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Editors’ Vox is a blog from AGU’s Publications Department.

After a 6-year term as Editor-in-Chief of Tectonics, Taylor Schildgen has handed over the reins to Giulio Viola. Here, Dr. Schildgen reflects on her tenure as Dr. Viola discusses his priorities for the journal moving forward.

Wrapping up – Reflections from Outgoing Editor-in-Chief Taylor Schildgen

Taylor Schildgen, the outgoing Editor-in-Chief of Tectonics.

It has been a great privilege, and sometimes a challenge, to serve as Editor-in-Chief of Tectonics for the past six years. Only a few months into my term, which started in January 2020, many of us long accustomed to field-based work and teaching scrambled to adjust to travel restrictions, loss of access to classrooms, offices, and laboratories, and all of the personal challenges associated with the isolation and illness of the pandemic. Writing manuscripts quickly proved to be one relatively clear path of productivity for those of us with at least a little data on hand.

The associated onslaught of manuscripts (approximately 30% increase in submissions above pre-pandemic levels) quickly highlighted our need for greater geographic diversity on our editorial board, and an overall greater number of Associate Editors to help shepherd manuscripts through the review process. I’m delighted that in that process, we also managed to bring a higher percentage of women onto the editoral board, as well as people whose specialities helped to increase the range of the board’s expertise. The editorial board’s need to evolve and remain representative of the authorship community, with regards to geographic, methodological, and process expertise, will remain a challenge as the field itself continues to evolve, incorporating new technologies and new priorities.

Parallel to these efforts, and together with the other AGU journals, we have aimed to better clarify the Aims and Scope of each journal, to ensure the best chances that manuscripts submitted will be handled by Editors, Associate Editors, and reviewers that are most capable of providing constructive reviews. Since these adjustments, for manuscripts that go out to review, the median time to first decision has been about 2.5 months in the last three years, and the median time to final decision has ranged from 5 to 6 months.

Since 2022, our need to make our science more open and accessible led to the implementation of FAIR (findable, accessible, interoperable, readable) data guidelines at all AGU journals, together with Plain Language Summaries in most journals. I was pleased by the speed and relative ease with which these guidelines were taken up, and that the members of our community and editorial board were among the first to suggest modifications of the guidelines and helped to craft guidelines for authors.

Political threats to science have always existed, and on some level have always directly impacted our ability to conduct research. But for the AGU journals, never has the political threat to science and scientific publication been more acute than with the inauguration of Donald Trump as United States president in January 2025. Withholding of grant money awarded by the U.S. National Science Foundation, widespread layoffs at nearly all governmental research agencies, and uncertainty in the funding future have hampered both ongoing projects and the future careers of many of our deeply valued, often early-career colleagues. The Editors of Tectonics, led by Djordje Grujic, published an editorial in April 2025, “Tectonics in Turbulence: Defending Science in Unstable Times,” to highlight the impacts of these threats and provide links to effective counter actions.

Moreover, the hypocritically named “Restoring Gold Standard Science” executive order of 25 May 2025 purports a need for political nominees to assess which science can and cannot be published. AGU journal Editors-in-Chief, led by Michael Wysession, published a response in August 2025 titled “The Executive Order ‘Restoring Gold Standard Science’ is Dangerous for America” in AGU Advances to this blatant move toward censorship and attempt to sow distrust in science. Most recently, threats of detention by Immigration and Customs Enforcement, even for those with work permits, have chilled what was once a vibrant and open research environment. These changes not only affect U.S. based researchers, but also international colleagues who had plans for or who still hope to conduct research stays in the U.S. Regardless of the outcome of the next mid-term and subsequent presidential election, vulnerabilities to a global powerhouse in scientific research have been vividly exposed.

Finding ways to articulate the value of our research, both on practical, applied levels and for the pure satisfaction of human curiosity, remains crucial.

How do we move forward? Finding ways to articulate the value of our research, both on practical, applied levels and for the pure satisfaction of human curiosity, remains crucial. Sharing our research widely, with appropriate context so that results are reproducible and can be built upon, is a necessity. Holding ourselves and our colleagues to the highest level of scientific rigor and ethical behavior is a basic tenet of our work. And reaching out for new perspectives from throughout the diverse membership of our community is likely the best route to solving our hardest problems. Publications at Tectonics play but a small role in these aims, but facilitate the kinds of broad international collaborations and networks that accomplish far more lofty goals, and can provide a buffer against the negative impacts of any given political administration.

I wish to express my sincerest gratitude to our authors, who decide to publish their excellent work and innovative ideas in Tectonics; to our reviewers, who generously contribute their time to providing feedback and guidance to authors; to our Associate Editors, who help guide authors through this process and often provide additional constructive comments; to the AGU staff, who help manage communication and trouble-shoot the challenges we all encounter with the GEMS online submission system; to the Editors-in-Chief of the other AGU journals, who create a community of shared experiences and support that help AGU journals as a whole to adapt to changes in the publication landscape and maintain a forward-looking perspective; and to the other Editors of Tectonics (Laurent Jolivet, Margi Rusmore, Djordje Grugic, Federico Rossetti), who have kept a watchful eye over all, including the direction of the journal, the work load of the board, and were a continuous source of helpful advice to both me and the AGU staff regarding what we can do to improve the experience for everyone involved with the journal.

I have full confidence that the new Editor-in-Chief will take up leadership of the journal with the level of energy, enthusiasm, and care that this flagship of our community deserves.

Finally, I thank John Geissmann, the previous Editor-in-Chief of Tectonics who first brought me onto the editorial board in 2014, and since that time has been a true friend and mentor in various aspects of publications and life. It has been a tremendous pleasure and honor to work with you all. I have full confidence that the new Editor-in-Chief of Tectonics, Guilio Viola, will take up leadership of the journal with the level of energy, enthusiasm, and care that this flagship of our community deserves. And I look forward to reading your work in Tectonics.

Looking forward – Aspirations from Incoming Editor-in-Chief Giulio Viola

Giulio Viola, the new Editor-in-Chief of Tectonics.

I am grateful and honored to succeed Prof. Taylor Schildgen as Editor-in-Chief of Tectonics. I have long considered this journal to be at the forefront of publishing high-impact, multidisciplinary research on the evolution, structure, and deformation of the Earth’s lithosphere through time. Since publishing my first paper in Tectonics more than twenty-five years ago, I have always admired its blend of methodological rigor, vision, and editorial quality, all aspects that have grown even stronger under Taylor’s leadership.

After a career devoted to studying deformation from the grain to the plate scale, mentoring young scientists, and serving on editorial boards, I am thankful for the opportunity to help guide the journal through the scientific and publishing challenges ahead. Together with the Editors and the renewed board of Associate Editors, I hope to build further on the journal’s already strong foundation, continue to develop its strategic vision, and explore new topics and directions for our community.

My immediate priority is to improve turnaround times while maintaining the highest scientific standards and adhering to a clear and well-defined strategic plan for the journal’s scope. I want to offer authors a transparent, straightforward, and efficient editorial path, which I believe is one of the most important aspects of scientific publishing. By making our processes more transparent and efficient, we can allow authors to focus on what matters most, i.e., producing excellent science for our readers, and attract even more outstanding contributions.

Looking ahead, I see important opportunities for Tectonics. The societal relevance of our field has never been greater. Research in tectonics informs earthquake hazard assessment, critical metals exploration, waste disposal, energy storage, and the broader energy transition. Inspired by the “Challenges and Opportunities for Research in Tectonics” white paper prepared for the U.S. National Science Foundation, I hope to see even more contributions that address these pressing needs while continuing to support fundamental, curiosity-driven research.

We will continue to broaden the geographical representation of our editorial board and reviewer community, and we will explore mentorship initiatives to support early-career researchers, especially those from underrepresented regions, as well as early-stage Editors.

I am committed to fostering an open dialogue in which anyone interested in the journal and in the future of the journal can contribute.

The publication landscape is evolving rapidly. How do we keep authors, reviewers, and readers engaged? What role should new technologies, including generative AI, play in scholarly publishing? How can we reach a broader, truly global audience beyond the English-speaking community, especially given the societal impact of much of our research? Not all the answers are clear to me, but I am committed to fostering an open dialogue in which anyone interested in the journal and in the future of the journal can contribute.

No Editor-in-Chief works alone. The success of Tectonics depends on the dedication of editors, associate editors, reviewers, authors, readers, and our publisher. I hope to contribute scientific breadth, editorial experience, and a genuine commitment to an engaged community.

Tectonics has been an important part of my professional life for over two decades, and I take on this role with both enthusiasm and a strong sense of responsibility. I hope that new generations of researchers will feel the same appreciation for the journal and will continue to choose it to publish their very best work.

—Taylor Schildgen (tschild@gfz.de, 0000-0002-4236-4609), GFZ Helmholtz Centre for Geosciences, Germany; and Giulio Viola (giulio.viola3@unibo.it, 0000-0002-8383-3328), Università di Bologna, Italy

Citation: Schildgen, T., and G. Viola (2026), Editorial handover at Tectonics, Eos, 107, https://doi.org/10.1029/2026EO265005. Published on 4 March 2026. 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 © 2026. 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.

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

On very large scales, the precipitation response to warming is sometimes summarized as the “wet gets wetter and the dry gets drier.” This wet-gets-wetter response suggests that regions of tropical rainfall contract and intensify with warming. Ample evidence supports this response for the case of the annual-mean thermally driven Hadley circulation, in which moist air ascends near the equator and descends in the subtropics.

Sokol et al. [2026] test whether this response also applies to east-west overturning circulations, like the Pacific Walker circulation, in which air ascends in the western tropical Pacific and descends in the Eastern Pacific. In their idealized simulations of the Walker circulation, they find the opposite response: rainy regions expand as the surface warms, and the mean rainfall within them decreases, i.e., a “wet-gets-drier” response. They show that this response is driven by a rapid slowdown of the Walker circulation with warming, which is connected to changes in the vertical structure of the circulation. 

Citation: Sokol, A. B., Merlis, T. M., & Fueglistaler, S. (2026). No “wet gets wetter” in kilometer-scale mock-Walker circulations. AGU Advances, 7, e2025AV002040. https://doi.org/10.1029/2025AV002040

—Don Wuebbles, Editor, AGU Advances

Text © 2026. 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.

In temperate climates, the world slows down during the winter. Plants die or go dormant, animals hibernate, and snow blankets the ground. But soil below the snow is hardly frozen; it bustles with microbial life. All winter, these microscopic organisms feed on decomposing organic matter and release nutrients that will fuel plant growth in the spring.

Snowmelt is also a key component of nitrogen cycling. When snow melts each spring, microbial populations bloom and temporarily lock up available nitrogen in their biomass. This bloom is followed by a crash when the microbes die or decrease in number, releasing nitrogen back into the soil.

This microbial bloom-and-crash cycle has been observed in a variety of ecosystems, but the processes that cause it are not yet well understood. Climate change might further complicate what happens to the soil underneath snow. As warmer winters contribute to record low snowpacks, microbial activity may also change or slow. Nitrogen may be released into the atmosphere or exported into streams at different times or in different amounts—changes that would disrupt the nutrient balance that sustains plant life during the growing season.

A new study published in Nature Microbiology takes a peek at the microbial communities below the snow by tracing their chemical footprints in a high-elevation watershed in Colorado.

“What we wanted to do is to have a little bit more mechanistic understanding of the reasons why the [microbial] populations bloom, what types of nitrogen the soil microbiome uses to build biomass, and then, ultimately, what is the fate of that nitrogen after the population size crashes in spring?” said study author Patrick Sorensen, a microbial biogeochemist at the University of Rhode Island.

Digging in the Snow

The East River Watershed in Gunnison County, Colorado, is a high-altitude (9,022–13,123 feet, or 2,750–4,000 meters), mountainous area that is typically covered in multiple feet of snow between November and May. Most of its annual precipitation falls as snow, and over the past 50 years, spring snowmelt has been occurring progressively earlier.

“At this particular field site,” Sorensen said, “it’s pretty arid, so the soils were dry, even when there’s 6 feet of snow on top of them.” Credit: Patrick Sorensen

“Historically, we thought, just like trees are losing their leaves, that the soil was also dormant in the winter. It’s cold down there. If the plants aren’t providing any carbon inputs, maybe the microbes just aren’t active,” said Stephanie Kivlin, an ecologist at the University of Tennessee, Knoxville, who was not part of the study.

Researchers sampled the watershed six times over a period spanning the winter season, snowmelt, early growing season, and midsummer. “We snowshoed or cross-country skied out to the field site, dug snow pits, and that’s how we collected soils from beneath the snowpack,” said Sorensen. “Snow is a really good insulator, so the soils that we collect from underneath the snowpack are not frozen. At this particular field site, it’s pretty arid, so the soils were dry, even when there’s 6 feet of snow on top of them.”

Researchers split the soil samples into two groups for analysis. One set was tested for its physical and biochemical properties. The other was immediately flash frozen in dry ice to be sent to the Berkeley Lab for further genetic testing—meaning that scientists working on this project had to pack in coolers of dry ice and pack out soil samples through thick snow.

Blooming and Crashing

Research revealed that microbial populations in the soil were hardly dormant during the winter. Sorensen and colleagues divided the microbe populations into four groups:

• Fall-adapted organisms and bacteria were most active after plants had senesced.
• Winter-adapted organisms were most active when the snowpack was deepest.
• The snowmelt specialists were most active, and their numbers peaked as the snow melted.
• A final group, the spring-adapted microbes, thrived when the snow was gone and soils had warmed up.

Microbes take turns using different forms of nitrogen across the seasons, explained Sorensen. Winter-adapted microbes prefer inorganic nitrogen for their growth, while snowmelt specialists use organic nitrogen to build biomass when the soil is saturated. Once the snow is gone and soils have warmed, spring-adapted microbes take over to help convert nitrogen into a form that plants can use.

“These groups have adapted to use different types of nitrogen at different times of the year, and it’s related to the onset of snowmelt,” said Sorensen.

As snow melts and soils become saturated, the microbial population surges, rapidly incorporating nitrogen into their biomass. Their numbers then decline as conditions change.

Contrary to previous assumptions, Sorensen and colleagues realized that the bloom-and-crash cycle that microbial communities experienced during snowmelt was actually occurring much faster and in a much smaller window of time. While a typical winter lasts 120–150 days, the rapid microbial growth and decline occurs during the 60 or so days of active snowmelt, rather than gradually throughout the winter.

“It was shocking to me how much nitrogen was being cycled under the snow in the middle of the winter.”

“It was shocking to me how much nitrogen was being cycled under the snow in the middle of the winter. This is one of the first studies to really show the magnitude of that effect and who among the microbiome is doing all of that nitrogen cycling,” said Kivlin. “And, the other novel part is at snowmelt, there’s this huge flux of microbial activity, and then flux of nitrogen, probably creating available nitrogen for plants to grow once the snow has melted off of them.”

But as snowpack levels are decreasing due to warmer winters, soil microbial activity may be disrupted, Sorensen explained. Insulation from the snow keeps soils from freezing, so microbes can perform their bloom-and-crash cycle to release nitrogen as plants emerge from dormancy. More research is needed as the climate continues to warm—especially to examine how this process may affect soil microbe populations in regions beyond the mountains of Colorado.

“It’s possible that if that bloom-and-crash [cycle] starts to occur earlier and earlier in the year, but plants don’t start growing earlier, then those two processes could become decoupled. The consequences of that could be more nitrogen lost through aquatic ecosystems or through gaseous emissions. Either consequence is not great because nitrogen tends to be one of the nutrients that is most limiting for plant and microbial life on land,” said Sorensen.

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

Citation: Owen, R. (2026), When the snow melts, microbes bloom, Eos, 107, https://doi.org/10.1029/2026EO260073. Published on 4 March 2026. Text © 2026. 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.

Lithium mines located in arid regions of South America, China, and the United States are striking when viewed from above, appearing as sprawling, colorful pools popping out from the desert like a giant painter’s palette. The open-air pools are filled with brine pumped from underground reservoirs. Once on the surface, the water eventually evaporates, leaving behind concentrated lithium. Today, much of the world’s lithium is extracted this way.

• The Operational Land Imager on Landsat 8 captured this image of lithium mines in Argentina’s Jujuy Province, near the country’s border with Chile. Credit: NASA Earth Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey
• Salar del Hombre Muerto, a salt flat in Argentina, is a major source of lithium. Credit: Oton Barros (DSR/OBT/INPE)/Flickr, CC BY-SA 2.0
• A site in Silver Peak, Nev., is the only operational lithium source in the United States. Credit: Oton Barros (DSR/OBT/INPE)/Flickr, CC BY-SA 2.0
• In Chile’s Salar de Atacama salt flat, lithium is mined via brine well water evaporation. Credit: Oton Barros (DSR/OBT/INPE)/Flickr, CC BY-SA 2.0
• Silver Peak, Nev., has been home to many kinds of mining for the past century and a half. Lithium mining is one of the town’s newer mining ventures. Credit: Doc Searls/Flickr, CC BY 2.0
• Bolivia’s Salar de Uyuni, the largest salt desert in the world, is also an important source of lithium. Credit: Coordenação-Geral de Observação da Terra/INPE, CC BY-SA 2.0
• Evaporation ponds for mineral mining stand out starkly in satellite images, such as this one of Chile’s Atacama Desert. Credit: Contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

But what makes the mines so eye-catching is also a burden: Current mining methods using brine require vast swaths of land and water, and removing the brine from underground can cause freshwater reservoirs to flow into the open space, lowering the water table and contaminating water supplies in already dry regions. The evaporation process is also slow, taking 1–2 years.

Now, a new study published in Joule describes a novel lithium extraction method that is faster and potentially more environmentally friendly. The technique, which uses a unique chemical solvent, could also unlock lithium reserves in areas where conventional methods are infeasible because of land and water constraints. One such location is California’s Salton Sea, where brines contain enough lithium to build batteries for more than 370 million electric vehicles.

Flipping a Chemical Switch

The demand for batteries is driving scientists to develop more efficient lithium-extraction technologies, but the new study sprang from research on unique chemical solvents, called switchable solvents, that change properties under different conditions. Ngai Yin Yip, an environmental engineer at Columbia University and a senior author on the paper, was particularly interested in several switchable solvents that have an affinity for water at room temperature but repel it when it’s heated to 158°F (70°C).

“I like to think of this switchable solvent as a sponge.”

While studying this material, the team noticed that at room temperature, the solvent also attracted lithium, in addition to water. “I like to think of this switchable solvent as a sponge,” said Yip. “So it sponges up water and ions at lower concentrations.” Although the researchers don’t entirely understand why lithium interacts with the solvent this way, they think that the small size of lithium atoms might allow them to become encapsulated in water, essentially hitching a ride with the water.

The researchers started to see potential for lithium extraction and set up laboratory experiments to dig deeper. They mixed the solvent with beakers of brines, including one simulating the brine under the Salton Sea. When they mixed brines with the switchable solvent in laboratory beakers at room temperature, the solvent was attracted to water in the brine, and the solvent, water, and ions separated from the rest of the brine. The researchers then removed the layer of solvent, now containing water and lithium, from the rest of the brine, and raised the temperature. The heat switched the solvent to a hydrophobic state, in which it began “squeezing out” the water and ions for collection by the researchers, Yip said. The researchers then measured the amount of lithium and other positively charged metal ions, such as potassium, sodium, and magnesium, in the water.

While the water did contain small amounts of other cations, lithium was approximately 13 times more enriched in the solution than was sodium and 24 times more enriched than potassium in tests using the simulated Salton Sea brine.

Accessing the Inaccessible

“These kinds of technologies are really promising for having very low impact production of minerals.”

Yip said the new extraction method is much faster than current methods, and the solvents can also be reused to extract lithium from multiple batches of brine. The solvents are readily available and inexpensive, he said. “That was intentional, because we didn’t want to start off with a material that requires very elaborate synthesis.”

Alissa Kendall, a University of California, Davis industrial ecologist who was not involved in the study, found the study important because the Salton Sea region has geothermal power plants that could provide low-carbon heat, potentially even using waste heat from electricity generation. “These kinds of technologies are really promising for having very low impact production of minerals,” she said.

In future studies, Yip wants to better understand why the solvent pulls lithium along with water, as this interaction could be refined to improve the efficiency of lithium extraction. He also hopes to test the process’s scalability to determine whether industrial applications are feasible.

“This is really an engineered process,” Yip said, in that scientists both create the material and design the method to optimize its performance. “That can be helpful in terms of rapidly scaling up production to meet the forecasted increases in lithium demand over the coming decades.”

—Andrew Chapman (@andrewgchapman.bsky.social), Science Writer

Citation: Chapman, A. (2026), Engineering a cleaner way to extract lithium, Eos, 107, https://doi.org/10.1029/2026EO260071. Published on 4 March 2026. Text © 2026. 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.

Author(s): Katarina A. Nichols, S. X. Hu, Nathaniel R. Shaffer, Brennan Arnold, Deyan I. Mihaylov, Valeri N. Goncharov, Valentin V. Karasiev, William Trickey, Alexander J. White, Lee A. Collins, Duc Cao, and Rahul C. Shah

Accurate hydrodynamic modeling for laser-direct-drive (LDD) inertial confinement fusion (ICF) relies on precise calculations of the electron thermal conduction in all target materials. The nonlocal stopping range of electrons in ICF plasmas directly influences thermal conduction; yet, no first-princ…

[Phys. Rev. E 113, 035202] Published Wed Mar 04, 2026

In the ocean, a haze made from tiny bits of dead plants, animals, and microbes hangs in the upper reaches of the water. Each particle is just a fraction of a micrometer across, but together the carbon within these particles weighs about 700 billion tons—about as much as all the carbon in the atmosphere.

For decades, scientists have relied on a chemical fingerprint inside water molecules to determine where plants get their moisture. The method shaped our understanding of drought resilience, groundwater use, and ecosystem survival. But there was a problem. The fingerprints didn't always match.

For years, the Prairie Pothole Region has bothered me in a very specific way. On a map, it looks like a normal landscape: fields, gentle slopes, small streams. But hydrologically, it behaves like something else entirely. The surface is peppered with countless depressions—wetlands and "potholes"—that can store water for days, months, or even years. Most of the time, rainfall and snowmelt do not move cleanly downhill into channels. They disappear into storage. Then, sometimes, they don't.

There are many open questions about how our planet formed 4.55 billion years ago: When did plate tectonics start? When did the Earth's mantle begin to vigorously circulate in a process called convection? What was Earth like early in its lifetime? Because no rock records from the earliest years of the Earth remain, researchers turn to minerals called zircons, which are resilient against physical and chemical alteration over time and therefore preserve a precise chemical record about the moments in which they were formed.

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

The Amazonian forest takes up atmospheric carbon dioxide (CO2), thus helping to buffer the effect of global anthropogenic emissions on climate. As the climate changes, however, this previously reliable carbon sink may be at risk. Extreme weather events, such as the drought of 2023 in the Amazon region, are becoming more common. Although the Amazonian forest is adapted to climatic variation and drought to some extent, severe drought can lead to reduced photosynthesis and greater emissions from fires. Estimating this effect at a scale as large as the Amazon Basin is challenging.

Botía et al. [2026] use multiple approaches that generally show a net release of carbon from the basin during 2023, although there are differences among methodologies. Satellite-based measurements, biogeochemical models, and CO2 concentrations measured at a tall tower indicated a regional net release of carbon, but of varying amounts. A more localized method of tower-based eddy covariance measurements showed a net uptake of CO2, indicating that the local patch of forest was responding differently than the basin-wide estimates. In an accompanying Viewpoint, Liu [2026], these complex responses are nicely explained and summarized by the author.

Citations:

Botía, S., Dias-Júnior, C. Q., Komiya, S., van der Woude, A. M., Terristi, M., de Kok, R. J., et al. (2026). Reduced vegetation uptake during the extreme 2023 drought turns the Amazon into a weak carbon source. AGU Advances, 7, e2025AV001658. https://doi.org/10.1029/2025AV001658

Liu, J. (2026). The growing threat of extreme drought-heat to the Amazon carbon sink. AGU Advances, 7, e2026AV002309. https://doi.org/10.1029/2026AV002309

—Eric Davidson, Editor, AGU Advances

Text © 2026. 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.

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

The amount of time that mercury (Hg) spends in the atmosphere determines its global spread, and therefore the distribution of this toxic pollutant, even to remote ecosystems. Generally, previous studies have assumed the chemical lifetime of elemental mercury (Hg0) has been constant throughout history, mirroring the conditions of present-day (2010–2019). However, since pre-industrial times (about 1850), anthropogenic emissions have altered the concentrations of oxidants that affect the lifetime of Hg0, including bromine radicals (Br), hydroxyl radicals (OH), and ozone (O3).

Feinberg et al. [2026] use a state-of-the-art chemistry-climate model to analyze the effects of the changes in background composition between 1850 and now to examine the resulting effects on mercury deposition into water around the world. The increasing concentrations of OH and O3 lead to 16% faster Hg0 oxidation in today’s Northern Hemisphere, while the increased partitioning of Br to reservoir species slows Hg0 oxidation by 20% in the Southern Hemisphere relative to the 1850 atmosphere. These regional oxidation changes shift the pattern of where Hg deposits to the surface.

The shifts in Hg0 oxidation enhance deposition by 15% to tropical and subtropical oceans, which are critical regions for Hg exposure risks. The 1850 atmosphere, however, was more conducive to the spread of Hg to the remote Southern Hemisphere extratropics. This finding significantly affects the interpretation of the Hg deposition historical records from natural archives. This study reveals that the changing atmospheric composition has been a previously overlooked factor when considering human Hg exposure risk via altered Hg deposition patterns. 

Citation: Feinberg, A., Sonke, J. E., Cuevas, C. A., Li, M.-L., Acuña, A. U., Fernandez, R. P., et al. (2026). Shifts in atmospheric composition since the preindustrial era modified the transport and deposition of mercury. AGU Advances, 7, e2025AV002158. https://doi.org/10.1029/2025AV002158

—Don Wuebbles, Editor, AGU Advances

Text © 2026. 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

In the ocean, a haze made from tiny bits of dead plants, animals, and microbes hangs in the upper reaches of the water. Each particle is just a fraction of a micrometer across, but together the carbon within these particles weighs around 700 billion tons—about as much as all the carbon in the atmosphere.

Dissolved organic carbon (DOC), as these little bits are called, is a food source that sustains marine bacteria and a carbon store with huge implications for climate change. Yet scientists don’t understand what dictates the distribution of DOC throughout the ocean.

Owusu et al. set out to explain the distribution of DOC with a focus on the North Atlantic subtropical gyre, where the concentration of DOC is particularly high. Some scientists have hypothesized that certain hard-to-break-down forms of DOC are sucked into subtropical gyres by strong currents, then remain trapped there long-term. But this team had a different suspicion: The type and number of bacteria present in the gyre dictate how much DOC accumulates.

To test their theory, the researchers used a consumer-resource model to study how bacteria compete for DOC when they have access to varying levels of nitrogen, which can limit bacterial growth. When the researchers varied bacterial prevalence, DOC concentration followed quite naturally, they found. However, the rate at which dead organisms produced DOC did not fully explain the prevalence of DOC. The results are consistent with a recent study in which researchers sampled water from the gyre and found there weren’t enough bacteria around to take advantage of all the DOC they could be munching on.

The findings represent a switch from the long-dominant theory that the biochemical properties of DOC determine how easily it breaks down. The study suggests that the microbial makeup of ocean water is actually the prime deciding factor in how much dissolved organic matter it contains. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009257, 2026)

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

Citation: Sidik, S. M. (2026), Bacteria decide the ocean’s dissolved organic carbon abundance, Eos, 107, https://doi.org/10.1029/2026EO260072. Published on 3 March 2026. Text © 2026. 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

Atmospheric rivers (ARs) are coherent current structures in the atmosphere that transport moisture and are important elements to deliver water through heavy precipitation events. They can also cause substantial hazards in many regions of the world. Due to their intrinsically long and narrow extent and high variability, it is challenging to observe and detect trends in AR activity and characteristics. Yet, this would be crucial for water resource planning and adaptation strategies.

Based on hourly atmospheric reanalysis data and applying several identification tools, Scholz and Lora [2025] find that the frequency of ARs in mid-latitudes of both hemispheres has robustly increased since 1940. Particularly, in the Southern Hemisphere, over the eastern United States, the North Atlantic region and into western Europe (see Figure), with concurrent increases in precipitation and snowfall. Less obvious surface impacts of ARs are warm winters and extreme heat events.

The longer-term context for AR trends that is established by the authors helps climate model simulations to better assess this important feature of atmospheric circulations and eventually improve projections. These are crucial inputs for decision makers to make water management and hazard prevention fit for the future. However, for example, formal detection and attribution studies on ARs are still challenging due to the large uncertainties associated with this fine-scale feature of atmospheric circulation.

Citation: Scholz, S. R., & Lora, J. M. (2025). Widespread increase in atmospheric river frequency and impacts over the 20th century. AGU Advances, 6, e2025AV001888. https://doi.org/10.1029/2025AV001888

—Thomas Stocker, Editor, AGU Advances 

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The devastating wildfires in northern Canada in recent years have climate consequences that go far beyond smoke and carbon dioxide released into the atmosphere, according to a new study co-authored by two NAU researchers. The study, which looked at the various effects of fire in northern Canada and Alaska, wasn't all bad news: The researchers found fires in Canada, when coupled with snowpack, have a net cooling effect. That cooling, however, isn't enough to outweigh the warming effects of permafrost carbon released into the atmosphere from fires in Alaska.

Author(s): Tomohiro Tanogami, Makoto Sasaki, and Tatsuya Kobayashi

Magnetically confined fusion plasmas exhibit predator-prey-like cyclic oscillations through the self-regulating interaction between drift-wave turbulence and zonal flow. To elucidate the detailed mechanism and causality underlying this phenomenon, we construct a simple stochastic predator-prey model…

[Phys. Rev. E 113, 035201] Published Tue Mar 03, 2026

SummaryThe Mendocino Triple Junction (MTJ), where the Gorda, North American, and Pacific plates meet, is one of the most seismically active regions in California. The tectonic movements along the Mendocino transform fault zone (MTFZ), Gorda slab (GS), and northern San Andreas Fault systems (NSAF) lead to high background seismicity rates but relatively low aftershock productivity. To improve the understanding of earthquake processes in the area, we analyze relations between background seismicity, aftershock productivity, and stress parameters. We apply the nearest-neighbor approach to investigate the spatial distributions and properties of background and clustered seismicity, and invert focal mechanisms of events in Voronoi cells for features of the deviatoric stress field. The results indicate that the intensity of background seismicity and aftershock productivity decrease with distance from the MTJ, defined here for simplicity as the hypocenter of the 1992 Mw7.2 mainshock. We also find that the stress regime is the most compressive in the area directly surrounding the MTJ. In the MTFZ and GS, the compressive stress decreases with increasing distance from the MTJ, correlating with the reduced aftershock productivity and background seismicity. In the NSAF, the observed relations between the stress, aftershock productivity, and background seismicity are not clear, possibly due to crustal extension related to the slab window and elevated heat flow. Compared to the MTFZ and GS, the NSAF has a higher foreshock proportion, lower aftershock proportion, and small-to-medium mainshock magnitudes, indicating more swarm-like clusters in this region. The inverted stress regimes in the MTFZ and NSAF are dominated by strike-slip faulting. The GS exhibits mostly strike-slip and normal mechanisms despite the subduction environment, which may reflect slab bending and reactivation of preexisting normal faults.

SummaryUnderstanding when and where strong earthquakes occur is crucial for assessing seismic hazard. Changes in the b-value, which describes how frequently earthquakes of different sizes happen, have been investigated as possible indicators in the space-time vicinity of upcoming large earthquakes. In this study, we investigate short-term b-value variations in the central-northern Apennines (Italy) by comparing an observed earthquake catalogue spanning the period 1987–2025 with a 10 000-year synthetic catalogue generated by a physics-based earthquake simulator. The synthetic seismicity is produced using a three-dimensional seismotectonic model derived from the DISS database and an elastic-rebound framework for earthquake nucleation. We apply a stacking procedure to compute average b-values within symmetrical time windows of ± 15 days and 30 km distance from selected pivot events of moderate to large magnitude. The same methodology is consistently applied to both observed and simulated datasets, enabling a direct comparison of their temporal behaviour. The observed catalogue shows a statistically significant decrease in the b-value in the days preceding earthquakes with Mw ≥ 4.0, followed by a post-event recovery. A comparable pattern is reproduced by the synthetic catalogue, where a pronounced b-value drop precedes pivot events of Mw ≥ 4.5 and is systematically followed by an increase after rupture. The persistence of this behaviour across different magnitude thresholds in the simulated data supports its robustness. These results indicate that physics-based simulations can reproduce short-term b-value variations associated with earthquake nucleation, supporting the relevance of this parameter for investigating the physical processes governing seismicity.

A research team led by a Keele scientist has shed new light on how a mysterious rock formation in Oman was created, which could reveal new details about Earth's ability to store carbon dioxide (CO2). The study, led by Dr. Elliot Carter in Keele's School of Life Sciences, in collaboration with the Universities of Ottawa and Manchester, looked at geological evidence from Oman to better understand processes that occur in subduction zones, which is where one of Earth's tectonic plates sinks beneath another due to the plates colliding together. This process is active around much of the Pacific "Ring of Fire" today, for example.

The Florida Everglades is a complicated climate actor. The 1.5-million-acre wetland system remains a carbon sink, removing an average of 13.7 million metric tons of carbon dioxide from the atmosphere each year, but the system also releases methane. In a new study, Yale School of the Environment scientists have analyzed the greenhouse gas fluxes in its mangroves and fresh-water marshes, providing a more detailed approach for guiding restoration efforts.

Atmospheric rivers carry unfathomable amounts of water across the sky, bringing moisture to drought-stricken regions like the Western U.S. But whether a particular incoming atmospheric river storm will result in disastrous flooding has long been difficult for researchers to determine with confidence. Now, a new Desert Research Institute-led study demonstrates that accounting for soil saturation levels can substantially improve our early warning of potentially destructive flooding events.