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Growing up, many of us were taught to drop, cover and hold on during an earthquake. The guidance is straightforward, but how people actually respond when the ground starts shaking can be far more complicated. Now, UC Berkeley researchers are studying what happens in those critical moments and how fear and risk perception influence people's actions.

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

Electrons and ions respond differently to atmospheric winds and to magnetic fields. This generates a large-scale electrical current in the “dynamo” region of the Mars ionosphere, where the electrons preferentially gyrate around the magnetic field while the ions undergo collisions with the neutrals.

Delcourt and Mittelholz [2026] developed a “Neural-Curlometer” model – a new machine learning (neural network) computer model based on Ampere’s Law and Gauss’s Law, which they apply to analyze the magnetic field resulting from the large-scale dynamo currents and measured onboard NASA’s MAVEN satellite.

The authors find the reconstructed currents to form a hemispheric, seasonally varying vortex system in the altitude range of 125-220 km, with a transition in direction near 160 km and a correlation in the current density with the crustal magnetic field. Furthermore, the hemispheric vortex pattern is consistent with the predicted atmospheric wind circulation on Mars, as well as the transport driven by the Coriolis force and associated with seasonal CO2 condensation at the poles. The findings provide a data-driven proxy for atmospheric circulation at ionospheric altitudes and potentially serve as important new inputs for Martian general circulation models.

Left: Map of the current density of the ionospheric dynamo at 150 km altitude from the Neural-Curlometer model and using MAVEN magnetic field data in all four seasons, in the Mars Solar Orbital (MSO) frame and using a Robinson projection; the arrow lengths are proportional to the horizontal component of the current density. Right: Map of the corresponding average crustal magnetic field intensity near spring equinox. Credit: Delcourt and Mittelholz [2026], Figure 2a (left) and 2f (right)

Citation: Delcourt, T. & Mittelholz, A. (2026). Global Circulation of Martian Ionospheric Currents Revealed by Magnetometer Data. AGU Advances, 7, e2026AV002408. https://doi.org/10.1029/2026AV002408

—Andrew Yau, Editor, AGU Advances

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.

Earth may have been pushed deeper into a global deep freeze by something surprisingly ordinary: salt. Around 700 million years ago, Earth entered periods of extreme glaciation known as Snowball Earth, when ice is thought to have spread across much or potentially all of the planet's surface. Scientists have long known that expanding ice could have helped drive this transition: As bright ice replaces darker ocean water, more sunlight is reflected back into space, causing the planet to cool further and allowing even more ice to form.

Weather forecasts rely on many different kinds of data, including temperature, humidity and wind. For the first time, researchers, including those at the University of Tokyo, have demonstrated that a long-theorized improvement to weather models—adding data on water isotopes in the atmosphere—does work. They showed that incorporating satellite measurements of water vapor isotopes into weather models improves forecasts of atmospheric conditions for up to five days, including predictions of heavy rainfall in many regions.

SummaryTo address the challenge of assessing the reliability of three-dimensional (3D) magnetotelluric (MT) inversion results, we have developed a variational inference (VI) inversion framework (VI-MT) based on the Stein Variational Gradient Descent (SVGD) method. Through parallel particle optimization, we efficiently approximate the model posterior distribution, overcoming the computational limitation of traditional Markov Chain Monte Carlo (MCMC) methods. Synthetic tests show that the VI-MT inversion can effectively recover the synthetic model while reducing the tailing effect, and it can approximate the multimodal posterior distribution, providing quantitative uncertainty estimates. Furthermore, the VI-MT inversion is applied to the field MT data collected at the Weishan volcano in northeast China, with the posterior mean model consistent with the deterministic inversion model. A clear low resistivity body of ∼5 Ω·m with small uncertainties is imaged at depths of ∼2-6 km beneath the volcanic crater, suggesting the existence of a shallow magma chamber. Our study shows that the VI-MT inversion based on the SVGD method can efficiently solve the 3D MT Bayesian inversion, providing reliable model uncertainties.

SummaryCharacterizing electronically conductive minerals with spectral induced polarization (SIP) has been a longstanding goal of mineral exploration. A more comprehensive understanding of how mineral texture (e.g. disseminated grain versus veinlet forms) and mineral type influence SIP signals is required, as the polarization mechanisms at the electron conductor-fluid interface and their effect on SIP signatures remain incompletely understood. We performed laboratory measurements on synthetic copper (Cu) and graphite (Gr) samples prepared in disseminated grain and veinlet forms by mixing fixed concentrations of the electron conductor with a non-polarizable sand. Current density dependent SIP (complex impedance) responses were assessed by measuring at multiple current densities, and non-equilibrium was investigated by making measurements as a function of time. SIP responses that remained independent of current density were interpreted as evidence of non-Faradaic processes, with possible minor Faradaic contributions, being dominant. Conversely, current density dependent complex impedance responses were interpreted as an increased contribution from Faradaic polarization processes involving redox reactions at the electrolyte-electron conductor interface. Veinlet Cu samples exhibited strong current density dependent SIP responses and prolonged equilibration, in contrast to the negligible current density dependence of veinlet Gr and disseminated grain Cu and Gr samples. All samples that exhibited negligible current density dependence could be fit to a Pelton-Cole model, whereas samples exhibiting strong current density dependence could only be fit with a more flexible Debye decomposition model. Gr samples displayed a fluid-resistivity dependent peak in the phase response at a specific frequency consistent with mechanistic models, while Cu samples deviated from predicted behaviour. Measurements on rock cores were consistent with observations on synthetic samples, with the SIP response of a Cu bearing rock core exhibiting a clear dependence on current density, whereas the Gr bearing rock core showed negligible current dependence. The observed dependence of the phase and complex resistivity on current density, mineral type, and texture is consistent with differences in the relative importance of Faradaic and non-Faradaic polarization processes. These results suggest that distinguishing current-density-dependent Faradaic responses from current-independent non-Faradaic responses may improve the discrimination of mineralogical and textural characteristics using SIP measurements, although field-scale applications will be limited due to the lower current densities relative to those used in this laboratory study.

SummaryFull Waveform Inversion (FWI) leverages the amplitude and phase of full wavefield seismic data to obtain high-resolution subsurface structures by minimizing an objective function. However, FWI encounters severe cycle-skipping issues when the seismic data lack low-frequency components or the initial velocity model is significantly different from the true velocity model. Furthermore, an incorrect source wavelet can also directly affect the accuracy of inversion results. To overcome these challenges, we introduce the waveform-preserving source-independent wave-equation-based local-scale traveltime inversion (WPS-LTI) method. This approach aims to recover the low-wavenumber velocity structures as an initial velocity model, while reducing the influence of an incorrect source wavelet. In the WPS-LTI method, seismic data are processed via both convolution and deconvolution with reference traces, resulting in modified observed and synthetic seismic data that share the same seismic wavelet. This approach helps avoid waveform distortions typically introduced by conventional source-independent methods that rely solely on convolution. By preserving the waveform characteristics, we can use cross-correlation to compute more accurate local-scale traveltime differences, thus recovering accurate low-wavenumber velocity structures. Tests conducted on the Marmousi model and the Chevron 2014 blind test dataset demonstrate that the WPS-LTI method can significantly alleviate cycle-skipping issues and reduce the dependence on the source wavelet in FWI.

Two powerful hurricanes and a strengthening tropical storm on Wednesday were churning through the Pacific Ocean, where waters were being warmed by a historically strong El Niño climate episode.

Climate change is altering patterns of wildfire activity in Alaska, making fires larger and more common in some areas with historically low fire activity. Wildfires can be difficult to predict because they are affected by intricate interactions among factors including climate, ecology and weather. But a better idea of which fire pathways are more likely is important for future fire forecasting, adaptation and management strategies.

The Antarctic coastal zone is not simply the edge of the continent. It is a tightly coupled system where ice from the ice sheet extends over the seabed, initially resting on it and farther out floating as ice shelves. Here, mass, heat and nutrients are exchanged with the ocean through various processes. Even the smallest changes can have outsized consequences.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

Humanity is certain to exceed the warming limit set by the Paris Agreement, a legally binding treaty meant to cap the world’s carbon emissions, according to a new report from the United Nations Environment Programme (UNEP). 

Now, to reduce severe threats to human health, food security, water supplies, and more, societies will need to reach net-negative greenhouse gas emissions by not only cutting those emissions, but expanding carbon dioxide removal projects, a pathway called “overshoot, peak and decline.”

The 1.5°C (2.7°F) goal “must now be approached from above.”

Following such a pathway would require virtually eliminating greenhouse gas emissions by mid-century and rapidly deploying carbon dioxide removal technologies, including conventional tactics such as planting trees and restoring ecosystems, and new ones, such as carbon capture and storage.

“This is by no means an acceptable or preferred pathway,” the report stated. “It is simply the best remaining option.”

The 1.5°C (2.7°F) goal “must now be approached from above,” Inger Andersen, the executive director of UNEP, wrote in the report’s foreword. The report is the first time that UNEP has referred to staying beneath the 1.5°C (2.7°F) warming limit as impossible rather than unlikely.

An outline of the “overshoot, peak and decline” pathway that the United Nations Environment Programme has called the “best remaining option” to prevent the worst of climate change’s impacts. Credit: UNEP

The news that Earth will likely breach this limit was expected by climate scientists: In February 2025, a pair of studies published in Nature Climate Change determined that Earth had likely already entered the 20-year period in which global temperatures would exceed 1.5°C (2.7°F). 

In order to bring global temperatures back to the 1.5°C (2.7°F) mark, Earth’s warming must not exceed 1.8°C (3.2°F), the new report states. Beyond that mark, cooling Earth back to the 1.5°C (2.7°F) level this century “becomes increasingly challenging.”

Reaching the amount of carbon dioxide removal required for the “overshoot, peak and decline” pathway would be an enormous task for the world’s governments and economies. Technologies that remove carbon from the air and store it underground are still limited in scale, and so far, just 12 projects have been successful. Just to limit warming to 1.5°C (2.7°F), even without overshooting that limit, the world would need to deploy carbon dioxide removal technologies at rates faster than those seen for solar power, which is far from the current reality. 

Scientists aren’t sure Earth’s subsurface could even store the amount of carbon necessary to keep Earth at net-zero emissions. “Just maintaining net-zero CO₂ emissions could exhaust current estimated storage capacity in sedimentary basins by 2200,” the report stated. 

 
Related

•  Read the Report: “Limiting Overshoot—Navigating Exceedance of 1.5°C and Pathways Towards Return”
•  Climate Goals Missed, U.N. Says World Must Now Remove Carbon at Scale
•  Carbon Brief: Q&A: The Current State of ‘Carbon Dioxide Removal’ Around the World
• UNEP: Overshoot Explained: 5 Things to Understand About a World Beyond 1.5°C
 

Glen Peters, a senior researcher at the CICERO Center for International Climate Research in Norway who was not involved in the UNEP report, told The New York Times that various obstacles are in the way of large-scale carbon removal projects. Large amounts of land would need to be reforested for conventional carbon removal, for instance, which could spark conflicts with agriculture. Wildfires, as well as climate change itself, could prevent or damage plant growth.

Still, a rapid upscaling of carbon dioxide removal, paired with strong governance frameworks to ensure ethical deployment, is critical, according to UNEP. Without such action, the breaching of dangerous tipping points in Earth systems, such as irreversible changes to ice sheets or the slowing of the Atlantic Meridional Overturning Circulation (AMOC), will become more likely, paired with growing human and ecological suffering. 

“We need stronger political will,” Andersen wrote. “Decisions taken now and in the next few years will determine whether viable options remain to reverse warming towards 1.5°C.”

—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 science or scientists? Send us a tip at eos@agu.org. Text © 2026. AGU. CC BY-NC-ND 3.0
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The fact that the ocean gets colder as you go deeper is fairly intuitive, but a similar gradient exists along the surface of the ocean, even at scales of 1 kilometer to tens of kilometers. A new study, published in the Proceedings of the National Academy of Sciences, suggests that this horizontal gradient significantly contributes to the intensity of tropical cyclones, providing a potential tool for better storm warning systems.

Inside a lab at the University of Texas at Dallas, researchers have re-created a small-scale ocean environment where they can make waves build, break and crash into one another.

Urban heat adaptation will gain in importance as climate change progresses. Researchers at the Karlsruhe Institute of Technology (KIT) have analyzed how sociodemographic factors (nationality, age, and rent) correlate with heat exposure throughout Germany.

Source: Journal of Geophysical Research: Planets

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

木卫一（Io）是木星的第三大卫星，它不断受到木星及其另外两颗卫星——木卫二（Europa）和木卫三（Ganymede）——的引力作用而发生形变。木卫一内部由此产生的摩擦会产生极高的内部温度，从而引发遍布其表面的火山喷发。事实上，木卫一的火山活动比太阳系中任何其他天体都要活跃。

此前几乎所有对木卫一温度的观测都依赖于红外测量，而红外测量只能探测到木卫一最外层“表皮”的温度。如今，Brown等人首次测量到了木卫一的内部温度。

研究人员利用了美国宇航局“朱诺号”探测器上的微波辐射计在2023年12月和2024年2月近距离飞掠木卫一期间采集的数据，“朱诺号”自2016年以来一直在绕木星运行。

这些数据揭示了木卫一在微波波段的热辐射。微波波段的波长比红外线更长，使研究人员能够观测到木卫一表面以下数十米的深度。分析过程中，研究人员识别并剔除了部分由天空反射在木卫一表面造成的干扰信号，以确保最终获得真正反映木卫一特性的观测数据。

这些观测结果表明，木卫一表面上数十米的上层区域受到内部过程的强烈加热。与数据相符的两种可能解释是：热量可能通过近表面的导热层持续上升，或者近期熔岩流或热喷气孔释放的热量可能通过冷却的薄层地壳逸散到表面，考虑到木卫一上存在高耸的山脉，后一种解释的可能性更大。

对微波观测数据的进一步分析揭示了更多关于木卫一的信息。数据显示，木卫一的表面相对平坦，类似于地球上的平原。数据还表明，木卫一的上层密度低于固体岩石，可能类似于火山灰或浮石，而这层物质很可能位于其下方数米处密度更高的物质之上。

这些发现以及对朱诺号微波辐射计数据的进一步分析，将有助于我们更深入地了解木卫一，特别是其内部散热机制以及热量流动模式在其表面各处的差异。这项工作还有助于为未来探测木卫一或其他岩质或冰质天体的微波探测仪器的设计提供参考。(Journal of Geophysical Research: Planets, https://doi.org/10.1029/2025JE009622, 2026)

—科学撰稿人Sarah Stanley

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

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Source: Earth’s Future

Climate change is altering patterns of wildfire activity in Alaska, making fires larger and more common in some areas with historically low fire activity. Wildfires can be difficult to predict because they are affected by intricate interplays between factors including climate, ecology, and weather. But a better idea of which fire pathways are more likely is important for future fire forecasting, adaptation, and management strategies.

Littell et al. use temperature and precipitation data from an ensemble of five climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to assess how fire activity in boreal Alaska may change in the 21st century. Feeding the data into the Alaska Frame‐Based Ecosystem Code (ALFRESCO) landscape model to assess changing fire-vegetation dynamics, they present a range of fire and vegetation composition scenarios based on both moderate and high levels of future greenhouse gas emissions.

Though significant variation exists between how individual models calculate increases in burn area, the authors show that the more likely outcome under climate change, regardless of emissions pathway, is for the median annual area burned by wildfire in Alaska to increase—by more than double under a high-emissions scenario. Areas that currently see less wildfire, such as the Alaskan Arctic and western Alaska, could see up to an eightfold increase in wildfire activity. In addition, ecosystems are likely to be increasingly dominated by deciduous tree cover as spruce species are pushed out by fire.

Uncertainty over the future of Alaskan wildfires remains. Lower levels of warming combined with increased summer precipitation could keep wildfire activity within historical bounds, and the future balance of less-flammable deciduous trees to more-flammable spruce will also likely affect fire activity. The authors note one significant limitation to their current results is that the ALFRESCO model was trained on historical fire-vegetation dynamics. Future dynamics, such as increased flammability of vegetation under novel climates, could be substantially different, changing the evolution of fire activity in the region.

Key takeaways for fire managers include the fact that diversity in the age, species makeup, and spatial coverage of vegetation could potentially reduce the likelihood of larger fires. Maintaining and creating this variability in wildfire fuel through suppression, controlled burns, fuel treatments, and other methods could therefore be a useful management strategy. (Earth’s Future, https://doi.org/10.1029/2026EF008324, 2026)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), What will the future of Alaskan wildfire look like?, Eos, 107, https://doi.org/10.1029/2026EO260278. Published on 2 September 2026. 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Geochemistry, Geophysics, Geosystems

In the late 1980s, it became clear that partial melting of the mantle easily creates an interconnected network of melt-filled porosity that allows melt migration by porous flow at low degrees of melting. This overturned the batch melting paradigm that had previously governed thinking about mantle melting. Some of the clearest signatures and most important constraints on such “open-system” melting processes come from analyses of trace element concentrations in erupted basalts and residual mantle peridotites. A number of authors have since introduced analytical frameworks for exploring such trace element systematics, including the model of Ozawa [2001], which has had enduring success.

However, Ozawa’s model is complex to implement. The equations are challenging enough that a geochemist or petrologist contemplating applying the model to a new setting or data compilation faces a difficult programming task. Hence, the new and user-friendly graphical user interface (GUI) announced by Nishio et al. [2026] is a welcome advance. It allows novice users to apply the Ozawa model with confidence that the implementation is correct and to quickly visualize the consequences of various parameters, choices, and the quality of fit to their data.

As public databases of analytical results from globally distributed basalts and mantle rocks continue to grow, there are new opportunities for characterization of the range of melting environments that occur in Earth’s various tectonic settings. An easy-to-use tool for turning such raw data into meaningful constraints on processes beneath volcanoes should make it easier to realize such opportunities.

Citation: Nishio, I., Akizawa, N., Ozawa, K., Itano, K., & Waterton, P. (2026). A graphical user interface application to model open-system melting in the upper mantle. Geochemistry, Geophysics, Geosystems, 27, e2026GC013081. https://doi.org/10.1029/2026GC013081

—Paul Asimow, Editor, Geochemistry, Geophysics, Geosystems  

Text © 2026. The authors. CC BY-NC-ND 3.0
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Recently, heavy rains have caused flooding in Grand Canyon and Zion National Parks, resulting in the loss of at least two lives. In U.S. national parks, maintaining visitor safety can be complicated because it is difficult to measure who is in a park and where they are, much less what hazards they will face as extreme weather events become more common, according to Bing Pan, professor of recreation, park and tourism management at Penn State.

Author(s): Riddhi Bandyopadhyay, Subash Adhikari, Yan Yang, and William H. Matthaeus

A key principle underlying most turbulence theories is that the mean energy dissipation rate remains finite even as viscosity vanishes: the so-called zeroth law of turbulence. Although this property has been established for hydrodynamic and magnetohydrodynamic (MHD) turbulence, its validity in weakl…

[Phys. Rev. E 114, 035202] Published Wed Sep 02, 2026

Author(s): Jingwei Xing and Jianmin Yuan

The configuration path integral Monte Carlo (CPIMC) method is employed to perform first-principles simulations of warm dense matter based on atomic orbitals. The system is modeled as an ion sphere with a pointlike nucleus at its center, and the electronic many-body problem is solved using CPIMC with…

[Phys. Rev. E 114, 035203] Published Wed Sep 02, 2026