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Communities around the world have adapted to live on the year-round frozen soil of frigid environments, such as in the Arctic. However, rising temperatures have introduced a new challenge: What happens when the ground under houses and roads begins to melt?

In a strong El Niño winter, normally dry regions can suddenly drown in rain. NASA notes that "typically dry regions can experience nearly two times as much rain during a strong El Niño." Indeed, the blockbuster El Niños of 1982–83 and 1997–98 unleashed record-breaking California storms and unusually mild Northeast winters. These far-reaching effects—atmospheric "teleconnections" linking the tropics to North America—arise because Pacific warming steers the jet stream south and east.

Clear skies are important for astronomers—not just here on Earth but also on the alien planets they are looking at.

For the past 20 years, scientists studying exoplanets have been literally blinded by fog. Many “hot Jupiters” (massive gas giants orbiting extremely close to their host stars) are constantly wrapped in clouds. This overcast condition acts like a fogged-up window, blocking telescopes from getting a clear reading of the planets’ true composition.

Astronomers using the James Webb Space Telescope (JWST) have now lifted the fog veil by using a novel observation technique published in Science. The technique was used to analyze data from WASP-94A b, an exoplanet nearly 700 light-years away discovered about a decade ago. The scientists were able to detect and account for atmospheric clouds on WASP-94A b by analyzing the planet’s sunrise and sunset zones separately as it crossed in front of its host star.

“It’s almost like we were able to part the clouds and figure out what’s going on three-dimensionally with this planet.”

“It’s almost like we were able to part the clouds and figure out what’s going on three-dimensionally with this planet,” said study coauthor David Sing, a planetary scientist at Johns Hopkins University.

WASP-94A b is so close to the star that it is tidally locked, meaning its rotation has stopped and the same side always faces the star. This creates extreme temperature variations across the planet. While the dayside reaches torrid temperatures well above 1,600 K, the night hemisphere is about 450 K colder. These milder conditions on the dark side allow clouds made of magnesium silicate, a common mineral found in Earth’s rocks, to condense.

This extreme thermal variation drives powerful winds that circulate air throughout the atmosphere, carrying cloud-filled colder air from the nightside over to the dayside. The clouds don’t last long, though. Like morning fog dissipating in the Sun’s warmth, the silicate clouds of WASP-94A b evaporate shortly after they hit the scorching dayside. Because the planet’s weather patterns are locked in place by its synchronized rotation, the morning edge of the planet, where the winds move from nightside to dayside (what we view as the leading edge of the transit from Earth), is permanently overcast, while the evenings (the trailing edge) remain always clear.

Timing Is Everything

The key to this observation was not so much where to look, but when. From our vantage point, WASP-94A b crosses right in front of its star, allowing the researchers to capture the precise moments when the giant planet begins its transit and when it finally moves beyond the edge of the star. As starlight filtered through WASP-94A b’s atmosphere, astronomers separately measured its leading and trailing edges (also known as terminators, or limbs) at the times when the planet began and concluded its transit. By analyzing how the spectral signatures changed between these two phases, they were able to reveal the differences between the morning and evening hemispheres.

These measurements require extreme precision. “As the planet is going in front of the star, you have to measure it in that very short time where only part of the planet is blocking the star,” Sing said. “In only about 10 minutes, you have to get the spectra of a planet, which is really hard because planets are faint and the signals are small. We really needed JWST, the largest telescope in space, to be able to make that measurement that quickly.”

What unfolded was a totally unprecedented view of an exoplanet. “What we found was really surprising,” Sing said. “All of the clouds were basically piled up on the morning terminator, while the evening terminator, which is hotter, was clear.”

The team also realized that the clouds were floating much higher up than anyone anticipated—way above the stratosphere—and were made of surprisingly large particles. This suggests the atmosphere undergoes far more violent, turbulent mixing than previously predicted.

“It’s pretty clear they are magnesium silicate clouds,” Sing said. While scientists expected that this material would form clouds on these planets, “we haven’t really been able to show that before.”

“The study is a great example of how we can measure and understand the multidimensional and complex nature of exoplanet atmospheres,” said Hannah Wakeford, an astrophysicist at the University of Bristol in the United Kingdom who was not involved with the study. “Clouds are the most important part of a planetary atmosphere, and they play a major role in the amount of energy coming into and leaving the planet.”

A Different Composition

Breaking through the cloud barrier allowed researchers to see the true chemical makeup of this world. Previous observations of exoplanet atmospheres using the Hubble Space Telescope had to rely on an “average spectrum,” blending the composition of both sides of a planet on a single profile, mostly because Hubble can’t get a planet’s spectra as quickly and precisely as JWST does. As a result, researchers were getting wrong readings of essential components, such as the amounts of oxygen, carbon, and other heavy elements.

“That kind of rewrites much of what we’ve been learning with Hubble over the last few decades.”

These average spectrum readings meant that models were predicting that WASP-94A b had a heavy metal abundance up to 100 times greater than our Sun. By separating the limbs, the new observations have revealed that this number is actually closer to 10. “That kind of rewrites much of what we’ve been learning with Hubble over the last few decades,” Sing said.

Sing and his colleagues think the same findings could apply to countless other hot Jupiters. In fact, there’s nothing special about WASP-94A b, except that it has the right geometry. “Not all hot Jupiters will be good candidates to reveal this limb asymmetry,” Sing said. “For instance, if a planet just grazes across the bottom of the star during transit, you won’t be able to cleanly separate the two sides out.”

Getting a better handle on what hot Jupiters are made of is a significant step for planetary science and could also help refine atmospheric circulation models on Earth and beyond, Sing said.

Apart from WASP-94A b, the team applied the same method to eight other hot gas giants, discovering hints of similar cloud cycles in two of them: WASP-39 b and WASP-17 b. The team plans to continue studying similar planets with JWST, including a gas planet in the habitable zone of its host star.

—Javier Barbuzano (@javibar.bsky.social), Science Writer

Citation: Barbuzano, J. (2026), A hot Jupiter’s cloudy mornings and clear evenings provide clues to its chemistry, Eos, 107, https://doi.org/10.1029/2026EO260195. Published on 16 June 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.

Source: AGU Advances

This is an authorized translation of an Eos article. 本文是Eos文章的授权翻译。

过去25年间，印度季风发生了变化。印度西北部地区的降雨量比以往大幅增加，而印度-恒河平原则因降雨不足而面临干旱。

超过10亿人依靠季风维持南亚地区的经济稳定；这一气候系统的进一步变化可能导致大范围的困境。由于常用的气候模型无法捕捉到已经发生的季风变化，科学家们一直难以预测这种气候模式未来的发展趋势。

Mahendra等人指出，现有模型既不能充分反映大西洋温度的变化，也不能充分反映这些温度变化与全球其他地区气候模式之间的联系。因此，耦合模型往往无法预测这种季风转变。

具体而言，目前的气候模型缺乏将有关冷斑(cold blob)的信息纳入其中的能力，冷斑是位于格陵兰岛南部的一片冷水区域。当研究人员将冷斑添加到气候模型结果中时，他们发现，它可以改变急流，使其将水汽输送到印度西北部，同时阻止其他地区风暴系统的形成。这正是季风模式中观测到的那种转变。当一个大尺度风型以这种方式阻止较小尺度天气型的形成时，这种机制被称为正压调控机制(barotropic governor mechanism)。

这种正压调控机制也解释了为什么近年来全球中纬度地区观测到了更多的风暴活动。作者指出，这些结果强调了在构建气候模型时，将全球不同地区的各种过程联系起来的重要性。

—科学撰稿人Saima May Sidik (@saimamay.bsky.social)

This translation was made by Wiley. 本文翻译由Wiley提供。

Read this article on WeChat. 在微信上分享本文。

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.

While Reno families were celebrating the 1997 New Year, the Truckee River was surging into the city's downtown streets. A rainstorm was falling on the Sierra Nevada's deep snowpack, melting it rapidly and creating a hazardous situation for downstream communities.

Author(s): Beatrice Paraschiv, Dorina Ticoş, Nicoleta Udrea, Adrian Scurtu, Maria L. Mitu, and Cătălin M. Ticoş

Dust clusters with crystalline structure, formed by charged microparticles in complex plasmas, can undergo phase transitions under external influences. While many studies have focused on the effects of temperature and pressure on crystallization, it is worthwhile to investigate a different factor su…

[Phys. Rev. E 113, 065209] Published Tue Jun 16, 2026

Author(s): M. Khan, K. Churnetski, D. E. M. Barlow, R. Betti, C. Freeman, K. Glize, J. Kunimune, A. Lees, R. Mancini, A. Nutter, R. W. Paddock, S. Regan, C. Stoeckl, W. Theobald, N. Woolsey, and R. H. H. Scott

Shock-augmented ignition (SAI) [R. H. H. Scott et al., Phys. Rev. Lett. 129, 195001 (2022)] is an alternative inertial confinement fusion concept that is designed to achieve high energy gain by combining improved resilience to instabilities with enhanced fuel compression. In SAI, lower implosion vel…

[Phys. Rev. E 113, 065210] Published Tue Jun 16, 2026

Traditional global climate models were like early digital cameras—they had only about 10,000 pixels to cover the entire planet. At that low resolution, big storm systems looked like blurry blobs. You couldn't see their true shape, how long they lasted or where they dumped the heaviest rain.

SummaryThe Laji Shan-Jishi Shan Tectonic Belt (L-JTB), situated at a crucial tectonic transfer position on the northeastern margin of the Tibetan Plateau, is important for understanding regional deformation partitioning and seismic hazard. Although it has traditionally been regarded as a zone of relatively modest deformation, the 2023 Jishishan Mw 6.0 earthquake highlights the need to reassess its present-day kinematics and mechanical role. In this study, we integrate GNSS and Sentinel-1 InSAR data to derive a high-resolution three-dimensional interseismic crustal deformation field. We then apply an enhanced dip-aware velocity-profile model within a Bayesian framework to estimate the slip rates and locking characteristics of the major faults, and we further calculate the regional strain-rate field using a multiscale spherical wavelet approach. The results indicate that: (1) The L-JTB exhibits a modest average regional strain level relative to the first-order boundary faults to its north and south, but also displays pronounced along-strike heterogeneity and localized deformation focusing within the belt; (2) The Laji Shan Fault is characterized by a comparatively weak interseismic signal and is dominated by shortening and uplift, with only a minor fault-parallel component, whereas the Jishi Shan Fault is more strongly active, accommodating dextral strike-slip at 1.7 ± 0.3 mm/yr together with shortening-related dip-slip at 3.5 ± 1.2 mm/yr; and (3) the L-JTB is better interpreted as an internal strain transfer belt between the dextral Riyue Shan Fault and the sinistral West Qinling Fault, in which part of the transferred deformation is converted into crustal shortening, uplift, and localized internal strain. Our study reveals that even within a tectonic transfer belt characterized by only modest average regional strain, moderate earthquakes may still nucleate where deformation becomes localized through favorable stepover geometry, structural segmentation, and local strain focusing.

SummaryWe investigate the 410 km discontinuity (thereafter the ‘410’) beneath Europe using teleseismic S-to-P converted waves. This discontinuity—associated with the olivine–wadsleyite phase transition at the top of the mantle transition zone (MTZ)—is widely used as an indicator of thermal variations linked to mantle upwellings and subducting slabs. Our results reveal complex structures of the ‘410’, including closely spaced discontinuities above and below 410 km depth, within laterally confined regions (∼100-200 km wide). These features are predominantly aligned along a corridor extending from the western Alpine front (Western Alps, Rhone Graben) through the Eifel volcanic fields and the Eger Graben to the eastern Alpine front (Western Carpathians, northern Pannonian Basin, Eastern Carpathians), along the European Cenozoic Rift System (ECRIS). In several locations, the disturbed ‘410’ is associated with an elevated lithosphere–asthenosphere boundary (LAB), suggesting a link between lithospheric processes and MTZ structure. We interpret these observations as evidence for small-scale lithospheric dripping, potentially initiated during or following the Alpine orogenesis. Additional occurrences of apparent ‘410‘ doubling are identified beneath the southern Scandes and the northern Adriatic region; beneath the Scandes, this feature spatially correlates with extensional tectonics. Overall, our results indicate that the ‘410’ beneath Europe is strongly influenced by smaller-scale mantle dynamics, closely related to the ECRIS, rather than reflecting solely large-scale thermal anomalies.

SummaryRayleigh wave dispersion curves inversion is an important method for shallow shear wave velocity structure imaging, which can be achieved through different frameworks such as deterministic inversion and Bayesian inversion. The deterministic methods with fixed parametrization usually require pre-set model complexity, and are difficult to directly provide posterior uncertainty estimation. In contrast, trans-dimensional Bayesian method can probabilistically estimate the dimensions of the model during the sampling process and quantify the uncertainty of the inversion results. However, in the inversion of multimode Rayleigh wave dispersion curves, the posterior space usually has high-dimensional, multi-modal, and strongly nonlinear characteristics. How to achieve efficient posterior exploration and stable trans-dimensional mixing is still a key issue in practical applications. In response to this issue, we constructed and evaluated a trans-dimensional Parallel Tempering reversible jump Markov Chain Monte Carlo (PT-rjMCMC) inversion workflow for multi-modal Rayleigh wave dispersion curves in shear wave velocity imaging, denoted as All-Pair-Sweep PT-rjMCMC (APS-PT-rjMCMC). The method integrated Voronoi trans-dimensional parameterization, multi-modal dispersion likelihood function, reversible jump model update, and parallel tempering sampling into a unified framework. In the replica exchange stage, it adopted an all-pair-sweep replica-exchange schedule with randomized ordering to enhance the inter chain information propagation and trans-dimensional mixing ability under a limited number of temperature chains. The inversion results of synthesized model and measured data indicated that compared with the benchmark implementation, the workflow exhibited better performance in convergence behavior, posterior structure recovery, and layer identification. Our technology provides a solution that combines adaptability and reliability for fine survey of shallow geological structures. It is effectively improving the inversion accuracy of shear wave velocity structures under complex geological conditions. It has broad application space and significant application value in fields such as engineering survey, geological hazard assessment, and water resources investigations.

The Ontong Java Plateau in the western Pacific Ocean is the largest oceanic plateau on Earth, and its formation mechanism has not been well understood.

Over 40,000 seamounts—undersea mountains that don't breach the ocean's surface—are scattered across the ocean floor. Some form linear chains, while others occur as dispersed, isolated features that are not part of well-defined volcanic chains.

The warm Gulf Stream is maintained by coldness. The Barents Sea is a cooling machine. To predict how ocean currents in the Atlantic Ocean may develop, one needs to know what drives them. The hunt for driving forces has led researchers to follow the warm water from the Gulf Stream as far north as it gets.

Sedimentary basins—depressions in Earth's crust caused by tectonic activity—tend to be flat and are favored places to build cities. But during earthquakes, they can become natural resonance chambers.

Researchers have developed a new approach using data from NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite to observe the timing and progression of fall colors across landscapes.

The Arctic and northern high latitudes are warming about 2–4 times faster than the global average, allowing ancient permafrost to thaw and release stored carbon. These permafrost soils currently store roughly one-third of the world's organic soil carbon, much of which has remained frozen for thousands of years. As the soils thaw, organic matter from dead plants and animals within them starts to decompose, and greenhouse gases, including carbon dioxide, are released.

Changes in wind patterns play the leading role in influencing often devastating tropical rainfall changes, rather than simply the warming atmosphere holding more moisture, according to new research.

Planting trees is widely promoted as a natural solution to climate change. But a new study led by researchers from the Institute of Atmospheric Physics at the Chinese Academy of Sciences finds that the hydrological consequences of reforestation depend critically on how much the world warms.

From Antarctica’s frozen wilderness to the heights of Mount Everest, microplastics have been found in some of the most remote places on Earth. And their reach continues to expand.

A recent study published in iScience found that one of Nepal’s highest snow-fed lakes, situated at an altitude of 4,917 meters (16,132 feet) in the Himalayas, contains a significant amount of microplastic pollution. Researchers detected an average of 42 microplastic particles per liter of water, highlighting how microscopic plastic contamination has reached even some of the world’s most remote environments.

“It is yet another piece of evidence that our massive consumption of plastic in countries across the Global South is coming back to harm us. We are basically hitting an axe on our own foot.”

“It is yet another piece of evidence that our massive consumption of plastic in countries across the Global South is coming back to harm us,” said Tista Prasai Joshi, a water scientist at the Nepal Academy of Science and Technology in Kathmandu. “We are basically hitting an axe on our own foot.” Joshi, who was not involved in the new research, added that plastic use is so deeply woven into daily life that many people fail to recognize its effect on ecosystems. Rising tourism in countries like Nepal is only accelerating the spread, carrying microplastic pollution to remote corners of the Himalayas.

In 2019, marine scientist Imogen Napper and colleagues at the University of Plymouth reported a significant presence of microplastics in snow and stream water around the Everest Base Camp region, about 5,300 meters (17,388 feet) above sea level. The findings made headlines around the world.

Despite the publicity given the Everest Base Camp research, very few studies have examined microplastic pollution in highland lakes. Such studies are particularly important because water stays in these lakes much longer than in rivers, making them valuable archives of pollution, able to preserve evidence of contamination over years or even decades.

A Trip to Tilicho

To help address this gap in research, Sahil Shrestha, an environmental researcher at Tribhuvan University’s Institute of Engineering, Pulchowk Campus, and a colleague turned a couple of days of Himalayan trekking into a field expedition. Shrestha selected six accessible shoreline locations around Tilicho Lake for sampling. At each location, using his bare hands to prevent microplastic pollution from gloves, he submerged a stainless steel bottle about 20 centimeters below the water surface, opened the cap, filled the bottle, and resealed it before bringing the sample back for analysis.

Shrestha was particularly concerned about environmental contamination, as transporting samples from a remote lake to a laboratory in Kathmandu takes time, and contamination can occur en route. To account for possible contamination scenarios, he implemented several control measures.

“We carried a trip blank for this,” he said. “Essentially, in a rinsed and cleaned steel bottle, I carried distilled water throughout the trip.”

Because he knew the water was uncontaminated at the start of the trip, Shrestha could measure it again upon returning to the lab to see whether it became contaminated during the trip (for example, by being carried in a backpack). If the trip blank showed signs of contamination, the scientists could assume the collected samples were similarly contaminated and could subtract the known level of contamination from their analysis. Trip blanks and field blanks are standard quality assurance practices used in environmental chemistry research.

Shrestha also carried field blanks to account for possible microplastics in the air. At the field site, he poured distilled water from the laboratory into another bottle. The idea was to account for possible airborne microplastics that could later be subtracted to calculate the net microplastics in the water alone.

The sampling experience left a lasting impression on Shrestha, in part because he and his colleague had to carry up to 15 liters of water between sampling sites. “For two individuals, carrying so many liters of water around each site was a challenging yet fun part of the process,” he said.

Plastics Aplenty

Polyester, polyethylene, and polypropylene are commonly used in hiking gear, jackets, tents, plastic bottles, and bags, all of which can shed microplastics while visitors explore the area.

Once in the lab, Shrestha’s team carried out further analyses, including the removal of organic material, filtration, and microscopy to categorize the types of microplastics. They found that microplastic contamination was higher in areas of the lake more easily accessible to tourists. Polyester, polyethylene, and polypropylene were the main types detected. These materials are commonly used in hiking gear, jackets, tents, plastic bottles, and bags, all of which can shed microplastics while visitors explore the area, suggesting tourism was the most likely source of contamination.

Shrestha noted that there is not yet evidence that Tilicho Lake drains into rivers, but many Himalayan lakes do drain into rivers that, in turn, feed communities downstream. The findings hint that microplastic contamination at the water’s source has a far-reaching ripple effect on human health and downstream ecosystems.

Shrestha stressed the need for such research to inform policy and regulatory decisions.

“Tilicho Lake is situated in the Annapurna Conservation Area Project (ACAP) region, and these conservation programs should restrict trekkers from carrying plastic bottles and polyethylene bags,” he said. “Overall, the trekking gear industry is [contributing] significantly to microplastic pollution in remote regions, and this should be addressed through international collaboration.”

—Saugat Bolakhe, Science Writer

Citation: Bolakhe, S. (2026), Trekking tourism leaves a microplastic footprint in a high Himalayan lake, Eos, 107, https://doi.org/10.1029/2026EO260191. Published on 15 June 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.