Estimating the AMOC from Argo profiles with machine learning trained on ocean simulations Ocean Science DOI 10.5194/os-21-3541-2025 18 December 2025 The Atlantic Meridional Overturning Circulation (AMOC) is a large current system that helps regulating Earth's climate. Monitoring the AMOC relies on fixed instruments anchored to the seafloor. This study explores, in a high-resolution model, whether data from Argo floats, autonomous drifters collecting hydrographic profiles, can be used to monitor the AMOC cost-effectively with the help of Machine Learning. Results suggest that Argo floats can extend AMOC monitoring beyond current fixed arrays. Read more
An extrapolation algorithm for estimating river bed grain size distributions across basins Earth Surface Dynamics DOI 10.5194/esurf-13-1307-2025 18 December 2025 Characterizing the grain size of river sediments is necessary for estimating sediment transport rates in rivers. In order to understand sediment transport at large spatial scales, grain size information across river basins is needed, but methods for accomplishing this are limited. Here, I introduce a new method for using measurements of grain size in discrete locations to estimate full grain size distributions across entire watersheds. Read more
Injection near the stratopause mitigates the stratospheric side effects of sulfur-based climate intervention Atmospheric Chemistry and Physics DOI 10.5194/acp-25-18449-2025 18 December 2025 Injecting sulfur dioxide at 50 km – near the stratopause – offers a far safer and more effective climate intervention than conventional 25 km injection. Rapid downward–poleward transport distributes aerosols across 20–30 km, halving tropical stratospheric warming, reducing ozone recovery delays from decades to about 5 years, and enhancing global and polar cooling by over 20 %, while better preserving Arctic sea ice. Read more
Synergetic retrieval from multi-mission spaceborne measurements for enhanced aerosol and surface characterization Atmospheric Measurement Techniques DOI 10.5194/amt-18-7679-2025 17 December 2025 Developed SYREMIS (SYnergetic REtrieval from Multi-MISsion instruments) approach is based on three main principles: (i) harmonization of the multi-instruments L1 measurements, (ii) their “weighting”, and (iii) optimization of the forward models and the retrieval setups. It substantially enhances aerosol and surface characterization from spaceborne measurements. The approach can be extended to future missions, including synergy with multi-angular, multi-spectral, and polarimetric measurements. Read more
Water vapour dynamics as a key determinant of atmospheric composition and transport mechanisms Biogeosciences DOI 10.5194/bg-22-8005-2025 16 December 2025 Humidification of air reduces the abundances of dry-air gas components such as oxygen, explaining why tropical humidity can be "stifling". This is overlooked due to the common expression of gas concentrations as fractions of dry air. Such neglect of water vapour also masks the key role of its sources and sinks in activating transport mechanisms of other gases. Humidity should be quantified whenever reporting gas concentrations. Read more
Feedback-based sea level rise impact modelling for integrated assessment models with FRISIAv1.0 Geoscientific Model Development DOI 10.5194/gmd-18-10017-2025 15 December 2025 We present FRISIA version 1.0, a model for emulating sea level rise (SLR) and representing SLR impacts and adaptation in integrated assessment models (IAMs). FRISIA includes previously uncaptured coastal socio-economic feedback and a diverse set of impact strains, thereby improving the represenation of SLR impacts in IAMs. Here we describe the baseline behaviour of FRISIA, explore the effects of the additional feedback and showcase the coupling of FRISIA to an IAM. Read more
How do geological map details influence the identification of geology-streamflow relationships in large-sample hydrology studies? Hydrology and Earth System Sciences DOI 10.5194/hess-29-7173-2025 15 December 2025 We show that geological maps with varying levels of detail may influence the identification of geology–streamflow relationships across European catchments at multiple scales. At the large scale, controls varied between basins, with no map consistently superior. At the intermediate and small scales, however, higher geological detail consistently strengthened correlations, particularly for baseflow signatures, with the regional map highlighting controls more consistent with process understanding. Read more
Orbital-scale variability in the contribution of foraminifera and coccolithophores to pelagic carbonate production Biogeosciences DOI 10.5194/bg-22-7973-2025 12 December 2025 We present new high-resolution data of the relative contribution of the two main pelagic carbonate producers (coccoliths and foraminifera) to the total pelagic carbonate production from the tropical Atlantic in past warm periods since the Miocene. Our findings suggests that the two groups responded differently to orbital forcing and oceanic changes in tropical ocean, but their proportion changes did not drive the changes in overall pelagic carbonate deposition. Read more
Silicification in the ocean: from molecular pathways to silicifiers' ecology and biogeochemical cycles Ocean Science DOI 10.5194/os-21-3427-2025 11 December 2025 This review explores how various forms of marine life, from picoplankton to giant sponges, transform and control silicon to form silica-based structures, and how this process shapes the ocean silicon cycle. It also highlights the overlooked role of dynamic boundary zones where land, seafloor and ice meet seawater, and explains how combining biology and geochemistry can improve paleoceanographic proxies, biogeochemical models, and predictions of climate-driven changes in ocean productivity. Read more
Constitution of a multicentennial multirisk database in a mountainous environment from composite sources: the example of the Vallouise-Pelvoux municipality (Ecrins, France) Natural Hazards and Earth System Sciences DOI 10.5194/nhess-25-4881-2025 10 December 2025 This paper proposes a methodology to develop a long-range multirisk database. Combining scattered pre-existing records and intensive research in historical archives provides a 1600–2020 record of past events in a valley of the French Alps. It goes far beyond any inventory existing in terms of number of events, temporal coverage and detailed description of events characteristics in a mountain context. Spatio-temporal patterns are analysed, opening perspective for multirisk assessment. Read more
