Preprints
There are 7558 Preprints listed.
Stress-Conditioned Lightweight Flash-Drought Detection in the US Corn Belt Using MODIS NDVI and ERA5-Land
Published: 2026-07-29
Subjects: Hydrology, Meteorology
Flash-drought monitoring by classical indices averages predictive signal across calm and stressed years, blunting the signal exactly where it matters. We show empirically that the coupling between precipitation, soil moisture, vapor pressure deficit (VPD), and NDVI is stress-conditional: the hydrological pathway is visible when vegetation is already under stress (Spearman rho of about 0.18 for [...]
Northward Dust-Induced Shift of Tropical Atlantic Precipitation in CMIP6 Models
Published: 2026-07-29
Subjects: Life Sciences
Mineral dust has substantially increased since the pre-industrial period, particularly over North Africa and the Atlantic Ocean. However, the impacts of increased dust burden over the tropical Atlantic Ocean on the position of the Intertropical Convergence Zone (ITCZ) and regional precipitation remain poorly resolved. Here, we analyze seven CMIP6 models participating in the Aerosol Chemistry [...]
Intermediate-Evidence Substitution: A Benchmark Design Methodology for Isolating Numerical Derivation from Protocol Execution in Deterministic Climate Verification
Published: 2026-07-29
Subjects: Computer Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We introduce \textbf{Intermediate-Evidence Substitution (IES)}, a benchmark design methodology that changes evidence granularity while preserving task semantics: decisive aggregate statistics in benchmark evidence are replaced with the raw intermediate values from which they are derived, while task labels, decision protocols, thresholds, and evaluation criteria remain unchanged. IES functions as [...]
Residential Structure-Resolved Fuel Loading for Emissions Estimation in a Wildland–Urban Interface Fire
Published: 2026-07-29
Subjects: Engineering
Fuels in the Wildland-Urban Interface (WUI) include a variety of anthropogenic materials connected to historical and socio-economic backgrounds in addition to biomass. Yet current emission inventories rely on uniform fuel loading factors (FLFs) that treat all structures as compositionally identical. In this study, we develop a structure-resolved combustible fuel inventory for ~5,400 single-family [...]
Machine Learning-Based Sedigraph Reconstruction for Enhanced Sediment Yield Estimation in the Upper Blue Nile Basin
Published: 2026-07-29
Subjects: Civil and Environmental Engineering, Engineering
Sediment-laden runoff in Ethiopia’s Upper Blue Nile Basin (UBNB) threatens the ecological balance of Lake Tana and the operational efficiency of the Grand Ethiopian Renaissance Dam (GERD), a critical hydropower infrastructure. High sediment loads, driven by intense monsoon rainfall and erodible soils, exacerbate erosion and sedimentation, affecting water quality and the longevity of [...]
Detecting illegal water abstractions using Earth Observation and artificial intelligence: challenges, research gaps, and future directions
Published: 2026-07-28
Subjects: Artificial Intelligence and Robotics, Environmental Monitoring, Hydrology, Natural Resources Management and Policy, Remote Sensing, Water Resource Management
Water scarcity and unsustainable withdrawals are major environmental challenges, particularly in semi-arid and Mediterranean regions where agriculture places strong pressure on limited hydrological resources. Illegal or unreported water abstractions intensify these pressures by undermining ecosystem stability, policy compliance, and long-term water security. Although Earth Observation (EO) and [...]
Thermal migration and climatic de-territorialisation of North American professional sports leagues, 1950–2025
Published: 2026-07-28
Subjects: Geographic Information Sciences, Nature and Society Relations, Physical and Environmental Geography
Over the past seven decades, the four major North American professional sports leagues (NHL, MLB, NBA, NFL) have expanded and relocated across the continent, shifting their collective geography towards the Sun Belt. We quantify the climatic consequences of this movement by combining the complete franchise location history of the four leagues from 1950 to 2025 with ERA5-Land reanalysis data and [...]
SCI-OBS: Detection and Classification of People on the Beach and in the Surf Zone
Published: 2026-07-28
Subjects: Environmental Monitoring, Natural Resources Management and Policy, Oceanography, Remote Sensing
Understanding how many people use beaches and surf zones, and what they are doing there, is vital for safety, tourism and coastal management. Camera-based studies of coastal recreation have to date recovered attendance: a headcount, sometimes divided into coarse zones. This paper reports the accuracy at which the same infrastructure resolves attendance into activity composition, using a [...]
Using tectonic block modeling to quantify the impact of potentially–active faults on seismic hazard and risk in western Canada
Published: 2026-07-28
Subjects: Tectonics and Structure
In order to understand the impact of large, potentially active faults on seismic hazard and risk in western Canada, faults in the region are characterized using a geodetic-geologic block model. The results are then integrated into Canada's existing national seismic hazard and risk models. To do this, potentially active faults are mapped to build a block model around them; then, several thousand [...]
Effective Microbial Kinetics under Pore-Scale Transport Limitation: A Biofilm Effectiveness-Factor Theory
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics
Reactive-transport models of porous media usually evaluate microbial reactions with Monod kinetics and rate constants measured on well-mixed laboratory cultures, in which every cell is exposed to the same substrate concentration. In natural sediments and aquifers this assumption fails at the pore scale, because the cells are not suspended but reside in biofilms and aggregates attached to the [...]
Connectivity effects on fluid age and residence time distributions in two- and three-dimensional pore networks
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Pore-scale simulations are often run on a single plane cut from a three-dimensional image, because resolving the whole pore space is expensive. This study asks what that shortcut costs. What is at stake is the distribution of fluid ages, and above all its long tail, because that tail is what slow reactions respond to. We computed the distribution directly from the flow field, by labeling the [...]
Rapid SRO aluminosilicate formation in a narrow pH interval fractionates silicon isotopes
Published: 2026-07-27
Subjects: Earth Sciences, Geochemistry, Soil Science
Short-range ordered (SRO) hydrous aluminosilicates (HAS) are among the earliest secondary phases formed during incongruent silicate weathering, yet the timescales and silicon isotope (δ30Si) fractionation associated with their initial formation remains poorly constrained. We use stepwise room temperature NaOH titration to resolve pH buffering, Si–Al removal, and dissolved δ30Si evolution in two [...]
Reconstructing age and reactivity distributions from the moments carried by central-moment transport models
Published: 2026-07-26
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
A central-moment transport model follows a property that varies across a population, such as the age of water parcels or the decay rate of organic-matter particles. Instead of storing the whole distribution of that property, it keeps only a few summary numbers, the moments, and moves those through the model. But the distribution itself is usually what a scientist wants, so it has to be rebuilt [...]
Southeast African mangroves: an exceptionally young paleobotanical record
Published: 2026-07-25
Subjects: Paleobiology, Paleontology
Mangroves are pantropical intertidal forests that maintain coastal biodiversity, provide a wide range of ecological services and represent the most efficient blue-carbon ecosystems for mitigating global warming. A recent global initiative aims to reconstruct the historical biogeography of mangroves using comprehensive paleobotanical datasets from biogeographically coherent regions. This approach [...]
Open at the interface, closed at the core: neutrality claims in AI‑enabled geoscience infrastructure focusing on Africa – The case of Deep‑Time Digital Earth and GeoGPT
Published: 2026-07-25
Subjects: Earth Sciences, Geology
Geological data has become strategic infrastructure for resource assessment, investment negotiation, and economic sovereignty. Remotely hosted big data and Artificial Intelligence (AI) platforms are increasingly promoted for geoscience in the Global South, particularly Africa. Whether such platforms are genuinely geopolitically unaligned, and how this can be verified, has direct implications for [...]