Environmental and Earth Sciences

Abstract: Background: A 2023 preprint highlighted descriptive differences in several crime-related indicators across U.S. states, grouping them based on the percentage of their area with modeled groundwater nitrate levels exceeding 5 mg/L. Building on those initial findings, the current study presents a retrospective, exploratory reanalysis of this 48-state dataset. Methods: Our primary exposure variable was the historical modeled nitrate-area percentage (derived from the USGS GWAVA-DW model), while the primary outcome was the 2014 violent crime rate per 100,000 inhabitants, based on FBI Uniform Crime Reporting data. To evaluate Spearman’s rank correlation, we employed a two-sided Monte Carlo permutation test (100,000 permutations) alongside a paired-state bootstrap percentile interval (10,000 resamples). Eight secondary FBI crime outcomes were also assessed, applying the Holm adjustment for multiple comparisons. As complementary exploratory analyses, we examined a historical categorical grouping (≥10% versus <10% nitrate area) as well as alternative exposure cutoffs. Furthermore, singleton Moran spectral randomization (MSR) sensitivity tests were conducted in both Python and the reference R package adespatial (using 100,000 surrogate pairs across eight specifications). The differences between Python and R in p-values, null means, and null standard deviations all fell within three combined Monte Carlo standard errors. Results: The primary association proved to be negligible (ρ = 0.051; nominal permutation p = 0.728; 95% paired-state bootstrap interval: −0.249 to 0.351). Following the Holm adjustment, none of the secondary outcomes remained statistically significant. Comparing the groups based on the ≥10% threshold revealed a mean difference of 59.40 violent crimes per 100,000 inhabitants (95% Welch CI: −29.05 to 147.86; p = 0.169). Additionally, spatially constrained MSR tests run in the reference R implementation yielded non-significant results. Conclusions: Based on this dataset, there is no statistical evidence supporting a monotonic state-level association between the historical area-based nitrate indicator and 2014 violent crime rates. However, this finding does not definitively rule out the possibility of an underlying association. The results do not support individual-level, causal, or mechanistic interpretations. Furthermore, it should be noted that the primary permutation and bootstrap summaries rely on exchangeability assumptions and should not be treated as spatially robust regression estimates.

Abstract: Bihar's blue food economy, built on inland fisheries, makhana (fox nut) cultivation, and water chestnut (singhara) farming, is a major contributor to India's aquatic food production and a critical source of rural livelihoods, nutrition, and income. The state ranks fourth among India's inland fish producers, contributes roughly 90% of India's makhana output, and accounts for nearly 60% of the country's water chestnut production. Despite this scale, the sector faces mounting structural risks: climate variability, recurring floods and droughts, rising temperatures, water quality degradation, and disease outbreaks. These risks are compounded by a lack of integrated early-warning systems for water quality and climate monitoring, leaving farmers to react to visible losses rather than anticipate them. This paper reviews the current state of Bihar's three major blue food systems, their production trends, climatic and environmental requirements, and value chain challenges. The paper then presents Twingills, an AI-powered digital twin platform built on NatureDots' AquaNurch Foundation Model, as a proposed intelligence layer to close this gap through real-time and predictive intelligence at farm and landscape scales, forecasting, and timely decision support for farmers and other stakeholders.

Abstract: Marine tidal notches (MTNs) are widely recognized as reliable indicators of mean sea level and have been extensively used along carbonate coasts of the Mediterranean Sea, where tidal ranges are generally small, to reconstruct relative sea-level changes. MTNs develop primarily through the combined effects of carbonate dissolution associated with the interaction between marine and meteoric waters, bioerosion by intertidal organisms, and mechanical removal of weathered material by wave action. Previous studies have demonstrated that notch morphology reflects a combination of tidal range, lithology, and cliff-toe depth, while significant freshwater discharge may enhance notch development. In microtidal Mediterranean settings, the morphology and elevation of MTNs are therefore closely related to local sea-level conditions. Detailed surveys of MTNs throughout the Mediterranean have documented both typical tidal notches and anomalous morphologies. Among the latter, notches developed within ria-type coastal settings may progressively deepen from exposed to increasingly sheltered environments, producing landforms referred to as dipping marine notches (DMNs). Here, we investigated two sea caves in northwestern Sicily (central Mediterranean Sea), where contrasting notch shapes are preserved. At Capo Zafferano Cave, a present-day tidal notch progressively transforms into a dipping marine notch within less than 20 m of the cave entrance, whereas at Cala Rossa Cave a submerged notch remains closely associated with the corrected sea level, with repeated measurements ranging from 0.00 to −0.10 m. We evaluate the possible role of freshwater spring discharge in its formation and preservation. High-resolution geomorphological measurements were collected during repeated field surveys and corrected for short-term tidal variability using the Palermo tide-gauge record. The repeated measurements were quantitatively assessed using statistical analyses accounting for the repeated-measures structure of the dataset. Water-temperature measurements at Cala Rossa revealed a marked thermal anomaly, with temperatures reaching 25.0 °C in the freshwater-influenced inner sector compared with 28.8 °C at the cave entrance, consistent with the presence of a distinct freshwater-influenced water mass within the cave. Ecological and biological information were presented as a description of the study sites, providing a biotic context for the observed tidal notches. The results provided quantitative evidence for the reproducibility of the observed notch positions under different tidal conditions and support the interpretation of contrasting notch shapes as the result of different hydrodynamic and geomorphological processes. These findings highlight the importance of freshwater discharge, cave confinement, and local hydrodynamic conditions in controlling the development and preservation of tidal and submerged notches in Mediterranean carbonate coastal environments.

Abstract: Ground-level soil-moisture and microclimatic data are scarce in Mediterranean forests, although they are relevant for wildfire prevention and reforestation planning. This paper presents the design, deployment and field operation of a large-scale LoRaWAN-based wireless sensor network in a fire-prone Mediterranean forest in Valencia (Spain). The network comprises 133 operational low-power nodes within a circular area of approximately 7854 ha (5 km radius), deployed according to the WRB soil classification, with multi-depth soil-moisture probes, multi-height temperature and relative humidity sensors, two redundant gateways and solar-powered autonomous operation supported by an explicit energy budget. During a spring campaign (April–May 2025), the network captured a common soil-moisture recharge event followed by soil-dependent drying, with higher retention in calcic Kastanozems and faster drying in haplic Calcisols; mean volumetric water content ranged from 13% to 20% among soil units. As a proof of concept, the measurements were converted into a soil moisture deficit index referenced to field capacity and a relative atmospheric stress index, combined into a locally defined composite indicator that is positioned against the Canadian FWI System and the AEMET fire-danger index. The results demonstrate the feasibility of soil-aware, low-cost in situ monitoring that can complement operational fire-danger products and support reforestation planning.

Abstract: Precipitation forecasting at fine spatiotemporal resolution is essential for refined meteorological services, yet high-resolution data remain costly to obtain and operational model outputs (e.g., the Fuxi model at 0.25°) are too coarse to resolve small- and medium-scale precipitation structures. To address this gap, this paper proposes a precipitation forecast downscaling method based on a Correlation Diffusion Network (Diffusion-U-Net) that converts low-resolution Fuxi precipitation forecasts into high-resolution fields. The method combines the probabilistic generation capability of diffusion models with the multi-scale feature extraction advantages of U-Net, and introduces a correlation module with a channel-spatial dual attention mechanism to capture the spatiotemporal correlation features of precipitation fields. Evaluated on 2020–2023 Fuxi forecasts over North China, the proposed method outperforms traditional interpolation and deep learning baselines: it achieves a structural similarity index (SSIM) of 0.81 and a heavy-precipitation critical success index (CSI) of 0.72, and reduces the heavy-precipitation intensity bias by 6% relative to vanilla U-Net. The method restores small- and medium-scale precipitation details more accurately and provides technical support for refined meteorological forecasting.

Abstract: Danger ratings are built where fires have been recorded and used where they have not, so their value rests on how much of a fitted response survives a move to another landscape. We test that question on a benchmark assembled for Fujian province, southeast China, from 43,400 quality-filtered VIIRS and MODIS active-fire detections, daily reanalysis meteorology and terrain derivatives: 171 grid cells of 0.25°, 2922 days and 15,205 fire cell-days at a base rate of 3.04%. Models are fitted on the coastal belt and the lowland interior (2015–2019) and evaluated on the mountain interior in 2021–2022, a region absent from training. The model we propose keeps the response linear in standardized predictors, learns a prior over its coefficients from 24 source blocks, and constrains the humidity and wind coefficients by sign while training, which makes an increase of predicted probability with humidity, or a decrease with wind, unreachable for any input. On the held-out region it reaches an AUC-PR of 0.079 (95% interval 0.067–0.092), against 0.093 for logistic regression and 0.101 for a random forest, while its negative log-likelihood of 0.135 trails the best baseline at 0.123. Two consequences follow. Exact monotonicity is obtained at a measurable cost in sharpness, since every unconstrained model fails the wind test on 100.0% of matched pairs. Local labels do help as well: 256 labelled cell-days lift AUC-PR from 0.079 to 0.101, the same level a logistic regression reaches by refitting on those labels (0.103), so the closed-form update is a safe instrument, not a source of gain.

Abstract: Small Island Developing States (SIDS) face natural resource management challenges distinct from those of mainland nations. For example, land constraints necessitate a balance between ecosystem sustainability and food production. Therefore, this study aimed to identify optimal land-use patterns to balance competing interests, using the Bobonaro Municipality in Timor-Leste as a case. The methodology comprised Senti-nel-2 image interpretation, Random Forest classification, analysis of drivers of change, and CA-Markov projection modeling. Land Use and Land Cover (LULC) mapping was conducted for 2016, 2020, and 2024, with projections extending to 2032 and 2040 under four scenarios. These include Business as Usual (BAU), Forest Protection (FP), Agri-cultural Development (AD), along with Forest Protection and Agricultural Develop-ment (FPAD). The results showed that classification achieved an accuracy exceeding 89% and a Kappa coefficient greater than 0.87. Between 2016 and 2024, forests experi-enced the greatest decline, while savanna areas expanded significantly. Population, distance to roads, and elevation were found to be more strongly associated with LULC changes than rainfall or slope gradient. The scenarios show a trade-off between forest conservation and agricultural land availability. The FPAD scenario yielded the most balanced landscape configuration by maintaining forest cover, supporting agricultural land, and limiting savanna expansion.

Abstract: Precipitation measurements from two disdrometers (Thies LPM and OTT Parsivel²) and an optical sensor (Vaisala PWD12) are intercompared and evaluated against a Geonor T-200B precipitation gauge under low-wind conditions in Oslo. Proper use of those instruments in practical applications requires understanding their accuracy in measuring precipitation amounts and their reliability in reporting present weather. We establish a detailed, reproducible methodology to harmonize data from multiple precipitation instruments and meaningfully compare measurements of precipitation occurrence, amount, and type. The methodology is applied to one year of hourly and sub-hourly data from a test site in Oslo. Relative to the Geonor, liquid precipitation amounts are underestimated by the three devices by 3-18%; solid precipitation amounts are largely overestimated by the Parsivel2 (up to 100%), by 14-21% by the LPM, but are underestimated by 11-18% by the PWD12. The disdrometers agree nearly perfectly on liquid versus solid precipitation types, while the PWD12 detects more liquid and less solid precipitation. We identify two weather conditions that challenge the instruments: i) trace precipitation occurrence is inconsistently characterized and highly dependent on device detection thresholds, with the LPM reporting far more wet observations than any other instrument; ii) mixed-type precipitation is agreed upon only 53% of the time by the Parsivel2 and the LPM, and less than 20% by the PWD12. Our methodology can be reproduced to study other instrument combinations in other locations, and our results can help users of those instruments critically consider their measurements.

Abstract: Carbide slag is a bulk industrial solid waste, and its open‑air stockpiling causes severe environmental pollution. In this work, nano‑calcium hydroxide with high dispersity, high activity and large specific surface area was prepared from carbide slag via a coupled process consisting of high‑temperature calcination for impurity removal, controllable crystallization and organic surface composite modification. Key parameters including crystallization temperature, modifier dosage, modifier type and drying temperature were regulated by orthogonal tests to precisely control the nano‑crystal size of calcium hydroxide and effectively mitigate nanoparticle agglomeration. The effects of the four above‑mentioned parameters on the specific surface area of products were investigated using an L₉(3⁴) orthogonal array, and the optimal preparation conditions were determined. Combined with multiple micro‑characterization techniques including TG‑DTA, XRD, SEM and BET, the optimal process for synthesizing nano‑calcium hydroxide was established. Under the optimal conditions, the as‑prepared calcium hydroxide exhibited a grain size of 50–150 nm, a mass fraction of 95.1 %, a specific surface area of 48.97 m²/g, a bulk density of 0.65 g/mL and a pore volume of 0.24 cm³/g. This proposed process enables high‑value resource utilization of carbide slag and provides reliable technical support for preparing desulfurization and denitrification materials from industrial solid waste.

Abstract: This working paper describes the design and implementation of a containerized geospatial platform developed to disseminate and inspect the outputs of a multi-evidence framework for surface spectral anomaly prioritization in Paipa–Iza, Boyacá, Colombia. The underlying study processed multispectral imagery acquired by an unmanned aircraft system, identified anomalous spatial units using Isolation Forest, and subsequently examined independent hydrothermal, structural and satellite-derived thermal evidence. The platform exposes 27 nonredundant UAS footprints, 8,433 candidate anomaly zones, 21 hydrothermal springs and 91 fault geometries through a modular backend built with FastAPI and an interactive Streamlit–Folium interface. Domain-specific services support spatial intersection, evidence-based filtering and nearest-feature queries. A REST API provides GeoJSON responses and documented endpoints, while Docker Compose coordinates separate frontend and backend containers. The application also checks the integrity of loaded datasets against the counts and evidence categories reported in the analytical results. The case study identifies PAIPA-10 and PAIPA-16 as the two footprints with robust hydrothermal and structural convergence, comprising 680 candidate zones. The platform does not establish the existence, depth or productivity of geothermal reservoirs; its contribution is to make the analytical outputs accessible and internally consistent for subsequent exploratory assessment.

Abstract: Rapid urbanization and shifting modern transportation technologies have exposed traditional ancient cities to passive marginalization, heritage loss, and spatial fragmentation. Yet the long-term spatial succession patterns and micro-scale decline factors of their unlisted built heritage remain insufficiently quantified. Focusing on 347 modern historic buildings (1840–1949) in Kaiyuan Ancient City, China—historically a capital of four states and a key military stronghold across five dynasties—this study built a four-level GIS database integrating multi-period historical maps, terrain and pre-demolition surveyed basemaps, archival literature, and field surveys to investigate their spatiotemporal evolution, micro-spatial pathology, and non-stationary influencing factors. We constructed a multidimensional "Point–Line–Polygon–Volume" geospatial analytical framework that integrates Average Nearest Neighbor (ANN), Kernel Density Estimation (KDE), Standard Deviational Ellipse (SDE), Space Syntax, Spatial Autocorrelation, and Spatial Regression models. The results show a pronounced northwest–southeast clustering pattern of historic buildings. Rather than expanding outward like modern cities, the ancient city underwent unidirectional centripetal contraction and a southward centroid shift, with peripheral military–political lands converted to agricultural use and residential areas densified in the core, while at the micro-spatial scale grassroots property rights fragmentation doubled the proportion of dead-end streets within blocks, caused topological polarization along main arterial roads, and accompanied the physical compression of original courtyard green spaces by informal infill development. Structural reversal occurred in the influencing factors of spatial heterogeneity over the study period according to Geographically Weighted Regression (GWR). Early settlement patterns were primarily shaped by natural baseline constraints of topography and historical water systems that initially provided a flood-safe foundation and fostered water-oriented clustering before obstructing internal traffic; over time, socioeconomic factors dominated by railway capital deprivation and the outward relocation of the administrative center became the primary influencing forces, which pulled commercial spaces southward, filled central official plots with new construction, and preserved the traditional residential pattern in the northwest as public facilities acted as spatial anchors during turbulent periods through their shelter and relief functions. Targeted conservation strategies informed by these diagnostics combine road network unblocking and ecological restoration, differentiated zoning control and peripheral land utilization, and facility adaptive conversion and digital reproduction, clarifying the spatial patterns and evolutionary influencing factors of built heritage in marginalized historic towns while showing how multidimensional GIS quantitative analysis supports evidence-based micro-regeneration and classified dynamic revitalization for unlisted built heritage.

Abstract: The origin of biological membranes remains a fundamental unresolved problem in the transition from abiotic chemistry to cellular life. Although amphiphilic self-assembly can generate micelles, vesicles, and other supramolecular structures, membrane formation alone does not explain the emergence of functionally integrated and heritable cellular compartments. This review introduces the Abiotic Membrane Selection Principle (AMSP), a proposed mathematical and physicochemical framework in which biological membranes could have emerged through selection among numerous chemically distinct abiotic membrane populations rather than through the progressive evolution of one uniquely favorable lipid architecture. The model assumes the availability of chemically diverse amphiphiles, environmentally dependent self-assembly, differential molecular persistence, and the possibility of functional interactions between membrane composition and internal chemical networks. Representative sulfur-containing, sulfated, sulfonated, borate-associated, glycolipid, and ether-linked molecular architectures illustrate the potential diversity of primitive membrane systems. Combinatorial calculations demonstrate that nine amphiphilic components can generate 43,758 distinct compositions at 10 mol% increments and 3,108,105 compositions at 5 mol% increments, although only a subset may be physically capable of forming membranes. The proposed mathematical framework integrates thermodynamic mixing, membrane curvature, chemical stability, selective permeability, electrostatic properties, environmental robustness, growth, and compositional continuity into a multidimensional membrane-suitability landscape. Particular emphasis is placed on competing functional requirements, including the permeability–retention dilemma, the relationship between membrane persistence and chemical productivity, and the possibility of multiple environmentally dependent optimal compositions. Mathematical models further examine how environmental cycling, differential molecular retention, and reciprocal membrane–reaction network coupling could generate compositional memory and potentially support primitive heredity. The transition toward biological membranes is interpreted as a hypothetical process of progressive functional integration, eventually involving genetically regulated lipid biosynthesis and specialized membrane architectures. Sensitivity analysis, robust optimization, and experimentally falsifiable predictions are proposed to distinguish spontaneous membrane assembly from evolutionarily consequential compartmentalization. The central conclusion is that abiotic membrane diversity may have provided multiple physicochemical pathways toward cellular organization, whereas the emergence of biological membranes required the selection of systems capable of combining structural persistence, selective transport, chemical productivity, and hereditary continuity.

Abstract: I know of only one published body mass value for Tiktaalik roseae, given without uncertainty: 6.94 kg from a volumetric model (Hohn-Schulte et al., 2013). Here I make a new estimate using a model tested on living fishes, and propagate the primary measurement and calibration uncertainties through to the estimate. The equation is M = C·L·w·d, where L, w and d are the length, maximum width and maximum depth of the body. C is a coefficient measured on 157 extant fishes of known mass. In leave-one-species-out tests across seven species, the model predicts mass with median errors of 4–31% (4–14% for the five species retained for calibration; the two deep-bodied breams have the largest errors). None of these fishes is flattened like Tiktaalik, so I am extrapolating the model to shapes other than those tested. Hohn-Schulte et al. appear to use the body proportions of the published skeletal reconstruction of the holotype, NUFV 108, the smallest of the three articulated specimens. This reconstruction assumed about 45 presacral vertebrae; the count has since been revised to about 31. With 45 and 31 vertebrae respectively, the model estimates 5.5 kg (95% interval 3.0–10.4 kg) and 4.3 kg (2.1–8.9 kg) for the holotype. The holotype is dorsoventrally crushed. If crushing conserved cross-section area, these values would stay the same. If true depth was 25% greater, they would rise by about a quarter. Isometric scaling using published fin and humerus size ratios suggests 14–18 kg for NUFV 110 and 34–44 kg for the largest articulated specimen, NUFV 109 (95% interval 15–104 kg). Across fish species, C increases as bodies become flatter. Projecting that pattern out to Tiktaalik’s shape, well outside the data, would multiply all these masses by about 1.6–2.0. The intervals quoted here do not include this model-form uncertainty. A rough comparison suggests that under the published proportions, Tiktaalik is about as heavy as a generic fish of the same total length: the wide body compensates for the flattening. If the factors in the model are independent, a decomposition of the log mass variance shows that body length and relative width are the main sources of measurement uncertainty. If the commonly quoted 1.25–2.75 m is total length, it is 1.3–1.8 times the lengths suggested for the articulated specimens. A 2.75 m individual would weigh about 140 kg (50–400 kg) if that is total length, or about 220 kg (80–630 kg) if the caudal fin is not included. Testing C on flat-bodied animals and clarifying the basis of the length range would be the most useful next steps. All data and code are available.

Abstract: Proven alternatives to the conventional approach to wastewater treatment are often available but the conventional design is still selected by default. This paper describes a gated selection method that a practising engineer can apply to a live project in order to decide whether to adopt an alternative technology and to justify that decision. The method is based on sustainable compliance i.e. meeting the regulatory limits with a margin whilst improving the lifecycle efficiency, resilience and cost. It separates the functions that a treatment system must perform from the technologies that could perform them, records the project constraints in a register at four levels and then takes each candidate through six gated stages: screen, verify, score, de-risk, specify and operate. Six pass/fail exclusion tests are applied to remove the obviously unsuitable options prior to scoring, so that a fatal flaw cannot be made up for by some other strength. The survivors are then scored on four criteria using explicit weighting rules, with limited evidence being represented as a range rather than a single value; the conventional baseline is scored only as a comparator, and a baseline that has failed a constraint is not eligible for selection. Residual risk that no party will own will route the decision back to an earlier stage and full scale performance data will be fed back as evidence for future projects. The effort is matched to the project through three tiers, from a one page screen for low consequence work through to a pilot-backed assessment with formal lifecycle costing where the failure of the technology would be serious or it is new to the region. The method is illustrated by a worked example of the selection between aerobic granular sludge and conventional activated sludge and is supported by a template for each stage. It makes no assumption that the innovative option is better than the conventional one; it simply requires that every adoption and every decision to stick with the default be evidence based, risk managed, and defensible. It is intended for the practitioner and in particular the practitioner in a resource constrained environment and is presented as a decision making method rather than an empirically validated model.

Abstract: Biocapacity combines land area and productivity in an aggregate annual account. We examine the information retained by this total using a conserved-area two-land model with delayed ecological regeneration, demographic response and an imposed quality constraint. Conversion increases the model account when the receiving land class has the higher per-hectare contribution, even as ecological-capital land declines. In a representative simulation, biocapacity increases 39%, capital-land area decreases approximately 46%, and its modeled account contribution decreases 51.72%. Sharp static bounds quantify how independent land-area and quality observations restrict the compatible allocation set. Integrated contribution budgets distinguish conversion, maintenance and retirement, restoration, quality and fast-yield effects. In the 100-year fixed-demand simulation, conversion contributes 0.547925 gha, while the net account increase is 0.231310 gha; other contributions largely offset conversion. Budget closure improves under timestep refinement. The reduced fixed-demand equality relation reaches the minimum-area boundary without a fold or critical slowing; this result is specific to that comparison. Separately, National Footprint Accounts Edition 2026 values for 1961–2023 show world biocapacity increasing 24.86%, biocapacity per person decreasing 52.71%, and production footprint per person increasing 16.73%. Cropland, forest and built-up accounts contribute +24.06, -5.95 and +7.44 percentage points, respectively, to total biocapacity change. These are annual account changes rather than physical-stock observations. The results support reporting constituent accounts alongside independently measured ecological assets.

Abstract: Fires crossing international borders challenge nationally organised fire management, yet remain poorly quantified in South America. We combined national MapBiomas Fire burned-area maps for Argentina, Bolivia, Brazil, Colombia, Paraguay and Peru with VIIRS/MODIS active fires and MapBiomas land cover to delineate and characterise transboundary fire events along 14,934 km of borders between 2012 and 2025. We identified 360 events covering 9.23 Mha. The Bolivia–Brazil border concentrated 73.3% of the burned area, followed by Bolivia–Paraguay (15.0%), Brazil–Paraguay (7.4%) and Argentina–Paraguay (4.2%). Three years (2024, 2019, 2020) accounted for 70.8% of the area and the 52 events ≥10,000 ha for 97.6%. Of the 278 events with active fires, 84 showed a directed border crossing; these accounted for 73.7% of the burned area, were balanced between neighbouring countries and crossed a median of 2.5 days after ignition. Natural vegetation made up 94.0% of the burned area, whereas farmland hosted 18.7% of ignition points. Ranking 25-km border segments by recurrence, burned area and crossings identified 18 joint-attention zones, led by the southern Pantanal, that hold 76.1% of the burned area in the border strip on 6% of the border length. These results provide an empirical basis for binational fire management.

Abstract: Biofuel is the main drop-in low-carbon marine fuel available today, yet it made up only about 2.4% of bunker sales in Singapore in 2025. This paper assesses how market-based measures, infrastructure changes and supply-side adjustments affect biofuel uptake in Singapore's bunkering market. We develop an agent-based model in which vessels, bunker barges and terminals trade conventional low-sulphur fuel oil, a B24 blend and B100 through utility-driven deals. The model is calibrated on 2024 monthly sales data of the Maritime and Port Authority of Singapore (MPA) and validated out-of-sample on 2025, reproducing annual LSFO and B24 sales within 5% and 3%. Market-based measures are the only levers that raise biofuel uptake on their own, as doubling the carbon price raises the bio-containing share 3.5 times, and a small change in vessels' emission-penalty weight moves it significantly. Infrastructure changes have no effect at baseline prices but raise B100 sales by more than 70% once a carbon price exists. Supply cuts of up to 90% leave uptake unchanged, because bunker barges and terminals hold large spare capacity. Price signals should therefore come first, as access measures only work once a price signal exists. The framework extends to other ports and fuels.

Abstract: At present, substantial uncertainty surrounds climate change impacts on groundwater recharge, piezometric heads, and regional hydraulic gradients. This uncertainty is particularly pronounced in deep aquifers in semi-arid environments. Therefore, this study assessed the present and future impacts of climate change on the hydrodynamics of the Valle de León aquifer in central México. This assessment coupled surface-aquifer hydrological processes within a single integrated modelling framework. The methodology integrates the TETIS distributed hydrological model with MODFLOW and incorporates climate projections under different representative concentration pathway scenarios and Artificial Neural Networks within a unified modelling framework. The results indicate a mean annual groundwater drawdown ranging from 1.24 to 1.34 m. The largest drawdowns occur in the south-central part of the aquifer, modifying the regional hydraulic gradients towards the center of the cone of depression. This impact considers a simulated recharge rate corresponding to 12.8% to 13.3% of projected precipitation. The results indicate that projected recharge changes will not offset the persistent piezometric drawdown under the evaluated groundwater extraction rates.

Abstract: Karst bauxites preserve geochemical signatures of weathering processes and may provide insights into past climatic conditions. This study presents an integrated geochemical and paleoclimatic assessment of 96 samples from five Italian bauxite districts: Abruzzi, Murge, Gargano, Matese, and Caserta. Previously published whole–rock geochemical data were compiled and re–evaluated using weathering indices (CIA, CIA–K, and CALMAG), the Paleoclimatic Weathering Index (PWI), temperature and precipitation estimates (MAT and MAP), provenance–related diagrams, and multivariate statistical analysis. The results reveal significant differences among districts. Matese records the highest median mean annual temperature (MAT ≈23.5 °C) and precipitation estimates (MAP–CALMAG ≈1818 mm/yr), followed by Caserta and Murge, whereas Abruzzi records lower temperatures despite high estimated precipitation. Gargano displays the greatest variability in geochemical composition and reconstructed paleoclimatic parameters, indicating the presence of distinct geochemical populations. Provenance–related diagrams further highlight differences in parental–material affinity, underscoring the potential influence of initial composition on weathering indices and climatic estimates. Comparison with the Cretaceous climatic framework reveals temporal overlap between some bauxite-forming intervals and major climate phases, including the Cenomanian–Turonian Thermal Maximum. These results provide new comparative paleoclimatic insights into Italian karst bauxites, while highlighting the need to consider provenance and post–formational processes when interpreting climatic signals.

Abstract: After 54 years of dormancy, Calbuco Volcano (southern Chile) erupted on 22 April 2015, producing two explosive pulses and stratospheric eruption columns. This study investigates the dispersion and radiative effects of volcanic ash and sulfur dioxide (SO₂), including sulfate aerosol formation, using the updated Weather Research and Forecasting-Chemistry (WRF-Chem) v4.8 model. Simulations reproduce the observed large-scale transport of ash, sulfate, and SO₂, with generally good agreement with AERONET aerosol-loading observations and IASI/Metop-B SO₂plume observations. Remaining discrepancies in aerosol volume size distributions and plume vertical structure highlight sensitivities to eruption timing, plume intensity, vertical mixing, and chemical removal. A concentration-based 1 2 3 4 5 6 7 8 9 sampling framework identifies plume-affected grid cells, reducing background interference in radia- 10 tive forcing estimates. During 23–30 April 2015, ash dominated the short-term radiative response, 11 producing atmospheric heating of up to approximately 16 Wm⁻² and substantial surface cooling. 12 The ash-only experiment yielded near-neutral or slightly positive top-of-atmosphere (TOA) forcing, 13 whereas the combined ash–sulfate experiment produced negative TOA forcing. On 23 April, TOA 14 forcing shifted from approximately +3.8 to −3.2 Wm⁻². These findings indicate that ash controls the 15 magnitude of the short-term radiative response, while sulfate influences its net TOA sign.