Effects of geomagnetic mirror force and pitch angles of precipitating electrons on ionization of the polar upper atmosphere Annales Geophysicae DOI 10.5194/angeo-43-621-2025 23 October 2025 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. Read more
nextGEMS: entering the era of kilometer-scale Earth system modeling Geoscientific Model Development DOI 10.5194/gmd-18-7735-2025 23 October 2025 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. Read more
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. Read more
Insights into mesoscale eddy dynamics: a three-dimensional perspective on potential density anomalies Ocean Science DOI 10.5194/os-21-2527-2025 22 October 2025 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. Read more
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. Read more
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