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In August 2023, the German research vessel METEOR set sail on Expedition M192 to the Greek island of Milos with Dr. Solveig Bühring as chief scientist. The mission was to locate and investigate previously unknown hydrothermal systems. Now, three years later, a new study highlights the surprising discoveries resulting from this expedition. At a newly discovered hydrothermal system at intermediate water depths of 100 to 250 meters (328 to 820 feet), researchers demonstrated how different intensities of hydrothermal fluid flow shape microbial communities and control mineral formation on the ocean floor.

Deploying ocean iron fertilization—a strategy for carbon dioxide capture—in higher latitudes rather than near the equator could reduce environmental impacts while still achieving removal of carbon dioxide from the atmosphere, according to a modeling study published in Nature. The findings offer insight into best practices for maximizing carbon dioxide removal while reducing potential ecological trade-offs typically associated with iron fertilization.

Towering explosions, flowing bright red lava and heroic scientists battling to save communities at risk have become the defining image of volcanoes in popular culture, from disaster films to epic blockbusters. New University of Bristol–led research has found these cinematic portrayals create a distorted view of how volcanoes behave in the real world.

For communities across the Western Cape, cut-off low weather systems are a familiar threat. They can dump torrents of rain in a matter of hours, flooding roads, damaging homes and infrastructure, and, in the worst cases, causing loss of life. What scientists have long wanted to understand is why some of these storms become so destructive, and researchers at the University of Cape Town (UCT) found that the answer lies far offshore, in the warm waters of the Agulhas Current.

Extreme urban flooding is a growing challenge under climate change, threatening residents, infrastructure and urban systems. However, traditional emergency planning often relies on static population data and fixed facilities, failing to capture how people move during disasters.

Scientists have discovered a new way to determine how big an earthquake may become just seconds after it begins. In a new study published in Nature Communications, researchers from the U.S. Geological Survey (USGS) and Cal Poly Humboldt used signals picked up by fiber-optic cables—the same ones that deliver high-speed internet—to accurately estimate when a moderate to large earthquake is underway using data from the first four seconds of seismic wave arrivals.

Winters in Antarctica's Ross Sea have become stormier in recent decades, affecting sea-ice conditions and field operations, new University of Otago—Ōtākou Whakaihu Waka research shows.

Landslides cause an estimated $3 billion to $6 billion in damage and multiple fatalities annually in the United States. Those numbers could easily increase as housing needs spur development in landslide-prone areas and climate change increases the severity and frequency of heavy rains, which often trigger landslides. Despite the threat, there has never been a systematic, nationwide accounting of who is most at risk from landslides.

Luckily for Heather Lynch, Adélie penguins eat mostly two things: fish and krill. Krill have a distinct pink color that penguin poop retains. And penguins form colonies, meaning that together, they produce “absolutely prodigious quantities of guano,” she said.

To put it simply: We can see penguin poop from space.

A new study, published in Current Biology, uses satellite imagery of Adélie penguin guano to track how penguin diets and populations have shifted as sea ice in Antarctica has declined. The method has “totally opened our eyes to what’s going on across the continent,” said Lynch, an ecologist at Stony Brook University and coauthor of the new study.

“Linking diet to sea ice dynamics and population change is a key piece in the puzzle of how environmental change will influence the Southern Ocean ecosystem,” Alexandra Strang, a doctoral candidate at the University of Canterbury in New Zealand who was not involved in the new research, wrote in an email. Strang studies population changes in Adélie penguins using satellite imagery.

Guano Sleuths

“The satellite archive is like a time machine for Antarctica, so we can look at not just what penguins are eating now, but also what they were eating all the way back to the earliest days of the Landsat satellite program.”

To parse out trends in Adélie penguin diets, Lynch and the research team first needed to determine whether satellite imagery could reliably capture actual differences in guano content and color. To do this, they analyzed the spectral signal (a quantitative measure of color) and nitrogen isotope content (an indicator of the types of prey present in guano) of 103 guano samples that had been collected from 16 breeding colonies on the Antarctic Peninsula.

Next, they analyzed daytime images of Antarctica from 1984 to 2013 captured by the Landsat program, a joint NASA–U.S. Geological Survey satellite program that has provided continuous images of Earth since 1972. The Landsat images allowed researchers to find penguin breeding colonies and their respective piles of colorful poop. Then, the team compared those images to sea ice data, also collected via satellites, from the National Snow and Ice Data Center that showed where sea ice in Antarctica is declining.

This Landsat satellite image of Adélie penguin colonies in the Danger Islands off the Antarctic Peninsula, taken on 22 January 2023, shows how penguins can color islands pink with their guano. Credit: NASA

“The satellite archive is like a time machine for Antarctica, so we can look at not just what penguins are eating now, but also what they were eating all the way back to the earliest days of the Landsat satellite program,” Lynch said.

The researchers found that penguin colonies in West Antarctica tended to eat diets higher in krill, while colonies in East Antarctica had diets higher in fish. They also found that diet was linked to population changes: Penguin colonies with diets higher in krill were more likely to have declining populations over the long term when compared to colonies with diets higher in fish. Decreased sea ice was associated with diets higher in krill as well.

Such patterns are an indicator that ecosystems in the Southern Ocean are changing in ways scientists should “probably understand better,” Lynch said.

Because of the fine temporal resolution of Landsat data—the satellites take images of each colony every 8 days—researchers were also able to identify diet patterns within years, including some that Lynch didn’t expect. She’d thought certain colonies would consistently be either krill specialists or fish specialists, but some colonies seemed to eat more krill in the summer than they did in either fall or spring.

“This rapid-repeat schedule of the Landsat program is really neat because it allows us to get week-to-week changes that we just otherwise wouldn’t have any handle on,” Lynch said.

Still, why penguins are changing their diets when sea ice melts remains uncertain. It’s possible that less sea ice alters fish populations, changing prey availability, but more research is needed, Lynch said. “That’s a question that we will hand off to our colleagues who work in the ocean.”

Big Questions, Big Data

“Getting these unbroken datasets decade after decade can be incredibly valuable, and their value plays out over time.”

Lynch said the study highlights the importance of workhorse programs like Landsat, which provide consistent information over long time periods. “Getting these unbroken datasets decade after decade can be incredibly valuable, and their value plays out over time,” she said. “It’s not always obvious—we don’t know what kinds of questions we’ll have 30 years from now [that satellites can help answer].”

Scientists are just beginning to understand the extent to which satellite imagery can be used to understand ecological changes. There is a disproportionate amount of satellite imagery of the poles compared to the rest of the globe, meaning much of what ecologists are learning about satellites’ utility is happening in Antarctica. But what scientists learn there could be applied to ecosystems elsewhere in the world, Lynch said.

Casey Youngflesh, an ecologist at Clemson University, prepares penguin guano samples for analysis. Credit: Casey Youngflesh

“Often ecological signals are masked with lots of variability or ‘noise’ and so, to detect these ecological trends, we need long-term data,” Strang wrote. “With satellite imagery, we can do this. We can access more remote locations without having to be there, whilst drawing on the locations that we do have on-the-ground data from.”

For Adélie penguins, at least, the value of satellite datasets “will accrue over time,” Lynch said, continuing to help researchers answer questions about penguin diet, prey availability, and how Antarctic ecosystems are changing. For example, she wants to continue to use Landsat data to determine whether krill fishing affects penguin diets. “Those are the kinds of questions we can start to ask now that we can measure what they’re actually eating directly.”

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

Citation: van Deelen, G. (2026), Tracking penguin poop from space reveals Antarctica’s changing ecosystems, Eos, 107, https://doi.org/10.1029/2026EO260247. Published on 29 July 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.

The annual Asian monsoon is one of the most consequential components of the global climate system, pivotally affecting water availability, agriculture, and livelihoods for billions of people across much of East, South, and Southeast Asia. Even modest shifts in the timing or intensity of monsoon rainfall in a given location can lead to flooding, drought, and cascading socioeconomic impacts.

In 2024, for example, exceptionally heavy rains inundated large areas of eastern Bangladesh, affecting millions of people, damaging crops, and disrupting transportation and essential services. In contrast, delayed or below-average monsoon rainfall in parts of India has repeatedly reduced crop yields and strained water supplies, illustrating how both excess and deficient rainfall can have far-reaching consequences for food security and regional economies.

Despite decades of research, predicting the Asian monsoon’s variability from place to place and year to year remains difficult.

Despite decades of research into the complex interplays of tropical ocean conditions, land-atmosphere feedbacks, and large-scale circulation that drive the monsoon, predicting its variability from place to place and year to year remains difficult.

Traditionally, scientists have focused on studying tropical drivers such as the El Niño–Southern Oscillation (ENSO) and Indian Ocean variability. Increasingly, however, attention is turning toward processes far outside the tropics. Rapid environmental change in the Arctic, particularly the decline of sea ice, is emerging as a potential contributor to atmospheric variability that may extend into monsoon regions.

The Arctic is warming nearly 4 times faster than the global average, a phenomenon known as “Arctic amplification.” And since satellite observations of Arctic sea ice began in 1979, summer (minimum) sea ice extent has declined sharply—by about 12% per decade—exposing larger expanses of ocean surface, which absorbs more solar radiation than ice does, and accelerating regional warming [Screen and Simmonds, 2010; Serreze and Barry, 2011].

Arctic sea ice extents and concentrations have declined substantially in recent decades. The minimum ice extent in 2024, shown here, covered far less area compared with the 1981–2010 median. Credit: NOAA Climate.gov image, based on data from the National Snow and Ice Data Center

These changes are often framed as primarily polar concerns, but a growing body of research suggests they may also influence atmospheric circulation patterns affecting distant regions, including the Asian monsoon.

Arctic Amplification and the Jet Stream

Arctic amplification, driven largely by sea ice loss and albedo feedbacks [Screen and Simmonds, 2010; Serreze and Barry, 2011], reduces the equator-to-pole temperature gradient, a key driver of midlatitude atmospheric circulation. This effect has motivated one of the most widely discussed hypotheses about modern climate dynamics: that Arctic warming alters the behavior of the jet stream in ways that affect weather and climate at lower latitudes [Francis and Vavrus, 2012, 2015].

The hypothesis proposes that a weaker meridional (north–south) temperature gradient leads to reduced zonal (west–east) wind speeds and increased meridional meandering of the flow of the jet stream. In this framework, a “wavier” jet stream favors more persistent ridges and troughs, potentially allowing high-latitude weather anomalies to propagate into Eurasia and influence subtropical systems.

Though influential, this idea is far from settled. Subsequent studies have both supported and challenged different aspects of the hypothesis. Some observational analyses, for example, have suggested that episodic increases in the jet stream’s wave amplitude and the frequency of blocking events (stationary high-pressure systems that block other weather systems from moving through an area) are consistent with a weakened jet [Francis and Vavrus, 2015; Coumou et al., 2018]. Others, however, have found that internal atmospheric variability or forcing by tropical conditions alone can explain much of the jet stream’s observed behavior without requiring a prominent Arctic contribution [Barnes and Screen, 2015; Blackport and Screen, 2020].

Unraveling the nuanced cause-and-effect relationships between the Arctic and the jet stream is essential for interpreting potential downstream effects on the Asian monsoon.

Climate model experiments have further complicated the picture. Whereas some simulations reproduce jet stream responses consistent with the Francis-Vavrus mechanism, others show weak, negligible, or even opposite responses. These discrepancies arise in part because modeled atmospheric responses to Arctic forcing are sensitive to background conditions, including sea surface temperatures, stratospheric variability, and how transient eddies in the atmosphere are represented.

Meanwhile, synthesis studies have emphasized that Arctic amplification does not seem to produce a robust, uniform response in the jet stream. Instead, its influence appears to depend on season, region, and interaction with other climate drivers. In this view, Arctic change may alter the likelihood of certain circulation regimes, such as blocking patterns, occurring at given times and places, rather than causing lasting, systematic shifts.

Unraveling the nuanced cause-and-effect relationships between the Arctic and the jet stream, as a large body of recent research has aimed to do, is essential for interpreting potential downstream effects on the Asian monsoon.

Emerging Evidence of a Complex Connection

Recent studies have begun to investigate Arctic-monsoon linkages explicitly, though their results also reveal a complex picture.

Duo and Zhang [2025] used a combination of observational datasets and climate model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to examine late-season (autumn) monsoon dynamics over Southeast Asia. Their analysis showed that reduced Arctic sea ice is associated with delayed monsoon retreat and increased rainfall during the postmonsoon transition, which the researchers attributed to Arctic-induced circulation changes weakening zonal winds and enhancing moisture convergence over Southeast Asia. Their results highlight that Arctic forcing may influence not only seasonal precipitation averages but also monsoon timing.

Zhang et al. [2024] used reanalysis data alongside coupled climate model experiments from the Polar Amplification Model Intercomparison Project (part of CMIP6) to explore interdecadal variability in the East Asian summer monsoon. They found that Arctic sea ice loss can generate stationary wave responses across Eurasia that alter circulation in the upper troposphere and modulate monsoon strength and rainfall distribution. Their simulations also suggested that Arctic forcing contributes to longer-term variability in monsoon circulation and rainfall that is superimposed on anthropogenic warming trends.

Recent studies indicate that declining Arctic sea ice does not trigger a uniform monsoon response.

In other work, Sardana and Agarwal [2025] examined the influences of spring sea ice variability in the Barents and Kara Seas on the Indian summer monsoon using 6 decades of observational data. They reported that reduced sea ice in the Barents-Kara region is associated with suppressed rainfall over northern India, proposing that the shortage of sea ice alters large-scale atmospheric circulation patterns and weakens moisture transport into the subcontinent.

The studies above indicate that declining Arctic sea ice does not trigger a uniform monsoon response. Whereas Duo and Zhang [2025] identified enhanced late-season rainfall as a result of sea ice loss, Sardana and Agarwal [2025] found that it suppressed monsoon rainfall. Zhang et al. [2024], meanwhile, showed that Arctic sea ice loss modulates long-term variability in the East Asian summer monsoon rather than producing a consistent increase or decrease in monsoon rainfall.

These differences likely arise because of the different regions, seasonal timings, and teleconnection pathways considered in each study. Rather than contradicting one another, however, the studies collectively suggest that Arctic influences on the Asian monsoon are spatially and temporally heterogeneous.

How Arctic Signals Travel South

In addition to outlining monsoon effects associated with Arctic sea ice loss, recent research has proposed several mechanisms to explain physically how ice loss may influence storm systems thousands of kilometers away (Figure 1).

Fig. 1. Arctic sea ice loss may be linked to Asian monsoon variability in a variety of ways, including those illustrated here. Declining sea ice enhances Arctic amplification and weakens the equator-to-pole temperature gradient, altering the jet stream’s structure, the propagation of Rossby waves, and land temperatures across Eurasia. These atmospheric adjustments may then influence the timing, intensity, and spatial distribution of Asian monsoon rainfall, including delaying monsoon retreat. Credit: Neha Kushwaha

Jet stream modulation is one possible mechanism. As noted earlier, Arctic amplification can alter atmospheric temperature gradients and the strength and structure of the polar jet stream. A wavier jet may favor persistent ridges and troughs over Eurasia that can promote the divergence of winds in upper atmospheric layers, as well as vertical motion and moisture transport relevant for monsoon dynamics [Serreze and Barry, 2011].

The propagation of Rossby waves, large-scale atmospheric waves driven by Earth’s rotation, is another potential mechanism. Changes in heat fluxes and pressure-temperature conditions (i.e., geopotential heights) over the Arctic surface may excite stationary Rossby wave trains that propagate into Eurasia. These wave trains can reorganize subtropical high-pressure systems and monsoon troughs, thereby affecting atmospheric convection and rainfall distribution [Zhang et al., 2024; Duo and Zhang, 2025].

Land-atmosphere feedbacks, including Arctic-induced circulation changes, can enhance warming over Eurasia, particularly during spring. This warming may modify land-sea thermal contrasts, a key driver of monsoon circulation. Changes in snow cover and soil moisture can amplify or dampen these contrasts, introducing additional regional variability [Serreze and Barry, 2011; Zhang et al., 2024].

An emerging line of research suggests that Arctic variability may also influence monsoons indirectly via the stratosphere. Sea ice loss can modify the flux of Rossby waves entering the stratosphere, potentially weakening the polar vortex. The resulting atmospheric circulation anomalies can propagate downward from the stratosphere into the troposphere and affect midlatitude circulation patterns that govern monsoon systems [Barnes and Screen, 2015].

The effects of transient eddies in the atmosphere add additional complexity. Changing Arctic temperature gradients can modify eddy formation, influencing how energy is transferred and, in turn, affecting both large-scale wave patterns and the growth and decay of synoptic weather systems that contribute to monsoon variability.

Limitations on Current Understanding

The Arctic-monsoon connection does not occur via a single linear pathway but through a network of interacting atmospheric processes operating across scales.

The variety of mechanisms above demonstrates that the Arctic-monsoon connection does not occur via a single linear pathway but through a network of interacting atmospheric processes operating across scales. Despite growing interest in this connection, substantial uncertainties remain regarding the relative importance and robustness of different mechanisms and their specific effects on the Asian monsoon. Resolving these uncertainties is not an easy problem to parse.

Tropical drivers such as ENSO continue to dominate interannual monsoon variability, often overshadowing the effects of high-latitude influences [Turner and Annamalai, 2012]. Furthermore, observational records of Arctic sea ice and its relationship with Asian monsoon variability are relatively short compared to the timescale of Arctic change, limiting our ability to detect robust, long-term relationships [Barnes and Screen, 2015].

Studies using climate models show considerable spread in monsoon responses to Arctic forcing. Differences in model resolution and representations of sea ice and atmospheric dynamics lead to varying outcomes, including in the magnitude and even direction of monsoon responses.

Another key uncertainty lies in the timescales of responses. Although some studies identify interannual links between Arctic variability and monsoon behavior, others emphasize decadal or longer-term modulation [Zhang et al., 2024; Sardana and Agarwal, 2025]. This distinction raises an important question: Are observed relationships indicative of a persistent physical connection, or do they emerge intermittently under favorable background conditions? Addressing this question will require the availability of longer observational records and conducting targeted model experiments designed to isolate the effects of Arctic forcing.

Furthermore, interactions between Arctic and tropical drivers remain poorly constrained. For example, Arctic-induced atmospheric circulation anomalies may reinforce or counteract ENSO-related patterns. This nonlinearity complicates attribution and suggests that Arctic influences are best understood within a multidriver framework, rather than in isolation.

Why This Matters in a Warming World

Understanding Arctic-monsoon teleconnections is not merely an academic exercise; rather, it carries significant implications. The monsoon underpins food security, water resources, and economic stability across much of Asia. If changing Arctic conditions influence background atmospheric states, they may undermine these crucial needs by affecting the likelihood and timing of rainfall and drought, including extreme events.

Ice loss may act as a risk amplifier, subtly reshaping the conditions under which monsoons evolve.

Although current evidence does not support a simple causal chain between Arctic sea ice decline and effects on the Asian monsoon, ice loss may act as a risk amplifier, subtly reshaping the conditions under which monsoons evolve. As Arctic warming continues and the region undergoes further rapid transformation, whether and how these teleconnections could strengthen and interact with other climate drivers in complex ways remain open questions.

Recognizing these connections challenges the traditional view of monsoons as purely tropical systems and highlights the need for a hemispheric perspective in climate research and prediction. Improving seasonal forecasting, refining climate projections, and anticipating extreme events will increasingly require accounting for cross-latitude interactions.

The Arctic-monsoon connection ultimately illustrates a broad principle: Climate change is not simply a collection of independent regional trends, but a global network of linked processes. Understanding these links is essential for managing risk in a world where distant changes can have local consequences.

References

Barnes, E. A., and J. A. Screen (2015), The impact of Arctic warming on the midlatitude jet-stream: Can it? Has it? Will it?, Wiley Interdiscip. Rev. Clim. Change, 6(3), 277–286, https://doi.org/10.1002/wcc.337.

Blackport, R., and J. A. Screen (2020), Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves, Sci. Adv., 6(8), eaay2880, https://doi.org/10.1126/sciadv.aay2880.

Coumou, D., et al. (2018), The influence of Arctic amplification on mid-latitude summer circulation, Nat. Commun., 9(1), 2959, https://doi.org/10.1038/s41467-018-05256-8.

Duo, Y., and J. Zhang (2025), Arctic ice loss is delaying monsoon retreat over the Indochina Peninsula, npj Clim. Atmos. Sci., 8, 364, https://doi.org/10.1038/s41612-025-01241-3.

Francis, J. A., and S. J. Vavrus (2012), Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophys. Res. Lett., 39(6), L06801, https://doi.org/10.1029/2012GL051000.

Francis, J. A., and S. J. Vavrus (2015), Evidence for a wavier jet stream in response to rapid Arctic warming, Environ. Res. Lett., 10(1), 014005, https://doi.org/10.1088/1748-9326/10/1/014005.

Sardana, D., and A. Agarwal (2025), Impact of spring sea ice variability in the Barents-Kara region on the Indian summer monsoon rainfall, Sci. Rep., 15, 37790, https://doi.org/10.1038/s41598-025-21544-y.

Screen, J. A., and I. Simmonds (2010), The central role of diminishing sea ice in recent Arctic temperature amplification, Nature, 464, 1,334–1,337, https://doi.org/10.1038/nature09051.

Serreze, M. C., and R. G. Barry (2011), Processes and impacts of Arctic amplification, Global Planet. Change, 77, 85–96, https://doi.org/10.1016/j.gloplacha.2011.03.004.

Turner, A. G., and H. Annamalai (2012), Climate change and the South Asian summer monsoon, Nat. Clim. Change, 2(8), 587–595, https://doi.org/10.1038/nclimate1495.

Zhang, X., et al. (2024). The role of Arctic sea ice loss in the interdecadal trends of the East Asian summer monsoon in a warming climate, npj Clim. Atmos. Sci., 7, 174, https://doi.org/10.1038/s41612-024-00717-y.

Author Information

Neha Kushwaha (neha24@iiserb.ac.in), Indian Institute of Science Education and Research Bhopal, India

Citation: Kushwaha, N. (2026), Arctic sea ice loss may be reshaping the Asian monsoon, Eos, 107, https://doi.org/10.1029/2026EO260249. Published on 29 July 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: Geophysical Research Letters

Rising atmospheric carbon dioxide (CO₂) is cooling the upper atmosphere, but it is also changing how the atmosphere responds to natural disturbances. One important example is a sudden stratospheric warming (SSW), a wintertime event that disrupts atmospheric circulation from the stratosphere to the edge of space. Because SSWs can alter the ionosphere, they can affect satellite operations, radio communications, and navigation systems.

Using a whole-atmosphere model, Kumar et al. [2026] investigate how the atmospheric response to strong SSW changes in a future climate with doubled CO₂. They find that CO₂-driven cooling changes upper-atmosphere winds, making the response increasingly different between the Northern and Southern Hemispheres. These changes produce larger hemispheric differences in atmospheric composition and ionospheric plasma density. The study provides new insight into how climate change could influence future space weather and its impacts on modern technology.

Citation: Kumar, S., Oberheide, J., & Martinez, B. C. (2026). Impact of doubled CO2 on the response of the mesosphere, thermosphere, and ionosphere to the 2008–2009 sudden stratospheric warming. Geophysical Research Letters, 53, e2026GL121817. https://doi.org/10.1029/2026GL121817  

—Huixin Liu, Editor, Geophysical Research Letters

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.

Author(s): S. Jiang, X. F. Shen, O. Rosmej, S. P. Zhu, X. T. He, A. Pukhov, and B. Qiao

Placed in the context of the pursuit of monoenergetic proton beams accelerated by lasers, this work explains the fact that they are not observed in experiments. The authors show that this is due to the to the transverse inhomogeneity of the laser and that this can be overcome with flat top laser profiles.

#AdvancingField #ClearMotivation

[Phys. Rev. E 114, 015222] Published Wed Jul 29, 2026

In June 2026 I recorded 48 fatal landslides causing 131 fatalities. 2026 continues to be atypical in terms of the temporal pattern of fatal landslides.

This is my regular update for the number of fatal global landslides, focusing on June 2026. As usual, this data has been collected in line with the methodology described in Froude and Petley (2018) and in Petley (2012). References are listed below – please cite these articles if you use this analysis. Data presented in these updates should be treated as being provisional at this stage as I will reanalyse them prior to formal publication, and other events will emerge.

Note that this data excludes landslides triggered by earthquakes.

The headline figures are as follows:

June 2026: 48 fatal landslides causing 131 fatalities.

This is the number of landslides by month in 2026 to the end of June:-

The number of global fatal landslides in 2026 by month to the end of June.

Last month I once again noted that 2026 was proving to be atypical in terms of the pattern of fatal landslides. This has continued through June, with the total number recorded in this month once again being lower than for both February and March. It is surprising that the June total is lower than that of May, as well. We would normally expect to see the monthly landslide total increasing from April through to July. This may indicate that patterns of rainfall this year are varying from the norm. More research is needed.

My preferred way of presenting this data us to use the cumulative total by pentad. This graph is to pentad 30, which captures all of the June data:-

The cumulative total number of global fatal landslides in 2026 by pentad to the end of June.

The shows that the number of fatal landslides in 2026 continues to run way ahead of the long term mean, and within noise was equivalent to the exceptional year of 2024 (albeit with a different temporal pattern).

The end of June marks the start of the Northern Hemisphere monsoon season, and the uptick in the number of recorded landslides is clear in the graph. It will be interesting to see the July data as the monsoon gets into full swing.

I hope to be able to produce the July 2026 data next week.

References

Froude, M. and Petley, D.N. 2018.  Global fatal landslide occurrence from 2004 to 2016.  Natural Hazards and Earth System Sciences 18, 2161-2181.

Petley, D.N. 2012. Global patterns of loss of life from landslides. Geology 40 (10), 927-930.

Return to The Landslide Blog homepage 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.

On July 23, R/V Kronprins Haakon cast off from the coal quay in Longyearbyen. Around 30 researchers and 20 crew members will spend the next 50 days sailing toward the North Pole as part of the Polhavet 2050 research program.

SummaryDistributed Acoustic Sensing (DAS) is an emerging technology that turns existing optical-fiber cables into high-density seismic arrays, generating vast amounts of observational data in various contexts. Consequently, large-scale storage, transmission and processing of DAS data present both challenges and opportunities in seismology. In this study, we propose a data compression and seismic detection workflow based on compressive sensing (CS) and apply it to DAS data from the Taiwan Milun Fault Drilling and All-inclusive Sensing (MiDAS) project. Our algorithm achieves a compression ratio of at least 15, with reconstructed data from specific earthquakes compatible with standard seismological algorithms. Additionally, we migrate the detection algorithm to the compressed domain, enabling quasi-real-time, high-accuracy seismic detection. This approach demonstrates the feasibility of directly processing compressed data, reducing computational burdens in DAS processing. Furthermore, we discuss an empirical criterion for determining the maximum compression ratio of a given signal based on CS. Our workflow is compared with other mature compression algorithms across eight different datasets to demonstrate its advantages, limitations, and applicability. Generally, the CS algorithm is more effective for high-SNR event-oriented DAS applications rather than continuous noise-dominated monitoring. Collectively, these results highlight the potential of the CS algorithm in advancing the development of efficient, user-friendly DAS data products.

SummaryThe pore-crack network, characterized by the distribution of pore aspect ratios and porosity, controls the seismic properties of a rock. The increase in laboratory ultrasonic velocity with effective pressure reflects the closure of microcracks, thereby allowing the pore-aspect-ratio spectrum to be inverted through rock-physics modelling. Previous studies on sandstone samples have suggested that the pore-aspect-ratio spectrum (porosity distribution vs. pore-aspect-ratio distribution) follows a power-law distribution; however, its robustness across different lithologies, model dependence, and origin remain poorly understood. In this study, these questions are further investigated. We compile laboratory ultrasonic velocity-pressure data from 50 rock samples spanning a wide range of lithologies and porosities. Then we invert the power-law exponent (the slope of the power-law distribution) from these data by integrating the pore-aspect-ratio spectrum into two independent rock-physics models: the existing Kuster-Toksöz (KT) model and the multi-crack wave theory (MCWT) that incorporates the squirt-flow mechanism. The inversion results show that both models obtain power-law pore-aspect-ratio spectra across lithologies, with the MCWT showing improved modelling of the squirt-flow effect in saturated P-wave velocities, leading to smaller fitting errors. Theoretical modelling explains the differences between the two models in their fitting behavior and inverted power-law exponent values. Furthermore, we demonstrate that the power-law pore-aspect-ratio spectrum can be derived from widely observed power-law fracture length and aperture distributions of the crack system. The result also establishes a relationship between the power-law exponent and porosity that well explains the global data trend from inverting the velocity-pressure data of rock samples. The significance of the power-law exponent and the applicability of the E-porosity relationship are also discussed. Our findings support a robust power-law pore-aspect-ratio spectrum across different lithologies and highlight its simplicity and practical applicability for analyzing velocity-pressure data in cracked-porous rocks.

Could taking plant biomass and burying it in the deep, anoxic parts of the ocean be a workable large-scale strategy for carbon sequestration? The concept has intrigued scientists for years, and now a recent international workshop led by UC Santa Barbara researchers has taken the first steps toward developing it.

Around a quarter of the U.S. food supply is grown in California's Central Valley. Most of its crops, like rice, fruit trees and nut trees, are water-intensive and require extensive groundwater pumping during droughts. Over time, heavy water extraction has contributed to changes in the aquifer systems under the San Joaquin and Sacramento valleys. Although some of these changes can be reversed, a new study, published in the Proceedings of the National Academy of Sciences, indicates that large parts of the Sacramento Valley may have undergone irreversible ground compaction during recent droughts, leading to a permanent loss of groundwater storage.

In August of 2020, intense winds accompanied a severe thunderstorm that ripped through the Great Plains. Gusts up to 100 miles (160 kilometers) per hour produced 26 tornadoes, destroyed crops, took roofs off houses, knocked out power, and killed four people.

The storm was a derecho—a fast-moving, destructive windstorm that forms under unique conditions.

Radar shows the 10 August 2020 derecho at 1-hour time steps as it moved across the Plains and Midwest states. Credit: NOAA/NWS

Scientists track extreme weather phenomena like tornadoes, hurricanes, and derechos in detail to aid in forecasting and communication to the public. But definitions for derechos have always varied, and a comprehensive inventory of them had never existed, until now. A new study, published in the Bulletin of the American Meteorological Society, presents the country’s first archive of derechos, offering scientists a better opportunity to understand the drivers behind these destructive storms.

“We’re trying to objectively identify these events,” said Brian Squitieri, lead author of the new study and a meteorologist at NOAA’s Storm Prediction Center.

Assembling an Archive

“For a long time, meteorologists have taken the approach of ‘It’s hard to define a derecho, but I know one when I see one.’”

The definition of the term “derecho” has been difficult for scientists to pin down: “For a long time, meteorologists have taken the approach of ‘It’s hard to define a derecho, but I know one when I see one,’” said Michael Coniglio, a meteorologist at NOAA’s National Severe Storms Laboratory who was not involved in the new study.

In a 2025 paper, Squitieri and others put forth a new definition of the term that required a windstorm to meet strict requirements for wind gusts and develop from a “cold pool-driven mesoscale convective system” (MCS)—a specific type of thunderstorm cluster resulting from a collection of cold air.

Creating an archive of derechos required applying this new definition to past events. Squitieri ensured that the criteria focused on the distinct physical atmospheric processes that lead to a derecho, rather than “just any large-scale thunderstorm wind event,” he said.

With their criteria in hand, the research team analyzed 2 decades’ worth of detailed data from the Next Generation Weather Radar (NEXRAD) system, operated by the National Weather Service, the Federal Aviation Administration, and the U.S. Air Force. Within the NEXRAD data (1996–2025), they found 96 definitive derechos and 13 likely derechos.

Prior to the NEXRAD era, NOAA used hand-drawn paper maps to summarize radar data and collected storm reports in various formats. Squitieri and the research team combed through more than 2,000 paper maps and more than 22,500 storm reports to identify likely past derechos dating back to 1955. Still, without NEXRAD data, none of the likely derechos from 1955 to 1995 could fully fulfill the team’s criteria. Instead, they identified 48 likely derechos and 16 possible derechos.

“There have been lots of attempts at this over the years,” Coniglio said. The new study, he said, “is an incredibly detailed and thorough paper that I think is now the definitive piece of research that we have out there to know if something is a derecho or not.”

Derecho Behavior

From the new archive, the researchers were able to distinguish patterns in derecho behavior in the United States. The archive confirmed that derechos typically form in three corridors: the Midwest/Ohio Valley, the Northern Plains, and the Southern Plains.

The team also noticed the impressive impact of derechos in the data. “There are a lot of common factors that seem to stick out in reports [of derechos] that are a little bit more unique than what you see with a lot of other wind events,” Squitieri said.

In particular, the identified derechos had large, long-lasting effects on communities, sometimes being responsible for dozens of deaths or leaving towns without power for days. In many cases, derechos caused the worst power outages in a town’s or region’s history. “That’s quite a title for derechos to compete with, but some have achieved that,” Squitieri said.

Satellite imagery shows the 20 June 2025 derecho moving across North Dakota. Credit: CSU/CIRA & NOAA

Some written reports of derechos compared the destruction left in their wake to the effects of hurricanes. Squitieri emphasized that just because a certain windstorm doesn’t meet the derecho criteria doesn’t mean it’s not dangerous and that plenty of windstorms that are not derechos still have tremendous impacts.

Future Forecasts

The derecho archive is another step in NOAA’s goals of ultimately being able to better forecast derechos and better communicate derecho risk to the public. Scientists can use the archive to assess what conditions seem to be present for the formation of derechos compared to other wind events.

“We might be able to cue in on a clue for these higher-impact events more cleanly,” Squitieri said.

“Classifying these things ahead of time can help [meteorologists] understand what to look for and what to communicate to the public.”

The Storm Prediction Center has already begun to study the ambient environments that seem to create derechos to parse out signals that forecasters could use, with promising results, he added.

NOAA is also working to develop a MCS wind swath classification system similar to the Saffir-Simpson Hurricane Wind Scale to help forecasters communicate the risk of wind events to the public. This scale would classify all MCS wind swaths into two types: squall-line wind swaths and those driven by cold pools. Squitieri imagines that a 4 or 5 on the cold-pool-driven scale would be a derecho or “super derecho,” respectively, and lower numbers would be used to describe the risks posed by less severe storms. He hopes that such a scale would be operational sometime in 2027 or 2028.

“Classifying these things ahead of time can help [meteorologists] understand what to look for and what to communicate to the public,” Coniglio said.

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

Citation: van Deelen, G. (2026), What drives derechos? The first derecho archive could help meteorologists figure it out., Eos, 107, https://doi.org/10.1029/2026EO260245. Published on 28 July 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: Journal of Geophysical Research: Machine Learning and Computation

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

单个地震仪通常不足以可靠地探测地震或地下核试验等人类活动。因此，研究人员通常会结合分布在小范围地理区域内的多个地震仪的读数，来提高分析的可靠性。Köhler 等人的一项新研究表明，人工智能 (AI) 可以比传统技术更有效地整合来自多个传感器的读数，从而更可靠地探测微弱的地震信号。

研究人员利用挪威地震研究基金会 NORSAR和其他运营商运营的地震阵列 30 年的观测数据，并通过三种不同的方式训练了一个 AI 模型来探测地震信号。首先，他们每次使用一个台站的数据训练模型，然后应用该模型并将每个台站的结果合并。其次，他们使用传统技术合并同一阵列中多个传感器的信号，然后使用来自多个台站的这些合并信号训练模型。第三，他们将来自所有阵列台站的所有数据都提供给模型，让模型自行决定如何合并这些数据。

第二种方法（训练前合并信号）能够放大微弱信号，其信号检测精度在三种方法中最高。同时，第三种模型（由模型自行决定如何合并台站数据）是计算效率最高的策略，其精度介于其他两种方法之间。

考虑到需要在精度和速度之间取得平衡，研究人员建议在进行实时监测时由模型自行决定如何合并数据，而在可以接受较慢速度的情形中，可以在应用模型之前或之后合并数据。

然而，由于使用区域性有限的训练数据集，该模型对训练区域之外的区域泛化能力较差。若能使用全球数据进行训练，有望改进结果。这一问题主要出现在S波检测中，在P波检测的泛化能力方面则未出现类似问题。

总体而言，结果表明，人工智能可以通过帮助研究人员检测地震、地下核试验和其他地震活动中难以识别的微弱信号来提升地震监测能力。(Journal of Geophysical Research: Machine Learning and Computation, https://doi.org/10.1029/2026JH001249, 2026)

—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。

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