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Publication date: 1 November 2025

Source: Advances in Space Research, Volume 76, Issue 9

Author(s): Pei Chen, Zihan Zhou, Xuejian Mao

Publication date: 1 November 2025

Source: Advances in Space Research, Volume 76, Issue 9

Author(s): Kaitlin R. Roberts, Robert A. Bettinger

Publication date: 1 November 2025

Source: Advances in Space Research, Volume 76, Issue 9

Author(s): Byeong-Un Jo, Seungyeop Han, Jaemyung Ahn

Peatlands make up just 3% of Earth's land surface but store more than 30% of the world's soil carbon, preserving organic matter and sequestering its carbon for tens of thousands of years. A new study sounds the alarm that an extreme drought event could quadruple peatland carbon loss in a warming climate.

The ocean's smallest engineers, calcifying plankton, quietly regulate Earth's thermostat by capturing and cycling carbon. However, a new review published in Science by an international team led by the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona (ICTA-UAB) (Spain) finds that these organisms, coccolithophores, foraminifers, and pteropods, are oversimplified in the climate models used to predict our planet's future.

Late at night on 26 September 2024, Hurricane Helene made landfall on Florida's big bend. The physical damage was devastating and well-documented, but an additional, unseen potential impact lurked underfoot.

Madagascar's landscape tells a story of deep time: ancient rifting and geological tilting sculpted the island's dramatic topography and steered its rivers, setting the stage for the evolution of its extraordinary biodiversity.

Salt is an essential nutrient for the human body. But hundreds of millions of years before the first humans, salt minerals once shaped entire landscapes. They even determined where early life on Earth could thrive.

Scientists from the Department of Geography and Environmental Science at Queen Mary University of London have developed a simple model to show how buoyant plastic can settle through the water column and they predict it could take over 100 years to remove plastic waste from the ocean's surface.

Years ago, scientists noted something odd: Earth’s Northern and Southern Hemispheres reflect nearly the same amount of sunlight back into space. The reason why this symmetry is odd is because the Northern Hemisphere has more land, cities, pollution, and industrial aerosols. All those things should lead to a higher albedo—more sunlight reflected than absorbed. The Southern Hemisphere is mostly ocean, which is darker and absorbs more sunlight.

New satellite data, however, suggest that symmetry is breaking.

From Balance to Imbalance

In a new study published in the Proceedings of the National Academy of Sciences of the United States of America, Norman Loeb, a climate scientist at NASA’s Langley Research Center, and colleagues analyzed 24 years of observations from NASA’s Clouds and the Earth’s Radiant Energy System (CERES) mission.

They found that the Northern Hemisphere is darkening faster than the Southern Hemisphere. In other words, it’s absorbing more sunlight. That shift may alter weather patterns, rainfall, and the planet’s overall climate in the decades ahead.

Since 2000, CERES has recorded how much sunlight is absorbed and reflected, as well as how much infrared (longwave) radiation escapes back to space. Loeb used these measurements to analyze how Earth’s energy balance changed between 2001 and 2024. The energy balance tells scientists whether the planet is absorbing more energy than it releases and how that difference varies between hemispheres.

“Any object in the universe has a way to maintain equilibrium by receiving energy and giving off energy. That’s the fundamental law governing everything in the universe,” said Zhanqing Li, a climate scientist at the University of Maryland who was not part of the study. “The Earth maintains equilibrium by exchanging energy between the Sun and the Earth’s emitted longwave radiation.”

The team found that the Northern Hemisphere is absorbing about 0.34 watt more solar energy per square meter per decade than the Southern Hemisphere. “This difference doesn’t sound like much, but over the whole planet, that’s a huge number,” said Li.

Results pointed to three main reasons for the Northern Hemisphere darkening: melting snow and ice, declining air pollution, and rising water vapor.

To figure out what was driving this imbalance, the scientists applied a technique called partial radiative perturbation (PRP) analysis. The PRP method separates the influence of factors such as clouds, aerosols, surface brightness, and water vapor from calculations of how much sunlight each hemisphere absorbs.

The results pointed to three main reasons for the Northern Hemisphere darkening: melting snow and ice, declining air pollution, and rising water vapor.

“It made a lot of sense,” Loeb said. “The Northern Hemisphere’s surface is getting darker because snow and ice are melting. That exposes the land and ocean underneath. And pollution has gone down in places like China, the U.S., and Europe. It means there are fewer aerosols in the air to reflect sunlight. In the Southern Hemisphere, it’s the opposite.”

“Because the north is warming faster, it also holds more water vapor,” Loeb continued. “Water vapor doesn’t reflect sunlight, it absorbs it. That’s another reason the Northern Hemisphere is taking in more heat.”

Curiosity About Cloud Cover

One of the study’s interesting findings is what didn’t change over the past 20 years: cloud cover.

“The clouds are a puzzle to me because of this hemispheric symmetry,” Loeb said. “We kind of questioned whether this was a fundamental property of the climate system. If it were, the clouds should compensate. You should see more cloud reflection in the Northern Hemisphere relative to the Southern Hemisphere, but we weren’t seeing that.”

Loeb worked with models to understand these clouds.

“We are unsure about the clouds,” said Loeb.

“Understanding aerosol and cloud interactions is still a major challenge,” agreed Li. “Clouds remain the dominant factor adjusting our energy balance,” he said. “It’s very important.”

Still, Li said that “Dr. Norman Loeb’s study shows that not only does [the asymmetry] exist, but it’s important enough to worry about what’s behind it.”

Loeb is “excited about the new climate models coming out soon” and how they will further his work. “It’ll be interesting to revisit this question with the latest and greatest models.”

—Larissa G. Capella (@CapellaLarissa), Science Writer

Citation: Capella, L. G. (2025), New satellite data reveal a shift in Earth’s once-balanced energy system, Eos, 106, https://doi.org/10.1029/2025EO250399. Published on 23 October 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 titanic dangers icebergs pose to ships are well documented. Sometimes, however, icebergs themselves can capsize, creating earthquakes and tsunamis or even pushing entire glaciers backward. Most of those dramatic events occur right after the chunk of floating ice splits off from its source, but sometimes icebergs flip over in the open ocean.

Earlier lab experiments using simulated plastic icebergs showed that the energy released in capsize events can rival nuclear weapon blasts. But beyond an understanding that capsize events are likely related to melting induced by ocean warming, knowing why icebergs flip is a question that’s harder to answer. Large variations in iceberg size and shape, along with slow drifting across wide distances, make studying icebergs expensive and challenging.

One solution: make miniature icebergs in the lab and watch them melt under controlled conditions.

“Understanding the mathematics and the physics of what’s going on at a base level is important in order to scale up.”

“We wanted to study the simplest capsize problem we could come up with,” said Bobae Johnson, a physicist and Ph.D. student at the Courant Institute at New York University. She and her colleagues simplified and standardized iceberg shape to a cylinder of pure water ice 8 centimeters in diameter and 24 centimeters long. In their article for Physical Review Fluids, they described how each cylinder flipped several times over the course of a 30-minute experiment.

“It is good to look at these things on smaller scales because even what we were doing in the simplest setting gave us something very complex,” Johnson said. “Understanding the mathematics and the physics of what’s going on at a base level is important in order to scale up.”

From their experiments, Johnson and her colleagues linked the different rates of ice melt above and below the waterline to dynamic changes in the shape of the iceberg—including the location of the center of mass, which makes them flip. Despite the small scale of the experiments, the implications could be enormous.

“Icebergs play a key role in the climate system,” said Sammie Buzzard, a glaciologist at the Centre for Polar Observation and Modelling and Northumbria University who was not involved in the experiments. “When they melt, they add fresh, cold water to the ocean, which can impact currents.”

Icebergs, Soda Pop, and Cheerios

Real-world icebergs range in size from about 15 meters to hundreds of kilometers across, rivaling the size of some small nations. Tolkienesque mountain-like structures (“iceberg” literally means “ice mountain”) split off from glaciers, whereas flat slablike icebergs tend to break off from ice sheets like those surrounding Antarctica.

“An iceberg’s shape determines how it floats in the water and which parts are submerged and which parts sit above the ocean’s surface,” Buzzard said, adding that icebergs change shape as they melt or erode via wind and wave action. But the precise manner of this change is uncertain because in situ measurements are challenging. “If this erosion changes the shape enough that the iceberg is no longer stable in the water, [the iceberg] can suddenly flip over into a position in which it is stable.”

“Even if lab experiments aren’t exactly the same as a natural system, they can go a long way to improving our understanding of [iceberg capsizing].”

Whatever their major differences in shape and size, because they are fresh water floating on salt water, icebergs all exhibit the similar property that roughly 10% off their mass is above water, with the remaining 90% beneath. The similarities provided the starting point for the cylindrical iceberg experiments performed by Johnson and her collaborators.

A sphere or irregular body can rotate in many different directions, but a cylinder with a length greater than the diameter of its circular face floating in water will rotate along only one axis, effectively reducing the problem from three dimensions to two.

Standardizing the shape of the icebergs wasn’t the only simplification the team made. Under natural conditions, ice freezes from the outside in, which traps a lot of air. As icebergs melt, they sometimes release enough trapped air bubbles to make the surrounding water fizz like an opened can of soda pop. This effect can create chaotic motion in samples, so Johnson and collaborators opted to eliminate bubbles entirely in their experiment. To do so, they froze water in cylindrical molds suspended in extremely cold brine and stirred the water to drive residual air out—a process that took 24 to 48 hours for each cylinder.

This video depicts the flow of water beneath the surface of a melting model iceberg. Credit: New York University’s Applied Mathematics Laboratory

Finally, to keep the cylinders from drifting randomly in the ocean simulation tank, the researchers exploited the “Cheerios effect.” Floating cereal pieces tend to group together because of surface tension, so the team 3D printed pieces of flat plastic and coated them with wax. Placing those objects in the tank created a meniscus on either side of the cylinder, keeping it in place so the only motion it exhibited was the rotation they were looking for.

“The ice melts very slowly in the air and very quickly underwater,” Johnson said. In the experiment, that difference resulted in a gravitational instability as the center of mass shifted upward, making the whole cylinder flip. “Every time the ice locks into one position, it carves out a facet above the water and very sharp corners at the waterline, giving you a shape that looks quasi pentagonal about halfway through the experiment. We ran many, many experiments, and this happened across all of them.”

Buzzard emphasized the need for this sort of work. “Even if lab experiments aren’t exactly the same as a natural system, they can go a long way to improving our understanding of [iceberg capsizing],” she said. Every flip of a simulated iceberg could help us understand the effects on the warming ocean and the connection between small occurrences and global consequences.

—Matthew R. Francis (@BowlerHatScience.org), Science Writer

Citation: Francis, M. R. (2025), Melting cylinders of ice reveal an iceberg’s tipping point, Eos, 106, https://doi.org/10.1029/2025EO250390. Published on 23 October 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.

Located on the island of Sicily, in Italy, Mount Etna is one of the world's most active volcanoes. Documentation of its many eruptions stretches back as far as 2,700 years ago, with the most recent occurring in June 2025. The robust seismic, geological, geophysical, and geochemical data from the region are a scientific goldmine for the study of volcanoes.

Author(s): K. L. Baker et al.

A set of experiments in the SQ-n campaign attempts to increase the compression in layered implosions by reducing the design adiabat from 3.0 down to ∼2.6. The experiments utilize nanocrystalline high density carbon ablators driven by a ramped laser pulse drive. Contrary to expectations, the lower de…

[Phys. Rev. E 112, 045214] Published Thu Oct 23, 2025

SummaryTsunami warning systems implemented worldwide rely on the fast characterization of earthquake sources, in particular on the estimation of the moment magnitude Mw. Reliable estimation of Mw typically takes 10 to 20 minutes for large events based on conventional seismic signals. A promising alternative is the use of Prompt Elasto-Gravity Signals (PEGS), which are very low-amplitude gravitational perturbations induced by earthquakes that travel at the speed of light and can be recorded by broadband seismometers at time scales of a few minutes after origin time. We propose here a first implementation of real-time PEGS analysis to enhance the Peruvian earthquake monitoring system by enabling rapid magnitude estimation for large and potentially tsunamigenic earthquakes. We train a graph neural network to recognize the space-time structure of PEGS over a large international set of broadband seismic stations, even when their amplitudes are smaller than the noise level, and to rapidly estimate the magnitude and location of the source. Our results indicate that the PEGS-based system can estimate the magnitude of Mw ≥ 8.2 earthquakes, within 5 minutes after the event’s initiation, with sufficient accuracy for tsunami warning purposes. Simulated real-time tests confirm the viability of the PEGS-based approach for operational early warning, providing robust source estimations of large magnitude events to the Peruvian earthquake monitoring system that are valuable for tsunami warning.

SummaryMagnetotelluric (MT) data inversion seeks to recover resistivity models of the subsurface. Solving the inversion problem is a non-trivial task, as multiple plausible solutions can be recovered due to the non-linearity of the problem. To reduce this non-linearity, we propose a data-driven approach where a 1D cumulative resistance model is estimated from MT data via a direct data transformation. We define the cumulative representation of layered models as the weighted sum of layer thickness divided by resistivity from surface to any depth level, which is the cumulative conductance. Its inverse, cumulative resistance, is directly related to the real part of the impedance computed from MT data. We train a neural network to transform the MT impedance into a resistance model. The corresponding 1D resistivity model is obtained without a priori information. We validate our approach using synthetic and real data, opening the discussion for future developments of this new perspective.

SummaryIn this work, we address the characterization of porosity and water saturation in a synthetic model of a shallow alluvial subsurface using frequency electromagnetic and seismic data. The inversion method employs a Gauss-Newton scheme, where the Jacobian of the merged seismic and electromagnetic data is formulated with respect to the spatially heterogeneous petrophysical parameters. This is made possible by introducing realistic petrophysical relationships, which significantly reduce the number of unknowns in the inverse problem and incorporate a strong prior correlation between the information contained in both data types regarding the subsurface composition. The results obtained show that this Simultaneous Joint Petrophysical Inversion (SiJPI) produces reconstructions with clear improvements compared to Independent Petrophysical Inversion (IPI). Indeed, it greatly enhances the spatial resolution of subsurface mapping, as well as the quantitative estimation of porosity and saturation.

SummaryThe Xiaojiang fault system (XJFS) is located in the southeastern margin of the Tibetan Plateau, which has been considered as an ideal site to explore the traces and effects of past tectonic activity. In this study, we obtain a high-resolution P-wave velocity and azimuthal anisotropy model of the upper crust beneath the XJFS, utilizing the 2D Pg wave tomography method including both station and event depth corrections. The upper crust displays obvious heterogeneity of both azimuthal anisotropy and P-wave velocity underlying the XJFS. The large azimuthal anisotropy beneath the XJFS, especially the regions where several faults interact, suggests the cracks are widely distributed. Generally, the upper crust is featured by several high-velocity bodies separated by low-velocity anomalies. The high-velocity bodies are speculated to be related to the remnant magmatic rocks of the Emeishan large igneous province. The low-velocity anomalies are interpreted to represent fault damage zones which could be attributed to the strike-slip faulting/shearing along the faults and upwelling of deeply-sourced partial melts and fluids. The present tectonic activity in the XJFS is characterized by rigid block extrusion along strike-slip faults in the upper crust, which is consistent with the rigid block extrusion model. We further propose a tectonic model to display the evolution of the upper crust beneath the XJFS, in which the faults and fluids activity plays an essential role.

Pink granite boulders scattered across the dark volcanic peaks of the Hudson Mountains in West Antarctica, have revealed the presence of a vast buried granite body—almost 100 km across and 7 km thick, about half the size of Wales in the UK—beneath Pine Island Glacier.

Nearly 600 years ago, a massive volcanic eruption sent clouds of sulfurous gas and ash high into the atmosphere. The blast known as the 1458/59 CE event was so huge that it triggered decades of cooling, especially in the Northern Hemisphere.

Source: Journal of Geophysical Research: Biogeosciences

Just as the human body contains a multitude of symbiotic microbial companions, most plant species also live alongside microbial friends. Among these companions are mycorrhizal fungi, which help plants gather water and nutrients—particularly nitrogen—from the soil. In exchange, plants provide mycorrhizal fungi with an average of 3% to 13% of the carbon they pull from the atmosphere through photosynthesis and sometimes as much as 50%.

This carbon donation to support mycorrhizal fungi can incur a significant carbon cost for plants. But few groups have investigated how environmental factors such as soil temperature and nitrogen levels influence the amount of carbon flowing from plants to mycorrhizal fungi and how this flow is likely to shift with climate change. To fill this gap, Shao et al. derived a model that they call Myco-CORPSE (Mycorrhizal Carbon, Organisms, Rhizosphere, and Protection in the Soil Environment) that illustrates how the environment influences interactions between plants and mycorrhizal fungi.

When the researchers fed data from more than 1,800 forest sites in the eastern United States into Myco-CORPSE, they obtained some familiar results and also made some new discoveries. The model echoed previous work in suggesting that increasing the abundance of soil nitrogen, for example, through fertilizer runoff, decreases the dependence of plants on mycorrhizal fungi and therefore reduces the amount of carbon plants allocate to their microbial counterparts. But in contrast to previous studies, these researchers found that rising soil temperatures had the same effect of reducing the amount of nitrogen and carbon exchanged by fungi and plants. That’s because warmth accelerates the breakdown of organic material, which releases nitrogen. Increasing atmospheric carbon dioxide levels, on the other hand, will likely increase the reliance of plants on mycorrhizal fungi by increasing the growth rate of plants and therefore increasing their need for nutrients.

The Myco-CORPSE model also replicated observed patterns, showing that the two major kinds of mycorrhizal fungal species (arbuscular and ectomycorrhizal) behave differently: Arbuscular trees tend to donate less carbon to their associated fungi relative to how much ectomycorrhizal trees donate to theirs. The model also found that forests with a mix of both kinds of species typically accrue less carbon from plants than forests with less mycorrhizal diversity.

As forest managers navigate the many stresses that forests face today, promoting a diversity of mycorrhizal species within forests could optimize plant growth while minimizing the carbon diverted to mycorrhizal fungi, the researchers wrote. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009198, 2025)

This article is part of the special collection Biogeosciences Leaders of Tomorrow: JGR: Biogeosciences Special Collection on Emerging Scientists.

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

Citation: Sidik, S. M. (2025), How plant-fungi friendships are changing, Eos, 106, https://doi.org/10.1029/2025EO250397. Published on 22 October 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.