Preprints
Filtering by Subject: Physical Sciences and Mathematics
THE ROLE OF IRON CENTERS IN COAL OXIDATION: A SYSTEMATIC REVIEW AND QUANTITATIVE ESTIMATION OF SURFACE ACTIVE SITE DENSITY
Published: 2026-03-14
Subjects: Physical Sciences and Mathematics
Iron in coals occurs in various forms (pyrite, ultradispersed particles, ions in the carbon matrix) and plays a key role in oxidation processes, spontaneous combustion, liquefaction, and gasification. Although extensive experimental data have accumulated over recent decades, a systematic generalization linking quantitative estimates of the surface density of catalytically active Fe centers to [...]
The 1908 Tunguska event and some mini-Tunguskas
Published: 2026-03-14
Subjects: Education, Physical Sciences and Mathematics
This paper is a continuation of a series of works, devoted to various aspects of the 1908 Tunguska event. This paper is devoted to several events which can be called as mini-Tunguskas. Their manifestations are in some ways similar to the 1908 Tunguska event, only on a much smaller scale. Often initially such events were interpreted as meteoroidal bolides or even meteorite falls. However, the [...]
A Physics-Informed Data Science Approach to Quantifying Rain-Snow Fraction Dynamics in the Central Himalayas
Published: 2026-03-12
Subjects: Physical Sciences and Mathematics
Mountain studies worldwide have documented increases in rainfall fraction as an impact of climate change. Most mountain systems show an increasing trend in rainfall fraction due to shifting snow precipitation to rain. In Nepal, which occupies an 800 km-long belt of the Hindu Kush Himalaya, the precipitation phase trend is not well known. This study conducts a precipitation phase study in the [...]
Interpretable Relations between Tropical Sea Surface Temperature and U.S. Precipitation in Winter Season Forecasts
Published: 2026-03-12
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We explore the large-scale relations between anomalies of global tropical sea surface temperature (SST) and U.S. precipitation to assess the sources of December-February (DJF) predictability and skill. Canonical Correlation Analysis (CCA) is applied to forecasts from NOAA's latest seasonal prediction system, the Seamless System for Prediction and EArth System Research (SPEAR). We find that DJF [...]
Complete electrification worsens the net energy prospects of a transition based on wind and solar energy.
Published: 2026-03-12
Subjects: Engineering, Physical Sciences and Mathematics
Mitigating climate change largely relies on substituting fossil fuels with low-carbon, electricity-producing energy sources. This mass electrification deeply alters sectoral energy demand, as some sectors can be more efficiently electrified than others. Building transition infrastructure – such as solar and wind farms, grid extensions, and electric vehicles – at a sufficient pace to achieve [...]
Multi-decadal Barrier Island Fate Varies as a Function of Management Strategy
Published: 2026-03-11
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Barrier islands are highly dynamic components of sandy coastlines, making up 10% of coastlines globally. Barriers provide recreational opportunities, protect mainland communities from storms, support tourism, and provide ecologically important habitat. Using a spatially explicit barrier island model, CASCADE, calibrated to represent the historical dynamics of Ocracoke, a barrier island in the [...]
Evaluating global spectral unmixing techniques using imaging spectroscopy data for retrieval of green, non-photosynthetic vegetation, and soil fractional cover
Published: 2026-03-11
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics, Remote Sensing, Soil Science
Global estimates of fractional cover of green vegetation (GV), non-photosynthetic vegetation (NPV), and soil provide valuable information about the Earth system. As the new generation of Earth visible-to-shortwave infrared (VSWIR) imaging spectrometers take orbit, global fractional cover data will be obtainable with new and improved spectral unmixing algorithms. Using an ASD Field Spectrometer [...]
Fast and Slow Groundwater Reservoir Dynamics Revealed by Seismic Velocity Changes and Bayesian ICA in a Taiwan Mountain Ridge
Published: 2026-03-11
Subjects: Physical Sciences and Mathematics
Mountain block recharge (MBR) is an important but difficult-to-observe component of mountain water budgets, especially in steep terrain where groundwater measurements are sparse. In such settings, relative seismic velocity changes (dv/v) derived from ambient-noise interferometry provide a potential proxy for hydrological storage variations, but interpretation is complicated because each frequency [...]
HIGH-RESOLUTION DIGITAL TERRAIN MODEL FOR THE ITALIAN TERRITORY
Published: 2026-03-11
Subjects: Agriculture, Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Engineering Education, Environmental Sciences, Environmental Studies, Geography, Life Sciences, Mining Engineering, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
High-resolution digital terrain models are essential for environmental planning and territorial analyses, and provide foundations for geomorphological and hydrological applications, including flood and landslide modelling and geo-hydrological hazard and risk assessments. In Italy, airborne LiDAR surveys have improved the representation of terrain morphology in the last decade, but their coverage [...]
Mathematical Modeling of Coupled Heat and Mass Transfer with Phase Transitions in Heterogeneous Porous Soils: Mechanism of Soil Moisture Diffusivity Collapse during Freezing
Published: 2026-03-11
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 [...]
crstools 1.0.0: an R package for cartographic analyses
Published: 2026-03-11
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Life Sciences, Physical Sciences and Mathematics
Spatial analyses are central to ecological studies, underpinning applications ranging from species distribution modelling to conservation planning and macroecological inference. However, most of these require translating processes occurring on a spherical surface into a planar map, inevitably introducing distortion biases. Projection choice can therefore influence both visual interpretation and [...]
GEOCHEMICAL DIAGNOSTICS OF COAL GENOTYPES: METHOD, CALIBRATION, AND BASIN TYPOLOGY
Published: 2026-03-10
Subjects: Physical Sciences and Mathematics
This study presents a geochemical method for discriminating coal types based on vitrinite maceral composition (telinite vs. collinite), using trace element ratios normalized to a reference aluminum content of 1.5%. Analysis of 146 samples from 13 coal basins demonstrates that conventional geochemical proxies (V/Ni, Ni/Co, U/Th, V/Cr) are unreliable for paleoenvironmental interpretation, whereas [...]
Remote Forcing of Internal Waves in Regional Ocean Models
Published: 2026-03-10
Subjects: Engineering, Physical Sciences and Mathematics
Regional oceanic general circulation models with nested grids are an essential approach to allow the use of higher grid resolutions. High resolution is required for the study of smaller scale processes, such as submesoscale currents and the internal wave field, in particular the baroclinic tide. Limits of available computing power determine the size of the computational grid, setting the [...]
Rethinking Hydroclimatic Extremes: Occurrence of abrupt Drought-to-Heavy-Precipitation transition events
Published: 2026-03-09
Subjects: Engineering, Physical Sciences and Mathematics
Drought-to-heavy-precipitation abrupt transitions (sometimes called dry-to-wet extremes, whiplash events, or drought–flood transitions) are an emerging research focus. These are rapid shifts from a period of sustained drought (rainfall deficits, soil moisture stress, low streamflow) to intense precipitation or flooding over short timescales. Also described as climate whiplash events, they reflect [...]
A Multi-year Analysis of Supraglacial Lake Seasonal Dynamics in the Karakoram
Published: 2026-03-09
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Supraglacial lakes are a key feature of many debris-covered glaciers in the Karakoram region. These lakes are highly dynamic, often forming and draining rapidly on seasonal timescales. However, due to their small size and transient nature, they are largely absent from regional and global glacial lake inventories. In this study, we used Sentinel-1 synthetic aperture radar (SAR) imagery to examine [...]