Calibrated sea level contribution from the Amundsen Sea sector, West Antarctica, under RCP8.5 and Paris 2C scenarios The Cryosphere DOI 10.5194/tc-19-2527-2025 21 July 2025 Glaciers in the Amundsen Sea region of Antarctica have been retreating and losing mass, but their future contribution to global sea level rise remains highly uncertain. We use an ice sheet model and uncertainty quantification methods to evaluate the probable range of mass loss from this region for two future climate scenarios. We find that the rate of ice loss until 2100 will likely remain similar to present-day observations, with little sensitivity to climate scenario over this short time frame. Read more
Delineating the technosphere: definition, categorization, and characteristics Earth System Dynamics DOI 10.5194/esd-16-979-2025 18 July 2025 The technosphere – including buildings, infrastructure, and all other non-living human creations – is a major part of our planet, but it is not often considered as an integrated part of Earth system processes. Here we propose a refined definition of the technosphere, intended to help with integration. We also characterize the functional end uses, map the global distribution, and discuss the catalytic properties that underlie the exponential growth of the trillion tonne technosphere. Read more
Distribution of alkylamines in surface waters around the Antarctic Peninsula and Weddell Sea Biogeosciences DOI 10.5194/bg-22-3429-2025 18 July 2025 During the PolarChange expedition, volatile alkylamines, important players in nitrogen cycling and cloud formation, were measured in Antarctic waters using a high-sensitivity method. Trimethylamine was the dominant alkylamine in marine particles, associated with nanophytoplankton. Dissolved dimethylamine likely originated from trimethylamine degradation, while diethylamine sources remain unclear. These findings confirm the biological origin of alkylamines in polar marine microbial food webs. Read more
Observational constraints suggest a smaller effective radiative forcing from aerosol–cloud interactions Atmospheric Chemistry and Physics DOI 10.5194/acp-25-7299-2025 17 July 2025 This study addresses the long-standing challenge of quantifying the impact of aerosol–cloud interactions. Using satellite observations, reanalysis data, and a "perfect-model" cross-validation, we show that explicitly accounting for aerosol–cloud droplet activation rates is key to accurately estimating ERFaci (effective radiative forcing due to aerosol–cloud interactions). Our results indicate a smaller and less uncertain ERFaci than previously assessed, implying the reduced role of aerosol–cloud interactions in shaping climate sensitivity. Read more
Simulating vertical phytoplankton dynamics in a stratified ocean using a two-layered ecosystem model Biogeosciences DOI 10.5194/bg-22-3253-2025 16 July 2025 Phytoplankton contribute to half of Earth’s primary production, but not a lot is known about subsurface phytoplankton, living at the base of the sunlit ocean. We develop a two-layered box model to simulate phytoplankton seasonal and interannual variations in different depth layers of the ocean. Our model captures seasonal and long-term trends of the two layers, explaining how they respond to a warming ocean, furthering our understanding of how phytoplankton are responding to climate change. Read more
Long-term observations of atmospheric CO2 and CH4 trends and comparison of two measurement systems at Pallas-Sammaltunturi station in Northern Finland Atmospheric Measurement Techniques DOI 10.5194/amt-18-3109-2025 16 July 2025 This paper presents long-term observations of atmospheric CO2 and CH4 mole fractions and a comparison of two permanent and two mobile measurement systems located in Northern Finland. Furthermore, the observed mole fractions are compared against the mean marine boundary layer product for the Northern Hemisphere. The comparisons of all the systems show good agreement in relation to the World Meteorological Organization/Global Atmosphere Watch network compatibility goal limits for CO2 and CH4. Read more
Evidence for multi-rifting in the Variscan–Alpine cycle transition: insights from the European western Southern Alps Solid Earth DOI 10.5194/se-16-619-2025 14 July 2025 We address the transition between the Paleozoic Variscan and Alpine Mesozoic–Cenozoic cycles using tectono-stratigraphy and thermochronology. This transition unfolds through a multi-phase rifting history. An initial rifting stage occurred in the early Permian, followed in the early–middle Permian by a phase of transcurrent tectonics. This was succeeded by a period of erosion/non-deposition in the middle Permian. Crustal stretching in the Middle Triassic marked the onset of the Alpine cycle. Read more
Local versus far-field control on South Pacific Subantarctic mode water variability Ocean Science DOI 10.5194/os-21-1237-2025 11 July 2025 Subantarctic mode water in the South Pacific Ocean is important due to its role in the uptake and transport of anthropogenic heat and carbon. The Subantarctic mode water region can be split into two pools using mixed-layer-depth properties. Sensitivity experiments are used to understand the effects of heating and wind on each pool. It is found that the optimal conditions to form large amounts of Subantarctic mode water in the South Pacific are local cooling and upstream warming combined. Read more
First observations of continuum emission in dayside aurora Annales Geophysicae DOI 10.5194/angeo-43-349-2025 9 July 2025 We studied the first broad band emissions, called continuum, in the dayside aurora. They are similar to Strong Thermal Emission Velocity Enhancement (STEVE) with white-, pale-pink-, or mauve-coloured light. But unlike STEVE, they follow the dayside aurora forming rays and other dynamic shapes. We used ground optical and radar observations and found evidence of heating and upwelling of both plasma and neutral air. This study provides new information on conditions for continuum emission, but its understanding will require further work. Read more
Is drought protection possible without compromising flood protection? Estimating the potential dual-use benefit of small flood reservoirs in southern Germany Hydrology and Earth System Sciences DOI 10.5194/hess-29-2785-2025 7 July 2025 In this paper, we use models to demonstrate that even small flood reservoirs – which capture water to avoid floods downstream – can be repurposed to release water in drier conditions without affecting their ability to protect against floods. By capturing water and releasing it once levels are low, we show that reservoirs can greatly increase the water available in drought. Having more water available to the reservoir, however, is not necessarily better for drought protection. Read more