Preprints
There are 7774 Preprints listed.
Hydrogen gas (H₂) artificially generated during soil-gas sampling - Technical report
Published: 2026-10-05
Subjects: Physical Sciences and Mathematics
Surface gas geochemistry methods, including soil gas measurements, are widely used for natural hydrogen (H₂) exploration. It is known that H₂ can be artificially generated by mechanical friction during installation of soil-gas probes. However, it is frequently considered that artificial H₂ is produced only by drill bit rotation, although there are no systematic studies about its generation during [...]
A Stable Column ΔXCH₄/ΔXCO₂ Ratio over Los Angeles (2011–2025): An Inventory-Independent Test of Urban Methane Policy
Published: 2026-10-05
Subjects: Physical Sciences and Mathematics
We extend the column-averaged CH₄ and CO₂ (XCH₄, XCO₂) record from the California Laboratory for Atmospheric Remote Sensing (CLARS) through July 2025, spanning 15 years over the Los Angeles megacity. CLARS retrievals show persistent enhancements of both gases above the free-tropospheric background, with a strong excess correlation (R = 0.93) and an emission ratio ΔXCH₄/ΔXCO₂ ≈ 5.1 ppb ppm⁻¹ that [...]
COVID-19 Emission Reductions Reveal the Efficiency and Warming Impact of Short-Lived Greenhouse Gases
Published: 2026-10-05
Subjects: Physical Sciences and Mathematics
The COVID-19 response provided a natural experiment to quantify the climate forcing efficiency of short-lived pollutants. Using satellite-constrained reanalysis and chemistry-climate simulations, we isolate the radiative impacts of anthropogenic NOₓ reductions through two modes: a rapid ozone decrease and a slower methane-driven adjustment that dominates the net effect. Globally, these responses [...]
Natural aerosol variability can reverse the apparent air-quality response to abrupt emission reductions
Published: 2026-10-05
Subjects: Physical Sciences and Mathematics
Abrupt societal disruptions, including economic shocks, pandemic lockdowns, and armed conflicts, are widely used as natural experiments for attributing changes in air quality to changes in emissions. Such attribution commonly rests on observed concentrations: combustion tracers fall, and the resulting improvement is credited to reduced emissions. Here we show that coincident natural aerosol [...]
Bulk iron-sulfur ratio (Fe/S) conditional proxy for sulfurized, TOC-rich sediments: insights and comparison of compositional model with real data utilizing the Pyrite-TOC-Fe-S compositional space
Published: 2026-10-04
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Bulk iron-sulfur (Fe/S) ratio can be a proxy for sulfurized organic matter in organic-rich shales, particularly those prone to be siliceous or carbonate. First part uses a theoretical model of a compositional system consisting solely of iron, sulfur, TOC, and pyrite to demonstrate how the Fe/S ratio can indicate the presence of sulfurized organic matter using the model’s assumption of sulfur [...]
Carbon dioxide removal capacity of converting harmful macroalgal blooms in South Korea to biochar: a Monte Carlo assessment
Published: 2026-10-04
Subjects: Engineering, Environmental Engineering
Blooms of the drifting brown alga Sargassum horneri (golden tides) and of green-tide Ulva spp. strand on the coasts of South Korea every year and are collected by local governments. Pyrolysing this biomass to biochar has been proposed as a way to store carbon, but its carbon dioxide removal (CDR) capacity has not been quantified. We built a Monte Carlo model (100,000 draws) of the technical [...]
Parcel-Level Deforestation Hazard Rates in the Paraguayan Chaco: A Multi-Scale Empirical Analysis of Annual Clearing Dynamics on Large Cattle Ranches
Published: 2026-10-04
Subjects: Geographic Information Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Other Environmental Sciences, Physical and Environmental Geography, Remote Sensing
Cattle ranch expansion across the Paraguayan Chaco generates parcel-level clearing rates that appear inconsistent with regional deforestation statistics, raising concerns that REDD+ baselines constructed from proxy parcels overstate forest loss (a baseline over-crediting debate that turns on denominator consistency between parcel hazard and regional flows). Because parcels undergoing active [...]
Human health impacts of PFAS exposure: A second-order meta-analysis
Published: 2026-10-04
Subjects: Environmental Public Health, Public Health
Per- and polyfluoroalkyl substances (PFAS) are highly persistent synthetic chemicals with pervasive human exposure. Numerous meta-analyses have synthesised results on the association between PFAS exposure and human health, yet findings remain fragmented and often inconsistent across compounds, outcomes, and studies. We assessed the magnitude and consistency of associations between PFAS exposure [...]
Climate resilience from long-term low till adoption in US farms
Published: 2026-10-03
Subjects: Agriculture, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Sustainability
Low-intensity tillage (low till) has expanded rapidly in the United States since 2000. Evidence on its yield impacts has come mainly from field experiments and has been limited to short time horizons. Using satellite-based observations from more than 40 million field-year pairs across the U.S. Corn Belt from 1999-2023, we demonstrate that yield gains continue to accrue with longer duration of [...]
Improvement of Daily Temperature Forecasts from a Prediction Market
Published: 2026-10-03
Subjects: Applied Statistics, Atmospheric Sciences, Climate, Meteorology, Natural Resource Economics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Probability, Statistical Methodology, Statistical Models, Statistics and Probability
Prediction markets aggregate and distill the collective views of participants who have a financial stake in being correct. They have been shown to produce more accurate forecasts in realms like election results, which are not easily amenable to mechanistic modeling because they entail forecasting human behavior. It is far less clear that prediction markets should improve the accuracy of [...]
Fixed-ground multisensor monitoring resolves longitudinal vegetation condition and fuel-state structure in Southern California chaparral and oak scenes
Published: 2026-10-03
Subjects: Ecology and Evolutionary Biology, Environmental Monitoring, Environmental Sciences, Forest Sciences, Geography, Life Sciences, Physical Sciences and Mathematics, Plant Sciences, Remote Sensing, Social and Behavioral Sciences, Terrestrial and Aquatic Ecology
Wildfire-relevant vegetation and fuel conditions evolve through interacting changes in vegetation condition, three-dimensional fuel structure, thermal response, and atmospheric drying, yet these dimensions are commonly monitored separately. This study evaluated repeated fixed-ground multisensor monitoring at two fixed vegetation scenes in Placerita Canyon, California. Multispectral imaging, [...]
Counterfactual Evaluation of a Satellite-Connected Multi-Sensor Early-Warning System During the 26 August 2026 Bhote Koshi–Trishuli Disaster
Published: 2026-10-03
Subjects: Electrical and Computer Engineering, Engineering, Risk Analysis, Systems and Communications
The 26 August 2026 Bhote Koshi–Trishuli disaster raised an important question: could a warning system continue to reach people if local infrastructure failed? This study tests a proposed system using satellite communication, a reviewed river network, 15 radar-gauge stations, 2 candidate geophone stations, a camera site and 32 mapped target references. The analysis consists of two segments. The [...]
Local ETM+ to OLI EVI Harmonisation in Tropical Forest Environments
Published: 2026-10-03
Subjects: Geographic Information Sciences, Geography, Human Geography, Remote Sensing, Spatial Science
This report evaluates ETM+ to OLI EVI harmonisation in tropical forest environments us-ing 8,988,291 paired observations. Results show strong linear correspondence but substan-tial acquisition-to-acquisition variability. The empirical relationship differs markedly from the CONUS-derived framework of Roy et al. (2016), indicating that its direct application is not supported under the investigated [...]
Slopes rarely out-warm the floor a 2003–2025 MODIS assessment of deep surface-based night-time inversions over the Malang basin, East Java
Published: 2026-10-03
Subjects: Atmospheric Sciences, Meteorology
Nocturnal cold-air pools can trap heat and pollutants in basin cities, but tropical basins are seldom monitored. We assessed deep surface-based night-time inversions over the Malang basin, East Java, Indonesia, from 2003–2025 MODIS Terra and Aqua night-time land surface temperature (LST), using the difference ΔT between a slope band (900–1300 m; mean 1079 m) and the rural basin floor (≤ 600 m; [...]
Evaluating Bank Restoration and Stabilization in the Yellow River in Northern Indiana: Mitigation of Sediment and Nutrient Transport
Published: 2026-10-02
Subjects: Engineering, Life Sciences
The U.S. Geological Survey, in cooperation with the Kankakee River Basin and Yellow River Basin Development Commission, evaluated the effects of streambank remediation on the Yellow River in northwest Indiana. Two phases of remediation were completed on the Yellow River between 2021 and 2023, after assessments indicated it was a large contributor of sediment to the Kankakee River. Temporal [...]