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10 20 50

Drivers and impacts of westerly moisture transport events in East Africa

Anomalous westerly winds bring moisture into East Africa, increasing precipitation in the region. Using the first spatially unconstrained framework to detect this circulation and associated precipitation, we show westerlies contribute up to 60% of rainfall in Tanzania in January and February, and are more likely when the Madden Julian Oscillation and/or tropical cyclones are active over the Indian Ocean. This work highlights the complex interactions driving regional precipitation variability.

Automated mask generation in citizen science smartphone photos and their value for mapping plant species in drone imagery

We introduce an automated approach for generating segmentation masks for citizen science plant photos, making them applicable to computer vision models. This framework effectively transforms citizen science data into a data treasure for segmentation models for plant species identification in aerial imagery. Using automatically labeled photos, we train segmentation models for mapping tree species in drone imagery, showcasing their potential for forestry, agriculture, and biodiversity monitoring.

Reviews and syntheses: Best practices for the application of marine GDGTs as proxy for paleotemperatures: sampling, processing, analyses, interpretation, and archiving protocols

Many academic laboratories worldwide process environmental samples for analysis of membrane lipid molecules of archaea, for the reconstruction of past environmental conditions. However, the sample workup scheme involves many steps, each of which has a risk of contamination or bias, affecting the results. This paper reviews steps involved in sampling, extraction and analysis of lipids, interpretation and archiving of the data. This ensures reproducible, reusable, comparable and consistent data.

Milankovitch theory “as an initial value problem”: Implications of the long memory of ice advection

We describe a so far unrecognized physical phenomenon of orbital forcing modifying the terrestrial physics in such a way that instead of erasing the memory of initial conditions this memory is extended and initial values become major governing parameters.

Estimates of Atlantic meridional heat transport from spatiotemporal fusion of Argo, altimetry, and gravimetry data

Understanding how heat moves through the ocean is crucial to predicting future climate change confidently. This requires accurate records of heat transport throughout the ocean, but these are challenging to obtain by direct ocean observation. Here, we combine in situ and satellite-based observations to generate estimates of meridional heat transport for the period 2004–2020 at 3-month resolution across the Atlantic Ocean with improved accuracy compared to existing indirectly inferred estimates.

Global and regional sea-surface temperature changes over the Marine Isotopic Stage 9e and Termination IV

To better understand climate change in past warm periods, we studied global ocean temperature during an interglacial period about 330,000 years ago. Combining 98 records on common timeline, we found regional differences in the timing and amplitude of changes, which smoothed the global signal. We also show that the deglacial warming rate was about three times lower than today's global warming rate.

Formation of mega-scale glacial lineations far inland beneath the onset of the Northeast Greenland Ice Stream

The subglacial landforms beneath actively fast-flowing ice in Greenland have not been explored in detail, as digital elevation models have not had a high enough resolution to see these features. We use swath radar imaging to visualise landforms at the onset of an ice stream, revealing mega-scale glacial lineations, that would usually be assumed to be indicative of faster ice flow than the current velocities. Interpretation of the landscape also gives an indication of the properties of the bed.

Properties of large-amplitude kilometer-scale field-aligned currents at auroral latitudes, as derived from Swarm satellites

By using magnetic field recordings sampled at 50 Hz by Swarm A and C satellites around the quasi-coplanar orbit configuration, near 1 October 2021, we investigate the properties of kilometer-scale field-aligned currents (FACs) at auroral latitudes. The kilometer-scale (0.2-5 km) FACs exhibit short-lived (<1 s) randomly appearing large current density spikes (partly exceeding 100 µA m-2). Preferred occurrences are the noon to prenoon (nightside to dusk) sector around 80° (70°) MLat, respectively.

Thwaites Eastern Ice Shelf cavity observations reveal multiyear sea ice dynamics and deepwater warming in Pine Island Bay, West Antarctica

Thwaites Glacier is retreating due to warm ocean water melting it from below, but its thick ice shelf makes this heat hard to monitor. Using hot-water drilling, we placed sensors beneath the floating ice, revealing how surface freezing in Pine Island Bay influences heat at depth. Alongside gradual warming, we found bursts of heat that could speed up melting at the grounding zone, which may become more common as sea ice declines.

Review of interactive open-access publishing with community-based open peer review for improved scientific discourse and quality assurance

Over 25 years, the European Geosciences Union (EGU) has demonstrated the success, viability and benefits of interactive open-access (OA) publishing with public peer review in its journals, its publishing platform EGUsphere and virtual compilations. The article summarizes the evolution of the EGU/Copernicus publications and of OA publishing with interactive public peer review at large by placing the EGU/Copernicus publications in the context of current and future global open science.

The role of the tropical carbon balance in determining the large atmospheric CO₂ growth rate in 2023

The year 2023 saw unexpectedly large global atmospheric CO₂ growth. Satellite data reveal a role for increased tropical emissions. Larger emissions over eastern Brazil can be explained by warmer temperatures, which has led to exceptional drought, while hydrological changes play more of a role in emission increases elsewhere in the tropics. Broadly, we find that this situation continues into 2024.

Effects of geomagnetic mirror force and pitch angles of precipitating electrons on ionization of the polar upper atmosphere

The magnetic mirror force bends the orbits of electrons precipitating into the atmosphere. It has been suggested that relativistic electrons make much less ionization due to the force than if it did not exist, but the actual effectivity in the atmospheric electron density has not been revealed. We used conjugated observational data from the ELFIN (Electron Losses and Fields INvestigation) satellite and the EISCAT (European Incoherent SCATter scientific radar system) Tromsø radar to find that the electron density decreased by about 40 % at 80 km altitude because of the force.

nextGEMS: entering the era of kilometer-scale Earth system modeling

The Next Generation of Earth Modeling Systems project (nextGEMS) developed two Earth system models that use horizontal grid spacing of 10 km and finer, giving more fidelity to the representation of local phenomena, globally. In its fourth cycle, nextGEMS simulated the Earth System climate over the 2020–2049 period under the SSP3-7.0 scenario. Here, we provide an overview of nextGEMS, insights into the model development, and the realism of multi-decadal, kilometer-scale simulations.

Experiences and Lessons Learned from Designing and Testing of an Air System and a Drilling Fluid Circulation System Adapted for Subglacial Bedrock Sampling in Antarctica

Geoscientific Instrumentation, Methods and Data Systems
DOI 10.5194/gi-14-277-2025
23 October 2025

A multi-process drilling system (MPDS), comprising an air system and a drilling-fluid circulation system (DFCS) was developed in China for subglacial bedrock sampling. The air system and DFCS were highly integrated in 20 ft container for easy transportation and assembly. Both systems were tested in China and Antarctica. The experiences and lessons learned in designing and testing would be helpful to promote the development of subglacial bedrock drilling technology.

Insights into mesoscale eddy dynamics: a three-dimensional perspective on potential density anomalies

Mesoscale eddies, characterized by rotating currents, are ubiquitous in the ocean. However, their three-dimensional structure remains poorly observed and analyzed, with transport estimates often relying on approximations. To better quantify their shape, we propose a new theoretical framework based on geophysical fluid dynamics and apply it to field observations.

Representing soil landscapes from digital soil mapping products – helping the map to speak for itself

SOIL
DOI 10.5194/soil-11-849-2025
21 October 2025

Soil maps are useful for many applications, e.g., hydrology, agriculture, ecology, and civil engineering. The dominant mapping method is Digital Soil Mapping (DSM), which uses training observations and machine-learning to predict per-pixel. Accuracy is assessed by statistical evaluation at known points, but soils occur in spatial patterns. We present methods for helping the map to "speak for itself" to reveal patterns of the soil landscape.

MOSAiC studies of long-lasting mixed-phase cloud events and analysis of the liquid-phase properties of Arctic clouds

We studied the water and ice phases of Arctic mixed-phase clouds (MPCs) using dual FOV polarization lidar and Doppler radar on board Polarstern during the MOSAiC expedition. Two long-lasting Arctic MPCs and year-round statistics show persistent droplet activation and dominant immersion freezing, indicating well-filled cloud condensation nuclei and ice-nucleating particle reservoirs. These findings help explain MPC longevity and may improve cloud life cycle representation in weather and climate models.

Estimating return periods for extreme events in climate models through Ensemble Boosting

Weather extremes have become more frequent due to climate change. It is therefore crucial to understand them, but since they are rarer than average weather, they are challenging to study. Ensemble Boosting (EB) is a tool that generates extreme climate model events efficiently, but without directly estimating their probability. Here, we present a method to recover these probabilities for a global climate model. EB can thus now be used to find extremes with meaningful statistical information.

Mercury contamination in staple crops impacted by artisanal and small-scale gold mining (ASGM): stable Hg isotopes demonstrate dominance of atmospheric uptake pathway for Hg in crops

Air, soil, and three common staple crops were assessed at an artisanal and small-scale gold mining (ASGM) processing site, and mercury (Hg) contamination was observed at a farm ≈ 500 m from the processing site. Of the crop tissues examined, foliage had the highest concentrations. Mercury stable isotopes indicate uptake of mercury from the air to the foliage as the dominant uptake pathway. Using typical dietary data for Nigerians, Hg intake from these crops was below reference dose levels and generally safe for consumption.

AR6 updates to RF by GHGs and aerosols lowers the probability of accomplishing the Paris Agreement compared to AR5 formulations

We show that recent assessed updates to the future abundance and radiative forcing (RF) of greenhouse gases (GHGs) and tropospheric aerosols result in a 0.2 to 0.4 ⁰C rise in global mean surface temperature by the end of the century, relative to prior projections. For society to have confidence in achieving the 2 ⁰C warming limit of the Paris Agreement, the RF due to GHGs and aerosols must be placed close to the primary 2.6 W m⁻² Shared Socioeconomic Pathway scenario (SSP1−2.6) over the coming decades.

TICOI: an operational Python package to generate regular glacier velocity time series

While global annual glacier velocities are openly accessible, sub-annual velocity time series are still lacking. This hinders our ability to understand flow processes and the integration of these observations in numerical models. We introduce an open source Python package called TICOI (Temporal Inversion using linear Combinations of Observations, and Interpolation) to fuse multi-temporal and multi-sensor image-pair velocities produced by different processing chains to produce standardized sub-annual velocity products.

A dilatant visco-elasto-viscoplasticity model with globally continuous tensile cap: stable two-field mixed formulation

We present a simple plasticity model that can be used for robust modeling of strain localization in both shear and tensile failure regimes. The new model overcomes the difficulty related to combining these regimes and enables for particularly simple and reliable numerical implementation, which delivers regularized solutions that are insensitive to mesh resolution. We describe algorithmic details and demonstrate the applications to a number of relevant strain localization problems.

A tracer study for the development of in-water monitoring, reporting, and verification (MRV) of ship-based ocean alkalinity enhancement

Ocean alkalinity enhancement (OAE) is a carbon removal approach in which alkaline materials are added to the marine environment, increasing the ocean's ability to store carbon dioxide. We conducted an open-water experiment releasing and tracking a fluorescent water tracer. Under the right conditions, in-water monitoring of OAE does appear to be possible. We conclude with a series of practical recommendations for open-water OAE monitoring.

Mapping the safe operating space of marine ecosystems under contrasting emission pathways

Anthropogenic greenhouse gas emissions significantly impact ocean ecosystems through climate change and acidification, leading to either progressive or abrupt changes. This study maps the crossing of physical and ecological limits for various ocean impact metrics under three emission scenarios. Using Earth system models, we identify when these limits are exceeded, highlighting the urgent need for ambitious climate action to safeguard the world's oceans and ecosystems.

Tipping points in ocean and atmosphere circulations

In this work, we draw on palaeo-records, observations, and modelling studies to review tipping points in the ocean overturning circulations, monsoon systems, and global atmospheric circulations. We find indications for tipping in the ocean overturning circulations and the West African monsoon, with potentially severe impacts on the Earth system and humans. Tipping in the other considered systems is regarded as conceivable but is currently not sufficiently supported by evidence.

Place-based science from Okinawa: 18th-century climate and geology recorded in Ryukyuan classical music

Indigenous Ryukyuan music records the 18th-century climate and geology of the Ryukyu Kingdom (21st-century Okinawa Prefecture, Japan). By collaborating with Ryukyuan cultural practitioners, we find that two seafaring songs detail the winds, ocean currents, and volcanoes that historical voyagers faced during envoys to Kyushu, Japan. Educators can use such observations in place-based learning to increase environmental science engagement in 21st-century Okinawa and the Okinawan diaspora worldwide.

Extensive fire-driven degradation in 2024 marks worst Amazon forest disturbance in over 2 decades

The Amazon forest faces increasing wildfires due to extreme drought and human activity. In 2024, disturbances surged by 152 %, hitting a 20-year high. Forest degradation from fires grew by over 400 %, exceeding that from deforestation. Brazil and Bolivia were hit hardest. These fires released huge amounts of CO₂, 7 times more than in recent years, pushing the Amazon towards a dangerous tipping point. Urgent action is needed to prevent irreversible harm.

Increased future ocean heat uptake constrained by Antarctic sea ice extent

Future projections of global ocean heat uptake (OHU) strongly differ between climate models. Here, we reveal an observational constraint on future OHU based on historical Antarctic sea ice extent observations. This emergent constraint is based on a coupling between sea ice, deep- and surface ocean temperatures, and cloud feedback. It implies an upward correction of 2024–2100 global OHU projections by up to 14 % and suggests that previous constraints have underestimated future warming.

The coupled oxygen and carbon dynamics in the subsurface waters of the Gulf and Lower St. Lawrence Estuary and implications for artificial oxygenation

We combine two decades of oxygen data with new carbon observations and a tracer-informed model to quantify oxygen loss and carbon buildup in the deep waters of the Gulf and Lower St. Lawrence Estuary. We then test a novel idea: reoxygenating these waters with the oxygen produced as a by-product from green-hydrogen production. Our results suggest this could significantly reduce hypoxia, though full recovery would require larger inputs.

Insights from hailstorm track analysis in European climate change simulations

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-25-3693-2025
1 October 2025

Hailstorms can cause severe damage to homes, crops, and infrastructure. Using high-resolution climate simulations, we tracked thousands of hailstorms across Europe to study future changes. Large hail will become more frequent, hail-covered areas will expand, and instances of extreme hail combined with heavy rain will double. These shifts could increase risks for communities and businesses, highlighting the need for better preparedness and adaptation.

Visualising historical changes in air pollution with the Air Quality Stripes

The Air Quality Stripes images visualise historical changes in particulate matter air pollution in over 150 cities worldwide. The project celebrates significant improvements in air quality in regions like Europe, North America, and China while highlighting the urgent need for action in areas such as central Asia. Designed to raise awareness, the images aim to inspire discussions about the critical impact of air pollution and the global inequalities it causes.

Food trade disruption after global catastrophes

The global food trade system can handle small disturbances, but large disasters could cause major disruptions. We looked at how nuclear war or severe infrastructure loss would affect global trade in key crops. Both would be catastrophic, but a nuclear war would cause more severe disruptions, with many countries losing most of their food imports. Both scenarios highlight the need for better preparation to protect global food security.

Physiological responses to ultra-high CO₂ levels in an evergreen tree species

Biogeosciences
DOI 10.5194/bg-22-5069-2025
28 September 2025

As atmospheric CO₂ increases globally, plants increase the rate of photosynthesis. Still, leaf–gas exchange can be downregulated by the plant. Here we tested the limits of these plant responses in a fruit tree species under very high CO₂ levels relevant to the future Earth and to contemporary Mars. Plant water use decreased at 1600 ppm CO₂ and remained low at 6000 ppm. Photosynthesis significantly increased at 6000 ppm. In summary, ultra-high CO₂ may partly compensate for limited water availability.

Technical note: Pondi – a low-cost logger for long-term monitoring of methane, carbon dioxide, and nitrous oxide in aquatic and terrestrial systems

Biogeosciences
DOI 10.5194/bg-22-5051-2025
27 September 2025

The Pondi is a cost-effective, lightweight logger designed for long-term monitoring of carbon dioxide, methane, and nitrous oxide emissions in both terrestrial and aquatic ecosystems. It addresses key challenges in greenhouse gas monitoring by providing an automated, low-cost, solar-powered solution with cloud connectivity and real-time analytics. Its robust design enables deployment in diverse environmental conditions, supporting large-scale, high-resolution emission assessments.

Learning predictable and informative dynamical drivers of extreme precipitation using variational autoencoders

Large-scale atmospheric dynamics modulate the occurrence of extreme events and can improve their prediction. We present a generative machine learning method to identify key dynamical drivers of an impact variable in the form of targeted circulation regimes. Applied to extreme precipitation in Morocco, we show that these targeted regimes are more predictive of the impact while preserving their own predictability and physical consistency.

4D GPR imaging of a near-terminus glacier collapse feature

The Cryosphere
DOI 10.5194/tc-19-4045-2025
25 September 2025

We demonstrate the use of a drone-based ground-penetrating radar (GPR) system to gather high-resolution, high-density 4D data over a near-terminus glacier collapse feature. We monitor the growth of an air cavity and the evolution of the subglacial drainage system, providing insights into the dynamics of the collapse event. This work highlights potential future applications of drone-based GPR for monitoring glaciers, in particular in regions which are inaccessible by surface-based methods.

Impacts of eutrophication and deoxygenation on the sediment biogeochemistry in the Sea of Marmara

Biogeosciences
DOI 10.5194/bg-22-4953-2025
24 September 2025

This study aims to understand the impacts of deoxygenation and eutrophication on sedimentary biogeochemical processes in the Sea of Marmara. We showed that diffusive phosphorus and fixed nitrogen fluxes were markedly high under highly eutrophic and hypoxic areas of the Sea of Marmara. This benthic feedback may exacerbate the ongoing eutrophication and deoxygenation in the Sea of Marmara, which is now at risk of becoming one of the major marine dead zones.

Multidecadal trends in CO₂ evasion and aquatic metabolism in a large temperate river

Biogeosciences
DOI 10.5194/bg-22-4923-2025
23 September 2025

To understand the role of rivers in the global carbon cycle, this 32-year study tracked carbon dioxide in France's Loire River. We found emissions decreased over the long term, despite varying more than tenfold from year to year. While the river ecosystem shifted from algae to plant dominance, this decrease in emissions was primarily driven by reduced groundwater inputs. This shows that catchment-scale hydrology can be more important than in-river biology for a river's carbon footprint.

The Arctic Weather Satellite radiometer

The Arctic Weather Satellite (AWS), developed by the European Space Agency, highlights a new approach in satellite design, aiming to expand the network of operational microwave sensors cost-effectively. Launched in August 2024, AWS features a 19-channel microwave cross-track radiometer. Notably, it introduces groundbreaking channels at 325.15 GHz. In addition, AWS acts as the stepping stone to a suggested constellation of satellites, denoted as EUMETSAT Polar System Sterna.

Assessment of source regions of the Zambezi River: implications for regional water security

This study focused on the sources of the Zambezi River, revealing new insights into its longest tributary and Angola's key role in its flow. River expeditions and earth observation data show that Angola contributed approximately 73 % of the river's flow upstream of a major floodplain during the 2023 late wet season. We highlight Angola's wetlands, which support river health and help mitigate pollution. These findings stress the need for improved monitoring and regional cooperation in the basin.

Peatland development reconstruction and complex biological responses to permafrost thawing in Western Siberia

Biogeosciences
DOI 10.5194/bg-22-4797-2025
20 September 2025

Western Siberian peatlands regulate global climate, but their response to permafrost thaw remains poorly studied. Our study analyzed peat cores from a peat plateau and a lake edge to track changes over two centuries. We found that permafrost thawing, driven by rising temperatures, altered peatland hydrology, vegetation, and microbial life. These shifts may expand with further warming, affecting carbon storage and climate feedbacks. Our findings highlight early warning signs of ecosystem change.

The historical representation and near-future (2050) projections of the Coral Sea current system in CMIP6 HighResMIP

Ocean Science
DOI 10.5194/os-21-2001-2025
17 September 2025

We examined projected changes in Coral Sea temperature and currents through to 2050 using high-resolution CMIP6 models. Surface warming deepened by 30 m per decade, reaching 400 m by 2050. There was sub-surface cooling between 400 and 600 m. North Vanuatu Jet and North Caledonian Jet transports weakened, and the South Caledonian Jet strengthened. These changes may influence western boundary currents and upwelling dynamics on the Great Barrier Reef.

The 1538 eruption at the Campi Flegrei resurgent caldera: implications for future unrest and eruptive scenarios

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-25-3421-2025
16 September 2025

We compare recent unrest episodes at the Campi Flegrei caldera (Naples, Italy) with phenomena that occurred during the historical eruption in 1538. Besides proposing a new, accurate reconstruction of the ground movements in the area since the 8th century BCE, we deduce a striking similarity of the present unrest with the precursors to the 1538 eruption. We then infer that, if the ground uplift continues, earthquakes of up to magnitude 5 are expected, as well as a considerable eruption risk in the next few decades.

Drift-aware sea ice thickness maps from satellite remote sensing

The Cryosphere
DOI 10.5194/tc-19-3785-2025
16 September 2025

We developed a new method to map Arctic sea ice thickness daily using satellite measurements. We address a problem similar to motion blur in photography. Traditional methods collect satellite data over 1 month to get a full picture of Arctic sea ice thickness. But in the same way as in photos of moving objects, long exposure leads to motion blur, making it difficult to identify certain features in the sea ice maps. Our method corrects for this motion blur, providing a sharper view of the evolving sea ice.

ESD Ideas: Climate tipping is not instantaneous – the duration of an overshoot matters

Climate tipping points are not committed upon crossing critical thresholds in global warming, as is often assumed. Instead, it is possible to temporarily overshoot a threshold without causing tipping, provided the duration of the overshoot is short. In this Idea, we demonstrate that restricting the time over 1.5 °C would considerably reduce tipping point risks.

Linking crystallographic orientation and ice stream dynamics: evidence from the EastGRIP ice core

The Cryosphere
DOI 10.5194/tc-19-3805-2025
15 September 2025

A better understanding of ice flow requires more observational data. The EastGRIP core is the first ice core through an active ice stream. We discuss crystal orientation data determining the present deformation regimes. A comparison with other deep cores shows the unique properties of EastGRIP and shows that deep ice likely originates from the Eemian. We further show that the overall plug flow of NEGIS is characterised by many small-scale variations, which remain to be considered in ice flow models.

Organic soils can be CO₂ sinks in both drained and undrained hemiboreal peatland forests

Biogeosciences
DOI 10.5194/bg-22-4627-2025
14 September 2025

A 2-year study assessed the soil carbon dioxide (CO₂) balance of drained and undrained hemiboreal peatland forests across Estonia, Latvia, and Lithuania. The study sites included a wide variety of nutrient-rich organic soils, ranging from those near the threshold of organic soil definition to deep peat soils. The soils varied in pH, nutrient levels, and C : N ratio, which contributed to the observed behavior of the soils, demonstrating CO₂ sink and source dynamics under both drained and undrained conditions.

Severe beach erosion induced by shoreline deformation after a large-scale reclamation project for the Samcheok liquefied natural gas (LNG) terminal in South Korea

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-25-3239-2025
10 September 2025

This paper emphasizes the significance of evaluating changes in nearby shorelines prior to undertaking large-scale coastal construction projects, thereby offering insights into strategies that can minimize potential damage. As a result, the study provides an opportunity to explore the consequences of harbor and fishing port development, as well as large-scale reclamation, which can deform wave fields in coastal areas and intensify coastal erosion.

Multi-centennial climate change in a warming world beyond 2100

A new 10-member ensemble simulation with the state-of-the-art Earth system model was employed to study the long-term climate response to sustained greenhouse warming through to the year 2500. The findings show that the projected changes in the forced mean state and internal variability during 2101–2500 differ substantially from the 21st-century projections, emphasizing the importance of multi-century perspectives for understanding future climate change and informing effective mitigation strategies.

Failure of Marmolada Glacier (Dolomites, Italy) in 2022: data-based back analysis of possible collapse mechanisms

Natural Hazards and Earth System Sciences
DOI 10.5194/nhess-25-3027-2025
5 September 2025

The Marmolada Glacier collapse (3 July 2022), one of the deadliest in the Alps, caused 11 fatalities and occurred during an anomalously warm summer. Analysis links the failure to the combined action of permafrost degradation, elevated ice temperatures, hydrostatic pressure, hydraulic jacking and reduced basal friction. No single factor alone explains the failure. The event highlights how climate-driven thermal and hydraulic factors increasingly threaten the stability of cold mountain glaciers.