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. Read more
The Arctic Weather Satellite radiometer Atmospheric Measurement Techniques DOI 10.5194/amt-18-4709-2025 22 September 2025 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. Read more
Assessment of source regions of the Zambezi River: implications for regional water security Hydrology and Earth System Sciences DOI 10.5194/hess-29-4557-2025 21 September 2025 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. Read more
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. Read more
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. Read more
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. Read more
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. Read more
ESD Ideas: Climate tipping is not instantaneous – the duration of an overshoot matters Earth System Dynamics DOI 10.5194/esd-16-1523-2025 15 September 2025 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. Read more
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. Read more
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. Read more
