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

Large convective storms, known as mesoscale convective systems (MCSs), are the main drivers of extreme rainfall and severe weather. Accurately representing these storms in Earth system models is essential for predicting their variations and changes.

Feng et al. [2025] apply ten different feature tracking methods to assess MCSs in an ensemble of next-generation global kilometer-scale or storm-resolving simulations. Although different tracking methods produced somewhat different estimates of storm frequency and rainfall in observations, consistent patterns emerged when comparing model simulations with observations. While the models generally capture storm frequency well, they tend to underestimate the rainfall amount from these storms and their contribution to total precipitation, particularly over oceans. Most models predicted heavier MCS rainfall for a given amount of atmospheric water vapor compared to observations. Mesoscale Convective Systems tracking Method (MCSMIP) provides a framework for a more robust evaluation of model performance to guide future model development to improve predictions of storms and their attendant impacts.

Citation: Feng, Z., Prein, A. F., Kukulies, J., Fiolleau, T., Jones, W. K., Maybee, B., et al. (2025). Mesoscale convective systems tracking method intercomparison (MCSMIP): Application to DYAMOND global km-scale simulations. Journal of Geophysical Research: Atmospheres, 130, e2024JD042204. https://doi.org/10.1029/2024JD042204

—Rong Fu, Editor, JGR: Atmospheres

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.

Climate change is melting glaciers and permafrost in the mountains outside of Boulder, Colorado, exposing rocks and freeing up minerals containing sulfate, a form of sulfur, to flow downstream into local watersheds.

New research suggests that the negative effects of the ozone hole on the carbon uptake of the Southern Ocean are reversible, but only if greenhouse gas emissions rapidly decrease.

New research from an international group looking at ancient sediment cores in the North Atlantic has for the first time shown a strong correlation between sediment changes and a marked period of global cooling that occurred in the Northern Hemisphere some 3.6 million years ago. The changes in sediments imply that profound changes in the circulation of deep water currents occurred at this time.

A team led by Prof. Zheng Tianlu and Prof. Wei Jiang from the University of Science and Technology of China (USTC), has developed a novel technique known as All-Optical Atom Trap Trace Analysis.

How sensitively does organic carbon stored in soils react to changes in temperature and humidity? This question is central to a new study now published in Nature Communications.

Source: AGU Advances

Not all extreme weather hazards are sufficiently documented in global databases. For instance, life-threatening high-heat events that fall within climatological norms are often not included in hazard studies, and local or regional flash flooding events frequently go undetected by satellite instruments.

Texas has experienced more than its fair share of extreme weather over the past 20 years, including increasingly frequent flooding and heat events. Using widely accessible daily precipitation and temperature satellite data, Preisser and Passalacqua created a more complete picture of the flooding and heat hazards that have affected the state in recent years.

In consulting rainfall data from 2001 to 2020, the researchers designated a hazardous flood event as one that had an average recurrence interval of 2 or more years—meaning that an event of that magnitude occurred in a given area no more often than every 2 years. They compared their findings to the flooding events documented in the NOAA Storm Events Database and Dartmouth Flood Observatory (DFO) database. Their analysis captured 3 times as many flooding events as the DFO database did and identified an additional $320 million in damages.

The team also broadened the analysis of extreme heat. Many previous multihazard studies considered only heat waves, in which temperature exceeds a percentile, such as the 90th or 95th, for three consecutive days or longer. This study also considered heat events, or periods in which the wet-bulb globe temperature exceeds a 30°C health threshold rather than a given percentile. Using this definition, the researchers determined that between 2003 and 2020, Texas experienced 2,517 days with a heat hazard event—nearly 40% of all days. Heat hazard events affected a total of 253.2 million square kilometers.

The study defined combinations of floods and extreme heat as multihazard experiences. Using the average recurrence interval method, combined with the broader definition of hazards, the researchers found that parts of the state with large minority populations faced higher risk from multihazard events. This suggests that older methods may underestimate both the extent of multihazard risks and their disproportionate impact on marginalized communities, the researchers say. (AGU Advances, https://doi.org/10.1029/2025AV001667, 2025)

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

Citation: Owen, R. (2025), Scientists reveal hidden heat and flood hazards across Texas, Eos, 106, https://doi.org/10.1029/2025EO250191. Published on 16 May 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.

This article originally appeared on Inside Climate News, a nonprofit, non-partisan news organization that covers climate, energy, and the environment. Sign up for their newsletter here.

For the first time, scientists have mapped groundwater variables nationally to understand which aquifers are most vulnerable to contamination from orphan wells.

Oil and gas wells with no active owner that are no longer producing and have not been plugged are considered orphan wells. These unplugged wells can create pathways for contaminants like hydrocarbons and brine to migrate from the oil and gas formation into groundwater zones. Plugging a well seals off these potential pathways.

The researchers found that 54 percent of analyzed wells are within aquifers that supply 94 percent of groundwater used nationally.

USGS scientists Joshua Woda, Karl Haase, Nicholas Gianoutsos, Kalle Jahn and Kristina Gutchess published a geospatial analysis of water-quality threats from orphan wells this month in the journal Science of the Total Environment. They found that factors including large concentrations of orphaned wells and the advanced age of wells make aquifers in Appalachia, the Gulf Coast and California susceptible to contamination.

Using a USGS dataset of 117,672 documented orphan wells nationwide, the researchers found that 54 percent of the wells are within aquifers that supply 94 percent of groundwater used nationally.

“No matter where you live across the nation, you can go look at what’s happening in your backyard, how your aquifers compare to other aquifers and what the threats are,” said Gianoutsos.

Orphan Wells Pockmark Major U.S. Aquifers

The researchers mapped the locations of orphaned wells over principal and secondary aquifers using Geographic Information Systems datasets. They then analyzed the aquifers based on factors that could contribute to vulnerability to groundwater contamination, such as the average age of the orphan wells.

Older wells were subject to less regulation and are more prone to failure. The authors found that Pennsylvanian aquifers, which span several Appalachian states including Pennsylvania, present the “maximum confluence” of risk factors. The first oil wells in the country were drilled in Pennsylvania. Orphan wells can be over 100 years old and located near coal seams and residential water wells.

The Gulf Coast aquifers, including the Coastal Lowlands aquifer system, which stretches from Texas to the Florida Panhandle, were found to be susceptible in part because wells are located in areas like wetlands and open water that are more prone to contamination.

Credit: Inside Climate News

The analysis also considered the rates of pumping from each aquifer. That led them to the California Coastal aquifers and the Central Valley, where a high density of old orphan wells overlaps with highly urbanized areas and intensive groundwater use for agriculture.

The researchers found that the Ada-Vamoosa aquifer, in central Oklahoma, has the highest concentration of orphan wells per square mile of any principal aquifer in the country.

The authors note the paper is not an analysis of the amount of groundwater contamination from orphan wells or the number of leaking orphan wells. But they suggest that policymakers and researchers could use it as a basis to target aquifers for additional investigation.

“This could be a good starting point if someone wanted to do a local investigation,” said Woda.

Gianoutsos noted that the active list of orphan wells is changing as research into orphan wells and well plugging advances. He said some 40,000 orphan wells have been added to the national list since their dataset was created. Another approximately 10,000 orphan wells have been plugged in that time.

“The threats are still there,” he said. “Just as we discover more wells, we discover additional threats.”

The research was part of the U.S. Department of the Interior Orphaned Wells Program Office through the Bipartisan Infrastructure Law.

Parts of Pennsylvania Look Like “Swiss Cheese” from Drilling

A 2011 Ground Water Protection Council study found that orphan wells caused 41 groundwater contamination incidents in Ohio between 1983 and 2007.

Orphan wells have been linked to groundwater contamination in states including Pennsylvania, Ohio and Texas. A 2011 Ground Water Protection Council study found that orphan wells caused 41 groundwater contamination incidents in Ohio between 1983 and 2007. The study found orphan wells and sites caused 30 groundwater contamination incidents in Texas between 1993 and 2008.

The Pennsylvania Department of Environmental Protection (DEP) has reported several recent cases of orphan wells contaminating groundwater. An orphan well in Vowinckel in Clarion County contaminated a family’s drinking water before it was plugged last year, according to the DEP. Another orphan well in Shinglehouse, in Potter County, was plugged by DEP in 2024 with emergency funds after a homeowner reported contamination of their water well.

John Stolz, a professor of environmental microbiology at Duquesne University in Pittsburgh, has researched how fluids from oil and gas wells can migrate underground with unintended consequences.

We are going to have greater periods of drought, and these water resources are going to become far more valuable.”

Stolz said some of the wells in Pennsylvania are so old they were cased with wood or metal, unlike the cement that has been standard for decades. He said the wooden casings have often deteriorated completely. He said conventional drilling and more recent fracking have left much of Pennsylvania “looking like Swiss cheese.”

“It’s good to see a study that focuses on the water resources,” he said in response to the USGS study. “We are going to have greater periods of drought, and these water resources are going to become far more valuable.”

Stolz is studying a “frack-out” in the town of New Freeport in southwestern Pennsylvania. An unconventional well being fracked communicated with an orphan well over 3,000 feet away, forcing fluids to the surface. Residents of the town resorted to drinking bottled water, according to NBC News.

“The industry refuses to admit this stuff happens,” he said. “The reality is it happens on a somewhat regular basis.”

—Martha Pskowski (@psskow), Inside Climate News

Source: Journal of Geophysical Research: Oceans

In high-latitude Arctic fjords, warming seas and reduced sea ice are boosting seaweed growth. This expansion of seaweed “forests” could alter the storage and cycling of carbon in coastal Arctic ecosystems, but few studies have explored these potential effects.

Roy et al. present a snapshot of the carbon dynamics of seaweed in a fjord in Svalbard, a Norwegian archipelago in the High Arctic, highlighting key comparisons between different seaweed types and between various fjord zones. The findings suggest that warming-driven seaweed growth could lead to the expansion of oxygen-deficient areas in fjords, potentially disrupting local ecosystems.

A team from the National Centre for Polar and Ocean Research in Goa, India, led the Indian Arctic expeditions in 2017, 2022, and 2023. On these expeditions, researchers collected 20 seaweed samples and 13 sediment samples from a variety of locations across Kongsfjorden, a nearly 20-kilometer-long fjord in Svalbard. Then they analyzed the signatures of stable carbon isotopes and lipids (biomolecules made mostly of long hydrocarbon chains) in the seaweed samples.

They found that red, green, and brown seaweeds had different stable carbon isotope fingerprints, reflecting their distinct ways of obtaining carbon from their surroundings. However, the different seaweeds had similar lipid signatures, suggesting that they developed similar lipid synthesis processes in their shared Arctic fjord environment.

The researchers also detected differences in carbon isotope and lipid signatures in sediments from different parts of the fjord. These data suggested that inner-fjord sediments may contain organic matter from a variety of sources, including seaweed, fossilized carbon, and land plants imported by melting glaciers or surface runoff, whereas organic matter in outer-fjord sediments has a larger proportion of seaweed lipids.

Notably, sediment samples collected beneath areas of high seaweed growth showed chemical evidence of low-oxygen conditions, possibly because of microbes consuming oxygen while feeding on seaweed. If these microbes are the cause of the low-oxygen conditions, continued warming-driven growth of seaweed forests could lead to expansion of oxygen-starved zones in Kongsfjorden and other High Arctic fjords, potentially destabilizing these ecosystems, the researchers say. (Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2024JC021900, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Seaweed surges may alter arctic fjord carbon dynamics, Eos, 106, https://doi.org/10.1029/2025EO250187. Published on 16 May 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.

Noctilucent or night-shining clouds are rare, high-altitude clouds that glow with a blue, silvery hue at dusk or dawn when the sun shines on them from below the horizon. These ice clouds typically occur near the North and South Poles, but are increasingly being reported at mid- and low latitudes. Observing them helps scientists better understand how human activities may affect our atmosphere.

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

Using recent improvements in our understanding of volcanic emissions, as well as comparisons to ice core measurements of non-sea-salt sulfur, Fuglestvedt et al. [2025] developed revised estimates of the emissions of the Eldgjá eruption. These sulfur and halogen emission estimates were incorporated in an atmosphere/climate model simulation of the 10th century.

The resulting predictions show higher aerosol optical depth and more cooling during the eruption than predicted previously. In addition, the simulated effects on the ozone layer show depletions related to halogen emissions. The larger amount of cooling improves the comparison to tree-ring proxies of temperature. The work demonstrates that improved emissions resolve past disagreements between the simulated cooling from an atmosphere/climate model and the tree-ring based records of temperature, providing new insight on the consequences of a volcanic eruption 1,000 years ago.

Citation: Fuglestvedt, H. F., Gabriel, I., Sigl, M., Thordarson, T., & Krüger, K. (2025). Revisiting the 10th-century Eldgjá eruption: Modeling the climatic and environmental impacts. Geophysical Research Letters, 52, e2024GL110507. https://doi.org/10.1029/2024GL110507

—Lynn Russell, Editor, Geophysical Research Letters

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.

Author(s): Haidar Al-Naseri and Gert Brodin

For many purposes, classical plasma dynamics models can work surprisingly well, even for strong electromagnetic fields, approaching the Schwinger critical fields, and high frequencies, approaching the Compton frequency. However, the applicability of classical models tends to depend rather sensitivel…

[Phys. Rev. E 111, 055205] Published Fri May 16, 2025

Scientists know that changing tree leaves can indicate when a nearby volcano is becoming more active and might erupt. In a new collaboration between NASA and the Smithsonian Institution, scientists now believe they can detect these changes from space.

Warming in the Arctic is intensifying methane emissions, contributing to a vicious feedback loop that could accelerate climate change even more, according to a new study published in Nature.

Small things matter, at least when it comes to ocean features like waves and eddies. A recent NASA-led analysis using data from the SWOT (Surface Water and Ocean Topography) satellite found that ocean features as small as a mile across potentially have a larger impact on the movement of nutrients and heat in marine ecosystems than previously thought.