Estimates of Atlantic meridional heat transport from spatiotemporal fusion of Argo, altimetry, and gravimetry data Ocean Science DOI 10.5194/os-21-2743-2025 4 November 2025 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. Read more
Global and regional sea-surface temperature changes over the Marine Isotopic Stage 9e and Termination IV Climate of the Past DOI 10.5194/cp-21-1895-2025 3 November 2025 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. Read more
Formation of mega-scale glacial lineations far inland beneath the onset of the Northeast Greenland Ice Stream The Cryosphere DOI 10.5194/tc-19-5299-2025 31 October 2025 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. Read more
Properties of large-amplitude kilometer-scale field-aligned currents at auroral latitudes, as derived from Swarm satellites Annales Geophysicae DOI 10.5194/angeo-43-667-2025 30 October 2025 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. Read more
Thwaites Eastern Ice Shelf cavity observations reveal multiyear sea ice dynamics and deepwater warming in Pine Island Bay, West Antarctica Ocean Science DOI 10.5194/os-21-2605-2025 29 October 2025 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. Read more
Review of interactive open-access publishing with community-based open peer review for improved scientific discourse and quality assurance Atmospheric Chemistry and Physics DOI 10.5194/acp-25-13903-2025 28 October 2025 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. Read more
The role of the tropical carbon balance in determining the large atmospheric CO2 growth rate in 2023 Atmospheric Chemistry and Physics DOI 10.5194/acp-25-13053-2025 25 October 2025 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. Read more
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