with distinct climates and geography: New York City, Philadelphia, Phoenix, and North Carolina’s “Triangle,” which includes Raleigh, Durham, and Chapel Hill.

Compared with existing tools, the new method captured urban air temperatures at much higher resolution. It identified urban heat islands that were previously detected imprecisely or not at all, such as hot spots clustered in Philadelphia. In addition, it recognized the cooling effects of urban green spaces, such as New York’s Central Park. It performed well at both high and low temperatures, including during Phoenix’s hottest month on record (July 2023) and a cold blizzard event in Philadelphia and New York in January 2021. The new method also revealed that compared with other areas in the same city, more densely populated neighborhoods were more likely to experience hot temperatures and longer hot nights.

The researchers have made their method publicly available in the hope that it will aid research into the health impacts of heat. This work could also help inform public health initiatives to support communities facing extreme heat, they say. (GeoHealth, https://doi.org/10.1029/2025GH001451, 2025).

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Extreme heat in U.S. cities revealed at high resolution, Eos, 106, https://doi.org/10.1029/2025EO250296. Published on 10 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Community Science

In China, efforts to modernize agriculture through large-scale farming have pushed many smallholder farmers—who produce most of the country’s food—to the margins. One promising solution is “circular agriculture,” which focuses on sustainability, productivity, and rural economic development by encouraging cooperation between large- and small-scale farming operations.

In Community Science’s special collection on Transdisciplinary Collaboration for Sustainable Agriculture, Li and Nielsen [2025] examine a circular agriculture project in southwest China that combines pomelo growing with pig breeding. The authors conducted 35 interviews with smallholder farmers, government officials, employees from financial institutions, and various other stakeholders, capturing a wide range of interests and risks faced in this model.

Their findings show that local governments play a key role in creating platforms for cooperation, while agricultural cooperatives are central to business management. The study also reveals the challenge that government involvement is often politically motivated, and smallholders can lose both autonomy and fair representation in decision-making. The authors suggest that for circular agriculture to truly benefit everyone, smallholders need both a voice and power in shaping their future—without having their interests exploited.

Citation: Li, H., & Nielsen, J. Ø. (2025). Smallholders, capital, and circular agriculture—The case of combined pomelo and pig farming in southwest China. Community Science, 4, e2025CSJ000127. https://doi.org/10.1029/2025CSJ000127

—Claire Beveridge, Editor, Community Science

Text © 2025. The authors. CC BY-NC-ND 3.0
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On 1 July 2025, astronomers detected a visitor from the deep reaches of space. At the time of discovery, the object was just inside Jupiter’s orbit and was zipping across our solar system 4 times faster than the New Horizons probe sped past Pluto. It was first spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile, which was specifically designed to spot small, fast-moving objects like this. ATLAS sent out a public, automated alert, and when astronomers saw it, they quickly went to work calculating the object’s orbit and trajectory.

That’s when things got interesting. Backtracking the object’s path showed that its origins were not in the Oort cloud, the outermost region of our solar system responsible for most of the comets we see. Instead, the object’s journey started a long time ago in a star system far, far away.

The earliest observations of the object—now labeled 3I/ATLAS for being the third confirmed interstellar object (3I)—showed a distinct coma or haze of material surrounding a dense center.

“We knew we were going to get a 3I. We didn’t know when we were going to get a 3I.”

The trajectory of 3I/ATLAS suggests that it will escape the modest gravitational clutches of the Sun in mid-2026, and that time frame has contributed to a flurry of activity among scientists in the emergent field focused on studying interstellar objects (ISOs). Teams of researchers have secured time on some of the most prominent telescopes around the world and in space, combed through telescope archives for “precovery” images, run computer models and simulations, and released nearly three dozen quick-look research papers in astronomy’s preferred preprint repository.

“We knew we were going to get a 3I. We didn’t know when we were going to get a 3I,” said Michele Bannister, who researches small solar system objects at the University of Canterbury in Ōtautahi-Christchurch, Aotearoa New Zealand.

The speed of discoveries about this interstellar visitor outpaced efforts made when the first and second interstellar objects were discovered: 1I/’Oumuamua in 2017 and 2I/Borisov in 2019. One ISO might be a fluke, and two may be a coincidence, but three seemed inevitable. Astronomers took no chances in preparing for the likely arrival of another interstellar visitor.

Teams’ carefully laid plans have borne fruit, enabling rapid-response science, close international collaborations, and a united global effort to learn as much as possible about 3I/ATLAS before it disappears forever.

Planning for 3I

The arrival of ‘Oumuamua caught astronomers by surprise. It was the first discovery of its kind and wasn’t spotted until it was on its way out of the solar system. Researchers had a mere 2 weeks to get all the data they possibly could, taking their best guesses about what telescopes, instruments, and wavelengths would provide the best data on such short notice.

When something like ‘Oumuamua shows up, “you immediately write what’s called a director’s discretionary [DD] proposal,” explained Karen Meech, a planetary astronomer at the University of Hawai‘i’s Institute for Astronomy. “You scramble, you write a proposal, you submit it. The [telescope] director reads it and makes a decision without a review panel.” Bypassing a review panels speeds up the process but is less democratic.

Having found one ISO, researchers started putting in DD proposals every semester in case another one showed up.

“Astronomers are always trying to use these facilities as efficiently as possible.”

When Borisov appeared 2 years later, it was immediately obvious that it was radically different from ‘Oumuamua. The way observations were allotted on telescopes was also different—facilities became overwhelmed with the sheer volume of DD proposals, Meech said. That led to duplicate observations and some teams’ observations being bumped entirely when a newer, but identical, proposal came in. Telescopes have since worked out those kinks in the system to streamline the DD proposal process.

Anticipating the inevitable detection of a third interstellar object, many ISO observers took a different approach: target of opportunity (TOO) proposals. TOO is a process commonly used in branches of astronomy that study unpredictable phenomena like supernovas, kilonovas, gravitational waves, and gamma ray bursts. Researchers submit observing proposals for short observations of events that could happen at any time. If the event occurs, the team can trigger those telescope observations.

“Most collaborations, including ours, have preapproved dormant programs at the world’s largest telescopes ready to be activated when a suitable [ISO] candidate is confirmed,” said Raúl de la Fuente Marcos, who researches small solar system objects at the Universidad Complutense de Madrid in Spain. Before ‘Oumuamua, “such a discovery was considered highly unlikely. Now all the collaborations that have been involved in early data releases of 3I/ATLAS have such systems.”

Four images taken by the Hubble Space Telescope on 21 July track the motion of 3I/ATLAS through the solar system. Background stars are visible as streaks because the telescope followed the comet’s motion Credit: Images taken by David Jewitt/NASA/ESA/Space Telescope Science Institute (STScI), processed by Nrco0e via Wikimedia Commons, Public Domain

“Basically, if you give us more than a semester to plan, we will plan,” Bannister said. “Astronomers are always trying to use these facilities as efficiently as possible.”

De la Fuente Marcos and his team imaged and obtained spectra of 3I/ATLAS with the Gran Telescopio Canarias and the Two-meter Twin Telescope, both in Spain’s Canary Islands. Their observing program was triggered a mere 6 hours after 3I/ATLAS was confirmed as an interstellar object, allowing them to observe the comet from 2 to 5 July. Their results, published in Astronomy and Astrophysics, were the first to show that 3I/ATLAS’s spectrum is red and dusty, not too dissimilar from dusty solar system comets.

Teddy Kareta’s observations were more serendipitous. Kareta, a planetary scientist at Villanova University in Pennsylvania, already had time scheduled on the NASA Infrared Telescope Facility (IRTF) for 3 and 4 July. He learned about 3I/ATLAS the evening before his observing run and thought, “That’s too cool to be real,” he recalled.

“And then I woke up to about seven text messages, three missed calls, a dozen emails, most of which were saying, ‘Hey, I noticed you’re on the telescope because I checked the schedule— You’re gonna go out, right?’” Kareta said.

But the comet was coming in much faster than past ISOs and from a direction that made it challenging to observe.

“It was a very communal planning process, which I think for science often doesn’t happen so quick and on the fly.”

“People were coming up with observational plans on the fly,” Kareta said. “I pointed a 4-meter telescope at it for 2 full hours, and I think I got three useful images.”

There were plenty of emails, group chats, and Zoom calls trying to figure out the best telescope and camera settings.

“It was a very communal planning process, which I think for science often doesn’t happen so quick and on the fly,” Kareta said. “It felt more like a readiness exercise than it did like a traditional kind of planning….You need as many hands on deck as possible to make it work at all.”

Kareta and his colleagues’ infrared spectral observations, accepted for publication in Astrophysical Journal Letters, suggest that the comet may have a complex grain size distribution, grain compositions unlike solar system comets, or both.

A Broad Research Umbrella

By its galaxy-traveling nature, 3I/ATLAS quite literally connects comet science with the study of stars, planetary systems, and the galaxy.

ISO theorists have spent the time since Borisov’s departure working on a computer model that predicts the properties of interstellar objects across the galaxy. They had timed the release of their Ōtautahi-Oxford model for the beginning of science operations of the Vera C. Rubin Observatory and its Legacy Survey of Space and Time (LSST), which is expected to discover dozens of potential interstellar objects.

“We knew that LSST and Rubin were going to find loads, but we just thought this was going to happen in 6 months’ time, not now,” said Matthew Hopkins, who studies both ISOs and galaxy evolution at the University of Oxford in the United Kingdom.

Comet 3I/ATLAS “really did arrive with fantastic timing.”

Luckily, the model team, composed of people studying interstellar objects, comets, stars, and galaxy dynamics, was putting the finishing touches on a program that could analyze an ISO’s speed and orbital information and predict where in the galaxy it may have come from.

Comet 3I/ATLAS “really did arrive with fantastic timing,” Hopkins said.

The team jumped into action when the comet’s orbital characteristics were announced. It was detected when it was 670 million kilometers (420 million miles) away, traveling at nearly 60 kilometers per second and coming in at a steep angle. Bannister, part of Ōtautahi-Oxford’s New Zealand contingent, said that her team was able to share its results so quickly because it had members scattered from western Europe to New Zealand. After working all day, the New Zealanders could hand off the research to European team members, whose day was just starting. By tag teaming the science, they submitted their analysis to Astrophysical Journal Letters about 84 hours after the comet’s discovery. (It has since been published.)

The orbit of 3I/ATLAS will take it within the orbit of Mars, with close passes to both Mars and Jupiter. Credit: CSS, D. Rankin; Video recorded and edited by Renerpho via Wikimedia Commons, CC BY-SA 4.0

“Especially for 3I, given that it was time sensitive, we definitely wanted to share our results as we had them,” Hopkins said.

The Ōtautahi-Oxford model showed that because 3I/ATLAS entered the solar system at a much steeper angle than either ‘Oumuamua or Borisov, it likely came from a different region of the galaxy, a part known as the thick disk. Though most young and middle-aged stars, including the Sun, live in the narrow thin disk of the Milky Way, many older stars live in the thick disk. The trajectory of 3I/ATLAS suggests that it originated from a star system that could be more than 7.6 billion years old. Indeed, its parent star may already be dead.

The age of 3I/ATLAS has intrigued many researchers who study stellar populations, galaxy dynamics, the birth of exoplanetary systems, and astrobiology, fields that are usually disparate and siloed.

“If you’re studying interstellar objects, you’re sitting cleanly at the division between planetary science and traditional astrophysics.”

“If you’re studying interstellar objects, you’re sitting cleanly at the division between planetary science and traditional astrophysics,” Kareta said. “And I think that means that people from both groups immediately know these are important.”

“Our colleagues who do extragalactic science and supernovae are really excited to help with 3I, and so we’re trying to trigger everything we can on the big telescopes,” Meech said. Her group had been hoping to use the Keck II telescope in Hawaii to obtain high-resolution infrared spectra of the comet, but the telescope had been experiencing technical issues. A student studying kilonovas had TOO time on the nearby James Clerk Maxwell Telescope and donated it.

“He said, ‘You know what, [the kilonova is] not going to go off in the next 2 weeks. Let’s use it for this,” Meech recalled. “And so we got five nights of observations on this object.” Meech and her colleagues are still analyzing those data to understand the abundances of certain gases in 3I/ATLAS’s coma.

The Long-Term Strategy

Several weeks after its initial discovery, it is clear that 3I/ATLAS looks and behaves like a comet. It’s now millions of kilometers closer to the Sun than it was upon detection in early July, and more recent observations, including from the Hubble Space Telescope, James Webb Space Telescope, Very Large Telescope, and more, have shown a dusty coma emitted from the Sun-facing side and the beginnings of a traditional comet tail behind it.

Most of the earliest 3I/ATLAS papers are still undergoing peer review, and Kareta said that more research analyzing July observations will continue to trickle out. Too, groups that wrote early papers will be going back over their data to put them in context with newer information and provide deeper analyses of those initial quick looks.

Hubble imaged 3I/ATLAS on 21 July. The comet is shedding dust in the direction of the Sun (right) and is haloed by a coma. Background stars are streaked, as the telescope followed the comet’s movement. NASA, ESA, D. Jewitt (UCLA); Image Processing: J. DePasquale (STScI), Public Domain

However, with the early rush of observations mostly completed, some scientists are turning their attention to what they want to learn about 3I/ATLAS in the coming months.

“A lot of teams are still scrambling to get telescope time,” Meech said.

The comet will reach its closest approach to the Sun, a mere 35% farther than the Earth-Sun distance, on 29 October. Earth will lose sight of it in the Sun’s glare in early September, but by mid-August, 3I/ATLAS had already started outgassing, as predicted. Astronomers were eager to analyze the chemistry of the gases it emitted because that could give clues about its history.

“Stellar encounters this close are actually really rare for interstellar objects,” Hopkins said. This is probably 3I/ATLAS’s first encounter with a star since it was booted out of its own system, and its surface material has likely been frozen in time since then. “We can use that to learn some really cool things about the chemistry of its parent star halfway around the galaxy, even if it’s dead.”

Spectra obtained from 3I/ATLAS’s coma in mid-August showed strong signs of water ice, carbon dioxide, nickel, and cyanide—all expected of a comet emitting a mixture of gas and dust as it heats up. “Typically for comets, the first thing you see is CN, cyanide, not because it’s particularly abundant but because it interacts so strongly with sunlight,” Meech said.

“There’ll be a lot of happy arguments around ‘Where did this form in the disk of its home star, and what does that tell us about the conditions that were like in that protoplanetary disk.’”

Indeed, scientists are seeing an object not too unlike a domestic comet, and they’ll continue to monitor its outgassing as it gets closer to the Sun.

The outgassing of carbon monoxide would be particularly telling, as the compound freezes solid only in extremely cold conditions like those that exist in the outer reaches of a star system. So if 3I/ATLAS outgasses carbon monoxide, Hopkins explained, it would be a strong hint that the object may have formed in the coldest outer regions of its system’s protoplanetary disk.

“There’ll be a lot of happy arguments around ‘Where did this form in the disk of its home star, and what does that tell us about the conditions that were like in that protoplanetary disk,’” Bannister added.

Still, who knows? “These are representative fragments of star formation elsewhere. There’s no reason that every protoplanetary disk has the same chemical distribution,” Meech said.

Every snapshot researchers get from now until 3I/ATLAS’s departure will help them put together a holistic, time series picture of the comet as it heats up and evolves. No one even knows whether it will survive its closest approach to the Sun in October.

All eyes, and telescopes, will be trained on its predicted point of emergence in late November.

Time Enough for Everyone

The biggest advantage that scientists have with 3I/ATLAS that they did not have with 1I/’Oumuamua is time—time not only to make more observations and analyses but to enable the widest participation possible.

‘Oumuamua arrived in October, the middle of the academic semester. Scientists who could respond quickly tended to be senior-level researchers, those with fewer teaching responsibilities, and those at institutions with easier access to telescope facilities, Kareta explained. Early-career scientists, those involved with research programs, or those who had inflexible responsibilities were less able to contribute to the groundbreaking discovery in the two-ish weeks before the object disappeared.

“The longer we have to study it, that means more people can work on it, more brains can take a crack at the problem and…leave their mark on this object.”

With 2I/Borisov and now with 3I/ATLAS, a monthslong observation window has enabled a larger, more diverse group of scientists from around the world to participate in observing, analyzing, and discussing this discovery.

“The longer we have to study it, that means more people can work on it, more brains can take a crack at the problem and…leave their mark on this object,” Kareta said.

And that can be only a positive thing for this nascent, but growing, field of science.

“We’re 7 years into this field of small-body galactic studies,” Bannister said. “There’s a whole different generation of people coming into this than were involved in 1I and even 2I. That’s really exciting to see.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), How an interstellar interloper spurred astronomers into action, Eos, 106, https://doi.org/10.1029/2025EO250329. Published on 9 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Journal of Geophysical Research: Biogeosciences

This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un artículo de Eos.

La atmósfera terrestre transporta diminutas formas de vida celular, tales como esporas de hongos, polen, bacterias y virus. En sus recorridos, estos microorganismos se enfrentan a condiciones desafiantes como bajas temperaturas, radiación ultravioleta y falta de disponibilidad de nutrientes. Investigaciones previas han demostrado que ciertos microorganismos pueden resistir estas condiciones extremas y, potencialmente, permanecer en estado de latencia hasta depositarse en un entorno más favorable. Pero ¿podría la misma atmósfera ser también el lugar de un sistema microbiano activo, que albergue microorganismos en crecimiento, adaptados y residentes?

El estudio de estas formas de vida flotantes se denomina aerobiología, pero avanzar en este campo resulta complicado: no existe un método estandarizado para muestrear el aeromicrobioma, es común que las muestras microbianas se contaminen, y resulta difícil reproducir las condiciones atmosféricas en un entorno de laboratorio.

Martinez-Rabert y colaboradores sugieren que la modelización computacional y los enfoques teóricos podrían contribuir a mejorar la comprensión del aeromicrobioma. A partir de la información conocida sobre el metabolismo y la bioenergética de la vida microbiana—especialmente en ambientes extremos—, así como de la química y la física de la atmósfera, los marcos de modelización especializados pueden proporcionar información sobre el aeromicrobioma.

Ese enfoque de modelado ascendente, proponen los investigadores, les permitiría comprobar cómo el cambio de elementos individuales de la atmósfera terrestre afectaría a la proliferación de la vida microbiana que contiene. Por ejemplo: ¿los microbios están mejor adaptados a un estilo de vida “libre” en los gases atmosféricos, dentro de gotas o adheridos a partículas sólidas? ¿Qué fuentes de energía están disponibles para estos microorganismos? ¿Cómo influye la acidez de los aerosoles atmosféricos en la capacidad de los microorganismos atmosféricos para prosperar?

El grupo sugiere que, combinados con datos obtenidos mediante muestreos, experimentos y observaciones, los modelos teóricos podrían ayudar a los investigadores a evaluar la capacidad de nuestra atmósfera para sostener una biosfera microbiana e, incluso, a comprender mejor cómo los microorganismos influyen en la composición química de la atmósfera. Este trabajo, señalan, también podría resultar útil en el futuro para modelar cómo podría existir la vida en otras atmósferas planetarias. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009071, 2025)

—Rebecca Owen (@beccapox.bsky.social), Escritora de ciencia

This translation by Saúl A. Villafañe-Barajas (@villafanne) was made possible by a partnership with Planeteando and Geolatinas. Esta traducción fue posible gracias a una asociación con Planeteando y Geolatinas.

Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The United States could consume the added-sugar equivalent of as much as 7 billion additional cans of soda per year by 2095 as a result of climate change, according to a new study. 

A new analysis of food consumption patterns and weather data in the country, published in Nature Climate Change, showed that warmer temperatures increase household purchases of food and beverage products with added sugar, especially among low-income and less educated populations. 

“There’s a huge difference across different socioeconomic groups.”

“There’s a huge difference across different socioeconomic groups,” said Duo Chan, a climate scientist at the University of Southampton and coauthor on the new study. 

Researchers analyzed retail food and drink purchases in more than 40,000 U.S. households from 2004 to 2019 along with monthly average temperatures at the county scale. They found that the average adult male purchased about 0.70 gram of additional added sugar per day for every additional 1°C (1.8°F) of temperature between 12°C (53.6°F) and 30°C (86°F).

Researchers ran multiple regression analyses to rule out other factors that could have influenced the purchasing of sugary products. With the effects of other variables, such as changes in product price, removed, added-sugar intake remained significantly associated with temperature, Chan said.

“It’s the change in temperature that [leads] to the sugar intake,” said Pengfei Liu, an environmental economist at the University of Rhode Island and coauthor of the new study.

The trends, according to the authors, are probably driven by people choosing hydrating, sweet beverages and cold desserts to mitigate the effects of heat. The patterns are “common sense,” said Thalia Sparling, a public health researcher at the London School of Hygiene & Tropical Medicine who was not involved in the new research. “Of course, when it gets hotter, you’re going to want to sit on the porch with your friends and have a cold drink or eat more ice cream.”

Education and income levels of the heads of households influenced how sensitive those households’ sugar consumption patterns were to increases in temperature. Households in which the head of household had a lower income and was less educated increased their added sugar purchases more per degree of increased temperature. Purchases of sweetened beverages and frozen desserts constituted the bulk of the increased sugary purchases.

The study authors used Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models to project that warming temperatures in a high-emissions world could change diets enough to add nearly 3 grams of sugar per day to the average U.S. diet by the end of the century—equivalent to about 30 cans of soda per person per year. The projected effects were unequal among socioeconomic groups, too, with lower-income and less educated households expected to increase their sugar intake more than their higher-income, more educated counterparts. 

Dietary Inequality

“This is just another piece of evidence showing that the impacts of climate change on people are not equal.”

“This is just another piece of evidence showing that the impacts of climate change on people are not equal,” Sparling said.

Nutrition researchers have long known that lower-income groups eat less healthily, Sparling said, because of economic factors, lack of access to healthier foods, and even work environment. “People in communities with lower average [socioeconomic status] are less likely to have air-conditioned workplaces, schools, homes, or respite in other ways,” she said. Those without a way to escape the heat may be more likely to reach for cold, sweetened drinks or desserts for relief.

“Low-income people are most vulnerable to climate change in a lot of cases, and also in our case, in terms of excessive sugar intake,” Chan said. 

Higher added-sugar consumption can increase the risk of various health problems such as obesity, diabetes, and heart disease. But because the causes behind health problems are so complex, much more research would be needed to link warming to specific increases in disease, Sparling said.

She stressed that the onus to improve dietary choices should not be all on the individual: “You have to look at systems level change,” she said. Policies such as taxes on sweetened beverages have decreased added sugar consumption in some cities and countries. Education in communities, schools, and churches can also help people form healthier habits, Sparling said. 

More research is needed to determine whether the trends seen in the United States are reflected across the globe, said Pan He, an environmental social scientist at Cardiff University and first author of the new study. Then, scientists could have an even more comprehensive understanding of how global food consumption patterns may adapt to climate change, she said. 

“I hope our study may shed light on future evidence in developing countries, where sugary-beverage intake is already high and rising heat could further threaten nutrition security,” wrote Yan Bai, an economist at the World Bank and coauthor of the new study, in an email.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

Citation: van Deelen, G. (2025), Heat spurs unequal consumption of sweet treats, Eos, 106, https://doi.org/10.1029/2025EO250333. Published on 8 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Imagine a farmer standing in her field—or even sitting at home—when she gets an alert from a handheld device: Her crops are showing signs of stress, not from heat, drought, or lack of nutrients in this case, but from a pesticide spill detected upstream. The alert doesn’t come from a lab test conducted days after the initial contamination. Instead, it is generated in real time by a portable biosensor containing a protein derived from a pig’s nose.

Chemical-sniffing sensors, though not yet widely adopted in agriculture or environmental science, represent an emerging field of research and development.

The protein has been reprogrammed to mimic the molecular recognition capabilities of animal olfaction, allowing it to detect specific volatile chemicals associated with pesticide contamination and enabling rapid on-site detection. With this early warning, the farmer can act swiftly to mitigate negative impacts and protect both her crops and future yield.

Chemical-sniffing sensors like this, though not yet widely adopted in agriculture or environmental science, represent an emerging field of research and development. They also offer viable new tools for addressing urgent 21st century environmental challenges related to climate change, rapid industrialization, urban sprawl, deforestation, and agricultural intensification, which threaten biodiversity, food security, and public health globally.

In response to these challenges, the United Nations’ Sustainable Development Goals (SDGs)—particularly SDG 6 (Clean Water and Sanitation), SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), SDG 14 (Life Below Water), and SDG 15 (Life on Land)—call for integrated, data-driven approaches to environmental monitoring and management that support environmentally, economically, and socially responsible practices.

Implementing these goals, especially in remote regions and developing nations, requires affordable, scalable methods for monitoring air, water, and soil resources that deliver timely and actionable information. Naturally occurring animal proteins, paired with biosensing technology, offer a promising foundation.

A Transformative New Approach

Detecting pollutants in air, water, or soil often requires sending samples to distant laboratories for gas chromatography, mass spectrometry, or other high-precision analyses. These tools are indispensable for regulatory science because they deliver highly accurate, standardized measurements of trace contaminants that can withstand legal and policy scrutiny. However, the time required to collect, ship, and analyze samples delays results and limits their usefulness for rapid, local decisionmaking.

Conventional in situ monitoring systems, such as stationary air- and water-quality stations, provide continuous data but are expensive to install and maintain. As a result, they are typically sparsely distributed, provide limited spatial coverage, and require significant power, connectivity, and upkeep. Together the high costs and infrastructure demands of current methods make them impractical for widespread field deployment, especially in remote, resource-limited, or rapidly changing environments.

Biosensors present a viable, transformative alternative. Compact, energy-efficient, and often portable, these devices combine biological recognition elements, such as enzymes, antibodies, or odorant-binding proteins (OBPs), with signal transducers to detect specific compounds on-site, in real time, and at low cost. Notably, these devices can sense volatile chemicals and bioavailable pollutant fractions, making them well-suited to complement or even replace traditional environmental monitoring tools in certain settings.

Fig. 1. The structure of a porcine odorant-binding protein (pOBP) is shown by this ribbon diagram. A molecule of butanal, a volatile organic compound used in industrial manufacturing applications, is depicted within the binding cavity of the protein. Credit: Cennamo et al. [2015], CC BY 4.0

OBPs, a class of tiny but mighty proteins found in the olfactory systems of insects and vertebrates, are especially appealing options (Figure 1). They detect trace amounts of odorants—the molecules behind scents—in complex, chemically noisy environments. Whether it is a moth navigating miles to find a mate, or a mammal sniffing out food, OBPs enable detection of a few key molecules amid thousands.

Today researchers are repurposing OBPs to sniff out the chemical by-products of modern life. These proteins possess high thermal and chemical stability, are easy to synthesize, and are remarkably versatile. They can be integrated into portable devices and miniaturized sensors, affixed to biodegradable materials, and genetically engineered to target specific chemicals in soil, air, or water.

OBPs in Action

Despite their promise, biosensors remain underrepresented in discourse and planning related to environmental monitoring and sustainability. More often than not, prototypes developed and tested in the laboratories fail to reach broad application in the field. Specific uses of OBPs have remained largely siloed within biomedical and entomological research.

However, emerging applications of OBPs align closely with key geoscience priorities, including tracking pesticide and industrial runoff, monitoring volatile compounds and mapping soil emissions, and identifying plant health indicators tied to environmental stress and drought. Several proof-of-concept and real-world demonstrations are already underway, highlighting how OBPs can detect a range of pollutants across different environments.

Fig. 2. These prototype biosensors (top), with the gold-plated sensing area at the far left of each, were designed to detect benzene in the environment. The diagram (bottom) illustrates the process by which the sensing surface was chemically functionalized with pOBP (pink ribbon diagram). Credit: Capo et al. [2022], CC BY 4.0

Porcine OBPs have been engineered to detect BTEX pollutants (benzene, toluene, ethylbenzene, and xylene) originating from pesticides and petroleum runoff that threaten groundwater and soil health (Figure 2) [Capo et al., 2022, 2018]. Bovine OBPs, immobilized on cartridge-like devices, can selectively bind and remove triazine herbicides from water, demonstrating potential for both detection and remediation of the pollutant in water treatment [Bianchi et al., 2013].

Sensors coated with bovine and porcine OBPs detect trace, mold-related volatile organic compounds (VOCs) such as octenol and carvone [Di Pietrantonio et al., 2015, 2013], which is relevant to both indoor and outdoor air quality monitoring and mitigation of post-harvest crop losses. Low-cost, OBP-functionalized devices have also demonstrated selective detection of butanal, a common VOC linked to industrial and urban particulate matter [Cennamo et al., 2015].

In addition to bovine and porcine OBPs, rat OBP derivatives have been customized and immobilized on sensing platforms to enable simultaneous VOC profiling for air and water pollution diagnostics [Hurot et al., 2019]. Furthermore, insect OBPs, embedded in fluorescence-based biosensors, have shown efficacy for detecting bacterial metabolite, offering a possible approach for rapid coliform bacteria screening in drinking water [Dimitratos et al., 2019].

Beyond environmental and water quality applications, OBPs from multiple species have also been used to monitor for plant-emitted VOCs that signal stress, disease, drought, or pest infestation in agricultural systems [Wilson, 2013], providing valuable insights into crop health and enabling early intervention strategies.

The Potential Is Enormous

Integrating OBPs into environmental monitoring systems opens new frontiers in climate-smart agriculture, distributed sensing networks, and adaptive land use management.

Integrating OBPs into environmental monitoring systems opens new frontiers in climate-smart agriculture, distributed sensing networks, and adaptive land use management. These sensors offer lab-grade sensing of emissions from sources such as livestock waste, fertilizer application, and wetland activity. They may also enable real-time monitoring of greenhouse gas precursors and early detection of soil degradation, microbial shifts, or drought stress—all delivered through devices small enough to fit in your pocket.

Early detection of pollutant leaks or VOC hot spots could inform land use strategies that mitigate volatile emissions, improve air quality, and strengthen climate adaptation. OBP sensors’ low power requirements and biodegradability make them ideal for decentralized deployments, especially in low-resource or remote areas. Engineered differently, these proteins could even serve in preventative technologies as molecular sponges or scavengers that capture and bind VOCs before they accumulate or disperse.

Ultimately, OBPs could enable more data-driven decisions in conservation and climate policy, while offering novel tools for mapping environmental dynamics (e.g., tracking the spread of wildfire smoke plumes, monitoring methane emissions, or detecting waterborne coliforms across river networks) at finer spatial and temporal resolutions than current technologies permit.

From the Bench to the Biosphere

We envision a future in which OBPs are central to smart agriculture platforms, mobile environmental sensing labs, and biodegradable field-deployable kits. The underlying technology is sound, but breakthroughs like this don’t happen in isolation. Cross-disciplinary collaboration is crucial to accelerate and scale this development, reduce risks of field deployments, and ensure that innovations are aligned with real-world policy and practice.

We propose several pathways to support this collaboration and innovation. For example, targeted workshops and research consortia could facilitate dialogue among molecular biologists, environmental engineers, and Earth scientists to identify priority research questions and focus efforts on specific environmental challenges.

Key questions for advancing OBP-based sensing include the following: Which pollutants and ecosystem signals are most critical for understanding today’s environmental challenges? How can OBPs be tuned to target specific compounds under varying soil, air, or water conditions? What substrates can effectively host OBPs for real-world sensing without compromising environmental safety?

As part of this dialogue, environmental scientists could contribute by generating regional maps of priority VOCs linked to specific issues such as crop stress, emissions from peatlands, or urban air pollutants, guiding optimization of OBP-based sensors. Similarly, chemists and bioengineers could collaborate to expand the library of OBPs with tailored affinities for emerging pollutants, such as pharmaceutical residues, industrial solvents, or novel agrochemicals, broadening the range of compounds detectable in real-world settings. In parallel, data scientists and systems engineers could develop machine learning models to decode complex VOC signatures captured by OBP sensors, enabling real-time diagnostics, pattern recognition, and predictive analytics across environmental monitoring networks.

Expanding access to knowledge and resources represents another key pathway for advancing OBP-based sensing.

Expanding access to knowledge and resources represents another key pathway for advancing OBP-based sensing. Developing curated, open-source, and searchable repositories of OBPs from diverse organisms with characterized binding affinities for high-priority VOCs would accelerate biosensor design and prototyping. Such repositories should follow FAIR (Findable, Accessible, Interoperable, Reusable) data principles to maximize their usefulness across disciplines and platforms.

In the United States, agencies such as the National Science Foundation, the Department of Agriculture, EPA, and the Department of Energy could accelerate progress by hosting seed funding workshops to define shared goals, barriers, and applications and by providing joint funding for interdisciplinary biosensing projects.

Establishing and sharing experimental field test beds such as smart farms, urban air zones, and wetlands would enable pilot testing of OBP-based sensors alongside conventional instruments. These biosensors could be integrated into existing monitoring networks like the National Ecological Observatory Network and the Long Term Ecological Research Network. Their outputs could feed into land use, emissions, and ecological models to improve the spatiotemporal resolution of environmental data.

Building on these test beds and integrated networks, collaborating researchers could report cross-disciplinary benchmark studies and coauthor seminal papers detailing protocols, use cases, and best practices for OBP-based biosensing. This coordinated effort would guide future research and help establish the field’s credibility with regulators and funding agencies.

Clearing Barriers on the Road Ahead

For all of the upsides of OBP-based biosensing, several technical and logistical issues must be addressed before their widespread deployment is achieved.

Despite their superior stability compared to enzymes or typical antibodies [Dimitratos et al., 2019], OBPs remain susceptible to denaturation or degradation during prolonged environmental exposure. Environmental conditions such as humidity, pH, and salinity can affect their performance, underscoring the need for robust protocols to stabilize and calibrate these proteins across diverse ecosystems.

Advancing real-time data acquisition and remote monitoring with OBP-based biosensing also requires progress toward integrating the proteins with digital platforms in scalable and reproducible formats. Key challenges include reducing sensor-to-sensor variability, increasing sensor lifespans, and converting biological signals into stable, digitized outputs.

Realizing the technology’s broader potential will require rigorous technical validation, clear regulatory guidance, and proactive efforts to educate and engage stakeholders.

In addition to technical barriers, regulatory frameworks and approval pathways for OBP-based sensing technology remain underdeveloped, and concerns about the lack of standardized validation protocols and the effects of releasing recombinant proteins into agricultural or environmental settings persist. Moreover, low awareness among end users, including farmers and land managers, may hinder trust and uptake of the technology. Realizing its broader potential will thus require rigorous technical validation, clear regulatory guidance, and proactive efforts to educate and engage stakeholders across sectors. Notwithstanding these challenges, the promise is clear: OBPs offer a flexible and powerful approach for monitoring environmental changes and climate risk, helping to protect ecosystems, food systems, and communities. Once known primarily to entomologists, these little scent-sniffing proteins could become an unexpectedly powerful tool for advancing environmental resilience.

References

Bianchi, F., et al. (2013), An innovative bovine odorant binding protein-based filtering cartridge for the removal of triazine herbicides from water, Anal. Bioanal. Chem., 405, 1,067–1,075, https://doi.org/10.1007/s00216-012-6499-0.

Capo, A., et al. (2018), The porcine odorant-binding protein as molecular probe for benzene detection, PLOS One, 13(9), e0202630, https://doi.org/10.1371/journal.pone.0202630.

Capo, A., et al. (2022), The porcine odorant-binding protein as a probe for an impedenziometric-based detection of benzene in the environment, Int. J. Mol. Sci., 23(7), 4039, https://doi.org/10.3390/ijms23074039.

Cennamo, N., et al. (2015), Easy to use plastic optical fiber–based biosensor for detection of butanal, PLOS One, 10(3), e0116770, https://doi.org/10.1371/journal.pone.0116770.

Dimitratos, S. D., et al. (2019), Biosensors to monitor water quality utilizing insect odorant-binding proteins as detector elements, Biosensors, 9(2), 62, https://doi.org/10.3390/bios9020062.

Di Pietrantonio, F., et al. (2013), Detection of odorant molecules via surface acoustic wave biosensor array based on odorant-binding proteins, Biosensors Bioelectron., 41, 328–334, https://doi.org/10.1016/j.bios.2012.08.046.

Di Pietrantonio, F., et al. (2015), A surface acoustic wave bio-electronic nose for detection of volatile odorant molecules, Biosensors Bioelectron., 67, 516–523, https://doi.org/10.1016/j.bios.2014.09.027.

Hurot, C., et al. (2019), Highly sensitive olfactory biosensors for the detection of volatile organic compounds by surface plasmon resonance imaging, Biosensors Bioelectron., 123, 230–236, https://doi.org/10.1016/j.bios.2018.08.072.

Wilson, A. D. (2013), Diverse applications of electronic-nose technologies in agriculture and forestry, Sensors, 13(2), 2,295–2,348, https://doi.org/10.3390/s130202295.

Author Information

Ishani Ray (isray@okstate.edu) and Smita Mohanty, Department of Chemistry, Oklahoma State University, Stillwater

Citation: Ray, I., and S. Mohanty (2025), Protein-powered biosensors with a nose for environmental ills, Eos, 106, https://doi.org/10.1029/2025EO250330. Published on 8 September 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Journal of Geophysical Research: Oceans

Antarctic ice is melting. But exactly which forces are causing it to melt and how melting will influence sea level rise are areas of active research. Understanding the decay of ice shelves, which extend off the edges of the continent, is particularly pressing because these shelves act as barriers between ocean water and land. Without ice shelves, the continent’s glaciers would flow freely into the ocean, hastening sea level rise.

In January 2015, a group of researchers used hot water to drill a hole through 740 meters of the Ronne Ice Shelf. They then lowered a mooring carrying temperature, salinity, and current sensors through the hole into the ocean below. A radio echo sounder deployed 15 meters from the mooring kept tabs on ice thickness. For the next 3 years, the instruments took measurements every 2 hours; these measurements were sent to a solar-powered data logger on the surface and then on to researchers via satellite.

Anselin et al. recently used these measurements to probe the forces responsible for melting ice shelves.

The tide is a major force contributing to ice shelf melting, the researchers found. As the tide rises, the water rushes across the bottom of the shelf. Friction between the shelf and the water causes the current just beneath the ice to slow. This slowdown leads to strong mixing within the ocean, and this mixing brings heat to the ice base, driving high melt rates. Because the strength of tides varies depending on the positions of the Sun and the Moon relative to Earth, ice shelf melting has a cyclical pattern, with melting ebbing and flowing every 2 weeks.

However, current models of melt rates fail to capture the full extent to which tidal mixing and warm ocean water combine to melt ice. When analyzing data from additional sites, scientists should focus on how the interaction between tides and ice shelves leads to melting, the researchers say. (Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2025JC022524, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2025), Strong tides speed melting of Antarctic ice shelves, Eos, 106, https://doi.org/10.1029/2025EO250331. Published on 8 September 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Atmospheres

Atmospheric circulations are chaotic and unpredictable beyond a certain time limit. Quantifying predictability helps determine what forecast problems are potentially tractable. However, while predictability of weather close to the surface is a much-studied problem, showing a prediction limit of approximately 10 days, less is known about how predictable the atmosphere is at higher layers.

Garny [2025] applies a high-resolution global model to study atmospheric predictability from the surface to the mesosphere/lower thermosphere (MLT; 50-120 kilometers altitude), providing new understanding of coupling between atmospheric levels and fundamental behavior of the upper atmosphere. The author shows that the MLT is somewhat less predictable than lower atmospheric layers due to rapid growth of ubiquitous small-scale waves, with predictability horizons of about 5 days. However, atmospheric flows in the MLT on larger horizontal scales of a few thousand kilometers can remain predictable for up to 3 weeks.

This research highlights the importance of high-resolution, ‘whole atmosphere’ models to understand and predict circulations in the middle atmosphere and coupling from the surface to the edge of space.

Citation: Garny, H. (2025). Intrinsic predictability from the troposphere to the mesosphere/lower thermosphere (MLT). Journal of Geophysical Research: Atmospheres, 130, e2025JD043363. https://doi.org/10.1029/2025JD043363

—William Randel, Editor, JGR: Atmospheres

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Dust plays a major role in the formation of ice in the atmosphere. A new analysis of satellite data, published in Science, shows that dust can cause a cloud’s water droplets to freeze at warmer temperatures than they otherwise would. The finding brings what researchers had observed in the laboratory to the scale of the atmosphere and may help climate scientists better model future climate changes.

In 1804, French scientist Joseph Louis Gay-Lussac ascended to about 23,000 feet (7,000 meters) in a hydrogen balloon from Paris, without supplemental oxygen, to collect air samples. He noted that clouds with more dust particles tended to have more frozen droplets.

In the 20th century, scientists found that pure water can remain liquid even when cooled to −34.5°C. But once even tiny amounts of material, such as dust, are introduced, it freezes at much warmer temperatures.

“It’s like Schrödinger’s cat. Either there’s an ice crystal, or there’s a liquid droplet.”

In 2012, researchers in Germany were finally able to test this directly in a cloud chamber experiment. They re-created cloud conditions in the lab, introduced different types of desert dust, and gradually cooled the chamber to observe the temperatures at which droplets froze.

For Diego Villanueva, an atmospheric scientist at ETH Zürich in Switzerland and lead author of the new study, it was striking that scientists had uncovered these processes in the lab, yet no one had examined them in such detail in nature.

The challenges were obvious. To watch an ice crystal nucleate, researchers would need instruments on an aircraft or balloon to catch a micrometer-sized droplet in a cloud at just the right moment. “It’s like Schrödinger’s cat,” said Daniel Knopf, an atmospheric scientist at Stony Brook University who was not involved in the work.. “Either there’s an ice crystal, or there’s a liquid droplet.”

In the new study, Villanueva and his colleagues analyzed 35 years of satellite data on cloud tops across the Northern Hemisphere’s extratropics—a region spanning the U.S. Midwest, southern Canada, western Europe, and northern Asia. The researchers wanted to see whether dust influenced whether cloud tops were liquid or ice. They focused on cloud tops, rather than entire clouds, simply because the tops are visible in satellite imagery.

Desert Dust and Cold Clouds

Villanueva and his colleagues examined two satellite datasets covering 1982–2016, trying to infer microscopic details of cloud tops such as the number of ice crystals or droplet sizes. One dataset tracked whether cloud tops were liquid or ice, and the other measured how much dust was in the air at the same time. Although the team examined global patterns, they focused on the northern extratropical belt, where mixed-phase clouds are common and large amounts of dust from deserts like the Sahara and Gobi circulate.

But the “dataset quality was just so poor that everything that came out was basically just noise,” Villanueva added. In the end, the researchers focused on a simpler detail: the fraction of clouds with ice at their tops. “This took me nearly 3 years,” Villanueva said.

The analysis revealed that regions with more dust had more ice-topped clouds. The effect was strongest in summer, when desert winds lift the most dust.

A distinctive pattern emerged: A tenfold increase in dust roughly doubled the likelihood of cloud tops freezing. “You’d need 100 times more dust to see freezing become 4 times as frequent,” Villanueva explained.

“I think the study is quite elegant.”

The new work showed that the same processes researchers have observed at the microscale in laboratories occur at much larger scales in Earth’s atmosphere. Even after accounting for humidity and air movement, dust remained the key factor for ice nucleation in most instances, though there are exceptions. In some places, such as above the Sahara, few clouds form despite the presence of dust, perhaps, the authors suggest, because the movement of large swaths of hot air prevents freezing.

“I think the study is quite elegant,” Knopf said. He explained that taking 35 years of satellite data, finding a relationship between dust levels and frozen cloud top rates, and then showing that it lines up perfectly with lab experiments is basically “the nail in the coffin” for proving dust’s role in ice nucleation. Scientists now have robust satellite evidence of dust aerosols directly affecting cloud freezing, matching what laboratory experiments had predicted.

The finding has implications for climate modeling. To predict the effects of climate change more accurately, models must account for dust and the ways it affects cloud freezing and helps shape precipitation. Liquid-topped clouds reflect more sunlight and cool the planet, whereas ice-topped clouds let in more sunlight and trap heat.

However, Knopf noted that there is more work to be done to understand exactly what the new observations mean for scientists’ understanding of climate. “If you want to really know the precipitation or climate impacts [of dust], you really need to know the number of liquid droplets or the number of ice crystals,” he said.

Villanueva is motivated to keep looking at clouds and aerosols. In the next 10–20 years, the Earth may have drier surfaces because of climate change, which will likely produce more dust aerosols in the atmosphere. He added, “I want to know how clouds will respond in the scenario.”

—Saugat Bolakhe (@saugat_optimist), Science Writer

Citation: Bolakhe, S. (2025), Dust is the sky’s ice maker, Eos, 106, https://doi.org/10.1029/2025EO250328. Published on 5 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

This story was originally published in the Louisiana Illuminator.

Despite being called a “cruise,” the people on board The Pelican described the experience on the hypoxia monitoring expedition as very different from the elaborate dinners on a towering vacation ship or booze- and buffet-filled Caribbean itinerary.

Passengers describe waves up to 5 feet high in the Gulf of Mexico, swinging the 116-foot research vessel like a pendulum, plaguing anyone who didn’t have sturdy sea legs with bouts of seasickness. Daytime temperatures in late July soared ever higher as sweat dripped down the backs of hard-hat covered heads.

The guests on board The Pelican weren’t seeking pleasure or status. They were unpaid students and researchers who say they weathered the conditions in the name of science itself.

“It’s not glamorous, but it is very important.”

“It’s not glamorous, but it is very important,” said Cassandra Glaspie, assistant professor at Louisiana State University and the chief scientist for the National Oceanic and Atmospheric Administration’s annual hypoxia cruise.

The 11-day voyage provides vital information on the sea life and environmental conditions within the seasonal low-oxygen zone that develops off the coast of Louisiana. The data the cruise collects informs state and federal efforts to reduce the size of the “dead zone” and sheds light on impacts to those who rely on the water for their livelihoods, like shrimpers and fishermen.

Now, after its 40th year and 38th hypoxia cruise, The Pelican’s annually planned journey faces challenges to stay afloat, potentially undermining decades of research and future plans to get the dead zone under control.

A Decades Long Struggle

Biologists, undergraduate student researchers and crew alike celebrated the cruise’s 40th anniversary aboard The Pelican with a party that had an “old bird” theme, chosen to honor the boat, which has also been sailing for 40 years.

The Pelican and the hypoxia cruise’s 40th anniversaries party on the water. Credit: Yuanheng Xiong

More than just an excuse to eat cake (with rainbow sprinkles), the purpose of the cruise is to capture information snapshots of just how bad conditions get in the dead zone.

“We bring water up to the surface. We have a little chemistry lab…to figure out what the oxygen level is chemically, and then we can validate that against what our sensors are telling us,” Glaspie said.

The low-oxygen area appears annually as nutrients, primarily from agricultural fertilizers from the massive Mississippi River Basin, drain downriver and spur algae overgrowth.

Algae eat, defecate and die, using up the oxygen in the water when they decompose and sink to the bottom. Fish, shrimp and other marine life leave the low oxygen area when they can and suffocate when they can’t, putting pressure on the vital commercial Gulf fishery and the people who rely on it. Exposure to low-oxygen waters can also alter reproduction, growth rates and diet in fish species.

Glaspie took over the work of coastal scientist Nancy Rabalais, who launched the maiden cruise in 1985 and led it for decades after. Every summer begins with a forecast of the zone’s predicted size, estimated by various scientific models and measurements of nitrogen and phosphorus throughout the river basin taken throughout the year.

“A lot of times with pollution, you hear anecdotal evidence of how it might be increasing cancer rates or it might be causing fisheries to fail,” Glaspie said. “Here, we have an actual, measurable impact of nutrient pollution in the Mississippi River watershed.”

The Mississippi River/Gulf of America Hypoxia Task Force, an interagency federal, state and tribal effort to reduce the size of the dead zone, uses data from the cruise to determine whether it is meeting its goals.

In the past five years, the dead zone has been as large as 6,700 square miles, and even larger in previous years, reaching nearly the size of New Jersey.

While still more than two times the size that the Task Force wants, the Gulf dead zone was slightly smaller than forecasted this year, about the size of Connecticut at around 4,400 square miles.

Federal and state officials lauded the limited success of the zone’s smaller size in a July 31 press conference held to discuss the results of the hypoxia cruise’s 2025 findings. They also called for continued work.

“It requires strong collaboration between states, tribes, federal partners and stakeholders,” said Brian Frazer, the EPA’s Office of Wetlands, Oceans and Watersheds director.

Mike Naig, Iowa’s agriculture secretary, said states should be “scaling up” initiatives to reduce nutrient pollution.

Whether or not this will actually happen is uncertain.

Funding Cuts

Since the Trump administration took office, funding for nutrient reduction efforts upriver as well as money to operate the cruise itself have been scaled back or cut entirely.

The Environmental Protection Agency’s 319 and 106 funding programs under the Clean Water Act are the main funding mechanisms for states to reduce nutrient pollution throughout the Basin. Those grants aren’t funded in President Trump’s proposed FY 2026 budget, said Frazer.

The 106 programs have historically doled out $18.5 million annually, according to the EPA, with additional money sometimes allocated from Congress. The 319 program provided $174.3 million in FY 2025.

The cuts to these programs are not yet final. Congress can decide to add in additional funding, and has in past years.

States rely on both funds to reduce and monitor nutrient runoff in their waters, said Matt Rota, senior policy director for Healthy Gulf, a nonprofit research group. Rota has monitored policy changes surrounding the Gulf dead zone for more than 20 years, and he questions whether current reduction strategies can be maintained, let alone efforts redoubled.

“It’s always good to see a dead zone that’s smaller than what was predicted,” Rota said. “I am not confident that this trend will continue.”

“It’s a relatively inexpensive program. … This is baseline stuff that our government should be doing.”

Aside from cuts to reduction efforts, money for The Pelican’s annual cruise is also slipping away. Glaspie said that, ideally, the cruise has 11 days of funding. It costs about $13,000 a day to operate the vessel, she said.

“It’s a relatively inexpensive program” with big payoffs for seafood industry workers who rely on the water for their livelihoods, Rota said. “This is baseline stuff that our government should be doing.”

Funding for the hypoxia cruise has been part of the National Oceanic and Atmospheric Administration’s annual operational budget, making it a more reliable source than grant funding. But with the Trump administration taking a hatchet to government-backed research, there is increasing uncertainty over whether The Pelican and its crew will embark upon future missions.

This year, Glaspie said, NOAA defunded a day of the cruise. The Gulf of America Alliance, a partnership group to support the Gulf’s economic and environmental health amongst the five bordering states, stepped in to make up the difference. Glaspie said having that additional day was a saving grace for the research.

“This is a fine-tuned machine, and the consequences for cutting it short are really predictable and well-known,” she said. “If I’m asked to create an estimate of the surface area of hypoxia, and we’re not able to cap off the end in Texas waters, I’m not really going to be able to give a reliable estimate.”

Even without additional cuts, Glaspie said she already conducts the hypoxia cruise “on a shoestring budget.” Researchers on board don’t get paid, and every person who supports its mission—besides the crew that runs the boat—are volunteers.

“It’s tough for me to not pay people. I mean, they’re working solid 12-hour shifts. It is not easy, and they are seasick for a lot of this, and they can’t call home,” Glaspie said. “It doesn’t sit well with me to not pay people for all this work, but this is what we’ve had to do because we don’t have the money to pay them.”

Students Jorddy Gonzalez and Lily Tubbs retrieve the CTD sensor package after measuring dissolved oxygen at a regular stop on the annual hypoxia cruise while students watch. Credit: Cassandra Glaspie A Rapidly Changing Gulf

Defunding research as climate change intensifies—creating extreme heat in the Gulf—could further undermine hypoxia containment efforts and the consistency of decades worth of data collection.

“I think the rising temperatures is a big question,” Rota said.

“We have 40 years of data, which is almost a gold standard,” Glaspie said. “We’ve just reached that threshold where we can really start to ask some more detailed questions about the impacts of hypoxia, and maybe the future of hypoxia.”

Despite this year’s smaller zone surface area, low oxygen levels went deeper into the water than Glaspie had ever seen before.

“The temperature drops [as the water gets deeper], the salinity increases, and the oxygen just goes basically to zero,” she said.

In some areas, Glaspie’s measurements showed negative oxygen levels.

“Oxygen doesn’t go in the negative. It was just so low that the sensor was having trouble with it,” she said. “It’s the first time I’ve seen it like this.”

She also noticed unusually large amounts of algae on the surface of the water “like ectoplasm in Ghostbusters.”

The smaller-than-forecasted size of the dead zone surprised researchers on The Pelican who saw just how deep the low oxygen levels went.

“None of us really thought until the estimate came out that it was below average size because we’re able to see the three-dimensionality of it. That’s not really incorporated into that estimate,” Glaspie said.

She also noticed unusually large amounts of algae on the surface of the water “like ectoplasm in Ghostbusters.” Toxic algae blooms can kill fish and other sea life as well as poison humans.

“If I had to say what would be important for us to monitor in the future, it would be these algal blooms, and making sure that we’ve got a good handle on which ones have harmful species,” she said.

This is why Glaspie, donned in her sun-protective clothes and work boots, braves the waves, the heat and the journey across the Gulf every year.

“This is our finger on the pulse of our nutrient pollution problem that Louisiana is inheriting from the entire country,” Glaspie said. “We cannot take our finger off that pulse. It is unfair to Louisiana. We have this pollution problem. We need to understand it.”

—Elise Plunk (@elise_plunk), Louisiana Illuminator

This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouri in partnership with Report for America, with major funding from the Walton Family Foundation.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Permafrost is considered a critical global component of the cryosphere given its climate-sensitive nature and its key geomorphological and ecosystem role. Permafrost is also affected by wildfires which may cause the crossing of a tipping point in cryospheric systems. In fact, wildfires may reduce vegetation, destroy organic layers, modify surface albedo, leading to active layer thickening and ground subsidence. Permafrost itself is subjected to long term deformation after wildfires, but this deformation is currently poorly understood.

Cao and Furuya [2025] use remote sensing to explore ground surface deformation signals across multiple fire scars in the past five decades in North Yukon. The authors find that post-permafrost evolution follows three distinct phases characterized by land subsidence soon after the event and final recovery of the permafrost over a 50-year timescale, which implies soil uplift. Such an uplift phase is rarely reported and is related to vegetation regeneration and soil greening after the fire. These provide thermal protection, suggesting a critical mechanism of permafrost recovery. These findings highlight the resilience of boreal-permafrost systems against wildfires, but continuous monitoring is needed as wildfire and climate change intensify.

Citation: Cao, Z., & Furuya, M. (2025). Decades-long evolution of post-fire permafrost deformation detected by InSAR: Insights from chronosequence in North Yukon. AGU Advances, 6, e2025AV001849. https://doi.org/10.1029/2025AV001849

—Alberto Montanari, Editor-in-Chief, AGU Advances

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Undergraduate research experiences (UREs) in science, technology, engineering, and mathematics (STEM) offer students hands-on research experience and essential professional skills and connections to prepare them to succeed in the workforce. They also cultivate students’ sense of belonging, confidence, and identity—and promote retention—in STEM fields [National Academies of Sciences, Engineering, and Medicine, 2017; Rodenbusch et al., 2016].

To be effective, UREs should be thoughtfully designed to meet the needs of students who may otherwise miss out on career opportunities tied to networking and community-building through such programs. Existing URE programs have followed a range of approaches, but traditionally, many have been centered around short-duration, time-intensive, individual, mentor-directed experiences, such as full-time summer internships in field or laboratory settings. However, these traits can inadvertently exclude some student populations, a concern that is leading many programs to modify their structure and design to engage broader groups.

To lower barriers to participation in UREs, we developed the Authentic Research through Collaborative Learning (ARC-Learn) program at Oregon State University (OSU). ARC-Learn, which ran from 2021 to 2024 and comprised two overlapping student cohorts, offered a long-term, low-intensity program focused on Arctic science and inclusive mentorship. It was designed to help students engage in a science community, foster identities as STEM professionals, and develop critical scientific and data literacy skills and 21st century competencies such as teamwork and communication.

Table 1. Design Features of ARC-LearnFeatureDescriptionDuration18 months (2 academic years)Intensity2–4 hours per weekLocationOn campus or remoteMentorshipMultiple mentors working in teams with multiple studentsTopic selectionStudent drivenStudent supportMentors, peers, program administrators, academic advisorsMentorship developmentInclusive mentorship training, facilitated peer learning communityResearch tasksDevelop research question, find data and analyze data, draw conclusions, and present findingsStudent developmentDiscover own strengths as researchers, work with a team, supplemental training in missing skills

ARC-Learn incorporated alternative design features (Table 1) to meet the needs of students who do not typically have access to time-intensive field or lab-based UREs, such as transfer students, remote students, and those with dependent care, military service, and other work commitments [Scott et al., 2019] or who have nontraditional enrollment patterns (e.g., dual enrollment in both university and community college, varying enrollment from term to term).

The program was framed in the context of Arctic science because of the region’s outsize effects on climate, ecosystems, and communities globally and to engage students with long-term research investments in polar regions [Marrongelle and Easterling, 2019]. The Arctic also offers a dynamic and interdisciplinary context for a URE program, enabling students to follow their interests in investigating complex science questions. In addition, numerous long-term Arctic monitoring programs offer rich datasets useful in all kinds of STEM careers.

Despite encountering challenges, the ARC-Learn model proved successful at engaging and motivating students and also adaptive as program organizers made adjustments from one cohort to the next in response to participant feedback.

The ARC-Learn Model

With support from mentors and peers, students experienced the whole research arc and gradually took ownership of their work.

Each ARC-Learn cohort lasted 2 academic years and included a dozen or more students. Participants received a stipend to offset costs associated with participation, such as childcare and missed work time, and had the option of obtaining a course credit each term to meet experiential learning requirements. With support from mentors and peers, they experienced the whole research arc and gradually took ownership of their work through three key phases of the program.

Early year 1: Build research teams. Some URE mentorship models involve a mentor primarily driving selection of a research topic and the student completing the work. In ARC-Learn, students learned from multiple mentors and peers, while mentors supported each other and received feedback from students (Figure 1). The students self-selected into research teams focused on a broad topic (e.g., marine heat waves or primary productivity), then developed individual research questions based on their strengths and interests.

Fig. 1. Some models of undergraduate research experiences have involved a mostly one-way transfer of knowledge from a single mentor to a single student, with the mentor deciding the research topic and the student completing the work. In ARC-Learn, students learned from multiple mentors and peers as part of small-group research teams, while mentors supported each other and received feedback from students.

Mentor-student teams met every other week—and students met one-on-one with mentors as needed—to support individual projects. The entire cohort also met twice a month to discuss topics including the fundamentals of Arctic science and the scientific process and to report out on progress toward milestones.

Late year 1 to middle of year 2: Develop research questions and find and analyze data. With no field or lab component to the program, ARC-Learn students worked exclusively with existing data. These data came from NASA and NOAA satellite-based sources such as the Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer, and Soil Moisture Active Passive (SMAP) instruments; shipboard sources such as NOAA’s Distributed Biological Observatory, the Alaska Ocean Observing System, and the University-National Oceanographic Laboratory System’s Rolling Deck to Repository; and the National Science Foundation’s (NSF) Arctic Data Center and NOAA’s National Centers for Environmental Information.

Students often revised their research questions or the datasets they used multiple times to produce meaningful findings (Figure 2). Notably, access to these datasets proved critical to the educational experience of ARC-Learn students, highlighting the importance of maintaining them in public archives for future URE activities.

Fig. 2. ARC-Learn students developed their own research questions and worked exclusively with existing data to answer them. Students often revised their research questions or datasets multiple times to produce meaningful findings.

Many students struggled with finding, cleaning, analyzing, and interpreting data, often because of limited experience with tools such as geographic information system software and programming languages such as Python and R. At times, the required expertise was beyond even their mentors’ knowledge. Hands-on skill development workshops during cohort meetings connected students with additional mentors proficient in specific platforms and tools to help fill knowledge gaps and help students overcome obstacles.

Although the students encountered occasional setbacks, they reported that achievements such as settling on a final research question and creating rich data visualizations proved deeply rewarding and motivated further progress.

Late year 2: Share the results. Over several months, students created research posters with feedback and support along the way from their teammates, mentors, and the entire cohort. The program concluded with a grand finale, featuring on-campus gatherings for remote and in-person students, a dress rehearsal poster session, a celebratory dinner, and final presentations at a university-wide undergraduate research symposium.

Zoe’s Story

After a successful 7-year military career, Zoe enrolled at OSU to study the Arctic through her participation in ARC-Learn. As a student in cohort 2, she experienced several challenges along the research arc before finding success, and her experience helps illustrate the program’s model.

Zoe joined fellow students and mentors in the Marine Heatwaves research team and then narrowed her focus by exploring scientific literature and talking with her primary mentor to understand physical and chemical factors associated with marine heat waves as well as their effects on ocean ecosystems. She developed several research questions focused on how factors such as atmospheric pressure and temperature have affected the development and extent of marine heat waves off Alaska since 2010.

As Zoe and her mentor considered available datasets and relevant literature further, they realized that her questions were still too broad given the number of variables affecting ocean-atmosphere interactions. At one of the full-cohort meetings, she shared her difficulties and frustrations, prompting another mentor to offer their help. This mentor worked with Zoe to understand a key meteorological feature—the Aleutian Low—in the area she was studying, as well as relevant data available through the European Union’s Copernicus Climate Change Service [Hersbach et al., 2023] and the appropriate analysis platform.

“We jumped in and learned it together. She helped me find the right data, which in turn, allowed me to finalize my research question,” Zoe said.

Nuanced and iterative feedback from mentors and peers guided ARC-Learn participants, including Zoe, to design posters that balanced visual presentations of data alongside descriptive text to explain research findings. Credit: Ryan Brown

From that point, Zoe quickly landed on a focused question that she could address: Does a disruption in the Aleutian Low lead to marine heat waves over the North Pacific region? The final step was to develop a visually striking poster to invite attention, questions, and ideas during the research symposium.

“Seeing other people interested in my research…was validating of me as a scientist.”

Zoe’s experience at the poster session captured what we heard from many other students in the program. Even after her 2 years of being immersed in her project and working with mentors and peers, she said she felt imposter syndrome as a student trying to become a scientist and thought no one would care about her research.

“But people were really interested,” she said. “Seeing other people interested in my research, able to read and understand it on a poster, [and] ask me questions and suggest ideas was validating of me as a scientist.”

A Responsive Approach to URE Design

Through ARC-Learn, program leads sought to expand knowledge about the benefits and challenges of a long-duration, lower-intensity, team-based URE model. Because it was a design-based research program, mentor, student, and coordinator feedback was collected and continually used to make program adjustments [Preston et al., 2022, 2024].

Feedback was collected through pre-, mid-, and end-of-program surveys, as well as pre- and end-of-program interviews, and analyzed by a research and evaluation team. Findings were reported to the program leads, who also met regularly with external expert advisers to get additional recommendations for adjustments. By running two overlapping cohorts (the second started when the first was halfway completed), organizers could address issues that arose for the first cohort to improve the experience of the second one.

Lessons from ARC-Learn are documented in a practitioner guidebook, which discusses practical considerations for others interested in implementing alternative URE models [Brown et al., 2024]. In the guidebook, we examine each design component of ARC-Learn and offer recommendations for designing UREs that meet enrolled students’ specific learning needs and develop their science skills to meet relevant workforce demands.

Novel elements of the Authentic Research through Collaborative Learning (ARC-Learn) program were important in influencing participants’ persistence and success.

A few valuable lessons learned include the following.

Attrition. Expect high attrition rates in UREs designed for nontraditional students, and do not react by making drastic program changes that risk sacrificing otherwise successful program elements. We observed a 45% attrition rate in each cohort, which is indeed high but perhaps not surprising considering the population involved in the program—largely transfer students and those with caregiving or work responsibilities.

Most participants who left did so because of life crises or obligations that paused their research and educational goals. This observation embodies the complexity of students’ lives and reinforces the need for continually creative, flexible, inclusive program structures. For those who completed ARC-Learn, novel elements of the program (e.g., working in teams) were important in influencing their persistence and success.

Remote research applications. The first cohort started in 2021 entirely via remote instruction during the COVID-19 pandemic, before eventually transitioning to a hybrid approach as in-person instruction resumed. All ARC-Learn students in cohort 1 returned to campus, except one Ecampus student, who remained online. The program team and mentors struggled to balance the needs of the remote student, who eventually became somewhat detached from their research team.

As teamwork, camaraderie, and inclusivity are important qualities of the program, we decided for cohort 2 to recruit enough Ecampus students (plus two dedicated mentors) to form a research team of their own. The remote team was engaged and productive—meeting deadlines and producing high-quality work—highlighting the potential of all-remote URE models for students who might otherwise lack access to meaningful research opportunities.

Student-driven research. ARC-Learn empowered students to pursue their own research questions, fostering their autonomy and ownership of their work. However, the open-endedness of selecting their own research paths and the lack of guardrails proved challenging for participants.

We thus hired a program coordinator to provide one-on-one logistical support; establish clear expectations, timelines, and scaffolded assignments; and arrange workshops to teach programming and data analysis skills. This approach, as reported by students who worked with the coordinator, helped many program participants stay on track and ultimately complete their research project.

Mentor coordination. Enabling student success also meant supporting mentors. Organizers provided inclusive mentorship trainings and facilitated a peer learning community. They also made programmatic adjustments in response to experiences in the first cohort.

The student-driven nature of the research sometimes resulted in mismatches between student interests and mentor expertise in cohort 1. So in cohort 2, we engaged mentors earlier in the planning process to define thematic areas for the research teams, creating topics broad enough for students to find an area of interest but narrow enough for mentors to provide guidance. In addition, many mentors had field schedules typical of polar scientists, often resulting in weeks to months at sea. We purposefully paired mentors and asked about planned absences so we could fill any gaps with additional support.

Overall, students in cohort 2 reported feeling highly supported and valued by their mentors and that mentors created welcoming environments to ask questions and solve problems together.

A Foundation to Build On

Participants gained a deep understanding of the complexities and challenges of modern science as well as knowledge and skills needed in scientific education and careers.

From students’ feedback—and the research they did—it’s clear that participants who completed the ARC-Learn program gained a deep understanding of the complexities and challenges of modern science as well as knowledge and skills needed in scientific education and careers. The program thus highlights paths and lessons for others looking to develop successful alternatives to traditional UREs.

Many former ARC-Learn students are continuing to develop research skills, particularly in polar science, through internships and employment in field and lab research efforts. Zoe is working toward a bachelor’s degree in environmental sciences and exploring interests in environmental hazards, conservation, and restoration. For her, the program served as a foundation from which she is building a career and establishing confidence in herself as a scientist.

“I thought I’d have to play catch-up the whole time as an older, nontraditional student,” she said. But through the experience, “I realized I could start anywhere.”

Acknowledgments

ARC-Learn was a collaboration between OSU’s College of Earth, Ocean and Atmospheric Sciences and STEM Research Center. This work is supported by the U.S. NSF (award 2110854). Opinions, findings, conclusions, and recommendations in these materials are those of the authors and do not necessarily reflect the views of NSF.

References

Brown, R., et al. (2024), ARC-Learn Practitioner Guidebook: Practical considerations for implementing an alternative model of undergraduate research experience, Ore. State Univ., Corvallis, https://doi.org/10.5399/osu/1177.

Hersbach, H., et al. (2023), ERA5 monthly averaged data on single levels from 1940 to present, Copernicus Clim. Change Serv. Clim. Data Store, https://doi.org/10.24381/cds.f17050d7.

Marrongelle, K., and W. E. Easterling (2019), Support for engaging students and the public in polar research, Dear Colleague Letter prepared for the U.S. National Science Foundation, Alexandria, Va., www.nsf.gov/funding/opportunities/dcl-support-engaging-students-public-polar-research/nsf19-086.

National Academies of Sciences, Engineering, and Medicine (2017), Undergraduate Research Experiences for STEM Students: Successes, Challenges, and Opportunities, 278 pp., Natl. Acad. Press, Washington, D.C., https://doi.org/10.17226/24622.

Preston, K., J. Risien, and K. B. O’Connell (2022), Authentic Research through Collaborative Learning (ARC-Learn): Undergraduate research experiences in data rich Arctic science formative evaluation report, STEM Res. Cent., Ore. State Univ., Corvallis, https://doi.org/10.5399/osu/1156.

Preston, K., J. Risien, and N. Staus (2024), Authentic Research through Collaborative Learning (ARC-Learn): Undergraduate research experiences in data rich science summative evaluation report, STEM Res. Cent., Ore. State Univ., Corvallis, https://doi.org/10.5399/osu/1178.

Rodenbusch, S. E., et al. (2016), Early engagement in course-based research increases graduation rates and completion of science, engineering, and mathematics degrees, CBE Life Sci. Educ., 15(2), ar20, https://doi.org/10.1187/cbe.16-03-0117.

Scott, G. W., S. Humphries, and D. C. Henri (2019), Expectation, motivation, engagement and ownership: Using student reflections in the conative and affective domains to enhance residential field courses, J. Geogr. Higher Educ., 43(3), 280–298, https://doi.org/10.1080/03098265.2019.1608516.

Author Information

Ryan Brown (ryan.brown@oregonstate.edu), Laurie Juranek, and Miguel Goñi, College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis; and Julie Risien and Kimberley Preston, STEM Research Center, Oregon State University, Corvallis

Citation: Brown, R., L. Juranek, M. Goñi, J. Risien, and K. Preston (2025), An accessible alternative for undergraduate research experiences, Eos, 106, https://doi.org/10.1029/2025EO250326. Published on 4 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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