Preprints
There are 7999 Preprints listed.
Worldwide inference of national methane emissions by inversion of satellite observations with UNFCCC prior estimates
Published: 2025-10-02
Subjects: Atmospheric Sciences, Environmental Engineering
Meeting climate policy goals to reduce methane emissions under the Paris Agreement and the Global Methane Pledge requires nations to set targets and quantify reductions. Individual countries report emissions by sector to the United Nations Framework Convention on Climate Change (UNFCCC) but there are large uncertainties. Here we optimize 2023 national emissions at up to 25 km grid resolution for [...]
Climate Change Projections for the Central Peruvian Coast (2006–2100) Using CMIP5 Models: Agricultural Impacts and Implications for the Growth of Chenopodium quinoa Willd in Arid Zones
Published: 2025-10-01
Subjects: Agriculture
We evaluated climatic data for the central coastal region of Peru (Lima) as simulated by the climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The models were: MIROC-ESM, CSIRO Mk 3.6, CNRM-CM5, GFDL-CM3, IPSL-CM5A-MR, and MPI-ESM-LR, with respective spatial resolutions of 2.81° × 1.77°, 1.875° × 1.86°, 1.4° × 1.40°, 2.5° × 2.0°, 2.5° × 1.27°, and 1.875° × 1.875°. [...]
Hydrogeology and assessment of the effect of oil-production activities in the Midway Valley area, western Kern County, California
Published: 2026-04-16
Subjects: Environmental Sciences
The southwestern San Joaquin Valley, California includes oil fields and oil-field water disposal facilities, (ponds and injection wells). The Tulare Formation and overlying alluvium comprise the main aquifers in the study area and are commonly used for produced water disposal. Water quality in the aquifers is naturally brackish (total dissolved solids (TDS) 3,000-10,000 mg/L) across most of the [...]
Peatland Mid-Infrared Database 1.0.0
Published: 2025-10-06
Subjects: Biogeochemistry, Soil Science, Terrestrial and Aquatic Ecology
Systematic collections of peat mid-infrared spectra and other peat properties are scarce, but useful to understand peat chemistry and develop spectral prediction models. The Peatland Mid-Infrared Database ('pmird') stores 3877 mid-infrared spectra of peat, peat-forming vegetation, and dissolved organic matter, together with measurements of other peat properties that were collated from previous [...]
Unified Granular Intrusion Dynamics for Planetary Materials
Published: 2025-10-02
Subjects: Physical Sciences and Mathematics
Granular friction μ is a sensitive and poorly understood function of packing fraction ϕ. Every granular material has a distinct critical volume fraction ϕc that delineates two mechanical deformation modes – compaction for ϕ < ϕc, and dilation for ϕ > ϕc. Here we examine the relation(s) between friction and packing fraction, using quasi-static penetration tests in materials ranging from [...]
Direct requested-time modelling of space--time fractional seismic attenuation on fixed operators
Published: 2026-07-22
Subjects: Physical Sciences and Mathematics
Space--time fractional attenuation models represent dissipative memory and effective nonlocal dispersion in seismic wave propagation, but Caputo history marching is expensive when only selected receiver--time responses are required. Matrix Mittag--Leffler representations are classical; their use as a costed fixed-model response-query workflow for seismic attenuation is less developed. We [...]
Accessible Climate and Impact Model Output for Studying the Human and Environmental Impacts of Nuclear Conflict
Published: 2025-10-03
Subjects: Agriculture, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
Nuclear winter refers to the suite of physical and biological consequences that may follow nuclear conflict, particularly the cooling and darkening of Earth’s surface due to black carbon soot in the upper atmosphere. While the associated changes in temperature, precipitation, and food system productivity have been the subject of climate modeling for decades, the outputs of models used to project [...]
A Field Study on Background Radiation Variability with Elevation in Eastern Nepal
Published: 2025-10-03
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
This research investigates how environmental radioactivity varies with altitude in the diverse landscapes of Eastern Nepal. Employing two calibrated Geiger–Müller (GM) counters, background radiation was recorded as counts per minute (cpm) across selected sites in the districts of Dhankuta, Panchthar, Taplejung, and Ilam. Data were geo- referenced using GPS to correlate radiation levels with [...]
Transformer Assisted U-Net for Marine Litter Detection on Sentinel-2 Imagery
Published: 2025-10-05
Subjects: Environmental Monitoring
The contamination of marine environments with man-made litter is a growing nation-wide concern. Satellite imagery combined with deep learning–based detection models has emerged as a robust and cost-effective solution for large-scale marine litter monitoring. In this article, we present a novel deep learning-based scheme to detect marine litter using Sentinel-2 imagery based on the Deep UNet [...]
Geochronology of Taung and other southern African australopiths
Published: 2025-10-05
Subjects: Physical Sciences and Mathematics
One century after the Taung juvenile’s discovery, its age and that of many other southern African australopiths remains unknown. This lack of accurate geochronological constraints leaves important questions unanswered, including the temporal relationship between the South African fossil sites and their well dated eastern African counterparts. Previous age estimates for the Taung fossil range from [...]
Database of Generated Rock Microstructures and their computed Geometrical and Hydraulic properties
Published: 2025-10-06
Subjects: Earth Sciences, Materials Science and Engineering
There is a strong link between a material’s microstructural features and its macroscopic physical properties. However, heterogeneities in real-world rock microstructures often result in strong cross-correlations between the microscopic features, making it difficult to evaluate the influence of individual characteristics. Minkowski functionals (MFs), a set of measures derived from integral [...]
Curlew 1.0: Spatio-temporal implicit geological modelling with neural fields in python
Published: 2025-10-10
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
We present curlew, an open-source python package for structural geological modelling using neural fields. This modelling framework incorporates various local constraints (value, gradient, orientation and (in)equalities) and tailored global loss functions to ensure data-consistent and geologically realistic predictions. Random Fourier Feature (RFF) encodings are used to improve model convergence [...]
Advances in UAV-Based Methane Emission Monitoring: Sensors, Sampling Geometry, and Quantification
Published: 2026-10-30
Subjects: Engineering, Physical Sciences and Mathematics
Unmanned aerial vehicles (UAVs) are one key platforms for monitoring methane due to their flexible deployment with spatial scales between ground-based sensors and crewed aircraft This review synthesises research on UAV sensing technologies, flight and sampling strategies, quantification methods, and validation practices. It finds that quantitative performance depends on the combined choice of [...]
Contrasting patterns of deforestation and reforestation in India’s tropical dry woodlands
Published: 2025-10-07
Subjects: Environmental Studies, Remote Sensing, Social and Behavioral Sciences
Tropical dry woodlands are key ecosystems for global biodiversity, carbon storage, and forest-based livelihoods in some of the poorest regions of the world. Many of these woodlands have been historically converted and degraded, and while recovery occurs in some areas, the pressure on remaining tropical dry woodlands remains high. Despite this, our understanding of spatial patterns of tropical dry [...]
Paleoclimate pattern effects help constrain climate sensitivity and 21st-century warming
Published: 2025-10-07
Subjects: Atmospheric Sciences, Climate
Abstract: Paleoclimates provide examples of past climate change that inform estimates of modern warming from greenhouse-gas emissions, known as Earth's climate sensitivity. However, differences between past and present climate change must be accounted for when inferring climate sensitivity from paleoclimate evidence. The closest paleoclimate analog to near-term warming from greenhouse-gas [...]