Feed aggregator

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

Baroclinic instability, which converts vertical wind shear into energy in storms, is the main driver of the growth of midlatitude storms. However, previous investigations of the relationship between baroclinicity and storm growth have been limited to case studies, idealized simulations, or region-specific analyses.

Hadas and Kaspi [2025] use 83 years of ERA-5 data to analyze the growth and tracks of midlatitude storms. The ERA-5 dataset provides a much wider dataset for analysis, including an estimated 100,000 cyclones and 50,000 anticyclones. The authors find that while storm intensity increases linearly with baroclinicity under mild conditions, under more extreme conditions the traditional linear relationship between baroclinicity and storm activity becomes nonlinear. They attribute this shift to a decrease in the storm growth time with baroclinicity. Based on a Lagrangian analysis, the authors then propose a nonlinear correction better accounting for the relationship of baroclinicity and storm activity under extreme conditions. Such a correction is found to be crucial for advancing our understanding of midlatitude climate.

Citation: Hadas, O., & Kaspi, Y. (2025). A lagrangian perspective on the growth of midlatitude storms. AGU Advances, 6, e2024AV001555. https://doi.org/10.1029/2024AV001555

—Alberto Montanari, Editor, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Described as "Earth's kryptonite twin," jadarite is a rare and fascinating mineral that quickly caught the attention of scientists and Superman fans alike.

A combination of sewage overflows and coastal winds could be sending billions of airborne microplastic particles into the world's coastal towns and cities, a new study published in the journal Scientific Reports suggests.

Northern Australia's annual monsoon season brings relief to drought-stricken lands and revitalizes crops and livestock for farmers. But a study of 150,000 years of climate records shows that the monsoon is likely to intensify—triggering a higher risk of flooding while worsening the impact of droughts in East Asia.

Author(s): Z. J. Chen, Qing Wang, D. J. Liu, S. T. Zhang, R. J. Cheng, X. X. Li, S. Y. Lv, Z. M. Huang, Z. Y. Xu, Qiang Wang, Z. J. Liu, L. H. Cao, and C. Y. Zheng

A moving space-time electron grating can split a laser pulse into two parts, functioning as a pulse splitter. In this paper, the evolution of dynamic gratings generated by two counterpropagating laser pulses with different frequencies is investigated. These gratings are characterized by finite lengt…

[Phys. Rev. E 112, 015203] Published Wed Jul 09, 2025

Yesterday, catastrophic flood swept down the Bhote Kosi river through Tibet and Nepal. At least 28 people have been killed. There is speculation that this might have been a GLOF.

On 8 July 2025, a catastrophic mudslide / flood suddenly struck the Rasuwagadhi border crossing point between Tibet and Nepal, causing extensive damage. The Himalayan Times reports that there are nine confirmed victims, with a further 19 people missing, in Nepal. Xinhua reports that eleven people are missing in Tibet, but it is unclear as to whether the Nepal figures include these people.

The scale of the event is impressive. All India Radio has posted this video to Youtube:-

Meanwhile, the Nepali Times has reported that the bridge at the at the Rasuwagadhi border crossing point was destroyed, along with a significant part of the infrastructure at that location. Four hydroelectric schemes have been damaged or destroyed (Rasuwagadi, Trisuli III, Trisuli and Benighat), removing 8% of Nepal’s generation capacity.

Rasuwagadhi is located at [28.27875, 85.37808], on the Bhote Kosi river. It is going to be important to understand what has happened to cause this flood. There is speculation that this was a glacial lake outburst flood (GLOF), which is very possible. It could also have been the collapse of a landslide dam or a high altitude landslide that transitioned into a debris flow. I’ll keep an eye on the satellite imagery over the coming days, but at the peak of the monsoon, it may take some time to get a clear image.

Kirsten Cook of the Université Grenoble Alpes has posted to Bluesky some seismic data from a station near to Kathmandu (a long distance downstream of Rasuwagadhi), which shows the flood:-

thehimalayantimes.com/nepal/rasuwa…Another destructive Himalayan flood, this time transboundary. And like most of these, we can see the seismic signals created by the flood at a DMG station near Kathmandu. The flood is visible seismically about an hour before it arrived at the Nepali border…

— Kristen Cook (@kristencook.bsky.social) 2025-07-08T21:07:08.342Z

The annual time period in which cross-border trade between Tibet and Nepal is possible is short, so the damage to the border infrastructure is likely to have significant implications for Nepal. The loss of the electricity generating capacity is likely to be a greater issue in the long term.

I have highlighted previously that I am concerned that the risks associated with these catastrophic landslides / floods in Himalayan valleys are not being adequately considered. This is the third time in four years that such an event has caused massive damage to power generation infrastructure (after the 2021 Chamoli event and the 2023 Sikkim event). The investment cases for these projects much be increasingly difficult to justify, which will have a range of significant wider economic implications.

Return to The Landslide Blog homepage Text © 2023. 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.

SummaryWe used broadband ocean bottom seismometer (BBOBS) data from the RHUM-RUM experiment to derive the compliance function and estimate the shear velocity (Vs) structure of the subsurface at several sites beneath the Indian Ocean. The primary objective is to map the geological features of poorly explored marine regions, utilizing the compliance function, a measure of seafloor deformation in response to infragravity pressure signals at low frequencies (0.003 to 0.04 Hz). Compliance is the transfer function between vertical displacement and pressure, which is most sensitive to subsurface shear velocities. Our analytical process involves several data processing steps, including the removal of glitches, filtering out seismic events, minimizing tilt effects, calibrating pressure gauges, searching over the frequency and coherence domains to determine the optimal data window, and performing depth-velocity inversion using Monte Carlo method, specifically the Metropolis-Hastings algorithm. We present the ’ComPy’ software, which automates these processing steps for seafloor compliance analysis. The data, recorded over 13 months in 2012-2013 over a large region stretching from La Reunion Island to the Central Indian Ridge (CIR) and the South-West Indian Ridge (SWIR) (water depths of 3 to 5 km), confirm the stability of the compliance function over time. Depth-velocity inversions of the derived compliance measurements, using the Metropolis-Hastings algorithm, illuminate the Vs structure of the oceanic crust down to 8 km. Low Vs anomalies in the crust at the SWIR are consistent with significant serpentinization of a crustal component of tectonically exhumed mantle-derived peridotites.

SummaryIn this study, we present a new algorithm and accompanying software for 3D gravity inversion of density structures. The algorithm combines the strengths of the Bayesian approach-which incorporates prior model information through a variogram model-with the advantages of the Tikhonov regularization framework to address the challenge of depth resolution. We also provide a detailed derivation of the procedure for calculating and fitting the 3D experimental variogram, which serves as a fundamental input to the algorithm. The software implementing the proposed algorithm was developed using the widely adopted computational programming language Matlab. To evaluate its effectiveness, we conducted four representative experiments, ranging from simple to complex scenarios. The synthetic results demonstrate that incorporating model covariance constraints yields a more localized and better-focused density distribution compared to results obtained without such constraints. Additionally, we tested the algorithm's robustness by introducing noise into the observation data. The results show that the proposed method is resistant to noise and maintains strong performance. Finally, we applied the algorithm and software to real field data and compared the results with those from previous studies. The comparison confirms that our method is capable of producing reliable, high-resolution 3D density models, with the added advantage of integrating prior information.

Understanding whether lakes are fed predominantly by groundwater or rainwater is critical to managing our water resources in the face of droughts and shortages, new research has found.

Across Europe and around the world, melting glaciers are reshaping landscapes and climate systems. Researchers Elzė Buslavičiūtė and Dr. Laurynas Jukna from the Institute of Geosciences at the Faculty of Chemistry and Geosciences, Vilnius University, explain how satellite data is used to monitor glacier movement, assess their response to climate change, and calculate these changes through remote sensing technologies from space.

New research finds that not only will climate change make heat waves hotter and longer, but the lengthening of heat waves will accelerate with each additional fraction of a degree of warming.

A large increase in atmospheric methane between 2020 and 2022 raised concerns that tropical wetland emissions had surged in response to a changing climate, but a study led by the University of Michigan shows that this was not the case. The methane must have come from somewhere else.

A daily mismatch between temperature and humidity, observed in certain mountain and waterside regions, helps regulate atmospheric dryness. According to a new study published in Science Advances, this protective effect may weaken under global warming.

Over the past two centuries, humans have locked up enough water in dams to shift Earth's poles slightly away from the planet's axis of rotation, according to recent research.

Forests are a crucial resource for carbon mitigation, currently offsetting around 20% of North American carbon emissions. As temperatures continue to rise, scientists are rushing to understand how climate change is affecting forests and their carbon sequestering abilities. A new study, published in the Proceedings of the National Academy of Sciences, provides some valuable insight into how warmer winters might hinder the ability of trees to store carbon—despite warmer summers encouraging their growth.

The ocean absorbs carbon from the atmosphere, but exactly how much is uncertain. For instance, estimates from the 2023 Global Carbon Budget ranged from 2.2 billion to 4 billion metric tons of carbon per year. One source of this uncertainty may be that the effects of bubbles have not been incorporated into air-sea carbon flux estimates, according to a new study by P. Rustogi and colleagues published in Global Biogeochemical Cycles.

Existing sea level rise models for coastal cities often overlook the impacts of rainfall on infrastructure. Researchers at the University of Hawai'i at Mānoa discovered that by 2050, large rain events combined with sea level rise could cause flooding severe enough to disrupt transportation and contaminate stormwater inlets across 70% of Waikīkī on O'ahu, Hawai'i, due to interactions with water in the Ala Wai Canal.

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

Atmospheric models describing climate change rely on accurate depictions of chemical transport. Prather [2025] examines the different ways to define the troposphere, a highly chemically heterogeneous domain influenced by a range of chemical sources and sinks, from lightning, wildfires, and pollution to convection and rainfall.

The author builds on previous work proposing the use of the artificial age-of-air tracer e90. After calibrating the e90 tracer, Prather demonstrates its application in calculating the mass of the troposphere and troposphere ozone values, using output from UC Irvine’s chemical transport model, ozonesondes representing northern and southern mid-latitudes and the tropics, and satellite ozone profiles. This work presents a practical demonstration of the calibration of an age-of-air tropopause that could potentially be applied more widely in other models or other age-of-air tracers.  

Citation: Prather, M. J. (2025). Calibrating the tropospheric air and ozone mass. AGU Advances, 6, e2025AV001651. https://doi.org/10.1029/2025AV001651

—Kristina Vrouwenvelder, Executive Editor, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Incoming radiation from the Sun is balanced by reflected and emitted radiation from Earth, but greenhouse gases trap radiation in Earth’s atmosphere, causing energy to accumulate in the atmosphere, oceans, and land.

Mauritsen et al. [2025] discuss how recent work analyzing Earth’s energy imbalance reveals that it is increasing much faster than predicted and is now almost double what has been predicted by climate models. The current discrepancy between the measured energy imbalance and that predicted by climate models is likely caused by a decrease in Earth’s solar reflectivity, possibly because models have not correctly accounted for sea surface temperature patterns or effects of aerosol particles.

Understanding these changes in Earth’s energy imbalance and their effects on global warming is critical to science and policy. However, these measurements rely heavily on several satellites scheduled for decommissioning, threatening our understanding of our climate future.

Citation: Mauritsen, T., Tsushima, Y., Meyssignac, B., Loeb, N. G., Hakuba, M., Pilewskie, P., et al. (2025). Earth’s energy imbalance more than doubled in recent decades. AGU Advances, 6, e2024AV001636. https://doi.org/10.1029/2024AV001636

—Kristina Vrouwenvelder, Executive Editor, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Global Biogeochemical Cycles

The ocean absorbs carbon from the atmosphere, but exactly how much is uncertain. For instance, estimates from the 2023 Global Carbon Budget ranged from 2.2 billion to 4 billion metric tons of carbon per year. One source of this uncertainty may be that the effects of bubbles have not been incorporated into air-sea carbon flux estimates, according to Rustogi et al.

When waves break, they create multitudes of tiny bubbles that carry gases such as carbon dioxide back and forth between the atmosphere and water. Models used to evaluate how fast this exchange occurs typically rely on measurements of wind speed, assuming that wind speed directly relates to the prevalence of bubble-forming waves. However, waves can be affected by other factors as well, meaning this assumption doesn’t always hold.

To assess the role of bubbles in air-sea carbon exchange in more detail, scientists applied a recently developed “bubble-mediated gas transfer theory” to the ocean. As with other models, the bubble-mediated approach incorporates wind strength, but uniquely, it also accounts for wave conditions that form gas-carrying bubbles. The researchers compared the results from their new model to a simpler, wind-only model that ignores the effect of bubbles.

The two models yielded similar estimates for total annual ocean carbon storage, but the bubble-mediated model showed much higher variability, both seasonally and regionally; in some instances, local fluxes it indicated differed by 20%–50% from the wind-only model. The bubble-mediated model also suggested that intense wave activity in the Southern Hemisphere leads to much higher carbon storage than in the relatively calm Northern Hemisphere—a difference that’s not obvious in the wind-only model.

That north-south difference could have implications for interpreting and projecting carbon cycle dynamics in a changing climate. With average wind speeds and wave heights likely to increase with global warming, it is essential to anticipate accurately how these changes will influence ocean carbon storage, the authors say.

The work is also important for marine carbon dioxide removal projects aiming to enhance carbon uptake to mitigate climate change effects, they note. A prerequisite for these efforts is quantifying how much carbon the ocean takes up naturally. Without a comprehensive understanding of the processes affecting uptake, the impacts of such interventions may be vastly under- or overestimated. (Global Biogeochemical Cycles, https://doi.org/10.1029/2024GB008382, 2025)

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

Citation: Sidik, S. M. (2025), More bubbles means more variation in ocean carbon storage, Eos, 106, https://doi.org/10.1029/2025EO250244. Published on 8 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.