MOSAiC studies of long-lasting mixed-phase cloud events and analysis of the liquid-phase properties of Arctic clouds Atmospheric Chemistry and Physics DOI 10.5194/acp-25-12955-2025 21 October 2025 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. Read more
Estimating return periods for extreme events in climate models through Ensemble Boosting Weather and Climate Dynamics DOI 10.5194/wcd-6-1147-2025 20 October 2025 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. Read more
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 Biogeosciences DOI 10.5194/bg-22-5591-2025 20 October 2025 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. Read more
AR6 updates to RF by GHGs and aerosols lowers the probability of accomplishing the Paris Agreement compared to AR5 formulations Earth System Dynamics DOI 10.5194/esd-16-1739-2025 16 October 2025 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. Read more
TICOI: an operational Python package to generate regular glacier velocity time series The Cryosphere DOI 10.5194/tc-19-4555-2025 15 October 2025 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. Read more
A dilatant visco-elasto-viscoplasticity model with globally continuous tensile cap: stable two-field mixed formulation Geoscientific Model Development DOI 10.5194/gmd-18-7035-2025 14 October 2025 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. Read more
A tracer study for the development of in-water monitoring, reporting, and verification (MRV) of ship-based ocean alkalinity enhancement Biogeosciences DOI 10.5194/bg-22-5511-2025 13 October 2025 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. Read more
Mapping the safe operating space of marine ecosystems under contrasting emission pathways Biogeosciences DOI 10.5194/bg-22-5435-2025 9 October 2025 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. Read more
Tipping points in ocean and atmosphere circulations Earth System Dynamics DOI 10.5194/esd-16-1611-2025 8 October 2025 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. Read more
Place-based science from Okinawa: 18th-century climate and geology recorded in Ryukyuan classical music Geoscience Communication DOI 10.5194/gc-8-251-2025 8 October 2025 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. Read more