Feed aggregator

In the middle of the Antarctic winter, during months of darkness when temperatures often dip below −30°C, the continent warmed dramatically. In July and August 2024, temperatures in parts of East Antarctica rose by up to 28°C above average and stayed high for more than two weeks. To put that in perspective, a similar anomaly in the UK would push January temperatures into the mid-30°Cs.

The Hayward fault, part of the larger San Andreas fault system, runs 74 miles through the East Bay of the San Francisco Bay Area. The fault is overdue for an earthquake that could cause extensive damage to such a dense population zone.

Rivers worldwide are under severe stress: they are warming, losing oxygen, and as a result emitting increasing amounts of greenhouse gases. Researchers at Karlsruhe Institute of Technology (KIT) have now quantified these global trends over a period of more than two decades. Their results show that rising temperatures and anthropogenic land use are fundamentally transforming river systems, with serious consequences for the climate. The findings have been published in Global Change Biology.

A Florida International University student has exposed a hidden driver of coastal flooding, and it could help improve warning systems for entire communities. Earth and Environment Ph.D. student Dafrosa Kataraihya's latest research, published in Natural Hazards, shows that winds hundreds of miles away are a culprit of coastal flooding.

Changes in nutrient dynamics caused by rising water temperatures and altered stratification patterns due to climate change are promoting the growth of harmful algal blooms. This is the outcome of a new long-term study led by the University of Bayreuth and conducted in the Franconian Lake District. The researchers report their findings in the journal Water Resources Research.

Antonio has spent the past seven years running toward fires that most others run from. A firefighter in the Brazilian Amazon since 2019, he works inside the Chico Mendes Extractive Reserve, one of the most biodiverse places on Earth. But things are changing, and fast. "2024 was the most extreme year for fires," Antonio said. "I had never seen anything like it. The forest burned like dry pasture—it was frightening for those of us who risk our lives to protect it."

The conversion of Brazil's native biomes into agricultural areas has resulted in an estimated loss of 1.4 billion tons of soil carbon. This amount is equal to the emission of 5.2 billion tons of carbon dioxide (CO₂) equivalent, a unit of measurement used to standardize the emission of different greenhouse gases, and was calculated based on data collected from studies conducted over the past 30 years.

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 has terminated the positions of every member of an independent board meant to govern the National Science Foundation (NSF).

The National Science Board directs and approves large funding decisions for NSF’s approximately $9 billion basic science research budget. It is meant to function independently from the federal administration to keep science funding insulated from political pressure and budget cycles.

“I have watched the systematic dismantling of the scientific advisory infrastructure of this government with growing alarm, and the National Science Board is simply the latest casualty.”

In a 24 April notice from the Presidential Personnel Office, all the scientists serving on the board were informed their positions had been eliminated. The emails dismissing board members provided no reason for the termination.

“I am deeply disappointed, though I cannot say I am entirely surprised,” Willie E. May, one of the terminated board members and vice president of research and economic development at Morgan State University in Maryland, told The New York Times. 

“I have watched the systematic dismantling of the scientific advisory infrastructure of this government with growing alarm, and the National Science Board is simply the latest casualty,” he said. 

Ranking member of the House Committee on Science, Space, and Technology Zoe Lofgren (D-CA) called the terminations “the latest stupid move made by a president who continues to harm science and American innovation.”  

 
Related

•  Trump Ousts National Science Board Members 
•  Trump Fires Board Members of Group That Oversees U.S. Science Funding
•  The State of the Science 1 Year On: Academia and Research
•  Trump Fired the Entire National Science Board. Here’s Why That Matters
•  Get Involved: AGU Science Policy Action Center
 

The terminations come after a year that shocked higher education and research budgets. Last year, NSF granted 51% less funding to scientists than the 2015-2024 average and terminated hundreds of active grants. Last May, the Trump administration proposed cutting $5 billion from NSF’s budget, though the proposal was rejected. The president’s budget request for fiscal year 2027 once again proposes to reduce the foundation’s budget by more than half. In a February 2026 meeting of the National Science Board, NSF leadership said the foundation was seeking to reduce grant solicitations.

The Trump administration has also restructured scientific advisory groups elsewhere in the federal government, eliminating 152 federal advisory committees at science agencies, merging all of the Department of Energy’s advisory committees into one and dismantling the Environmental Protection Agency’s research office.

“Without a functional National Science Board in the near term, the agency is left without the guidance and oversight of independent experts, and the public is left without information on how NSF is carrying out its mission,” Gretchen Goldman, president and CEO of the Union of Concerned Scientists, wrote in a blog post about the terminations. 

—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 © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Seeking Solutions to PFAS Pollution Chemical Companies Are Churning Out New PFAS. Where in the World Are They Ending Up? The Persistence of PFAS A Peculiar Polymer Paired with Sunlight Could Remove PFAS Tracing the Path of PFAS Across Antarctica Pollution Is Rampant. We Might As Well Make Use of It.

Per- and polyfluoroalkyl substances (or PFAS) have been widely used in thousands of common nonstick, waterproof, or stain-resistant products since the 1950s. These “forever chemicals” do not break down easily: PFAS make their way into the air, soil, and water, as well as into human and animal bloodstreams and to some of Earth’s most pristine environments. They have been detected even in Antarctica, despite its reputation as a relatively untouched landscape far from the types of products—fast-food wrappers, firefighting foam, nonstick cookware—that contain PFAS.

Research into how PFAS arrive in Antarctica is limited, and most tends to focus on the continent’s coasts, rather than its interior. A new study published in Science Advances aimed to fill some of these gaps by examining PFAS accumulation across a 1,200-kilometer stretch of Antarctica, from the snow pits of Zhongshan Station in East Antarctica to the 4,093-meter peak of Dome A. By examining layers of snow collected from the coast to the interior, researchers sought to better track and understand how PFAS levels vary by location and how these forever chemicals have been able to travel long distances through the upper atmosphere to be deposited in remote regions.

“For substances to get there, they have to be able to transport long distances,” said Ian Cousins, a chemist at Stockholm University and one of the study’s authors. “We know PFAS are very persistent, so that helps. By looking at the patterns of the PFAS contamination in the samples, it gives us clues as to how they’re transported.”

PFAS Arrive by Air and by Sea

Along the 1,200-kilometer route, researchers from the Chinese Academy of Sciences collected 39 snow samples at 30-kilometer intervals, scraping the first few centimeters of snow from the surface to analyze for traces of PFAS.

Zhongshan Station sits near Prydz Bay, and there, researchers collected snow from a 1-meter-deep pit, with samples taken every 5 centimeters. At Dome A, the summit of the East Antarctic Ice Sheet, samples were collected at 10-centimeter intervals from another snow pit; this one was 3 meters deep, providing information about the past several decades of PFAS use.

“It’s quite interesting that we see the historical production record of PFAS in this pit on the top of this mountain in Antarctica,” said Cousins.

PFAS pollution arrives in Antarctica in two ways: via upper atmospheric transport and sea spray. Some PFAS are formed in the atmosphere when volatile precursor chemicals like fluorotelomer alcohols used in textile and paper products break down through reactions with sunlight and oxidants into more stable compounds. The resulting PFAS are later deposited into the snow and ice through precipitation.

Storm winds near the coast create sea spray. “When you have waves, it makes bubbles in the ocean. When the bubbles burst, these sea spray aerosols can be super enriched with PFAS. This has been shown to be a very important transport route,” Cousins said.

To distinguish between sources, researchers measured sodium in the snow to trace the ocean’s salty influence. Sodium levels decreased farther inland, reflecting the fading influence of sea spray toward the interior of the continent. But surprisingly, PFAS concentrations actually increased moving from the coast into the interior.

“That was kind of a bit counterintuitive to me,” explained Cousins, who said he expected PFAS levels to be highest near the coast. “You see the opposite, actually.”

The inland increase is likely explained by higher snowfall totals in the coastal regions, which lead to PFAS concentrations becoming diluted. Inland, where snowfall is lower, even small amounts of PFAS can result in relatively higher concentrations within snow samples.

Additional factors shape PFAS distribution. PFAS levels are higher at the onset of precipitation events when they are rapidly removed from the air. Temperature inversions, too, can trap chemicals. In coastal areas, PFAS are more influenced by sea spray in the winter, whereas stronger sunlight drives the degradation of atmospheric precursors into PFAS in the summer months.

PFAS Presence at Both Poles

This new study also offers implications for the way that PFAS circulate globally. Though industrial activity in the Northern Hemisphere contributes most heavily to PFAS emissions, large-scale atmospheric circulation allows these compounds to reach polar regions. Rapid transport in the upper troposphere may act as an efficient pathway to shuttle PFAS across both hemispheres before they are deposited in the cold, remote regions at both ends of Earth.

“This completes the global picture with agreeing measurements at both poles, solidifying our understanding of the global distribution and drivers of PFAS contamination.”

Even though PFAS levels are higher in the Arctic, both polar regions show similar trends in PFAS concentrations since the 1990s. “It really matches decades of the same records that have been reported from the Arctic,” said Cora Young, an atmospheric chemist at York University, who was not involved in the new study.

“This completes the global picture with agreeing measurements at both poles, solidifying our understanding of the global distribution and drivers of PFAS contamination. The role of CFC [chlorofluorocarbon] replacements, changes in regulation, all of these things are important in the Northern Hemisphere and also the Southern Hemisphere,” said Young.

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

Citation: Owen, R. (2026), Tracing the path of PFAS across Antarctica, Eos, 107, https://doi.org/10.1029/2026EO260129. Published on 27 April 2026. Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Publication date: Available online 20 April 2026

Source: Advances in Space Research

Author(s): M.A. Hashad, A.M. Elazab, N.M. Ragab, T. Sharshar, H.M. Badran

Publication date: Available online 17 April 2026

Source: Advances in Space Research

Author(s): Oliver Hetherington, Livio Carzana, Erik Klein, Pieter Visser, Patric Seefeldt, Jeannette Heiligers

Venice has coexisted with the sea throughout its 1,500-year history, perhaps better than any other city on Earth. Yet over the past century it has flooded increasingly often, as the sea rises and the city itself sinks under its own weight.

SummaryThe Red Sea is one of the youngest ultraslow-spreading ridges on our planet and an ideal place to investigate the transition from continental rifting to oceanic spreading. Within this context, the Zabargad Fracture Zone (ZFZ) stands out as a particularly intriguing region. The ZFZ hosts notable features, including an offset in the Red Sea spreading axis, the Mabahiss Mons submarine volcano, and the Kebrit Deep brine pool. Additionally, this region is seismically active, posing a hazard to nearby coastal communities. Despite previous geophysical studies, few seismic velocity models image shallow subsurface structures in the ZFZ. In this work, we use approximately one year of seismic ambient noise recorded by five broadband stations and 14 ocean-bottom seismometers to estimate the shear-wave velocity structure of the ZFZ. For this, we compute vertical-vertical, radial-radial, and transverse-transverse noise correlations, obtain group- and phase-velocity dispersion curves of Rayleigh and Love waves in the 3 to 12 s period band, and employ transdimensional tomography to estimate 1-D and 3-D isotropic shear-wave velocity models of the ZFZ. Our 1-D velocity model suggests that, on average, the ZFZ crustal structure comprises a 1.5 km thick layer including hemipelagic sediments and evaporites, a 2.8 km thick oceanic basement, and a crust-mantle transition extending from 6.5 to 8 km below sea level. Meanwhile, our 3-D model agrees with previous geological and geophysical observations and reveals new subsurface structures. In particular, it shows low velocity areas to the east and south of Mabahiss Deep that correlate with known sedimentary basins. Moreover, our 3-D model contains a low-velocity area near Kebrit Deep that correlates with a region of low seismic activity and a recently inferred spreading-axis segment. Based on previous evidence of inactive hydrothermal vents, we infer that this low-velocity area indicates higher basement temperatures near Kebrit Deep compared to other areas. Lastly, our 3-D model displays a velocity contrast in the southern ZFZ that correlates with a contrast in free-air gravity anomalies and a gradient in evaporite topography. Based on these observations, we interpret this velocity contrast as a lineament related to folded evaporites. Our findings present new constraints on the crustal structure of the ZFZ and serve as a reference for other young ultraslow-spreading ridges.

A study led by Wageningen University & Research shows that human interventions have significantly changed tides in river estuaries over the past centuries. In many regions around the world, the difference between high and low tide has increased, and the tidal wave is moving inland faster. These changes often appear to have a greater impact than the effects of sea-level rise.

Imagine your favorite sunny beach. Anywhere will do. You look out and see the ocean stretching to the horizon. To a glaciologist, that view is not just water; it's melted ice. Our new study shows that the best case sea-level rise scenarios may now be out of reach. The work is published in the journal Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

A critical ocean current that regulates Antarctica’s climate may have formed only once continents separated and winds aligned with new ocean passageways, according to a new study published in the Proceedings of the National Academy of Sciences of the United States of America.

Today, the Antarctic Circumpolar Current transports more than 100 times as much water as all of Earth’s rivers combined and, critically, insulates the Antarctic Ice Sheet from heat at lower latitudes. A clear picture of the origins of this current can help scientists further understand the relationships between contemporary ocean dynamics, the global climate, and ice formation in Antarctica.

“It’s very interesting to learn more about this current, how it developed, and what role it played in the climate change that was happening at that time,” said Hanna Knahl, a paleoclimatologist and doctoral student at the Alfred-Wegener-Institut in Germany and lead author of the new study.

The Birth of a Current

About 34 million years ago, Earth was undergoing a climatic shift, now known as the Eocene-Oligocene transition, during which atmospheric carbon dioxide decreased and the planet cooled.

Earth’s tectonic plates in the Southern Ocean moved away from each other, opening and deepening bodies of water such as the Tasmanian Gateway and the Drake Passage, which separate Antarctica, Australia, and South America.

For years, scientists hypothesized that the alignment of these newly formed waterways, along with westerly winds, could have channeled ocean water and spurred the formation of the Antarctic Circumpolar Current.

“The exact position of the westerly winds and their relative position to the [ocean] gateways have to click together.”

To test that hypothesis, Knahl and her colleagues simulated conditions of the early Oligocene Southern Ocean with a coupled model that included ocean dynamics, atmosphere and wind patterns, temperatures, ice sheet growth, and precipitation. The research team compared these simulations to data from actual Antarctic sediment cores and scans of the ocean floor.

Results confirmed that westerly winds were necessary for the Antarctic Circumpolar Current to form.

“The exact position of the westerly winds and their relative position to the [ocean] gateways have to click together,” Knahl said.

Joanne Whittaker, a marine geophysicist at the University of Tasmania who was not involved in the new study, was a coauthor of a 2015 study that proposed westerly wind alignment played a role in the formation of the current. Knahl’s study presents a more sophisticated model of the early Oligocene Southern Ocean and is a great next step in the investigation of the current’s origins, Whittaker said.

“They did a really nice job of taking a range of different people’s work and linking it all together,” she said.

Oligocene Understandings

“If you can have a model that works in the past, it’s going to give you confidence that it’s going to work for the future, as well.”

Scientists often use Earth’s past behavior to better understand how Earth systems may behave in the present or future. “If you can have a model that works in the past,” Whittaker explained, “it’s going to give you confidence that it’s going to work for the future, as well.”

The Eocene-Oligocene transition is a key to understanding the relationship between atmospheric carbon, ocean dynamics, and the glaciation of Antarctica, Whittaker said. Knowing how the current’s behavior affected carbon uptake millions of years ago helps scientists model how the present current’s behavior might also affect atmospheric carbon.

In addition to carbon uptake, the new research hints at how changes in westerly winds may influence the advance and retreat of the Antarctic Ice Sheet. Some modeling and proxy data indicate the westerly winds that spurred the Antarctic Circumpolar Current’s formation 34 million years ago have shifted in the past century and may continue to shift in the future. Understanding the role these winds initially played in the current’s development may shed light on the current’s present ability to guard the Antarctic Ice Sheet from warmer air masses.

There are still Oligocene patterns that require more research to sort out, though. For example, modeling in the new study showed interesting asymmetries in the timing of the development of different parts of the Antarctic Circumpolar Current, Knahl said. Scientists know from proxy data and modeling that similar asymmetry exists in the history of the Antarctic Ice Sheet; the ice sheet in East Antarctica began to form about 7 million years before the ice sheet began to form in West Antarctica.

“It could be interesting to see if there’s a connection between the asymmetries that we see here,” Knahl said. “Are they linked, or were they more or less independent?”

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

Citation: van Deelen, G. (2026), Widening channels and westerly winds together formed Earth’s strongest current, Eos, 107, https://doi.org/10.1029/2026EO260126. Published on 24 April 2026. Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

TianQin is a geocentric space-borne gravitational wave detector, which is proposed to detect the gravitational wave by measuring tiny displacements using inter-satellite laser interferometry. However, the space surrounding the orbit and laser links of TianQin is not a vacuum—but filled with plasma, which can bend the laser links and induce pointing accuracy noise in the gravitational wave detection.

Based on a global magnetohydrodynamic model, Zhou et al. [2026] use a ray-tracing method to obtain the laser deflection caused by laser propagation through plasma, and to evaluate the pointing accuracy noise.  The result shows that the laser deflection effect caused by large-scale space plasma distribution under quiet to moderate space weather conditions does not represent a fundamental risk to the TianQin mission. However, during severe space weather events, the laser propagation effect could become a considerable noise in the gravitational wave detection.

This work establishes a connection between space weather and gravitational wave detection. Furthermore, this work raises awareness of the impact of space weather on other high-precision electromagnetic wave measurements in space.

Citation: Zhou, S. W, Su, W., Zhou, S. Y., Li, C. F., & Zhang, J. X. (2026). The pointing error due to laser propagation in space plasma for TianQin gravitational wave detection. Space Weather, 24, e2025SW004784. https://doi.org/10.1029/2025SW004784

—Jiuhou Lei, Editor, Space Weather

Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Thousands of slips in Tairāwhiti in January. The loss of eight lives in the Bay of Plenty later that month. And, days ago, landslides that damaged homes, forced evacuations and blocked roads across the North Island.

SummaryWe present the results of a three-dimensional seismic tomography study of the upper crust beneath a quadrant of the peak ring structure of the Chicxulub meteorite impact crater, Mexico. Reflection and refraction travel-times from a grid of seismic profiles recorded by a 6 km streamer and 48 ocean bottom seismometer stations were inverted to give a well-resolved three-dimensional velocity model to a maximum depth of 6-8 km. The model comprised the thin water layer, a layer of low seismic velocity post-impact sedimentary infill, and the crater basement, which was separated from the fill by the interface representing the top of the crater, defined by normal incidence reflection picks. The crater basement shows a cylinder-shaped feature extending vertically downwards beneath the topographic peak ring to at least 8 km, the depth of resolution of this survey, characterised by slower seismic velocities than in the surrounding rocks at the same depth. This result supports and extends the observations of previous seismic refraction work in the peak ring, and also of scientific drilling, that the material in the peak ring has significantly reduced seismic velocity compared to typical granitic basement lithologies. We used the velocity model to perform a pre-stack depth migration of a key seismic reflection profile. In the best-fitting model presented here the prominent dipping reflector previously identified on seismic reflection profiles, which projects to the outer edge of the peak ring, dips inwards and crosses the low velocity cylinder without an apparent first order contrast in impedance. This result implies that the reflectivity of this dipping reflector is due to a thin, high-contrast layer such as entrapped impact melt or hydrothermal alteration within the overturned structures. We also identify well-imaged slump blocks from the crater rim/inner ring inwards, variations in the height and width of the peak ring, and associated variations in the velocity contrast that characterises the anomaly beneath the peak ring.

The South Asian summer monsoon sustains billions of people today. For a long time, the prevailing scientific view has held that the formation and intensification of the South Asian summer monsoon were primarily controlled by the rapid uplift of the Tibetan Plateau. However, geological records present a long-standing puzzle from the Early to Middle Miocene (25 to 15 million years ago): the South Asian monsoon rainfall was remarkably strong, even though the Somali Jet—the primary wind system transporting moisture—was relatively weak.