EOS

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

The Trump administration is planning to dismantle the National Center for Atmospheric Research (NCAR), one of the world’s leading climate and Earth science research laboratories, according to a statement from Russ Vought, director of the White House Office of Management and Budget, to USA Today. 

Vought called the facility “one of the largest sources of climate alarmism in the country” and said the administration had already started a comprehensive review of activities at the laboratory. 

“Vital activities such as weather research will be moved to another entity or location,” Vought said. 

 

Related Content

•  Trump moves to dismantle major US climate research center in Colorado
•  Russ Vought post on X
•  Statement from UCAR President Antonio Busalacchi
• Get Involved: Speak Out to Save NCAR Today

The National Science Foundation established NCAR in 1960 as the foundation’s first federally funded research and development center. Among other work, NCAR researchers use both models and observations to study weather, air quality, water management, and solar storms. NCAR’s Derecho supercomputer, housed in Wyoming, allows researchers across the country to run detailed models stimulating phenomena such as cyclones and major wildfires.

Among other innovations, scientists at NCAR invented dropsondes, devices that drop from aircraft to measure pressure, temperature, and humidity during storms. They use models that predict how inclement weather will affect road safety. They are developing a turbulence detection system to allow aircraft to avoid rough spots, working to improve hurricane prediction, and projecting atmospheric conditions months in advance to provide guidance for U.S. military planners.

The news comes as international Earth and space scientists, many of whom will likely be affected by the news, gather at AGU’s annual conference in New Orleans. Some took to social media to express their disappointment.

“NCAR is quite literally our global mothership,” climate scientist Katherine Hayhoe wrote on Bluesky. “Everyone who works in climate and weather has passed through its doors and benefited from its incredible resources. Dismantling NCAR is like taking a sledgehammer to the keystone holding up our scientific understanding of the planet.”

NCAR is quite literally our global mothership. Everyone who works in climate and weather has passed through its doors and benefited from its incredible resources. Dismantling NCAR is like taking a sledgehammer to the keystone holding up our scientific understanding of the planet.Unbelievable.

— Katharine Hayhoe (@katharinehayhoe.com) 2025-12-17T02:59:29.336Z

Other scientists expressed similar sentiments.

It is hard to overstate how critical @ncar-ucar.bsky.social is to climate science in the US and around the world. It's the beating heart of our field. Generations of scientists have trained there, and almost everyone I know relies on deep collaborations with NCAR scientists. It's end is unthinkable.

— Kim Cobb (@kimcobb.bsky.social) 2025-12-17T02:50:46.254Z

This is absolutely insane and so incredibly shortsighted. NCAR is a global pillar for all atmospheric science and holds the highest of standards for research excellence. We collaborate with NCAR; source data from them; they pioneer scientific breakthroughs.This must not go quietly.

— Brian Matilla (@bxmatilla.bsky.social) 2025-12-17T05:25:14.802Z

As someone not with NCAR, I use NCAR-based software everyday to help identify and track regions of excessive precipitation to help NWS forecasters protect lives and property. NCAR is extremely valuable and we need them.

— Noah Brauer (@noaabrauer.bsky.social) 2025-12-17T04:16:52.073Z

NCAR is home to about 830 employees, but it is not clear how many employees or programs the dismantling will affect. According to a senior White House official who spoke to USA Today, the effort will begin immediately, and includes closing the center’s headquarters: the Mesa Laboratory in Boulder, Colo. The official also flagged several programs the administration considers wasteful, such as efforts to make the sciences more inclusive and research into wind turbines.

In a 16 December statement posted on the NCAR website, Antonio Busalacchi, president of the University Corporation for Atmospheric Research, which manages NCAR, said the center was aware of the Trump administration’s proposal, but had not received additional information.

“NSF NCAR’s research is crucial for building American prosperity by protecting lives and property, supporting the economy, and strengthening national security,” he wrote. “Any plans to dismantle NSF NCAR would set back our nation’s ability to predict, prepare for, and respond to severe weather and other natural disasters.”

In a livestream about the news on Wednesday morning, weather and climate scientist Daniel Swain said NCAR is set to be dismantled for “reasons that do not align with the interests of Americans, which do not align with the interests of really anybody, anywhere in the world.”

“I think this is the moment to be reaching out to your lawmakers and speaking with journalists about the value of NCAR and what would be lost, what will be lost, if the current plan is fully put into motion,” he said.

To voice your support for NCAR, visit this AGU page, where you can find email text and a call script to share with your representatives.

—Emily Gardner (@emfurd@bsky.social), Associate Editor, and 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 how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
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It’s now become easier to forecast the next eruption of Alaska’s Bogoslof volcano.

New research led by Pavel Izbekov, a volcanologist at the Alaska Volcano Observatory, is applying the foundations of diffusion chronometry—the study of chemical change in crystals over time—to a new eruption forecasting approach. Izbekov’s team used crystal clusters and their collective records of magma to date and discern the cause of the 2016–2017 Bogoslof volcanic eruption.

They found that around 180 days before the eruption, the volcano experienced a rapid ascent of magma to a shallow storage chamber under the surface of the volcano, where it accumulated until it erupted. These findings can be used in tandem with other monitoring methods to more accurately anticipate the next eruption at Bogoslof and other volcanoes.

“Understanding how [volcanoes] work, understanding what precedes an eruption, and the ability to forecast volcanic behavior is extremely important for our safety,” Izbekov said. The team presented their findings on 17 December at AGU’s Annual Meeting 2025 in New Orleans.

Crystal Clusters as Clocks

A volcanologist reconstructing the history of magma with zone records is “like a forensic detective trying to figure out a crime scene in a crystal,” said Hannah Shamloo, a volcanologist at Central Washington University who was not involved in the new research.

A volcanic crystal grows from its core outward, developing concentric zones each time it experiences a major event. Visible under an electron microprobe, the zones resemble a tree’s growth rings, which capture the chemical reactions spurred by a particular event. The innermost zones near the crystal’s core reflect early life events, while the outermost zones along the rim depict activity later in life.

“If you look at the pair [of crystals], which responded to the same event simultaneously, well, we’re in business.”

The challenge is that multiple events can yield the same chemical reaction within a zone. To eliminate competing possible causes of the Bogoslof eruption, Izbekov and his colleagues looked not just at one crystal, but at a cluster of crystals of different types. If volcanologists look not just at the plagioclase, whose zone records they can attribute to a few possible explanations, but also at a clinopyroxene, whose zone records point to a different set of explanations, they can find a common denominator by the process of elimination.

“If you look at the pair, which responded to the same event simultaneously, well, we’re in business. This is the beauty of this new approach,” Izbekov said.

From Past to Future

Bogoslof was an optimal case study for cluster chronometry because the magma in its chamber below the seafloor is rich in crystals that record clear responses to pressure and temperature changes.

The team analyzed plagioclase-clinopyroxene-amphibole clusters within samples of basalt that erupted from Bogoslof in August 2017, toward the end of a 9-month eruption period. The conjoined crystals shared zone boundaries, indicating that they experienced the same events in the magma chamber.

One event stood out because the three minerals responded very differently: The clinopyroxene crystals suddenly decreased in magnesium content, the plagioclases decreased in anorthite content, and the amphiboles stopped growing. Izbekov and his team determined that decompression, a rapid drop in magmatic pressure that happens when magma ascends toward the volcanic surface, is the best explanation for all three distinct responses across the crystals’ zones.

Now, when a seismometer picks up signs of decompression at Bogoslof, a roughly 180-day countdown until eruption can begin.

The researchers then attempted to date the decompression event and found that it happened no more than 180 days prior to the end of the second eruption in August, around early March 2017. They validated their detective work in the cluster investigation by comparing their results with those from established geochemical monitoring methods. Monitors had picked up higher seismic activity and sulfur dioxide emissions—two indicators of magma’s ascent through the crust and the corresponding drop in pressure—at Bogoslof in March 2017, which supported the team’s findings.

In the future, when a seismometer picks up signs of decompression at Bogoslof, a roughly 180-day countdown until eruption can begin—if an eruption happens when expected, it would further validate the diffusion chronometry technique.

Predictive Power of Crystals

Shamloo was encouraged by the results but cautioned that there was still much to decipher about how crystals record a volcano’s inner workings.

“There’s a lot that can happen to the crystal record that can confuse a geologist,” Shamloo said.

The temperature of the magma at the point of diffusion is one of those confusing, yet essential, components. While the exact temperature of the basalt is unknown, Izbekov and his colleagues “did a careful job handling their assumptions for their model to minimize uncertainty,” Shamloo said.

“I do think relying on the crystal record in general is becoming a useful ‘monitoring’ tool for volcanoes,” Shamloo said. “There is power in reading the crystal record to really understand eruptive histories and potentially how a volcano will erupt in the future.”

—Claudia Steiner (@claudiasteiner.bsky.social), Science Writer

Citation: Steiner, C. (2025), Crystal clusters contain clues to magma’s past and future eruptions, Eos, 106, https://doi.org/10.1029/2025EO250475. Published on 17 December 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.

Years before the first telescope was invented, sky-gazers made their rooms into pinhole cameras and took pen to paper, drawing the Sun and the little dark spots that moved across its face day by day. Sunspot drawings date back more than 2,000 years to astronomers in ancient China and, many centuries later, to Western scientists like Galileo and Kepler.

Now science historians worldwide have come together to compile and digitize 400 years’ worth of sunspot drawings in the hopes of illuminating solar activity of the past and informing our present understanding. Solar physicist Andrés Muñoz-Jaramillo used this digitized collection of sunspot observations to develop a collection of software tools to analyze solar cycles and reconstruct missing gaps.

“When we think about how much our capability of observing the [solar] cycle has evolved during the past decades—it’s incredible,” said Muñoz-Jaramillo, a senior research scientist at the Southwest Research Institute in Boulder, Colo. “The quality, resolution, cadence, everything.”

Learning from the Past

Solar cycles typically last 11 years, but Muñoz-Jaramillo said that the best instruments for observing the Sun, like the Parker Solar Probe and the Solar Dynamics Observatory, have been around for only about 2 decades. To understand solar variability going back centuries, researchers must look to techniques of the past.

“Whenever we’re dealing with long-term variability, we don’t have the luxury of waiting 100 years to get better data,” said Muñoz-Jaramillo.

Before the invention of the photograph, astronomers would point a solar telescope at the Sun and use the eyepiece to project the image upon a surface covered with paper. They would sketch the sunspots they observed that day and denote the time and date. Over time, the spots appeared to move across the page and grow or shrink or change shape. Some of these records of solar activity have survived to the present day, often gathering dust in neglected corners of archives.

Historians have been diligently collecting and digitizing centuries of drawings and creating detailed logs of the position and size of spots over time. Researchers are now using these logs to study the long-term variability of the Sun.

“A huge part of this work is done by our historian friends. They are like detectives.”

“A huge part of this work is done by our historian friends. They are like detectives,” said Muñoz-Jaramillo. “The real heroes are those that went from archives to basements and traveled all over the world and talked with people, convinced them to let them in, allowed them to take pictures.”

But hundreds of years’ worth of data are difficult to handle. So Muñoz-Jaramillo and his colleagues developed a computational framework to support the efforts of solar cycle researchers worldwide. This collection of software tools uses Bayesian statistics to fill in the gaps where sunspot data may not be available.

“You can make these statements now in a probabilistic way about what went on in these historical periods,” said Muñoz-Jaramillo.

The researchers used this new framework to learn more about the Maunder Minimum, a time period in the 15th century when the Sun was less active and very few sunspots were observed—a few dozen in comparison to the tens of thousands typically observed. With so few data points, any additional information can help scientists better understand the solar activity of the time, Muñoz-Jaramillo said. They also examined another slow activity period in the late 16th century called the Dalton Minimum and compared recent solar activity to that of previous centuries.

Using this framework, they learned that the Maunder and Dalton Minima might have been preceded by other cycles with deep minima in solar activity spread far apart in time. Some heliophysicists speculate that there may be entire solar cycles’ worth of observations missing, Muñoz-Jaramillo said.

Muñoz-Jaramillo and his colleagues presented these results on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

Spotting the Sun’s Evolution

Solar cycle researchers typically observe cycles with what are known as butterfly diagrams, plots of the time and latitude of sunspots. These plots can be used to understand the long-term variability of the Sun by comparing modern and historic data and noting parallels between them. Researchers can reconstruct past solar cycles using this new computational framework and can analyze them using butterfly diagrams to better understand how the Sun has changed in recent centuries.

“It’s a service to the community. We put all these things together to make it easier for any modern scientist to work with.”

“This study is highly innovative because, until now, reconstructions of past solar activity have relied solely on sunspot counts,” José Manuel Vaquero Martínez, a physics professor at the Universidad de Extremadura who was not involved in the study, said in an email. “In contrast, this approach incorporates not only the number of sunspots but also their positions. In other words, it leverages our understanding of how solar active regions (in this case, sunspots) evolve to reconstruct past solar activity.”

The team hopes their work will enable researchers to tap into the treasure trove of historical data more easily than before, Muñoz-Jaramillo said. “It’s a service to the community. We put all these things together to make it easier for any modern scientist to work with.”

—Daniella García Almeida, Science Writer

Citation: García Almeida, D. (2025), Sunspot drawings illuminate 400 years of solar activity, Eos, 106, https://doi.org/10.1029/2025EO250477. Published on 17 December 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: AGU Advances

Earth system models offer insight into how climate change will affect communities. But residents of those communities are rarely consulted on the design and deployment of these models, which can lead to the models being misused in local decisionmaking. To bridge this divide, Cheng et al. collaborated with Indigenous communities in two regions to model the effects climate change will have on their land.

In the Arctic Rivers project, the researchers worked with Indigenous communities across Alaska to model how climate change will alter rivers and streams. In the Mid-Klamath project, the researchers worked with the Karuk Tribe in Northern California to study how different wildfire management strategies would affect local hydrology.

In both cases, mismatches existed between the methodology available to the researchers and the needs of the end users, and the collaborators mitigated these mismatches to varying extents. In the Arctic Rivers project, for example, constraints on computational resources limited the number of future scenarios the researchers could model. Thanks to involvement from the project’s own Indigenous Advisory Council and the Yukon River Inter-Tribal Watershed Council, the researchers were able to prioritize the scenarios most relevant to the communities.

In the Mid-Klamath project, on the other hand, misunderstandings at the start of the project led the researchers to choose a modeling tool that didn’t fully meet the expectations of the tribe. More extensive discussions during early stages of the project could have avoided this issue, the researchers noted, and the National Science Foundation has recently begun to change its granting system to allow for these early discussions.

Accurately communicating the limits of the available technology is crucial, the researchers wrote. For example, one member of an Alaskan community stated that conditions in the region were changing so quickly that they needed subseasonal projections in addition to decade-scale projections. Unfortunately, the former were beyond the technical expertise of the scientists involved in the project. But scientists were careful not to mislead the community into thinking such a thing was possible in that project.

Cultural humility and spending ample time with Indigenous communities are both cornerstones of successful collaborations, the researchers wrote. At the same time, it’s important to acknowledge the capacity constraints that many scientists face. In addition, it is valuable to offer roles involving reasonable time commitments to scientists with fewer resources, so as not to exclude them from the codesign process. (AGU Advances, https://doi.org/10.1029/2025AV001921, 2025)

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

Citation: Sidik, S. M. (2025), Climate modeling for communities, with communities, Eos, 106, https://doi.org/10.1029/2025EO250473. Published on 17 December 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.

NOAA released this year’s Arctic Report Card on 16 December at AGU’s Annual Meeting 2025 in New Orleans. The report gives an update on changes to the region’s climate, environment, and communities and documents these changes for future scientists looking to the Arctic’s past.

In 2025, parts of the Arctic experienced record-breaking temperatures, low sea ice extent, and other extreme climate events. Credit: NOAA’s Arctic Report Card 2025

After 2 decades of the U.S. government producing the annual report, however, datasets and resources used to create it may be under threat as federal science agencies lose staff and plan for funding uncertainties.

“There is growing concern over how the U.S. will be investing in Arctic research,” said Matthew Druckenmiller, an Arctic scientist at the National Snow and Ice Data Center and lead editor of the report.

Another Year of Arctic Records

From October 2024 to September 2025, the time period analyzed by the report, Arctic surface air temperatures were the warmest on record. The past year in the Arctic marked the region’s warmest autumn, second-warmest winter, and third-warmest summer ever.

This year, the Arctic also had the most precipitation ever recorded, with its wettest spring on record and higher than normal winter snow cover. “To see both those records [precipitation and surface air temperature] set in a single year was remarkable,” Druckenmiller said.

Seasonal surface air temperature anomalies (in °C) for (a) autumn 2024, (b) winter 2025, (c) spring 2025, and (d) summer 2025. Temperature anomalies are shown relative to their 1991–2020 means. Hatching indicates the warmest seasonal temperatures since 1940. Source: ERA5 reanalysis air temperature data were obtained from the Copernicus Climate Change Service. Click image for larger version. Credit: NOAA’s Arctic Report Card 2025

Sea ice in the Arctic continues to hit new lows: Maximum sea ice extent this winter was the lowest observed in the 47-year satellite record. As sea ice shrinks, the Arctic becomes less reflective, exacerbating climate change as the region absorbs, rather than reflects, more heat from the Sun. Ice on land also continues to melt—the Greenland Ice Sheet lost mass in 2025, as it has every year since the late 1990s.

As the region warms, the Arctic Ocean and associated waterways are changing, too. “Atlantification,” a northward intrusion of warm, salty water from the Atlantic, is altering the Arctic Ocean, leading to decreased winter sea ice and creating conditions for more frequent algal blooms. How this influx of water will affect ecological communities in the Arctic remains one of the biggest unanswered scientific questions about the Arctic, said Igor Polyakov, an oceanographer at the University of Alaska Fairbanks and coauthor of the report.

Data Difficulties

Data included in the report are collected by the Arctic Observing Network (AON), an internationally coordinated system of data observation and sharing.

But obstacles impede the system’s ability to monitor the Arctic, according to report authors. Sparse ground-based observation systems, unreliable infrastructure, limited telecommunications, and satellites operating beyond their mission lifetimes are hindering data collection and sharing. “Persistent gaps limit the AON’s ability to fully support Arctic assessments and decision-making,” the authors write.

Science agencies such as NOAA, NASA, and the National Science Foundation and the Interior Department contribute significantly to AON, but all faced staff and budget reductions in 2025. These changes could affect AON and its ability to publish the Arctic Report Card, “jeopardizing long-term trend analyses and undermining decision-making,” the authors write.

Though the Arctic Report Card team received “great support” from NOAA and the report was successfully published, “there were some difficult moments this year,” Druckenmiller said.

“Data doesn’t interpret itself.”

In particular, the shutdown of climate.gov, the NOAA website that housed most of its climate science information, slowed the team’s ability to create the report’s graphics. The federal shutdown in October and November delayed the processing of key datasets, notably one from NASA that documented surface air temperature.

In addition, the report points out that federal budget proposals for 2026 may affect multiple datasets and observation systems used in the report. The three primary sea ice–observing systems (CryoSat-2, Soil Moisture and Ocean Salinity (SMOS), and Ice, Cloud, and land Elevation Satellite 2 (ICESat-2)) are all operating past their mission lifetime, as well. And in July, the Department of Defense decommissioned its Defense Meteorological Satellite Program, which tracked meteorological, oceanographic, and solar-terrestrial physics in the Arctic and elsewhere.

“When these long-standing data products are decommissioned, you really lose a lot of data continuity, which is really important if you’re going to accurately document long-term trends,” Druckenmiller said.

Losing expert scientists at federal science agencies, labs, universities, and research institutions will likely pose challenges, too, he added. “Data doesn’t interpret itself.”

Indigenous-Led Data Collection

Rapid changes to the Arctic are stressing the human communities there: Permafrost thaw releases potential toxicants into drinking water, wetter weather contributes to flooding, and changes to snowfall and ice affect travel. The remnants of Typhoon Halong brought extreme winds and surging water to Alaska’s southwestern coast in October 2025, flooding communities and forcing more than 1,500 residents to evacuate.

Data give these communities—many of which are majority Indigenous—a better ability to respond to climate change, and a weaker AON could impede flood prediction and community adaptation plans, the report states.

As the availability of federal data and resources remains uncertain, Indigenous-led monitoring networks highlighted in the report have provided another model.

Sentinels from the Indigenous Sentinels Network and two NOAA officials conduct surveys on northern fur seal rookeries on St. Paul Island, Alaska. Credit: Hannah-Marie Ladd, NOAA’s Arctic Report Card 2025

The Indigenous Sentinels Network, for example, is a tribally owned and operated cyber infrastructure system supporting Indigenous-led environmental monitoring. Sentinels collect observational data on a range of environmental systems, from wildlife to coastal erosion to tundra greening. The data collected are governed by the communities that collect them and used locally for decisionmaking, collaborative research projects, and climate adaptation planning.

The Building Research Aligned with Indigenous Determination, Equity, and Decision-making (BRAIDED) Food Security Project, another example of an Indigenous-led monitoring project, tracks mercury in locally harvested foods to ensure food safety. All the samples are processed and tested locally on St. Paul Island in Alaska.

“These are models that can be used for resilience everywhere.”

This type of place-based, community-led monitoring is “foundational to understanding and responding to rapid change” facing the Arctic, said Hannah-Marie Ladd, program director for the Indigenous Sentinels Network and author of the new report.

“Indigenous-led monitoring can, and always has, complemented federal science by providing year-round, place-based observations that are often missing” from short-term field seasons, she said. “[Sentinels] live in these environments, and they can detect changes earlier and interpret them with cultural and ecological context that is often missing when outside entities come into a new relationship with a place.”

Such a framework will become only more valuable as the Arctic, and the rest of the world, warms. “These are models that can be used for resilience everywhere,” Ladd said.

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

Citation: van Deelen, G. (2025), Amid the Arctic’s hottest year, Arctic science faces a data deficiency, Eos, 106, https://doi.org/10.1029/2025EO250482. Published on 16 December 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.

Extreme wildfire events are becoming more frequent globally, a pattern that carries a risk for human health. Inhaling smoke from fires can send small bits of particulate matter into airways, aggravating asthma and decreasing lung function. But another, far less understood danger is hitching a smokey ride alongside these aerosols: fungi.

Researchers are increasingly recognizing how wildfire smoke can scatter microorganisms like fungi into the air. This phenomenon is part of a budding field called pyroaerobiology, explained Leda Kobziar, a wildland fire scientist at the University of Idaho in Moscow who has been studying the relationship between airborne spores and wildfire smoke since 2018.

New research from Kobziar’s team has confirmed that smoke-borne fungal spores can cause lung disease in mice. Her team took smoke samples from wildfires, isolated the fungal species within them, and exposed mice to these samples. Many of the mice soon showed symptoms of lung disease. The team will present its findings on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

Catching Fire

“It was really an unknown that there were living microorganisms in wildland fire smoke. I think most people assumed that it was sterile because it comes from a hot fire.”

Studying the living side of smoke is a relatively new practice. “It was really an unknown that there were living microorganisms in wildland fire smoke. I think most people assumed that it was sterile because it comes from a hot fire,” said Phinehas Lampman, a former wildland firefighter, coauthor on the study, and wildland fire scientist at the University of Idaho.

The first study exploring the problem was published in 2004 by then–high school student Sarah Mims and her father, who used a smoke detector attached to a kite to collect fungal samples and correlate them with smokey days.

While there are more pyroaerobiologists today than there were 20 years ago, there are still many unanswered questions about what, how, and to what effect fungal spores travel with smoke.

For the new study, Kobziar, Lampman, and their team developed drone-based sampling systems to collect fungal samples and record conditions like temperature and humidity in wildfire smoke. Over a period of 4 years, the team conducted more than 100 drone flights into grassland and conifer forest fires across nine different areas, including sites in Utah, California, Kansas, and Florida.

A majority of the sampling was done at prescribed burns intentionally set by firefighters to reduce wildfire hazard. The controlled nature of prescribed burns allowed the researchers to get up close to fires and better maneuver their drones for sampling.

The team found that wildfire smoke from the prescribed burns contained spore concentrations of up to 400,000 spores per cubic meter, 4 times higher than the threshold that has been shown to decrease lung function.

To find out whether the fungal species present in smoke pose a health risk, the team used spores from the smoke samples to grow and isolate fungal colonies. They found 110 unique fungal taxa, 9 of which were identified to be potential human pathogens.

The researchers then exposed mice to these isolated samples. Over the course of a few weeks, the animals developed symptoms of lung disease in response to three different fungal taxa, suggesting that some fungi in wildfire smoke have the potential to negatively affect human health as well.

Exploring Health Impacts of Fungi in Smoke

Prescribed burns typically burn the same biomass as wildfires, so the composition of fungi in the smoke is likely similar. “But wildfires have a very different size footprint and typically generate a lot more power,” Kobziar said, explaining that large natural fires have the potential to generate much more advection of air and carry more diverse microbes.

Clouds of wildfire smoke with large distributions can act as vectors and scatter potentially dangerous fungi into new areas, said coauthor Borna Mehrad, a pulmonologist at the University of Florida in Gainesville.

“As fires become more frequent, this will become a progressively bigger issue. It’s something that we as physicians hadn’t even considered.”

“As fires become more frequent, this will become a progressively bigger issue,” he said. “It’s something that we as physicians hadn’t even considered.”

Despite the concerning finding, it’s important to note that not all fungi dispersed by wildfire smoke are a concern for human health, said Jennifer Head, an epidemiologist at the University of Michigan in Ann Arbor who was not involved in the new research. “The species of fungus matters a lot in terms of what is the risk posed to human health.” She stressed the need for future research to characterize which fires, and where, are most concerning as vectors for dangerous fungi.

Looking forward, the team seeks to differentiate the various causes of lung disease and uncover what proportion of negative health effects are caused by smoke-borne fungi. The team hopes their findings could help protect people on the frontlines of major burns, like wildland firefighters.

“This is really just the opening of the box of discovery,” Kobziar said.

—Alonso Daboub (@AlonsoDaboub), Science Writer

Citation: Daboub, A. (2025), Fungal spores in wildfire smoke could cause lung disease, Eos, 106, https://doi.org/10.1029/2025EO250470. Published on 16 December 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.

During the ninth century BCE, King Mesha reigned over Moab, a kingdom located in what is now Jordan. Details of how King Omri of Israel ruled the Moabites, Mesha’s subsequent rebellion, and numerous construction projects Mesha undertook as monarch were recorded on a slab of stone around 840 BCE.

The Moabite Stone, found in 1868 in modern-day Dhiban, Jordan, and now on display at the Louvre Museum in Paris, tells a story seemingly contemporaneous with one from the biblical Book of Kings, but from a different perspective. Artifacts that illuminate biblical times hold great importance for archaeologists, museums, and collectors—so much that forgeries fetch great sums.

Artifacts from the biblical era are so valuable that in one infamous example, an entire class of reproductions, the Moabite forgeries, was created soon after the discovery of the Moabite Stone. The Moabite forgeries consist of clay vessels, figurines, and other items crafted in the 19th century. Some are inscribed with Phoenician script selected from the real Moabite Stone. The inscriptions on the Moabitica, as the forgeries are called, translate to nonsense, and the clay used to fashion the frauds came not from Jordan but from clays around Jerusalem.

This photograph of Moabitica pottery, a known forgery, features symbols written in Phoenician that translate to nonsense. This particular piece has been sampled for future paleomagnetic analysis. Credit: Published with the permission of the Institute of Archaeology of the Hebrew University of Jerusalem; photo by Mimi Lavi, Conservation Lab. Eos thanks Daphna Tsoran, Curator of the Collection Room at the Institute of Archaeology of the Hebrew University of Jerusalem, for permission to access this object.

The Moabite forgeries and other fakes can be used to validate ways to authenticate archaeological finds. In a pair of studies that will be presented at AGU’s Annual Meeting 2025, Scripps Institution of Oceanography postdoctoral scholar Yoav Vaknin will explore ways to verify archaeological finds using something that’s hard to imitate—Earth’s paleomagnetic field.

A Record in Clay

Earth’s magnetic field, which has both a direction and a strength, changes over time. North and south swap poles every so often. The intensity of the field—how strong it is at a particular location or at a particular time—also rises and falls.

“You can use these changes as a dating tool for archaeology,” explained Vaknin. “But first, you need to know how it changed over time.” To that end, Vaknin and colleagues had previously conducted a study compiling paleointensity measurements of the magnetic field for well-dated antiquities at the time they were produced, painstakingly reconstructing how the intensity changed in and around the Levantine region.

“We can use this reconstruction of the field to date [an] object.” This technique is also how forgeries can be detected.

“Artifacts are known to be really good magnetic records in part because they’re fired to really high temperatures,” said Courtney Sprain, a paleomagnetist at the University of Florida who was not involved in this study. In the kilns and ovens that harden clay, temperatures can reach 1,200°C (2,192°F). At these temperatures, chemical reactions cause new minerals to form, including iron-rich magnetite that locks in the status of Earth’s magnetic field—both direction and intensity—at around 580°C (1,076°F). Because pots don’t remain in place after they’ve been fired, the direction isn’t especially useful. But the magnetic field’s intensity is.

A marked increase in magnetic field intensity, more than twice that of today’s field, took place in the Levant from about 1050 to 700 BCE. Called the Levantine Iron Age anomaly, it has been documented across the region, recorded in artifacts and rocks from Cyprus, Israel, Jordan, Syria, and other locales.

Because the paleointensity timeline has been established for the region, “if we have materials that aren’t well dated, we can use this reconstruction of the field to date [an] object,” Vaknin said. This technique is also how forgeries can be detected.

Real or Fake

The Iron Age overlaps with much of the biblical period, Vaknin said. This is the time when many of the Bible’s stories—like those of King Mesha and King Omri—took place.

This time is an important part of human history, so people want these artifacts. As a result of this demand, Vaknin said, “they’re worth a lot of money.”

If an artifact comes to or from an antiquities market, private collection, or museum without information about the archaeological dig where it was excavated, “we don’t know how it got there,” said Vaknin. “There isn’t a method that’s really 100% secure to say if something is authentic.”

Researchers often disagree in their assessments of authenticity, with debates spilling into the academic literature about whether important items are legitimate or mere imitations.

If the artifact looks like it came from this time but has a magnetic field of today, “then it’s clearly fake.”

Measuring the paleomagnetic intensity of a disputed artifact can help archaeologists determine whether the artifact was made recently or during a time with a distinctly different paleomagnetic field than today’s. For instance, in Vaknin’s work, he demonstrates that forgeries were clearly fired at a time with today’s magnetic field intensity—not at the time of the Levantine Iron Age anomaly. If the artifact looks like it came from an earlier time but has a magnetic field of today, “then it’s clearly fake,” Vaknin said.

With this proof of concept, Vaknin and his colleagues have begun to look at artifacts of unknown authenticity that are under vigorous debate.

One limitation of the method is that it works only for authenticating artifacts from times when the paleomagnetic field was very different from the modern field, Vaknin cautioned. He and his colleagues are addressing that limitation by combining novel modeling and experiments related to how the magnetization of an item of interest can detectably change at low temperatures—the topic of another AGU25 presentation.

“This is one of the really cool examples of where [paleomagnetic] data can help with the study of archeology in general,” said Sprain regarding Vaknin’s work on using paleointensity. “Any artifacts that were from this area [and] from that time period, they have to have this strong magnetic signal.”

—Alka Tripathy-Lang (@dralkatrip.bsky.social ), Science Writer

Citation: Tripathy-Lang, A. (2025), Credible or counterfeit: How paleomagnetism can help archaeologists find frauds, Eos, 106, https://doi.org/10.1029/2025EO250449. Published on 16 December 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.

The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

Yesterday, I posted about the landslide disaster that struck Malalak in Sumatra at the end of November 2025. Unfortunately, that is just a tiny component of the catastrophe that has occurred in this part of Indonesia.

The BGS has used imagery released under the Disaster Charter to map landslides triggered by this event in Sumatra – their map shows a lower estimate of 4,326 landslides, but this is a massive underestimate:-

British Geological Survey map of landslides triggered by the November 2025 rains in Sumatra.

This is a dramatic image, and the BGS have done a great job to compile this map, but it covers just a small part of the affected area (Malalak is not in this part of Sumatra), and the mapping does not capture all of the landslides. For example, the southern banks of Takengon Lake, in the centre of the image, has no mapped landslides. However, this is how that area looked on the 30 November 2025 Planet Labs PlanetScope satellite image (the centre marker is at [4.57347, 96.87513]:-

Landslides on the southern side of Lake Takengon in Sumatra triggered by the November 2025 rains. Image copyright Planet Labs, used with permission, collected on 30 November 2025.

This is a classic situation that I have described repeatedly in recent years – intense rainfall triggering hundreds of thousands of shallow landslides, which then form channelised debris flows. Take a look at the area on the immediate banks of the lake. This is this area as of 28 October 2025 and on 29 November 2025:-

Planet Labs images from 28 October 2025 and on 29 November 2025 (https://www.planet.com/).

Note the devastation that the channelised flows have inflicted on the communities. This pattern is replicated over a massive area of Sumatra. I wonder if this is the largest landslide event on record in terms of the number of individual failures, surpassing even Cyclone Gabrielle in New Zealand.

Loyal reader Alasdair MacKenzie kindly highlighted that there is some footage of the debris flows at Malalak on social media:-

Acknowledgement

Thanks as always to Planet Labs (2025) for their amazing imagery.

Return to The Landslide Blog homepage Text © 2023. 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.

Located in the western portion of the Brazilian Amazon, Terra Indígena do Vale do Javari (Valea do Javari Indigenous Land) is one of the world’s largest continuous patches of pristine tropical rainforest and harbors the world’s highest concentration of noncontacted Indigenous peoples.

The region gained global attention in 2022 with the assassinations of Brazilian anthropologist Bruno Pereira and British journalist Dom Phillips. The murders revealed the increasing pressure locals face in preserving the environmental and cultural integrity of their way of life and staving off the organized crime that often accompanies illegal logging and poaching in the region.

Wildfires are contributing to this pressure, and researchers are using innovative mapping techniques to try to understand their dynamics within the territory and its surroundings. A team of biodiversity and remote sensing experts based in Brazil and the United States will present some of their findings on 16 December at AGU’s Annual Meeting 2025.

Mapping wildfires around the still-pristine region may help identify priority areas for conservation and inform policy planning in forest protection, said coauthor Gabriel de Oliveira, a remote sensing and vegetation dynamics researcher with the University of South Alabama.

“Our goal was to understand whether the forest’s natural resistance to fire has held firm over 4 decades and how pressures in the surrounding landscape might be changing that,” said de Oliveira.

“Vale do Javari is certainly a highly threatened region because it is far from everything and very much at the mercy of organized crime.”

The team used MapBiomas Fire Collection data, which record the annual and monthly mapping of burned areas in Brazil from 1985 to 2024. They supplemented these data with additional satellite-derived thermal information to map where fires have occurred since 1985 inside Vale do Javari and surrounding buffer zones extending 50, 100, and 200 kilometers outward.

Researchers who study fire in the Amazon see this ongoing study as a valuable brick in the growing wall of knowledge about fire in protected lands. “They’re using MapBiomas data to see what has burned and how often it burned,” said Ane Alencar, science director at the Amazon Environmental Research Institute (IPAM Amazônia).

“Vale do Javari is certainly a highly threatened region because it is far from everything and very much at the mercy of organized crime. Any tool or study that reveals the threats facing that Indigenous land is very valuable, so it looks quite interesting,” she added.

Ultimately, de Oliveira hopes the new research will help inform conservation strategies in the area. “If we could detect where fire is already recurring or creeping closer, we could begin to identify zones that deserve urgent attention from policymakers,” he said.

Finding Patterns

Fires have become a growing concern in isolated Indigenous lands across the Amazon.

According to a recent analysis by the Observatory of Isolated Indigenous Groups, the past 25 years of satellite data show that in 2024, more than 10,000 hot spots (burn scars) were detected in Brazil alone. The analysis was conducted between January and September across 67 Indigenous territories and protected areas with isolated groups and represents both a 221% increase above the long-term average and a roughly 50% increase from its previous peak in 2010.

The landscapes of Indigenous and protected areas are typically less disturbed compared with the rest of the Amazon, so an abrupt spike in hot spot activity signals processes that researchers say deserve close attention.

A similar pattern emerges when considering not just the number of hot spots but their scope, the total area burned within Indigenous lands across Brazil. For most of the past decade, that figure remained around 1.5 million hectares per year. But in 2024, during one of the most severe droughts on record, total burned area inside Indigenous territories jumped to about 3 million hectares, an increase of 81%, according to IPAM Amazônia. Nearly a quarter of all area burned in the Amazon in 2024 occurred within Indigenous territories.

For researchers who study territories such as Vale do Javari, these trends are troubling not only because they indicate rising fire pressure but because Indigenous lands play critical roles in ecology and public health. A 2023 study showed that Indigenous territories act as major buffers against wildfire smoke, for instance, preventing large amounts of particulate pollution from reaching more densely populated areas nearby. A 2025 analysis identified Vale do Javari as one of Brazil’s most significant hot spots for future species discovery, meaning that habitat loss there could extinguish biodiversity that scientists have not even documented yet.

Those broader patterns align with what de Oliveira and his collaborators are observing on the ground and in satellite records. Their analysis showed that the forest interior of Vale do Javari remains relatively resistant to burning, but the surrounding landscape has changed markedly. In the 200-kilometer buffer zone, annual burned area has risen sharply in recent decades, with some of the highest values on record appearing in the past 2 years. “The signals are strongest at the edges,” de Oliveira said. “You see repeated fire in certain locations, and those are the places where degradation begins.”

To detect degradation that might not yet appear in traditional deforestation maps, the team also examined thermal anomalies from Landsat and Sentinel data. Deviations in surface temperature, de Oliveira said, can indicate canopy opening or drying under the trees. “A healthy, closed canopy regulates energy very efficiently,” he explained. “But when the canopy thins or fire has passed through multiple times, the ground heats up more. That thermal signature tells us something is happening below the leaves, even before clear-cutting takes place.”

The group validated some of these signals with fieldwork in regions just outside the Indigenous territory. They have not yet worked inside Vale do Javari itself.

The researchers found that small paths, recurring burn scars, and subtle canopy disruptions appear to align with known routes used for illegal logging, poaching, and other forms of encroachment. “It’s not the classic pattern of a large clear-cut,” said de Oliveira. “It’s a much slower, quieter process—fire escaping from pasture or burning the same patch of forest two or three times until it loses its resilience.”

Research as a Conservation Tool

“Repeated fire—especially combined with extreme drought—moves the system toward collapse.”

The gradual erosion of forest health is one of the team’s main concerns. “If a forest burns once, it can recover,” de Oliveira said. “But repeated fire—especially combined with extreme drought—moves the system toward collapse. You may not see deforestation immediately, but the structure and function of the forest are already changing.”

De Oliveira and his fellow researchers hope their maps will serve as a tool for early intervention, particularly in the buffer zones with the highest fire risk. The next step, de Oliveira said, is to work with local and federal agencies to establish targeted conservation strategies that extend beyond Indigenous land boundaries.

“Protection cannot stop at the line on a map,” he added. “We need buffer zone policies and monitoring systems that recognize how these landscapes are connected. Vale do Javari is still a stronghold, but the data show that what happens around it will determine its future.”

—Meghie Rodrigues (@meghier.bsky.social), Science Writer

Citation: Rodrigues, M. (2025), Fire encroaches on one of the Amazon’s most pristine Indigenous lands, Eos, 106, https://doi.org/10.1029/2025EO250467. Published on 15 December 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.

As Earth’s population continues to grow and strain environmental resources, researchers are increasingly examining how humans might one day build settlements beyond Earth. Not many construction materials can withstand extreme temperatures and low-pressure environments like those that exist on Mars, however. New research explores an unconventional candidate: ice.

“This study…is expanding and questioning, How do we support life on other worlds?” said Rafid Quayum, a postbaccalaureate student at Harvard University and a researcher on the project. “Can we come up with a solution that’s environmentally friendly and also inspired by Earth’s systems?”

Ice, Quayum’s team says, offers a rare combination of benefits that can mitigate many of the environmental challenges astronauts would face: It absorbs radiation, transmits visible light, and can create a passive greenhouse effect inside enclosed habitats. That assumes, of course, that astronauts can harvest it.

Icy Habitats

Humans have been building temporary and permanent structures out of ice and snow for centuries. From the igloos and quinzhee of some Inuit peoples in Greenland and the Canadian Arctic to Kamakura in Japan, people have long recognized that ice can retain heat, keep out the elements, and be sourced in many cold environments.

But while ice retains its insulating qualities in environments beyond Earth, it may not be readily available, explained Armin Kleinboehl, a planetary scientist at the Jet Propulsion Laboratory in Pasadena, Calif., who was not involved in the study. Sourcing ice locally, especially on Mars, would be challenging. While Mars’s poles contain abundant ice, their harsh seasonal cycles make them unsuitable for long-term habitats, he said.

Unlike shelters built from regolith, ice domes would allow natural light to filter in, an advantage for both plant growth and human psychological well-being.

“If you were to build a build a habitat in those regions, you would want people to get out before the polar winter sets in,” Kleinboehl said. Instead, mission planners often target the northern midlatitudes, where shallow subsurface ice may be easier to access, he added.

Still, ice has certain advantages as a building material. Unlike shelters built from regolith, the fine layer of planetary topsoil made of dust, soil, and broken rock, ice domes would allow natural light to filter in, an advantage for both plant growth and human psychological well-being, Quayum said.

What’s more, even if surface ice isn’t easily accessible in the regions on Mars where humans might want to build, the resources are abundant on icy worlds like Ceres and Callisto, the researchers noted. Sourcing the ice from other planetary bodies could reduce the energy and cost of transporting materials from Earth.

Keeping Warm in Cold Environments

Quayum’s team modeled hypothetical ice domes that could be built on Mars’s surface, explored techniques to create them, and simulated what the conditions would be like inside. They placed their simulated domes at the midlatitudes of Mars, where ice is less accessible than at the poles but sunlight is more abundant. In these regions, daily temperatures swing from −56°C to −37°C, which is not enough to melt the ice, according to the model.

Removing dust and regolith allows the resulting ice shell to transmit sunlight while acting as radiation shielding.

In addition to temperature, Mars’s atmospheric pressure, which is less than 1% of Earth’s, also presented a challenge. Because liquid water cannot exist stably at such low pressures—it boils and freezes almost simultaneously—the team proposed using vacuum distillation to purify locally sourced ice. With this technique, heated ice vaporizes rather than melts. The vapor can then be captured, condensed into a liquid under high pressure, purified, and refrozen into clear, contaminant-free ice. Removing dust and regolith during this process allows the resulting ice shell to transmit sunlight while acting as radiation shielding, Quayum explained.

In the modeled ice domes, hydrophobic seals reinforced the dome by preventing any interior melted water from seeping into the shell, where it could weaken the ice. An aerogel insulating layer further slowed heat transfer to keep the outer layer below its melting point. Inside the habitat, sunlight warmed the air.

“There will be convection, like on Earth, to mix heat around, which should result in a fairly uniform temperature throughout [the dome],” said Robin Wordsworth, a planetary scientist at Harvard University and a researcher on the project.

The heat from that air then moved outward through the ice by conduction, a process that prevented the shell from losing strength. Temperature models and 3D structural simulations suggest the dome could remain stable at average Martian temperatures of roughly −58°C.

The team will present these results on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

Testing Beyond Theory

The team said that a lot of research is still needed to determine whether ice domes could be a viable habitat for future Martian astronauts. Like Earth, Mars has seasonal variations that could affect the long-term durability of the domes, an effect they hope to investigate further.

To try to move Mars ice habitats beyond theory, the researchers aim to conduct field tests in extreme environments on Earth that mimic Martian conditions, such as the subzero temperatures of Antarctica and low-pressure environments like the Himalayas. If those are successful, structural habitability could eventually be tested on Mars itself.

“It would be something really exciting for scientists to be able to travel to other planetary environments, conduct field work, and be able to stay in habitats…using ice,” said Quayum.

—Olivia Maule (@ocmaule), Science Writer

Citation: Maule, O. (2025), Could future Mars habitats be made of ice?, Eos, 106, https://doi.org/10.1029/2025EO250456. Published on 15 December 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.

Taking the train or subway can be a time and cost-efficient way for city dwellers to commute. But during the summer months, some metro riders risk exposure to extreme heat, the deadliest weather-related hazard in the United States, while walking to and from stations.

A team of researchers at George Mason University in Fairfax, Va., analyzed the surface temperatures of walkways within a 10-minute walk of the three U.S. metro systems with the largest ridership. Then, they considered how socioeconomic factors, such as age and race, and development patterns, such as parking lots and indoor walkways, were related to differing levels of heat exposure.

The project began out of curiosity, said Luis Ortiz, an urban climate scientist at George Mason University. “It combines two of my big passions,” he said. As a longtime urban heat researcher and avid public transit user, Ortiz sought to answer a question from his day-to-day life: “If you’re a pedestrian using public transportation, what does your heat exposure look like?”

Black, Asian, and Hispanic commuters experience higher exposure to extreme heat.

The scientists combined station ridership data and Landsat 8 estimates of surface temperature to map where pedestrian public transit users were most exposed to heat on the New York City Subway, the Washington Metro, and the Chicago “L.” Ortiz will present the results on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

The researchers found that the correlation between socioeconomic and demographic variables and surface temperatures were highest for the Chicago L and lowest for the Washington Metro. One pattern the researchers observed across all three cities is that commuters with minoritized identities, including Black, Asian, and Hispanic commuters, experience higher exposure to extreme heat, said coauthor Alireza Ermagun, a transportation scientist. So, too, do elderly populations and metro users between age 25 and 44.

Researchers analyzed the surface temperatures within a 10-minute walk of a metro station in three U.S. cities. Credit: Luis Ortiz, George Mason University

One result from the Washington Metro system seemed to contradict these correlations: Some of the hottest stations are in relatively wealthy areas of northern Virginia. Researchers attribute the unexpected finding to people driving to metro stations and parking a car. “They have massive parking lots there that get very hot in the afternoon,” Ortiz said.

A Green Solution

Urban planners should use research like this to strategize where to put shade and green space, said Nadav Sprague, an environmental epidemiologist at Harvard University who was not involved in the study. “Having access to shade is very important,” he said.

Many of the walking routes with high heat exposure have very few trees, Ortiz said. He said that trees “solve several of the issues” that cause heat stress by providing shade, reducing heat radiation into the body, and cooling the air.

“The best shade shelters are the trees.”

Transit users agree. “The best shade shelters are the trees,” said Jasper Elysian, a student at the University of Illinois Chicago who takes public transit to school, work, and almost everywhere. When it’s available, Elysian uses shade to combat the heat but said they would like to see more trees near transit stops.

Quantifying heat exposure to understand who is exposed and how is important, Sprague said, because it’s a hyperlocal problem requiring localized solutions. This research “gets at the point that each…place [faces] different implications of climate change.”

To better understand each city’s specific challenges, Ortiz and Ermagun said they want to collect more data on how often people in these cities in different socioeconomic situations use public transit and whether this usage is affected by the heat exposure they endure.

Recognizing that cities and counties have limited budgets, Ermagun hopes the team’s analysis will help decisionmakers identify where funds can be most useful in mitigating climate vulnerability. The ideal audience for this work, he said, is transportation designers.

—Pepper St. Clair (@pepperstclair.bsky.social), Science Writer

Citation: St. Clair, P. (2025), City dwellers face unequal heat exposure en route to the metro, Eos, 106, https://doi.org/10.1029/2025EO250461. Published on 15 December 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.

The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

In the last few days on November 2025, Cyclone Senyar brought torrential rainfall to parts of Indonesia, and in particular to Sumatra. At the time or writing, at least 1,022 people are known to have been killed and 206 more are missing.

One area that has been particularly badly impacted is Malalak, which is located in Agam Regency in West Sumatra – at [-0.39384, 100.27425]. This is a Google Earth image of the town, collected in February 2025:-

Google Earth image of Malalak in Indonesia, collected in February 2025.

Note the presence of the volcanoes close to the town, and the deeply incised river channels. This is a location at risk from channelised debris flows.

Unfortunately, this is a cloudy place, so obtaining good imagery is hard. But on 1 December 2025, Planet Labs captured an image using their PlanetScope sensors that give a sense of what has happened. This is the image:-

Satellite image of Malalak in Indonesia, in the aftermath of the catastrophic debris flows. Image copyright Planet Labs, used with permission, collected on 1 December 2025.

The sources of the landslides in the images remain hidden. However, it is evident is five substantial channelised debris flows that have affected the area, many of which have multiple upstream sources. There are some smaller events too. There is a high level of destruction as many of these landslides have flowed through the urban areas.

Reuters has a gallery of images of the aftermath of the landslides at Malalak, and there is some footage of the aftermath of the events too:-

Hopefully, imagery will become available that gives a sense of the source of these failures. In my mind, to be in a town with multiple channelised debris flows from different directions is hellish. This scenario appears to have occurred in several locations in Indonesia at the end of November.

Acknowledgement

Thanks as always to Planet Labs (2025) for their amazing imagery.

Return to The Landslide Blog homepage Text © 2023. 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 Alaska, winter is more than a season—it is survival. For Indigenous communities in Aniak, St. Mary’s, and Elim, snow and frozen rivers guide travel, hunting, and fishing. But those conditions are becoming less reliable in the Arctic, the fastest-warming region on Earth.

“The spring and the fall seasons are crunching in on the time frame where there’s enough snow and safe conditions to be able to move around,” said Helen Cold, a subsistence resource specialist with the Alaska Department of Fish and Game.

Indigenous communities “know their river better than anyone else in the world.”

With the Arctic Rivers Project, scientists and community leaders are racing to track changes in Alaska’s winters and plan for the future. By combining Indigenous Knowledges with high-resolution climate models, a team is working to build a collection of “storylines” to capture winter shifts and serve as tools for adaptation.

“There’s been a big movement in climate science to use narrative approaches to describe impacts,” said University of Colorado Boulder hydrologist Keith Musselman, who will present the research with his team on 15 December at AGU’s Annual Meeting 2025 in New Orleans. After all, Indigenous communities “know their river better than anyone else in the world.”

Voices from the River

Musselman and his colead, Andrew Newman, a hydrometeorologist at the National Science Foundation’s National Center for Atmospheric Research, leaned on local leadership by creating an Indigenous Advisory Council of 10 regional representatives. The council shaped research questions and ensured Indigenous Knowledges guided methods, data, and interpretation throughout the project.

To understand initial concerns, the research team convened the 2022 Arctic Rivers Summit to hear directly from community members. During the summit, council members emphasized the importance of inclusive planning to address climate change in ways that safeguard both people and ecosystems. In conjunction with the summit, interviews and workshops captured observations of shorter winters, thinner snowpack, midwinter thaws, and hazardous river ice. One respected elder and 15-time Iditarod racer shared that in his lifetime, he has witnessed more intense snowfall events and reduced snow persistence. Some communities also voiced concerns about more frequent coastal storms and shifts in wildfire patterns driven by lightning during dry periods.

Indigenous Knowledge holders shared their knowledge during a participatory mapping workshop in Kotlik, Alaska, as part of the Arctic Rivers Project. Credit: Nicole M. Herman-Mercer, USGS

Such shifts have major consequences, including reduced food security for Indigenous people who rely heavily on the land. Michael Williams, an Aniak tribal advocate and Indigenous Advisory Council member, said these climatic changes “make our hunting practices very dangerous.” Over the past 20 to 40 years, he has observed extreme temperatures in the area and a nearly 50% reduction in ice thickness on nearby rivers—changes that make traveling and hunting mammals, migratory birds, and fish a serious challenge.

“It has changed everything here,” Williams said. “It’s affecting our ways of life.”

Bridging River Wisdom and Climate Data

Researchers compared community observations with data from historical records, satellite measurements, and U.S. Geological Survey sensors to recreate past conditions and generate six climate scenarios for Alaska’s winters from 2035 to 2065. Beyond standard climate indicators like air temperature, the chain of models simulated hydroclimatic patterns such as streamflow, snowmelt timing, river ice dynamics, and fish population conditions.

Records corroborated what communities had observed for years, and the models indicated even harsher changes could be ahead, although northern regions could see increased snowpack as winter precipitation rises. Translating these results into usable guidance requires careful planning. Communities were both concerned and curious when shown initial results, asking to compare conditions across regions to understand what their neighbors were experiencing.

“If we don’t include [Indigenous voices], then we’re dead. We’re good as dead.”

The initial phase of the project, which involved gathering and analyzing information, ended in 2024. But to support effective, accessible communication, the team will continue codeveloping “narratives of change” that weave together datasets, Indigenous Knowledges, and lived experience. They’re also exploring how tools like maps and Facebook channels can help share science with affected communities, with the goal of supporting intuitive, locally led adaptation as climate change reshapes life in Alaska.

Past adaptation strategies have often fallen short in including Native realities, said Cold, who was not involved in the research. She thinks the Arctic Rivers Project’s approach is a step in the right direction toward more inclusive climate planning.

Community leaders echo that sentiment and emphasize the urgency of such efforts. “Mitigation planning has to be ongoing in our communities for the survival of our people,” Williams said. “If we don’t include [Indigenous voices], then we’re dead. We’re good as dead.”

—Cassidy Beach, Science Writer

Citation: Beach, C. (2025), Changing winters leave Indigenous Alaskans on thin ice, Eos, 106, https://doi.org/10.1029/2025EO250466. Published on 12 December 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.

Mangroves are a critical component of many coastal ecosystems, serving as havens for biodiversity, carbon sinks, barriers against storm-driven winds and waves, and bulwarks against erosion. But increasing levels of erosion from sea level rise, lack of freezing, higher-intensity storms, and land development are threatening these vulnerable, valuable ecosystems. The problem is especially poignant in Louisiana, which is losing land to the sea faster than any other state.

New research has found that sand made from recycled glass could help restore coastal mangrove ecosystems near New Orleans, serving as a growing medium for new mangroves and replenishing sediment that has washed away.

“New Orleans is a city of festivals,” said Kathryn Fronabarger, an ecologist and environmental compliance specialist at Tulane University in New Orleans and a researcher on the project. “There is a ton of glass waste in the city—glass beads, glass bottles.”

“At one point, a glass bottle was just thrown on the ground, trashed, discarded, put in a landfill,” Fronabarger said. “Now we’re seeing it used as a substrate in multiple states across the United States to build back parishes, build back communities.”

“When we hold those places together,” she added, “we preserve irreplaceable cultures and identities.”

Reuse, Recycle, Restore

Louisiana has the fastest rate of land loss in the United States, losing 28 square kilometers of coastal wetlands per year. That’s the same as losing an American football field’s worth of land every 100 minutes. Climate change is intensifying storms, and the barrier islands that had softened the storms’ impacts have disappeared under rising seas. This loss of protection has sped up coastal erosion.

“It’s absolutely a positive feedback loop, and if anything, it’s an exponential one,” Fronabarger said. The more land that erodes, the more that is exposed to future erosion. And while mangrove roots are great at trapping and retaining sediment, there still has to be sediment in which they can grow.

“Sediment is running out. Eventually, the solution collapses in on of itself.”

Although local and regional efforts have sought to create artificial reefs and barrier islands to prevent coastal erosion, no statewide programs have truly been effective at holding back the tides.

What’s more, the most common method of restoring eroded coastline, dredging riverbeds and transporting that sediment to the coast, damages river ecosystems, may not be suitable for growing mangroves, and is not sustainable in the long run.

“Sediment is running out,” Fronabarger said. “Eventually, the solution collapses in on of itself.”

Seeking an alternate approach to restoring coastal mangrove ecosystems, Fronabarger’s team looked into whether glass that had been ground down to its original form—that is, sand—could sustain mangrove growth.

The team collected 15–20 black mangrove propagules each from 15 parent plants in Grand Isle in 2023. They transported the propagules to a greenhouse and planted them in three different substrates: sediment dredged from the Mississippi River, recycled glass sand, and a 50:50 blend of both. Some plants were inoculated against fungal growth while others were not.

“I was never so happy to see a null in my life.”

The results surprised the researchers. They found that mangroves grown in glass sand developed the same amount of biomass as those grown in both the dredged sediment and the substrate blend. Inoculating the mangroves increased the plants’ survival rate from 70% to 93% but didn’t change the total biomass.

“I was never so happy to see a null in my life,” Fronabarger joked.

Another surprise was that the glass-grown mangroves had different a root structure than those grown in sediment or blended substrate despite the growing mediums having similar grain sizes. The structural roots of glass-grown mangroves were 26% thicker than those of sediment-grown mangroves, but the fine roots were 55% shorter. That could change the mangroves’ long-term stability in a turbulent coastal environment, the researchers said.

The team published these results in Restoration Ecology in July and will present its findings on 15 December at AGU’s Annual Meeting 2025 in New Orleans.

This illustration depicts how a black mangrove tree might grow in either recycled glass sand or dredged river sediment. In their experiments, the researchers grew mangrove propagules in buckets filled with different substrates and measured the plants’ root properties (extraradial and intraradial) and how inoculating against fungi (mycelium hyphae) affected growth. Credit: AC Frye From Trash to Treasure

“Recycled glass sand is increasingly being identified as a potential cost-effective source of local sediment for these types of projects, and evaluation of plant performance in this type of substrate is certainly needed and novel,” said Eric Sparks, who researches coastal estuary restoration at Mississippi State University. Sparks was not involved with the new research.

“The finding that root length in glass sand was 50% lower than in dredge sand controls really highlights the potential alternations in plant morphology that sediment substrate could influence,” he added. “Differences in root morphology could potentially influence how stable these plants are in the field when exposed to environmental factors like waves.”

“There certainly seems to be a place for recycled glass sand in the coastal restoration toolbox.”

Fronabarger said that the team wants to expand this research and test how glass-grown mangroves behave in wave flume experiments and natural environments. She also hopes to apply these same restoration ideas to other coastal areas experiencing erosion, like the Chesapeake Bay.

Is recycled glass sand a scalable solution to address coastal erosion? It depends on where you go, Fronabarger said. In cities like New Orleans with a lot of glass waste from production or consumption, it can certainly play a role. Other Gulf states like Texas, Mississippi, Alabama, and Georgia are beginning to implement large-scale glass recycling programs, too. But if there is little to no local glass to recycle, the solution is not very cost-effective.

“There certainly seems to be a place for recycled glass sand in the coastal restoration toolbox,” Sparks said.

“It’s a mindset,” Fronabarger emphasized. “It’s about taking what was once considered trash and turning it into restoration practices. I challenge people to think, ‘What have I considered trash, dilapidated or unusable, that actually can be implemented into a circular solution.’”

“It gives me a lot of hope for the future,” she said.

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

Citation: Cartier, K. M. S. (2025), Glass sand grows healthy mangroves, Eos, 106, https://doi.org/10.1029/2025EO250459. Published on 12 December 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.

NASA’s Artemis mission aims to put humans back on the Moon in less than 2 years, and the China National Space Administration plans to follow suit soon after.

As astronauts return to the lunar surface for increasing periods of time, they will need structures that shield them from the Moon’s intense temperature fluctuations. In a day, temperatures can swing from 121°C (249.8°F) to −131°C (−203.8°F).

“Lunar regolith has silicon, it has oxygen elements, it has carbon. We have everything that we need to build. We just have to come up with technologies to utilize it in different ways.”

A creative solution may lie in structures made from “mooncrete,” a concrete analogue made from Moon rocks. Lunar regolith concrete (LRC) can effectively regulate temperature when exposed to dramatic fluctuations, according to new research that will be presented on 15 December at AGU’s Annual Meeting 2025 in New Orleans.

“Lunar regolith has silicon, it has oxygen elements, it has carbon. We have everything that we need to build,” said coauthor Arup Bhattacharya, a building scientist at Louisiana State University in Baton Rouge. “We just have to come up with technologies to utilize it in different ways.”

Making Mooncrete

Lunar regolith is a thick layer of rocks and dust that covers the entire lunar surface. The material is packed with minerals that make it durable, including many elements used on Earth to make concrete. To turn regolith into usable building material, scientists combine it with a binding material like sulfur, which is also available on the Moon’s surface.

Because opportunities to collect Moon rocks are few and far between, all the LRC in existence was created from 40 grams of regolith acquired during the Apollo 16 mission more than 50 years ago. Most experiments today use LRC analogues made from materials available on Earth.

This 3D printed prototype shows a lunar dome habitat that could be made from lunar regolith concrete. Credit: Arup Bhattacharya

To investigate how mooncrete might react to extreme heat and cold, the research team used data from previous experiments on lunar regolith properties to simulate a dome-shaped structure made of LRC.

The simulated structure effectively maintained an indoor temperature of 22°C (71.6°F) when subjected to the harsh lunar temperature swings. In addition, the team found that mooncrete’s insulating effects were amplified when two layers were nested on top of one another, separated by a thin layer of empty space. Heat travels less efficiently in the vacuum of space than through solid materials, so separating layers of LRC with a layer of space makes it harder for either intense heat or intense cold to penetrate the walls.

A Cost-Effective Option

Bhattacharya is “very optimistic” that structures made of lunar regolith will be built on the Moon. Using regolith is also cheaper than other options: Though estimates vary depending on the type of material, sending just 1 kilogram (2.2 pounds) of supplies to the Moon could cost more than $100,000.

“It’s the most abundant material on the Moon, its thermal conductivity is relatively small, and it can produce concrete. I think these structures will definitely be produced.”

“We could save a lot of money if we could use materials found on the Moon to build these structures,” said Adhrit Maiti, a tenth grader at Baton Rouge Magnet High School in Louisiana and first author of the study.

The study fills an important gap in lunar habitat research, said Marcello Lappa, an aerospace scientist at the University of Strathclyde in the United Kingdom who was not involved in the study. Much of the current research focuses on how to collect and process lunar regolith, yet the safety of astronauts depends on how well LRC can handle intense temperature cycles.

“It’s the most abundant material on the Moon, its thermal conductivity is relatively small, and it can produce concrete,” Lappa said. “I think these structures will definitely be produced.”

—Kaia Glickman, Science Writer

Citation: Glickman, K. (2025), Astronauts could live in structures made from Moon rocks, Eos, 106, https://doi.org/10.1029/2025EO250464. Published on 12 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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Want to find schools in satellite images? Researchers say you can spot them by looking at tree cover because schools stand out as rectangular holes in the urban canopy.

Even though access to nature offers a variety of health and social benefits for students, researchers at the University of California (UC), Davis have found that trees on school grounds are declining across California. Declining tree canopy at schools can raise temperatures to dangerous levels, forcing kids to miss out on the benefits of spending time outside.

The researchers also conducted a field study to show how much schoolyard trees influence temperature. “Our motivation is thinking about a kid of around 8 years old playing in the schoolyard with their friends,” said UC Davis urban forestry scientist Luisa Velasquez-Camacho. “It’s very nice, but when you translate this scenario to Sacramento or the Central Valley at 2:00 p.m. in the hottest months, this is a nightmare because they don’t have natural shade.”

“Shade Is King”

To track changes in tree cover at schools, the researchers examined CalFire (California Department of Forestry and Fire Protection) tree canopy maps for more than 7,200 urban schools in California between 2018 and 2022. By quantifying the tree cover, they found that 85% of the schools had experienced tree loss over that time span, and some Central Valley school districts lost 25% of their tree cover. Schools had less than half the tree cover of surrounding urban areas. The results were published in Urban Forestry and Urban Greening.

“I can’t say the results are surprising,” said Kevin Lanza, an assistant professor of environmental and occupational health science at UTHealth Houston who wasn’t involved in the study. He said the findings align with existing studies on urban forestry and noted that trees can be lost in schools to make way for building expansions or because the cost of maintaining them is prohibitive. “Schools are more stressed than ever,” he said.

Scientists collected data such as temperature, radiation, and wind at children’s height. Credit: Emily C. Dooley, UC Davis

The researchers wanted to do more than document the loss of tree cover in schools; they wanted to investigate the health cost of losing those trees. To that end, said Alessandro Ossola, an ecologist at UC Davis and a coauthor of the research, “we took to the streets” in the summer of 2025, spending long days collecting weather data at school playgrounds across California.

The researchers deployed sensors collecting data on air temperature, humidity, radiation, and wind placed at children’s height around each playground. Using these data, they were able to calculate the thermal index, which is a measure of how the environment feels to a human body.

Then, they walked a sensor-laden cart around each playground—racking up over 200 miles (322 kilometers) over the summer—to map out microclimates. The researchers also scanned thermal radiation from common playground surfaces, including dry and irrigated grass, mulch, asphalt, and rubber.

Researchers walked a sensor-laden cart over 200 miles (322 kilometers) this summer while studying California playground temperatures. Credit: Jael Mackendorf, UC Davis

Although the team hasn’t fully analyzed the data yet, early results indicate that rubberized surfaces, often found around playground equipment, are particularly dangerous for reflecting radiation. “It was ridiculous for us to stay out there in the afternoon, even as adults. A kid is much closer to the ground,” Ossola said.

They saw the heat index reach 120°F (54°C) at some schools, and a single tree could drop surface temperatures by as much as 30°F (17°C) compared to direct sunlight. But while the air temperature often wasn’t dramatically different between direct Sun and shade, the thermal index dropped considerably under the shade because of the effects of radiation.

“Shade is king.”

“Shade is king,” said Lanza, and while artificial shade is better than nothing, trees can lower temperatures even more because the water vapor produced by evaporation from the tree leaves absorbs even more heat.

Once trees are lost, planting and maintaining replacement trees until they grow big enough to offer shade are a major hurdle. The researchers suggested that after their full analysis, the results could help guide schools on where to plant new trees and what species of trees will provide the greatest benefits.

Finding a Schoolyard Shade Strategy

Finding ways to manage temperatures is vital for children’s development because if temperatures rise too high, students are forced to remain inside, and for many, recess is their only chance to be in nature. Time spent in nature increases well-being and helps build healthy physical activity habits. UC Davis researchers are also conducting studies that suggest time outside can improve academic performance.

“It’s a matter of reenvisioning trees as an asset that can be budgeted.”

Lanza also noted that “low-income and Black and Latino communities are seeing larger losses of canopy than other communities,” indicating that the impacts of losing time in nature are likely not equitable across populations.

The ongoing work by universities and Green Schoolyards America, a nonprofit partner in this research, aims to use the findings to advocate for strategic investments in trees and other plants to improve students’ time spent outside. “It’s a matter of reenvisioning trees as an asset that can be budgeted,” Ossola said. “If we are negating these opportunities to be close to nature, we are missing the bus, not just for academic outcomes but also in terms of public health in the future.”

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

This news article is included in our ENGAGE resource for educators seeking science news for their classroom lessons. Browse all ENGAGE articles, and share with your fellow educators how you integrated the article into an activity in the comments section below.

Citation: Chapman, A. (2025), California schools are feeling the heat, Eos, 106, https://doi.org/10.1029/2025EO250458. Published on 11 December 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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Source: Geophysical Research Letters

Around the world, phytoplankton in the upper ocean help to cycle key nutrients and regulate Earth’s climate by absorbing carbon dioxide. These photosynthesizing organisms rely on dissolved iron as an essential micronutrient, meaning that when iron levels drop, phytoplankton activity drops, too.

However, the full details of dissolved iron dynamics in the upper ocean are unclear, limiting our understanding of the effects on phytoplankton ecology, nutrient cycling, and the climate.

Now, Bates and Hawco report a new analysis of dissolved iron levels in the upper ocean near Hawaii. Between 2020 and 2023, they collected seawater samples on 21 separate research cruises to Station ALOHA (A Long-Term Oligotrophic Habitat Assessment), a marine research site located 100 kilometers north of Oahu, Hawaii. Back in the lab, they measured levels of dissolved iron and other elements in the samples and compared samples collected during different seasons.

The analysis reconfirmed a well-documented increase in dissolved iron levels at Station ALOHA in the springtime, which is caused by an annual increase in dust carried to the site by winds from Asia. However, the new data also revealed a previously undetected spike in dissolved iron in the winter that could not be explained by dust deposition.

Further analysis of the samples, including measurements of ratios between titanium and aluminum levels, suggested that the wintertime iron peak may have a far more local source: the Hawaiian Islands themselves. It is possible that increased wintertime rainfall boosts runoff of sediment from the islands, which is then transported to Station ALOHA by wintertime swells.

The researchers also used the new data to estimate that despite seasonal fluctuations in concentration, dissolved iron tends to cycle through the upper ocean at a relatively steady rate, with each molecule being replaced about every 5 months. Prior estimates reported turnover rates of anywhere from days to decades.

These findings could help improve understanding of phytoplankton’s various ecological roles, including nitrogen cycling and carbon uptake. (Geophysical Research Letters, https://doi.org/10.1029/2025GL118095, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Wintertime spike in oceanic iron levels detected near Hawaii, Eos, 106, https://doi.org/10.1029/2025EO250462. Published on 11 December 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Solid Earth

The Nankai subduction zone in southwest Japan has produced multiple M8+ earthquakes over the past 300 years, including the 1707 M8.7 Hōei earthquake, the 1944 M8.1 Tōnankai earthquake, and the 1946 M8.1 Nankaidō earthquake. As one of the most extensively studied subduction zones in the world, it has been the focus of numerous Integrated Ocean Drilling Program (IODP) expeditions aimed at improving our understanding of its seismogenic and tsunamigenic behavior.

Faulkner et al. [2025] compile all available laboratory friction data from Nankai Trough scientific drilling samples and integrate them with routine IODP mineralogical analyses. The dataset spans three transects—Kumano, Muroto, and Ashizuri—and includes material from 26 drilling sites. The experiments cover a wide range of slip velocities, from micrometers per second to meters per second, allowing systematic inversion of key frictional parameters.

This compilation shows that the frictional strength of these materials is generally lower than typical Byerlee friction and decreases with increasing clay content. However, the tendency for materials to weaken at higher slip rates—a key condition for earthquake nucleation—does not clearly correlate with clay abundance. Frictional stability analyses indicate a broad spectrum of possible fault-slip behaviors, from slow slip to earthquake-like failure, consistent with observations in nature. Overall, the findings highlight significant natural heterogeneity in frictional properties within a subduction environment and provide new constraints on the frictional characteristics of the shallow Nankai margin.

Citation: Faulkner, D. R., Zhang, J., Okuda, H., Bedford, J. D., Ikari, M. J., Schleicher, A. M., & Hirose, T. (2025). Synthesis of the laboratory frictional properties of a major shallow subduction zone: The Nankai Trough, offshore SW Japan. Journal of Geophysical Research: Solid Earth, 130, e2025JB031613. https://doi.org/10.1029/2025JB031613

—Alexandre Schubnel, Editor-in-Chief, JGR: Solid Earth

Text © 2025. The authors. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Water Resources Research

Using a combination of innovative approaches including observations and models, Platt and Dugan [2025] demonstrate how post-winter storm pulses of road salt lead to high concentrations of toxic substances in runoff water.

Surprisingly, the authors find that dilution is not an effective solution in this case, as discharge and snowfall magnitudes do not significantly impact concentrations. Key factors instead include the amount of road salt applied, land use, groundwater recharge and the base flow index. Thus, under conditions of increased groundwater recharge, road salt is stored in groundwater rather than running off.

However, this is not good news either, as it contributes to legacy effects. The authors use a random forest model with available data to show that smaller, ecologically important streams in the study region are at risk, providing a map of potential regions of road salt lightning strikes.

Citation: Platt, L. R. C., & Dugan, H. A. (2025). Episodic salinization of midwestern and northeastern US rivers by road salt. Water Resources Research, 61, e2024WR039496. https://doi.org/10.1029/2024WR039496

—Stefan Kollet, Editor, Water Resources Research

Text © 2025. The authors. CC BY-NC-ND 3.0
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Scientists of all stripes know the value of collecting and using data to answer research questions about everything from microscopic life to Earth system processes to space physics. But what about the value of data shedding light on peers within their own research communities?

Such data can help scientists better understand the makeup of their field and help them find and connect with colleagues. Compiled into an up-to-date, worldwide directory of researchers in a given discipline, for example, they could help people search for employment opportunities, identify possible collaborators, and suggest potential reviewers for papers and proposals.

These data can also help scientists who are early in their careers or otherwise less visible within their community to gain recognition. And they can be used to identify emerging research areas and trends indicating fields that are thriving or declining—important information not only for scientists themselves but also for funding bodies, oversight committees, and policymakers.

Researchers may have ideas of the approximate size and composition of their community, but hard numbers and comprehensive information are difficult to come by.

Researchers may have ideas of the approximate size and composition of their community based on conferences they attend and journal articles they read, but hard numbers and comprehensive information are difficult to come by. Demographic surveys conducted by professional societies or funding agencies typically provide incomplete information, because not everybody responds to them, they may cover single countries only, and they’re performed infrequently.

The need for workforce demographic data was highlighted in the recent National Academies’ Decadal Survey for Solar and Space Physics, which specifically called (in recommendation 4-1) for U.S. federal agencies to fund collection of this information to help determine the state of the profession.

An underused resource for this data collection is hiding in plain sight: the body of scientific articles produced by the research community. By combining the metadata from these articles with Open Researcher and Contributor IDs (ORCIDs) that uniquely identify authors, it is possible to extract accurate, current information about researchers and their work.

HelioIndex is a new, automated online directory that uses this approach to offer an evolving snapshot of the global community in the field of solar and heliospheric physics (SHP) [Young, 2025]. HelioIndex’s methods are generalizable and can be applied as long as researcher ORCIDs are widely used in research publications, meaning it offers a model for developing similar tools in many other scientific fields.

The Who, What, Where, and How Much of SHP

SHP includes science focused on all aspects of the Sun, from its interior through its atmosphere, out into the solar wind, and all the way to the outer edge of the heliosphere. HelioIndex currently identifies more than 2,300 active SHP researchers in about 60 countries, offering information about these scientists’ geographic distribution, institutional affiliations, areas of expertise (derived from journal article keywords), and publication records.

Figure 1 offers a glimpse of how HelioIndex can be used to consider geographic trends, for example, showing the 10 countries with the most researchers included in the directory. As of July, the United States had the largest share at 29.1%, followed by China and the United Kingdom.

Fig. 1. Tallies of HelioIndex authors located in the 10 most-represented countries in July 2025 and July 2022 are shown here, along with the corresponding percentages of the total number of authors.

Updated twice a month using freely available publication data, HelioIndex always provides the most recent data, but figures from earlier dates can be used to track changes over time. Figure 1 also compares the current numbers of researchers in HelioIndex in the top 10 countries with the corresponding numbers from 3 years earlier and shows how each country’s proportional share of the SHP community has changed during that time.

From July 2022 to July 2025, China, India, and the United States, for example, saw standout increases of 42%, 39%, and 33%, respectively, in their numbers of SHP researchers. The increases contributed to these countries’ growing shares of the global total population of SHP scientists during this 3-year period. Meanwhile, growth in several European countries in the top 10 has been smaller, leading to generally decreased shares of the overall community population.

These numbers demonstrate that overall, SHP as a field is growing. The extent of growth shown in different countries may help early-career scientists to decide where to pursue their careers. The data may also be valuable to national funding bodies for assessing their countries’ competitiveness and determining whether funding levels are appropriate.

An important function of HelioIndex is to enhance the visibility of researchers and their work, especially researchers who have few opportunities for recognition.

At the other end of the scale from the top 10 countries, almost half of the countries are represented in HelioIndex with five or fewer SHP researchers. An important function of HelioIndex is to enhance the visibility of researchers and their work, especially researchers in countries with smaller SHP research communities or who have few opportunities for recognition. Greater visibility can foster new collaborations and research directions and help researchers to prosper and develop research communities in their countries.

The publication and ORCID data used in HelioIndex also enable users to better understand publishing trends within the SHP community. For example, these data allow calculation of the average annual number of first-authored, refereed (FAR) articles per person across all HelioIndex authors.

Knowing this average—currently 0.68, which equates to about two FAR papers every 3 years—is valuable for managing expectations in the field. It may reassure young researchers feeling pressure to publish frequently to advance in their careers that success does not necessarily require such a rapid publishing pace. Meanwhile, if a researcher submits a grant proposal claiming their project will yield 10 FAR papers in a 3-year period, the HelioIndex data suggest that a reviewer considering the proposal would have a right to be skeptical!

Fig. 2. The distribution of career ages—a metric estimated from the publication date of an author’s first first-authored, refereed paper—across all HelioIndex authors, as of July 2025, is currently weighted toward early-career-stage researchers.

A “career age” can also be estimated for each HelioIndex author, using the publication date of their first FAR paper as age 0. This leads to a plot of age distributions (Figure 2), with vertical lines indicating boundaries between early-, middle-, and senior-career categories. The current median career age of all authors in HelioIndex is 9.9 years.

The age distribution and calculated career ages seemingly skew toward younger ages, likely because ORCIDs came into use only in 2009. Whereas most articles published since then will be linked to authors’ ORCIDs and thus included in the HelioIndex data, older articles may be missing for some researchers. However, it is clear from the long tail of the distribution that many senior authors have manually updated their ORCID records.

A Community-Specific Resource

HelioIndex differs from other resources that contribute to professional networking in that it serves a particular research community.

HelioIndex differs from other resources that contribute to professional networking such as ORCID, Scopus, and LinkedIn in that it serves a particular research community.

The procedure for populating HelioIndex begins with scheduled, automatic queries of recent scholarly literature—as captured in NASA’s Astrophysics Data System (ADS) bibliographic database—for articles related to SHP. Articles are likely to be flagged if they, for example, reference prominent review papers, mention a major SHP observatory or spacecraft, or include certain keywords (e.g., “solar flare”).

For each article found by the queries, the names and ORCID identifiers of the authors are gathered and added to a master list of potential HelioIndex authors. As journals generally do not have standard formats for specifying author affiliations, HelioIndex uses custom software to extract institution names and countries from affiliation information through string matching. (Affiliations listed in HelioIndex are updated routinely based upon an author’s most recent publication.)

Authors are included in HelioIndex based on meeting specific keyword criteria and publication criteria. Most journals require authors to assign several keywords to their articles to indicate the area of research to which their work belongs. For inclusion in HelioIndex, it is required that at least 15% of an author’s keywords across all their published articles contain “solar,” “Sun,” or “interplanetary.” This approach has proven effective in distinguishing SHP scientists from scientists in neighboring fields such as stellar physics and magnetospheric physics.

The publication criteria include having at least one refereed article published within the past 3 years, at least one FAR paper in their career, a career age of at least 2, and at least six total points (authorship of a FAR paper counts as two points and coauthorship of a paper counts as one point). These criteria have been chosen so that HelioIndex, at least initially, primarily represents the community of SHP researchers who have earned a doctoral degree and are part of the professional workforce.

Of course, it is difficult to ensure that the directory includes everyone it should in the SHP community. Using the criteria above, for example, it is possible that some early-career researchers—who perhaps haven’t published enough research yet—may be unintentionally excluded. Such issues can be overcome, however, because as the directory’s creator (and part of the SHP community myself), I can readily assess its completeness and adjust query parameters as needed, and I can directly respond to questions about or requests to be added to HelioIndex.

Listed authors can also check their own data, identify omissions or errors, and request not to be listed by name (though in such cases, their geographic and publication data still count toward the general statistics, such as shown in Figures 1 and 2, to maintain completeness).

Scientists Finding Scientists

In addition to providing basic demographic data about the current community of SHP scientists, HelioIndex can serve many other functions. Students and other researchers exploring career options can quickly assess where scientists in the SHP community are concentrated (or not) and use the keyword data to determine with whom their expertise and interests match. They can also browse publication lists to determine scientists’ interests, activity levels, and collaborators.

HelioIndex can also be used to identify potential reviewers for a submitted journal article by matching authors’ keywords to those used in the article. This usage allows an author (or journal editor) to suggest reviewers they may otherwise not have considered, helping diversify the reviewer pool and raise the visibility of peers. This use of HelioIndex may also benefit program managers at funding agencies looking for scientists to sit on review panels.

In just the few months since HelioIndex was publicly announced, traffic to it has been robust and feedback from users has been largely positive. In September and October, for example, the site received a combined 14,651 unique visitors—higher-than-expected traffic considering the modest size of the SHP community. Individuals have commented, for example, that HelioIndex has revealed researchers and research they weren’t previously aware of, and that it helps scientists “grasp the global view of the community of Solar Physics and Heliophysics in the world,” in the words of one midcareer scientist. These early indications suggest that HelioIndex is providing valuable services to many in this community, and seemingly even to many outside it.

The basic mechanics and principles of HelioIndex can be readily applied to develop similar resources for other scientific fields, no matter their size or scope.

Beyond SHP, the basic mechanics and principles of HelioIndex can be readily applied to develop similar resources for other scientific fields, no matter their size or scope, although specific aspects of the literature queries and keyword criteria would need to be adjusted. The initial article search, for example, would need to be modified to cover relevant journals and keywords. The keyword search would need updating too; to distinguish volcanologists from geoscientists in neighboring fields, say, the keyword search could require “volcano.” (Requiring “Earth” as well could help exclude those who study volcanoes elsewhere, such as on Mars or Io.) Author publication criteria could also be revised if, for example, average publishing trends in other fields differ from those in SHP.

As the ADS database is not currently complete for the Earth sciences or other fields outside of astrophysics, an alternative source for publication data, such as Web of Science or Scopus, may be needed. Furthermore, the approach of designing custom software to pull affiliation information from articles into HelioIndex, which worked well for the relatively small SHP research community, may be more challenging for larger fields with many more institutions represented.

HelioIndex demonstrates that scientific article metadata are a rich resource that can be efficiently and effectively mined to complement the sporadic data collected through researcher surveys. With a baseline of consistent and reproducible demographic data, geographic, temporal, and subject matter trends can be identified, providing a variety of valuable information about and for research communities.

References

Young, P. R. (2025), HelioIndex: A directory of active researchers in solar and heliospheric physics, Sol. Phys., 300, 77, https://doi.org/10.1007/s11207-025-02488-y.

Author Information

Peter Young (peter.r.young@nasa.gov), NASA Goddard Space Flight Center, Greenbelt, Md.

Citation: Young, P. (2025), Shining a light on the people behind solar science, Eos, 106, https://doi.org/10.1029/2025EO250457. Published on 10 December 2025. Text not subject to copyright.
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.