δ56DFe and δ56PFe ranged from −0.22 ‰ to +0.79 ± 0.07 ‰ and from −0.52 ‰ to +0.43 ± 0.07 ‰, respectively (relative to IRMM-14, 95 % confidence interval). Source signatures, biogeochemical processes and transport all contribute to these observations. Two distinct areas, one under continental influence (the western equatorial Pacific) and an open ocean region (the central equatorial Pacific), emerged from the data. In the area under continental influence, high PFe concentrations along with δ56DFe values systematically heavier than that of δ56PFe indicated an equilibrium fractionation and the co-occurrence of chemical fluxes from both phases toward the other. This exchange occurs through non-reductive processes, as previously proposed from three of the eight stations of this area (Labatut et al., 2014) and extends up to 1200 km from the coast. In the open ocean area, preservation of a DFe isotopic signature of ∼ +0.36 ‰ within the EUC, from Papua New Guinea to the central equatorial Pacific (7800 km), confirmed the origin of the DFe carried within this current toward the HNLC region. At the same depth, bordering the EUC at 2° N and 2° S at 140° W, light isotopic signatures suggested that iron was originating from the eastern Pacific oxygen minimum zones. These light signatures were also observed in deeper central waters, between 200 and 500 m. Our data did not allow conclusions about fractionation during uptake by phytoplankton, but indicated that any fractionation, if present, must be small, no larger than a few tenths of a per mil.
]]>The protection mechanisms (aggregation, clay mineralogy, microporosity and metal oxyhydroxides, MOOHs) showed large differences with different temporal patterns, where aggregation and clay mineralogy dominated during 10 ka of pedogenesis and MOOHs had a negligible effect. Ranking internal and external controls on SOC stocks revealed a decreasing influence of bioclimate > protection mechanism > erosion rate > land use > time.
Topsoil and subsoil SOC recovery after agricultural use revealed different dynamics, controlled by the history of environmental drivers and pedogenesis. Natural SOC recovery showed lowest rates for subsoils and highest rates for topsoils, with a strong control of erosion and pedogenetic history. The addition of ground rock of different mineralogies to enhance SOC sequestration had some effect, mainly for goethite, montmorillonite and a temporary effect of calcite. Our simulations demonstrate how SoilGen can improve understanding of soil processes, while also highlighting knowledge gaps, such as missing experimental insights in key SOC stabilization mechanisms.
Our study shows that soil models such as SoilGen cannot act as digital twins of a soil that represent the entire soil, as not all processes and parameters of the complex soil system are represented. These models can, however, form the basis of topical digital twins that target specific processes or properties. We provide a roadmap for developing such topical digital twins and recommend to start from a complex model that accounts for pedogenetic history.
]]>The resulting parametric IDF curves exhibit a fractal dimension and the present study takes a step towards better understanding the conditions influencing this fractal dimension and its spatial and temporal variability. To this end, we explore the dependencies across different timescales, using hourly precipitation data from convection-permitting (3 km) regional climate model simulations carried out with the HCLIM model over northern Europe. The analysis is applied to HCLIM simulations driven by boundary conditions from the ERA-Interim reanalysis, as well as from the EC-Earth and GFDL-CM3 global climate models for current and future climates following the RCP8.5 scenario.
We find that the relationship between wet-spell mean precipitation for different durations, and hence the sub-daily fractal dimension, is influenced by geographical conditions, as is also the wet-spell frequency. The results are consistent across different boundary conditions representing current climate conditions (reanalysis and global climate models), and showed little sensitivity to the driving model, indicating that different meteorological phenomena prevail in different regions and that these are well represented in the models. Future climate projections show changes in the fractal dimension and wet-spell frequency ratios with a general north-south gradient. Overall, the models indicate a shift towards fewer, but more intense wet-hours per wet day.]]>
A precise interferometric satellite analysis was conducted for spring 2024 based on ascending-descending combinations of TerraSAR-X image acquisitions. Two non-orthogonal horizontal component velocity fields were calculated, and ground-referenced with precise movement data acquired with three automated GNSS stations that had been placed on the ice. This allowed us to calibrate three simply connected subsets to each of the velocity field components: the MIS itself, the multi-year fast ice, and the first-year fast ice. These component fields then enabled us to calculate a near-complete 2D horizontal velocity field of ice motion in the area. This analysis was the basis for calculating the divergence field of the velocity as well as principal strain rate fields. The overall ice dynamics were then related to the areas where we expect a stabilizing effect of the fast ice on the ice shelf front, or where the ice shelf geometry suggests stabilizing effects.
Once the January–February 2025 fast ice breakout was complete, the MIS front began calving almost immediately, leading to a net retreat of the MIS front to a minimum beyond any other found in the Landsat 4–9 record. The dynamics of the fast ice were largely dependent on age, with the behavior of the multi-year fast ice resembling in most ways that of the adjoining MIS rather than the first-year fast ice, due to strong coupling at the MIS–multi-year fast ice interface. The divergence of the velocity field and the principal strain rates show convergence and compression of the fast ice in the embayment, providing evidence of a stabilizing effect and possible buttressing of the MIS by fast ice.]]>
By including interpretable AI diagnostics, CHROMAP provides a quantitative assessment of the importance of the 26 features over 11 years for each air quality indicator. Integrating all types of stations into the regressions, the evaluation carried out reveals that the performance scores have been significantly improved compared to CAMS reanalyses (~10 km resolution) used for downscaling; with a reduction in RRMSE on average over the period of about -33 % for NO2, -21 % for O3, -10 % for SOMO35, -22 % for PM2.5 and -37 % for PM10, and an increase in R2 of 28 %, 34 %, 18 %, 14 % and 36 %, respectively. In addition, a sensitivity analysis carried out on the static exposure of the population shows that significant differences can be found with values at high resolution, especially for NO2, thus impacting the calculation of the health impact.
By ensuring sufficient availability of in-situ observations and concentration fields from CTMs for downscaling, this methodology could be extended to additional air quality indicators and applied at higher temporal frequency, opening new opportunities for comprehensive air quality assessment.]]>
This study presents the results of the systematic and detailed surveys conducted in several sites affected by the storm, also providing detailed case studies. These surveys highlighted the critical issues detected during the disaster and identified appropriate intervention measures for reducing hydraulic risk in the Region. Many of these measures are innovative and will serve as guidelines for future land-use planning and for improving public education and awareness in flood-prone areas.
]]>Findings reveal three locally recognised categories of mitigation measures: (1) emission-limiting measures, such as blocking gas with waste materials; (2) adaptive measures, such as house ventilation or living on upper floors; and (3) awareness measures based on orally transmitted local knowledge such as avoiding mazuku zone early morning. Financial resources, gender and prior risk experience – often linked to length of residence – emerged as significant positive determinants of both motivation and perceived efficacy for the first two categories. Perceptions of awareness measures showed no significant variation across zones even between demographic profile groups. Spatial patterns in perceived implementation and perceived efficacy appear to reflect collective community mitigation implementation rather than based on individual risk mitigation assessment, with some measures perceived as effective despite limited physical evidence of reduced gas concentration.
The study supports the importance of co-creating mitigation strategies with local communities, adapting interventions to socio-economic realities and avoiding the importation of external mitigation measures that may lack contextual relevance. It also calls for complementary research measuring the actual effectiveness of these measures through physical monitoring of mazuku concentrations. These insights, grounded in a Global South context – characterised by rapid uncontrolled urbanisation, offer a valuable perspective for the development of inclusive and effective strategies of carbon dioxide diffuse degassing risk management.
]]>We apply this approach to monthly accumulation output from the HIRLAM–ECHAM Regional Climate Model (HIRHAM5; 1960–2022), the Modèle Atmosphérique Régional (MAR3.14; 1960–2022), the Regional Atmospheric Climate Model (RACMO 2.4p1; 1980–2022), and the Copernicus Arctic Regional Reanalysis (CARRA; 1991–2022). Initial mean point-wise biases of −7.4 % (HIRHAM), −0.5 % (MAR), 0.0 % (RACMO) and +10.1 % (CARRA) (1991–2022), statistically significant for all models except RACMO, are reduced to ± 0.3 % following adjustment. Resulting bias-corrected mean annual accumulation rates over the ice sheet are estimated at 469 mm yr−1 (HIRHAM), 412 mm yr−1 (MAR), 435 mm yr−1 (RACMO) and 408 mm yr−1 (CARRA) between 1991–2022. Inter-model agreement improves significantly in the observation-rich accumulation zone, with a 68 % reduction in standard deviation of mean accumulation estimates, but deteriorates by 27 % in the sparsely sampled ablation zone, highlighting the need for additional observational constraints. Model bias is dominated by the southern ice sheet, with the largest statistically significant contributions from the south-east for HIRHAM (−39 to −54 Gt yr−1) and MAR (+30 to +33 Gt yr−1), and the south-west for RACMO (+20 to +26 Gt yr−1) and CARRA (+34 Gt yr−1). Temporal trends and temperature sensitivities exhibit a pronounced east-west contrast, with the east dominated by strong positive responses and negative responses in the west.
The framework outlined in this study offers a scalable, transferable solution to improve accumulation estimates through enhanced integration of observational data, providing an improved input to ice-sheet models, with the potential to reduce uncertainties in future sea-level rise projections.
]]>Our results show a maximum in atmospheric persistence in July and August, associated with higher occurrence of Scandinavian Blocking, and relative minima in spring and autumn. The relationship between the large-scale atmospheric circulation and near-surface temperatures exhibits similar seasonal characteristics. For heatwave days, we find a statistically significant anomalous strong link between large-scale atmospheric circulation and surface temperatures from June to September. This relationship is generally not attributable to the occurrence of specific weather regimes. However, heatwaves in July and August are associated with higher atmospheric persistence due to an enhanced frequency of the persistent Scandinavian and European blocking weather regimes. Beyond atmospheric circulation, additional physical drivers of daily maximum temperature during heatwaves are analyzed: While surface net solar radiation shows a particularly strong link in June and July, soil moisture exhibits an anomalously high link in July and August. These findings highlight the critical role of intra-seasonal variations in shaping heatwave dynamics.
]]>The GPR data is characterized by strong signal scattering, typical for temperate ice with high water content, however the glacier bed is detectable in most profiles. GPR measurements reveal a maximum ice thickness of ~160 m along the central flowline and a mean thickness of ~81 m across the surveyed area. We further select three widely used, open-source ice-thickness models, GlabTop2, OGGM, and Millan et al. (2022), and compare their output to the GPR-derived ice thickness. All models systematically overestimate ice thickness across the surveyed area, with mean positive biases of ~37–40 m for GlabTop2 and OGGM and ~59 m for the Millan model, while only minor and localized underestimation occurs along the central flowline. These results highlight the limitations of predominantly geometry-based and velocity-informed modelling approaches when applied to small, temperate valley glaciers, where ice rheology and basal conditions may have greater influence on the resulting thickness than these algorithms allow.
The GPR data presented here is made freely available in the section “Code and data availability” and provides an updated ice thickness benchmark for the Hintereisferner, to be used for future model calibration and improvement for Alpine glacier evolution projections.]]>
We present an innovative sequenced zoning methodology that disaggregates seismotectonic behavior into three components (namely – crustal structure, observed seismicity and surface deformation) each analyzing several key features. We thus derive three novel, independent seismotectonic zonation models, each representing a different perspective on the seismogenic process. Additionally, we associate confidence levels with zone limits to each subsequent zonation model, by assessing feature homogeneity among neighboring zones. Afterwards, we propose a synthetic model which integrates all seismotectonic features by merging the most recurrent and highest confidence zone limits from the three independent zonation models. This approach intends to minimize zone mapping uncertainties by quantitatively assessing seismotectonic observations, and to yield reproducible and updatable models representative of the current state of seismotectonic knowledge. We subsequently compare the resulting zonation models and discuss their implications for seismic source characterization.]]>
This double flyby – Moon first, Earth second – enabled a large Delta-V gain while minimizing propellant use, redirecting JUICE toward its next destination: Venus (August 2025) and ultimately Jupiter (2031). The manoeuvre was unprecedented in complexity, requiring extremely accurate navigation, rigorous preparation, and coordinated operations across engineering, flight dynamics, and science teams.
Overall, JUICE demonstrated outstanding platform stability, navigation accuracy, and subsystem robustness during this critical milestone, validating the operational feasibility of LEGA as an enabling technique for complex interplanetary trajectories.
This paper is an executive summary of papers published on LEGA trajectory design [Schoenmaekers et al. (2014); Boutonnet et al. (2023)], navigation [Syndercombe et al. (2025)] and spacecraft operations [Heck et al. (2025)].]]>