Preprints
There are 6900 Preprints listed.
From 2D labels to 3D structure: Scalable label transfer and benchmarking of 3D vegetation models in rangeland ecosystems
Published: 2026-05-03
Subjects: Artificial Intelligence and Robotics, Biogeochemistry, Computer Sciences, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics, Remote Sensing
Three-dimensional (3D) characterisation of vegetation structure at the level of individual growth forms is critical for understanding ecosystem function and resilience, yet remains challenging in rangelands because vegetation is sparse, low-stature, and structurally heterogeneous. Recent 3D deep-learning models perform strongly in forests, but their transfer beyond closed-canopy benchmarks is [...]
A Mechanism Criterion Replaces Coupling Magnitude for Rainfall Inhibitory Skill Across Three Indo-Pacific Forcing Modes
Published: 2026-05-03
Subjects: Physical Sciences and Mathematics
CPAdry — the Conditional Precipitation Anomaly, dry phase — detects rainfall inhibitory mechanism failure across three forcing modes: the MJO (intraseasonal), ENSO, and IOD (interannual). Twenty assessments at eighteen Indo-Pacific sites using two-track methodology establish the governing principle: CPAdry returns meaningful skill only where the forcing mode imposes locally active inhibition — [...]
High-Alkalinity Algal Cultivation with Direct Air Capture: An Economic Feasibility Analysis
Published: 2026-05-02
Subjects: Engineering
Weather variability and CO₂ supply costs remain key barriers to the commercial viability of algal biofuel production. Recent experimental work has demonstrated that the algae Chlorella sp. strain SLA-04 achieves high productivity in extreme alkaline growth media (pH greater than 10), where the solution chemistry enables direct capture of atmospheric CO₂, eliminating the need for costly CO₂ [...]
Rules-Based Systems Modeling for Hydropower Forecasting in Multi-Objective Reservoir Systems: Application to California's Central Valley Project
Published: 2026-05-02
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Hydropower from large multi-objective reservoirs and water management projects constitutes the bulk of global reservoir-based generation. Yet accurate forecasting remains challenging because generation is governed not only by hydrology but by complex institutional rules, environmental regulations, and infrastructure constraints. This study demonstrates that a rules-based systems modeling [...]
Learning unresolved coastal dynamics in hydrodynamic models
Published: 2026-05-02
Subjects: Fluid Dynamics, Oceanography
Coastal hydrodynamic models play a vital role in understanding and predicting flooding, but practical computational constraints and uncertainties in boundary conditions and bathymetry lead to systematic errors in local sea level. We show that much of this error is not random but reflects a stable, site-specific response that can be learned from model output and observations. We develop a [...]
Extreme recharge triggers seismicity in a confined karst aquifer in southern Spain
Published: 2026-05-01
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Tectonics and Structure
Hydrological forcing during extreme recharge events can perturb crustal stress and trigger seismicity in a critically stressed crust, yet the coupling between aquifer dynamics and the spatio-temporal distribution of earthquake swarms remains poorly constrained. Here we document such a response during an exceptional rainfall episode in early 2026 that affected a confined karst aquifer in southern [...]
Control of natural hazard events through emergency landscaping
Published: 2026-05-01
Subjects: Geomorphology, Nature and Society Relations, Physical and Environmental Geography
Humans reshape the surface of the Earth through efforts to protect people and places from natural hazards. While some hazard defences, such as river levees, are permanent infrastructure, other measures, such as wildfire fighting, are responsive: they occur while a hazard event is in progress, actively intervening in its behaviour to mitigate its impact. Deliberate, concurrent, mitigating [...]
Making a difference takes time: assessing the impact of Colombian public land acquisitions on forest cover in the Andes
Published: 2026-05-01
Subjects: Environmental Studies, Geographic Information Sciences, Human Geography, Nature and Society Relations, Remote Sensing
Public land acquisitions (PLAs) are a promising conservation instrument, combining the permanence of protected areas with the voluntary, compensatory structure of payments for ecosystem services, yet causal evidence on their effectiveness remains limited. Colombia’s Article 111 mandate, which requires departments to allocate 1% of revenue to land acquisition for watershed protection, has produced [...]
How Do Discrete Global Grid Systems Actually Perform? A Systematic Benchmark Across Geometry, Computation and Relational Joins
Published: 2026-05-01
Subjects: Computer and Systems Architecture, Databases and Information Systems, Earth Sciences, Geographic Information Sciences, Software Engineering, Spatial Science
As geospatial datasets exceed the billion-row threshold, Discrete Global Grid Systems (DGGS) promise to replace expensive vector spatial joins with fast relational hash-joins on discrete cell identifiers. However, the real-world performance of different grid implementations and the upfront cost of converting vector geometries into grid indexes remains largely unquantified. This paper introduces [...]
Detecting and Explaining Persistent Road Underdevelopment in Greater Accra Region Using Multi-Temporal Geospatial Data and Machine Learning
Published: 2026-05-01
Subjects: Engineering, Physical Sciences and Mathematics
Uneven transport infrastructure development remains a persistent challenge in rapidly urbanising cities, where disparities in road conditions shape mobility, accessibility, and socio-economic op-portunities. In Greater Accra, Ghana, rapid urban expansion has produced a road network character-ised by strong spatial inequalities, with many neighbourhood roads remaining unpaved despite sur-rounding [...]
Recent intensification of eastern Pacific ENSO is unprecedented across the last millennium
Published: 2026-05-01
Subjects: Oceanography and Atmospheric Sciences and Meteorology
The Pacific El Niño-Southern Oscillation (ENSO) phenomenon generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of this system to climate warming is poorly constrained, due to data scarcity and climate model biases, making projections of future climate hazards uncertain. The geochemistry of Galápagos coral skeletons across the past [...]
When Irrigation Cannot Keep Pace: Aridification, Crop Composition, and the Spatial Concentration of Agricultural Water Use Efficiency Decline in Central Chile
Published: 2026-05-01
Subjects: Bioresource and Agricultural Engineering
Water scarcity under sustained aridification is among the most consequential threats to agriculture in Mediterranean-climate regions. Central Chile's ongoing megadrought (~2010-present), characterized by persistent precipitation deficits and intensified atmospheric evaporative demand-provides a natural experiment for examining how agricultural water use efficiency (WUE) responds to prolonged [...]
Challenges with Developing a Measurement-Based Basin Methane Intensity Estimate: A Case Study from the Haynesville
Published: 2026-05-01
Subjects: Environmental Indicators and Impact Assessment, Environmental Monitoring, Oil, Gas, and Energy
Methane intensity, the emissions relative to production, has been a focus in global regulations on oil and gas production and imports, given the climate benefits of methane emission reductions. Methodological frameworks to create annual measurement-based emissions inventory estimates and calculate methane intensity using snapshot measurements have been developed. However, there are still multiple [...]
Increasing lifetime exposure to extreme fire weather under climate change in Europe
Published: 2026-05-01
Subjects: Earth Sciences
Climate change increases fire weather globally. Hot, dry and windy conditions raise the likelihood of fires igniting and spreading and make suppression more challenging. With further warming, fire weather is projected to intensify across Europe, yet implications for today’s young generations remain unclear. Here, we analyse lifetime exposure to extreme fire weather across Europe using an ensemble [...]
Reduced geomagnetic shielding increased UV-B radiation at Earth’s surface during the Laschamps Event
Published: 2026-05-01
Subjects: Astrophysics and Astronomy, Atmospheric Sciences, Biochemistry, Biogeochemistry, Biology, Earth Sciences, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Geology, Geophysics and Seismology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Life Sciences, Paleobiology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences, Statistics and Probability
Exposure to excess UV-B radiation can harm organisms through DNA damage and oxidative stress, and has likely been a key ecological and evolutionary driver throughout Earth’s history. Here, we show UV-B at Earth’s surface was significantly increased during the Laschamps Event, the last major geomagnetic excursion ca. 41ka BP. During the Laschamps, we find significant and prolonged (lasting [...]