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A team of geophysicists and atmospheric scientists at Princeton's NOAA/Geophysical Fluid Dynamics Laboratory and the University of Maryland Center for Environmental Science has found evidence that a warming planet over the past 15 to 20 years has impacted the Atlantic Meridional Overturning Circulation (AMOC) and led to an increase in the number of flooding events along parts of the U.S. Northeast Coast (USNEC).

New research reveals mountain glaciers across the globe will not recover for centuries—even if human intervention cools the planet back to the 1.5°C limit, having exceeded it.

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.

As ocean levels rise, coastal communities face an ever-increasing risk of severe flooding. The existing infrastructure protecting many of these communities was not built to withstand the combined threat of rising seas and severe storms seen in this century.

Over the past few years, hurricanes in the Gulf of Mexico have broken records for their intensity and the speed at which they have evolved from tropical storms into major cyclones. Hurricane Beryl, for example, strengthened quickly in early July 2024 to become the earliest category 5 hurricane on record. A few months later, in October, Hurricane Milton set a record for intensifying from a tropical depression to a category 5 hurricane in a little over 2 days.

Ocean currents that circulate warm water, including the Loop Current, are well-documented contributors to conditions around the Gulf today.

A wealth of scientific research has implicated anomalously warm seas as the primary cause for intensifying storms in the region [e.g., Liu et al., 2025]. Ocean currents that circulate warm water, including the Loop Current, which transports water from the tropics to latitudes farther north, are also well-documented contributors to conditions around the Gulf today.

But how these currents have behaved in the past and how they are responding to climate change, which may have significant implications for coastal and inland communities adversely affected by cyclones, are not entirely clear. An interdisciplinary group of scientists from Mexico and the United States has been collaborating in recent years to find out.

Why the Loop Current Matters

The Loop Current (Figure 1), which enters the Gulf of Mexico from the Caribbean by way of the Yucatán Channel between the Campeche Peninsula and Cuba, is a major pathway for water flowing from the tropics to the high-latitude North Atlantic. It is a key component of global thermohaline circulation (currents driven by differences in temperature and salinity), providing roughly 85% of the Gulf Stream as it flows through the Straits of Florida, up the U.S. East Coast, and across the North Atlantic. This warm, salty water substantially influences the Gulf’s hydrography, as well as North American and European climate.

Recent research has shed light on concerning trends in the Gulf, the Loop Current, and the broader system of ocean currents. For example, warming upper layer waters in the Gulf appear to be exacerbating rising sea levels there [Thirion et al., 2024], and warm-core eddies shed from the Loop Current have been shown to be an important factor in the rapid intensification of recent Gulf hurricanes [Liu et al., 2025] (Figure 1).

Fig. 1. Eddies shed by the Loop Current into the Gulf’s central basin on 21 July 2018 are evident in this depiction of water velocity measurements (U.S. Navy model). These eddies can have either warm or cool cores. They fundamentally influence environmental conditions in the Gulf, from the temperature balance to biological diversity. The presence of warm-core eddies is now being implicated as a cause of rapid hurricane intensification [Liu et al., 2025] and accelerated sea level rise [Thirion et al., 2024].

Slowing of the Atlantic Meridional Overturning Circulation could have far-reaching consequences for the habitability and sustainability of communities all around the Atlantic.

The Loop Current and Gulf Stream together also form an important part of the Atlantic Meridional Overturning Circulation (AMOC). The AMOC is a fundamental component of Earth’s climate system, circulating water north and south through the Atlantic—and from the surface to ocean depths—while also distributing heat and nutrients. With the recently documented slowing of the Gulf Stream [Piecuch and Beal, 2023], concern is growing that a similar change in AMOC, perhaps in response to a warming planet, will upset the global heat balance in the Northern Hemisphere. This sort of change could have far-reaching consequences—from cooling temperatures in northern Europe to rapidly rising sea levels along the U.S. East Coast—for the habitability and sustainability of communities all around the Atlantic.

Since 2017, researchers at the University of Texas Institute for Geophysics (UTIG) and Universidad Nacional Autónoma de México (UNAM) have been collaborating to study the paleoceanographic (i.e., deep-time) history of the Loop Current. Among its activities, this team has gone to sea to acquire high-resolution subseafloor seismic images [Lowery et al., 2024] (Figure 2), generate high-precision seafloor maps, and collect samples from the seafloor.

A broad international effort is also ongoing to understand the Loop Current’s modern complexity [National Academies of Sciences, Engineering, and Medicine (NASEM), 2018], using data from moored instruments, glider measurements across multiple transects in the Yucatán Channel, and modeling (Figure 3). This effort has focused primarily on characterizing today’s Loop Current in the region between eastern Mexico and Cuba, where historical data are limited.

Delving into the Current’s History

A current has been flowing through the Gulf of Mexico since at least the Late Cretaceous (~100 million years ago), and like ocean circulation generally, that current has probably strengthened gradually since then. However, hypotheses about when a current of roughly the size and strength of the modern Loop Current first developed are still debated. Understanding this timing is important because it will implicate either a climatic or nonclimatic (i.e., tectonic) driver for its onset and could therefore inform ideas about whether and how the current will respond to climate change. Whereas this region is now relatively stable tectonically, the state of climate is changing rapidly.

Fig. 2. High-resolution seismic profiles (top) crossing the flank of Campeche Bank/Yucatán Platform, on the west flank of the Yucatán Channel, were collected during a 2022 research cruise. Shown here is profile 1005. The associated line drawing (middle) shows the drifts (i.e., offlapping sediment wedges) that will be targeted for coring (red arrows indicate prospective coring locations), as well as other labeled geologic features [Lowery et al., 2024]. Biostratigraphic analyses of cores will help researchers deduce the history of the Loop Current. Locations of the seismic profiles collected in 2022, including line 1005, are shown on the map (bottom), along with the locations of moored instrument arrays in the Yucatán Strait used by Candela et al. [2019] and of the Deep Sea Drilling Project’s (DSDP) Site 95, where cores were collected in 1970. (H = horizon; MS = marine sequence). Click image for larger version. Credit: Adapted from Lowery et al. [2024]

Building on previous seismic and coring expeditions, the U.S.-Mexico team collected high-frequency, multichannel seismic profiles, multibeam bathymetry, and surficial seafloor sediments (i.e., grab samples) in the Yucatán Channel in 2022 and 2024 (Figure 2) while aboard the UNAM vessel Justo Sierra. The primary imaging target was a series of offlapping sediment drift deposits laid down by the interaction of the Loop Current with the seafloor over millions of years.

Drift deposits are lens-shaped accumulations elongated along the axis of prominent boundary flows like the Loop Current and are promising archives for precision samplings (i.e., piston coring and drilling) and dating. Their fine-grained compositions and rich concentrations of microfossil skeletal remains of benthic (bottom-dwelling) and calcareous planktonic (floating) foraminifera provide valuable chronological markers and proxy records of ocean temperature and salinity, important for reconstructing past oceanographic and climatic conditions. Preliminary observations from samples collected confirm that these skeletal remains are diverse and excellently preserved.

The at-sea data acquisition in the Gulf led to two follow-on workshops. The first, held in Mexico City in August 2023, brought together international investigators to examine the new seismic data from the Yucatán Channel and begin to identify potential sites to propose for future drilling (Figure 2). The second, held in Austin, Texas, in September 2024, focused on integrating the paleoceanographic perspectives of the Loop Current with knowledge of its modern physical oceanography.

As illuminated during discussions at the Austin workshop, physical oceanographic measurements collected across the Yucatán Channel from 2012 to 2016 using moored instrument arrays (Figure 2) established the modern Loop Current’s temporal complexity for the first time [Candela et al., 2019]. The current varied, both spatially and in strength, across that 4-year observation period. Tides play an important role in influencing the current, with both semidiurnal and diurnal components; the strength of transport in the current varies by 5%–10%.

Fig. 3. Temperature (top; yellow is warmer, red to blue is cooler) and salinity (bottom; bluer is more saline, yellower is less saline) data were collected in the Yucatán Channel from 18 January to 20 March 2024 during MASTR, the Mini-Adaptive Sampling Test Run. Credit: Courtesy of A. Knap, Geochemical and Environmental Research Group, Texas A&M University

This work has led to a multiyear set of studies of the Yucatán Channel, coordinated by the U.S. National Academies of Sciences, Engineering, and Medicine [NASEM, 2018], to characterize further modern conditions in the Loop Current. The 2024 portion of this study, called the Mini-Adaptive Sampling Test Run (MASTR), applied enhanced observation capacities, combining near-real-time surface and subsurface data from a simultaneous deployment of instrumented gliders and drifters with background observations from Argo floats and modeling. MASTR observations confirmed the Loop Current’s short-term complexity over short timescales, and they improved the performance of numerical models, including NOAA’s Real-Time Ocean Forecast System, in representing the current’s vertical hydrographic structure [DiMarco et al., 2024] (Figure 3).

Linking the Loop’s Past to Its Present

A key overlap, as revealed by recent research [Lowery et al., 2024], between modern and ancient oceanography in this region involves the seafloor. Current strength plays a vital role in our knowledge of past and present Loop Current conditions because it moves the grains that eventually become the current’s sedimentary archive. Seafloor topography also drives turbulent mixing of seawater in the Gulf, influencing both current flow and eddy formation. It is clear that more work and collaboration are needed to link our understanding of the long-term evolution of the Yucatán Channel seafloor with the Loop Current and its history.

An important, and thus far understudied, question is how the Loop Current responded to past warm climate events.

An important, and thus far understudied, question is how the Loop Current responded to past warm climate events, such as the Middle Miocene Climatic Optimum (~17.5–14.5 million years ago) [e.g., Steinthorsdottir et al., 2021]. Thoroughly addressing that question will require scientific ocean drilling to sample and date key buried sediment layers (i.e., seismic reflectors) in the Yucatán Channel to build a picture of Loop Current history. Planning for this work is underway, with support potentially coming from the U.S. National Science Foundation (NSF), the Scientific Ocean Drilling Coordination Office (which NSF has just established), and the current International Ocean Discovery Programme (IODP3), a partnership among Japan, Europe, and Australia and New Zealand.

Another issue on the minds of researchers studying the Loop Current is how anthropogenically driven changes in the current might negatively affect coastal resiliency and estuarine health along the entire Gulf Coast. Emerging problems include risks from sea level rise [Thirion et al., 2024] and strengthening hurricanes, both of which are directly affected by Loop Current flow.

Community organizations such as the Galveston Bay Foundation in Texas are leading efforts to adapt to changes in coastal environments brought by storms and sea level rise by, for example, building terraces and bulkheads, developing “living shorelines,” and restoring coastal prairie and by communicating with the public. As the global climate continues to warm, more effort is required to enhance coastal resilience. Scientists must partner with community organizations to build public awareness of ongoing, human-induced climate change and to train students, the future leaders in environmental mitigation efforts.

In addition to coastal ecosystems, millions of people around the Gulf region are affected by the Loop Current and its influences on weather and sea level rise. Studying these effects requires active participation and collaboration among researchers and various entities in Mexico and the United States. Indeed, the studies noted here could not have been attempted or completed without such participation—and continued collaboration is essential to continuing to collect crucial data. Unfortunately, despite ongoing efforts from all parties to involve representatives from Cuba in these initiatives, meaningful engagement has yet to be achieved.

Our long-term goal is to continue the tradition of international collaboration in the study of the Loop Current, which demands intensified, sustained scrutiny, considering the enormous stakes as human-induced climate change continues.

Acknowledgments

The August 2023 workshop was funded by the U.S. Science Support Program of the International Ocean Discovery Program. The September 2024 workshop was funded by the Jackson School of Geosciences and the Teresa Lozano Long Institute for Latin American Studies, both at the University of Texas at Austin. We also thank the officers and crew of the Justo Sierra.

References

Candela, J., et al. (2019), The flow through the Gulf of Mexico, J. Phys. Oceanogr., 49(6), 1,381–1,401, https://doi.org/10.1175/JPO-D-18-0189.1.

DiMarco, S. F., et al. (2024), Results of the Mini-Adaptive Sampling Test Run (MASTR) experiment: Autonomous vehicles, drifters, floats, ROCIS, and HF-radar, to improve Loop Current system dynamics and forecasts in the deepwater Gulf of México, paper presented at the Offshore Technology Conference, Houston, Texas, 6–9 May, https://doi.org/10.4043/35072-MS.

Liu, Y., et al. (2025), Rapid intensification of Hurricane Ian in relation to anomalously warm subsurface water on the wide continental shelf, Geophys. Res. Lett., 52(1), e2024GL113192, https://doi.org/10.1029/2024GL113192.

Lowery, C. M., et al. (2024), Seismic stratigraphy of contourite drift deposits associated with the Loop Current on the eastern Campeche Bank, Gulf of Mexico, Paleoceanogr. Paleoclimatol., 39(3), e2023PA004701, https://doi.org/10.1029/2023PA004701.

National Academies of Sciences, Engineering, and Medicine (NASEM) (2018), Understanding and Predicting the Gulf of Mexico Loop Current: Critical Gaps and Recommendations, 116 pp., Natl. Acad. Press, Washington, D.C., https://doi.org/10.17226/24823.

Piecuch, C. G., and L. M. Beal (2023), Robust weakening of the Gulf Stream during the past four decades observed in the Florida Straits, Geophys. Res. Lett., 50(18), e2023GL105170, https://doi.org/10.1029/2023GL105170.

Steinthorsdottir, M., et al. (2021), The Miocene: The future of the past, Paleoceanogr. Paleoclimatol., 36(4), e2020PA004037, https://doi.org/10.1029/2020PA004037.

Thirion, G., F. Birol, and J. Jouanno (2024), Loop Current eddies as a possible cause of the rapid sea level rise in the Gulf of Mexico, J. Geophys. Res. Oceans, 129(3), e2023JC019764, https://doi.org/10.1029/2023JC019764.

Author Information

James A. Austin Jr. (jamie@ig.utexas.edu) and Christopher Lowery, Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin; Ligia Pérez-Cruz and Jaime Urrutia-Fucugauchi, Universidad Nacional Autónoma de México, Mexico City; and Anthony H. Knap, Geochemical and Environmental Research Group, Texas A&M University, College Station

Citation: Austin, J. A., Jr., C. Lowery, L. Pérez-Cruz, J. Urrutia-Fucugauchi, and A. H. Knap (2025), Ocean current affairs in the Gulf of Mexico, Eos, 106, https://doi.org/10.1029/2025EO250190. Published on 19 May 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

The Amazon Basin lost about 27,000 square kilometers of forest each year from 2001 to 2016. By 2021, about 17% of the basin had been deforested.

Changes to forest cover can affect surface albedo, evapotranspiration, and other factors that can alter precipitation patterns. And, as the largest tropical forest on Earth, the Amazon plays a crucial role in regulating climate. Previous studies have modeled the effects of deforestation on precipitation, but most used hypothetical or extreme scenarios, such as complete Amazon deforestation.

About 30% of Brazilian Amazon deforestation occurred in the states of Mato Grosso and Rondônia in recent decades. Liu et al. used the regional coupled Weather Research and Forecasting model to better understand the effects of deforestation on moisture cycles and precipitation in this area. The researchers also embedded a water vapor tracer tool, which can track sources of moisture throughout the water cycle, into the model. To ensure the data they provided to the model realistically represented both deforestation and regrowth, they used multiple satellite datasets.

The team conducted three simulations of the period 2001–2015: two that included the changes in surface properties shown in the satellite data and one control simulation. (The first year of the simulation was used to allow the model to reach equilibrium and was excluded from the analysis.) They found that a 3.2% mean reduction in forest cover during the included 14-year period caused a 3.5% reduction in evapotranspiration and a 5.4% reduction in precipitation. The reduced evapotranspiration caused warming and drying in the lower atmosphere, which then reduced convection; this reduced atmospheric convection explained nearly 85% of the precipitation reduction seen during the dry season, they found.

The researchers point out that their study highlights the key role land cover changes play in the region’s precipitation levels, as well as the importance of forest protection and sustainable forest management practices. They note that the reduced precipitation during the dry season has negative impacts on river flow, energy generation for hydropower plants, agricultural yields, and fire hazard. (AGU Advances, https://doi.org/10.1029/2025AV001670, 2025)

—Sarah Derouin (@sarahderouin.com), Science Writer

Citation: Derouin, S. (2025), Deforestation is reducing rainfall in the Amazon, Eos, 106, https://doi.org/10.1029/2025EO250192. Published on 19 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.

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
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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.