Preprints
There are 7999 Preprints listed.
Decadal Trends in the Quality of Groundwater Used for Public Drinking-Water Supply in California, 2004–2023, California Groundwater Ambient Monitoring and Assessment Program, Priority Basin Project
Published: 2026-02-25
Subjects: Earth Sciences, Hydrology
This study provides a comprehensive assessment of decadal changes in the quality of groundwater used for public drinking-water supply at 444 monitoring sites across California during 2004–2023. We assessed decadal step trends in groundwater quality for 145 water-quality constituents and geochemical indicators statewide and across geographic and land-use based network groups. We evaluated the [...]
LLM-augmented taxonomy for >4500 palaeopalynology genera
Published: 2026-02-07
Subjects: Earth Sciences, Environmental Sciences, Mathematics
Large Language Models (LLMs), being text-based, are ideal types of artificial intelligence to consider the complexities of palaeontological taxonomy because palaeontology depends on published textual descriptions as the primary, authoritative record of a taxon. This paper describes (1) the preparation of palynological (the study of organic-walled microfossils) taxonomic text contained within the [...]
DHAFGan: A Dense Hybrid Attention Fusion Generative Adversarial Network for Infrared and Visible Image Fusion
Published: 2026-03-22
Subjects: Computer Engineering
Aiming at the problems existing in the current infrared and visible light image fusion algorithms, such as insufficient perception of typical features, poor visual representation of the fusion results, and insufficient utilization of important secondary information, this paper proposes an infrared and visible light image fusion algorithm based on shallow-deep feature extraction and dual-channel [...]
Cube2sph-GPU: A GPU accelerated toolkit enabling flexible continental-scale regional and teleseismic full waveform inversion
Published: 2026-03-04
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
We present Cube2sph-GPU, a GPU-accelerated framework for continental-scale regional and teleseismic full-waveform inversion (FWI). Building upon the capabilities of SPECFEM3D_Cartesian, the toolkit introduces: (1) a flexible hybrid simulation scheme for tele-seismic simulations; (2) curvilinear C-PML; (3) spherical PDE-based kernel smoothing; and (4) highly optimized GPU kernels and I/O [...]
Accelerating 3D Magnetotelluric Forward Modelling with Domain Decomposition and Order-Reduction Methods
Published: 2026-02-06
Subjects: Applied Mathematics, Geophysics and Seismology
Three-dimensional (3D) magnetotelluric (MT) forward modelling is computationally demanding, limiting its use in global uncertainty quantification and sampling-based probabilistic inversion. Here, we introduce a novel forward-modelling framework that combines an iterative domain decomposition (DD) formulation with proper orthogonal decomposition (POD) reduced-order modelling to enable scalable and [...]
Multiple-Well Monitoring Site Adjacent to the Midway- Sunset and Buena Vista Oil Fields, Kern County, California
Published: 2026-02-12
Subjects: Earth Sciences, Geochemistry, Geology, Hydrology, Physical Sciences and Mathematics
Groundwater quality in and around oil fields in the Southern San Joaquin Valley is of interest to many California residents that rely heavily on groundwater for domestic, commercial, and agricultural use. To help assess the effects of historical oil-field activities and natural geologic sources on groundwater near the southwest margins of the Kern County Groundwater Subbasin, a multiple-well [...]
Reduced-order modelling of Cascadia’s slow slip cycles
Published: 2025-07-25
Subjects: Computer Sciences, Earth Sciences, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics
Slow-slip events (SSEs) modulate the earthquake cycle in subduction zones, yet understanding their physics remains challenging due to sparse observations and high computational cost of physics-based simulations. We present a scientific machine-learning approach using a data-driven reduced-order modelling (ROM) framework to efficiently simulate the SSE cycle governed by rate-and-state friction in [...]
Petrogenic Carbon Oxidation and Its Impact on the Carbon Balance in the Ganga River Basin
Published: 2026-05-15
Subjects: Earth Sciences
Based on sampling and investigation spanning several years, we conduct a comprehensive assessment of petrogenic organic carbon (OCpetro) oxidation and evaluate the net carbon budget in the Ganga–Hooghly River (GHR) basin, extending from the Himalayan mountainous catchments to the floodplains in India. Our multi-proxy approach combines data on rhenium (Re) concentrations, radiocarbon (pMC), stable [...]
Escape of near-inertial waves trapped in strong fronts through wave-wave interactions
Published: 2026-02-10
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Research on marine litter detection based on CNN-Transformer heterogeneous parallelism
Published: 2026-03-27
Subjects: Electrical and Computer Engineering
Aiming at strong background interference and low detection accuracy of small/deformed targets in marine debris detection, this paper develops a high-precision lightweight intelligent detection and recognition system. A multi-scenario dataset is built and data augmentation is used to tackle sample scarcity and domain shift; a CNN-Transformer heterogeneous parallel model YOLO-Trans is designed on [...]
Analysis of Orbit Determination Error Impact on Clutter Doppler Frequency for Space-Based Early Warning Radar
Published: 2026-04-03
Subjects: Aerospace Engineering
The accuracy of clutter Doppler frequency in space-based early warning radar (SBR) directly determines moving target detection performance, and satellite orbit determi-nation error is a important cause of clutter Doppler deviation. Taking satellite position and velocity in the Geocentric Celestial Reference System (GCRS) as core variables, this paper derives the analytical expression of clutter [...]
Paleomagnetic data from the Qaidam Block quantify post-middle Triassic convergence preceding eastern Eurasian assembly
Published: 2026-04-09
Subjects: Geology
Amalgamation of East Asian blocks with Eurasia involved progressive closure of several oceanic basins preserved as sutures. Since the Permian, the North China Block has undergone ~2500 km of paleolatitudinal motion relative to Eurasia, forming Mongol–Okhotsk suture in the north. Surprisingly, no evidence in its western part has been found to coordinate this motion, which is essential for a triple [...]
Harnessing naturally occurring sodium carbonate and bicarbonate for gigatonne-scale carbon dioxide removal
Published: 2026-03-06
Subjects: Engineering
Ocean alkalinity enhancement is a promising carbon dioxide removal (CDR) approach, but scaling up to gigatonnes (Gt) of CO2 per year will require safe, sustainable, and abundant alkaline feedstocks. Here, we propose the use of a relatively unexplored resource for OAE, namely naturally occurring sodium (bi)carbonates. We identified and mapped 109 such deposits globally, although quantitative [...]
Probabilistic Regional Conditioning of Natural Hazard Loss Models
Published: 2026-06-26
Subjects: Environmental Studies, Hydrology, Risk Analysis
Natural hazard risk models underpin decisions from insurance pricing to infrastructure investment, yet their accuracy depends on vulnerability functions rarely calibrated to local conditions. The most accurate vulnerability functions capture regional building characteristics through multi-variable models or large engineering-based loss-function databases, but need detailed asset-level data that [...]
Mathematical Modeling of Coupled Heat and Mass Transfer with Phase Transitions in Heterogeneous Porous Soils: Mechanism of Soil Moisture Diffusivity Collapse during Freezing
Published: 2026-03-12
Subjects: Physical Sciences and Mathematics
A mathematical model of coupled heat and mass transfer with water–ice–vapor phase transitions in heterogeneous porous soils is developed. The model comprises the Richards equation, the water vapor diffusion equation, and the heat transfer equation, coupled through a temperature-dependent hydraulic conductivity governed by the Kozeny–Carman relation and thermodynamic phase equilibrium described by [...]