Preprints
Filtering by Subject: Physical Sciences and Mathematics
Detecting and Explaining Persistent Road Underdevelopment in Greater Accra Region Using Multi-Temporal Geospatial Data and Machine Learning
Published: 2026-04-30
Subjects: Engineering, Physical Sciences and Mathematics
Uneven transport infrastructure development remains a persistent challenge in rapidly urbanising cities, where disparities in road conditions shape mobility, accessibility, and socio-economic op-portunities. In Greater Accra, Ghana, rapid urban expansion has produced a road network character-ised by strong spatial inequalities, with many neighbourhood roads remaining unpaved despite sur-rounding [...]
Reduced geomagnetic shielding increased UV-B radiation at Earth’s surface during the Laschamps Event
Published: 2026-04-30
Subjects: Astrophysics and Astronomy, Atmospheric Sciences, Biochemistry, Biogeochemistry, Biology, Earth Sciences, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Geology, Geophysics and Seismology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Life Sciences, Paleobiology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences, Statistics and Probability
Exposure to excess UV-B radiation can harm organisms through DNA damage and oxidative stress, and has likely been a key ecological and evolutionary driver throughout Earth’s history. Here, we show UV-B at Earth’s surface was significantly increased during the Laschamps Event, the last major geomagnetic excursion ca. 41ka BP. During the Laschamps, we find significant and prolonged (lasting [...]
Direct quantification of solar-induced chlorophyll fluorescence using compact solar-blind optical radiometers
Published: 2026-04-30
Subjects: Biogeochemistry, Earth Sciences, Environmental Monitoring, Environmental Sciences, Optics, Physical Sciences and Mathematics, Physics
Remote sensing of solar-induced chlorophyll fluorescence (SIF) provides a non-invasive, quantitative measure of plant photosynthetic activity, linking leaf-level physiology to canopy and ecosystem behavior and the global carbon cycle. Current SIF measurements rely on hyperspectral retrievals of the weak fluorescence signal from small changes in Fraunhofer lines or atmospheric absorption features [...]
Integrated Triassic sediment routing along eastern Gondwana (Australia)
Published: 2026-04-30
Subjects: Physical Sciences and Mathematics
Triassic continental sedimentary basins along the eastern margin of Gondwana record drainage reorganisation and sediment routing, but provenance links among adjacent basins remain uncertain. This study integrates detrital zircon U–Pb data and sandstone petrography from the Triassic Rewan Group and Clematis Group of the northern Bowen Basin with published palaeocurrent constraints and compares [...]
COMPARATIVE STUDY OF MONSOON AND IOD EFFECTS ON RAINFALL VARIABILITY IN NORTH AND SOUTH SUMATRA
Published: 2026-04-30
Subjects: Physical Sciences and Mathematics
Sumatra Island exhibits distinct rainfall characteristics between its northern and southern regions due to its equatorial position. Generally, Northern Sumatra displays a bimodal rainfall pattern driven by the movement of the Intertropical Convergence Zone (ITCZ), whereas Southern Sumatra follows a monomodal pattern influenced by the Asian-Australian Monsoon system. This study aims to evaluate [...]
Acceleration and Spatial Reorganization of Bank Erosion under Prolonged Sediment Starvation: Multi-decadal Evidence from the Vam Nao Channel
Published: 2026-04-28
Subjects: Physical Sciences and Mathematics
The reduction in sediment supply in major deltas worldwide is altering the morphological dynamics of river delta systems. However, the way in which this process leads to the spatial reorganization of erosion has not yet been fully quantified. This study analyzes shoreline variations in the Vam Nao channel, Mekong Delta, over the period 1988–2025 in order to clarify the morphological changes of [...]
Large climate model ensembles reveal underdispersion in seasonal Atlantic tropical cyclone counts
Published: 2026-04-28
Subjects: Atmospheric Sciences, Physical Sciences and Mathematics
Seasonal Atlantic tropical cyclone (TC) counts are commonly modeled as a conditional Poisson process, implying that the distribution of possible seasonal outcomes—the range of TC counts that could plausibly occur in a given year—exhibits equidispersion for a given climate state, with its variance equal to its mean. This assumption underlies many statistical frameworks used for seasonal TC [...]
Soil Remineralization in Agroecological Systems: A Critical Review
Published: 2026-04-28
Subjects: Agriculture, Earth Sciences, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics
Soil degradation threatens global food security, human nutrition, biodiversity, water resources, and climate stability by depleting soil organic matter, exhausting nutrient reserves, and disrupting carbon and nitrogen cycles. Conventional input‑intensive agriculture has delivered yield gains but has also contributed to widespread micronutrient deficiencies, nutrient loading of waterways, soil [...]
Assessment of riverbed evolution in the Vam Nao River under the influence of sand mining using a numerical model
Published: 2026-04-28
Subjects: Physical Sciences and Mathematics
Riverbed sand mining is a major anthropogenic driver of sediment imbalance and riverbank erosion in the Mekong Delta. This study investigates its morphological impacts using the hydrodynamic–morphological model HYDIST, coupled with a sand mining source function (Ssm), to directly simulate unsustainable sand mining. The model is applied to the Vam Nao River, a confluence connecting the Tien and [...]
Efficient Full-Waveform Inversion via QR-Based Data Selection
Published: 2026-04-28
Subjects: Earth Sciences, Physical Sciences and Mathematics
Full-waveform inversion (FWI) is computationally intensive due to the large number of data points, forward simulations, and model parameters. However, realistic acquisition geometries often produce highly redundant linearized systems. In this work, we reformulate post-acquisition data selection as a matrix row-subset selection problem acting directly on the Jacobian of the linearized inverse [...]
Understanding fiber-optic sensitivity to a wavefield: A framework to separate site amplification from orientation effects
Published: 2026-04-27
Subjects: Earth Sciences, Physical Sciences and Mathematics
When analyzing signals from Distributed Acoustic Sensing (DAS), the recorded amplitude across the array can be difficult to interpret, as it is influenced by many parameters. In this work, we explore the theoretical foundations of fiber sensing amplitude transfer functions. We begin with linear fiber segments and progressively extend to more complex geometries to create polarization [...]
A Report on Assumptions and Uncertainties in Modeling Nuclear Winter
Published: 2026-04-26
Subjects: Physical Sciences and Mathematics
Nuclear winter is arguably the biggest consequence of a nuclear war that the field seeks to prevent; experts study nuclear winter to prevent civilizational collapse and widespread catastrophe. A nuclear winter would be, for lack of better words, really bad. As long as the risk of nuclear war exists, so too will the catastrophic risk of a nuclear winter. Much of the modeling and research that [...]
Overshoot pathways of 1.5°C: reversible biophysical change, irreversible socioeconomic impacts
Published: 2026-04-25
Subjects: Physical Sciences and Mathematics, Social and Behavioral Sciences
Exceedance of 1.5°C in the near term is now unavoidable. Among pathways consistent with the remaining carbon budget, an overshoot pathway, in which exceedance is followed by decline to or below 1.5°C through net-negative emissions, is the best case of what remains achievable. Permanent exceedance produces strictly worse outcomes, yet even an overshoot pathway leaves lasting legacies. We propose a [...]
Spatial Assessment of Soil Erosion Risk Using RUSLE and GIS in Upland Agricultural Barangays of Candelaria, Quezon, Philippines
Published: 2026-04-25
Subjects: Physical Sciences and Mathematics
This study integrated Geographic Information System (GIS) and the Revised Universal Soil Loss Equation (RUSLE) model, A= R • K • LS • C • P, to assess soil loss and propose soil conservation strategies in Candelaria, Quezon, Philippines, addressing increasing erosion evidenced by collapsing hillsides, sedimentation, and soil displacement from construction. The RUSLE model, with adjustments in the [...]
Evaluation of H2O-CO2 solubility models in silicate melts: Precision and accuracy of vapor saturation pressure and composition
Published: 2026-04-25
Subjects: Physical Sciences and Mathematics
Solubility models for H2O and CO2 in silicate melt are crucial in igneous petrology and volcanology, in particular for calculating the pressure of vapor saturation of melts from their dissolved volatile content as a barometer, as well as melt and vapor compositions and proportions during degassing. We assessed the accuracy and precision of the calculated pressure of vapor saturation and [...]