Preprints
There are 6976 Preprints listed.
Machine Learning–Based Prediction of Atmospheric CO₂ Concentration: A Year– Month Trend analysis
Published: 2025-12-12
Subjects: Environmental Education
Atmospheric carbon dioxide (CO₂) remains the principal driver of contemporary climate change, yet accurately forecasting its temporal evolution requires models capable of capturing complex nonlinear and seasonal dynamics. In this study, we conduct a comprehensive evaluation of thirteen supervised machine-learning algorithms to model and predict long-term atmospheric CO₂ concentrations using [...]
Towards Entire Wavefield Inversion in Highly Scattering Volcanic Environments using Fourier Neural Operators
Published: 2025-12-12
Subjects: Physical Sciences and Mathematics
Seismic imaging in volcanic environments is highly challenging due to significant scattering of seismic waves on multiple spatial scales. When these wavefields are recorded on the surface by seismic arrays, seismograms generally contain information-rich codas in addition to ballistic first arrivals. Later reflected and refracted arrivals are often completely masked by the scattered coda waves. [...]
Vegetation Does Not Control Suspended Sediment Deposition in Salt Marshes
Published: 2025-12-12
Subjects: Physical Sciences and Mathematics
Intertidal marshes are valuable geophysical systems, but their extent is rapidly declining globally. Marshes tend to keep up with sea-level rise through suspended-sediment and organic-matter deposition, up to a marsh-specific threshold rate of sea-level rise. Studies that explore marsh survival often assume that inorganic sediment deposition rates are directly linked to the density of marsh [...]
An update of the LDEO fCO2-Residual method: algorithmic choices improve ocean carbon sink estimates
Published: 2025-12-12
Subjects: Physical Sciences and Mathematics
We evaluate the impact of various algorithmic design choices on reconstruction skill and estimated air-sea CO2 flux using the fCO2-Residual machine learning (ML) method (Bennington et al., 2022a) to reconstruct surface ocean fCO2. We reconstruct fCO2 globally over the period 1982-2023 by optimizing the hyperparameter selection process (ResidualOPT) and/or using ΔfCO2-Residual (subtracting fCO2atm [...]
Lower crustal magmatic processes and andesite genesis at Shiveluch Volcano
Published: 2025-12-15
Subjects: Earth Sciences, Physical Sciences and Mathematics
The silicic melts that eventually erupt at arc volcanoes are produced in the lower crust, yet, the storage conditions of magma in the lower crust have not been the topic of extensive study. In this study, we conduct and analyze hydrous piston cylinder experiments to determine the mid-to-lower magma storage conditions of primitive melt at Shiveluch, an arc volcano located in northern Kamchatka. [...]
Noisy Sampling Inherent to Daily Precipitation Observations and Implications About Return Level Inferences
Published: 2025-12-13
Subjects: Other Oceanography and Atmospheric Sciences and Meteorology
Daily precipitation observations form the backbone of the United States precipitation network. However, precipitation is episodic over minutes and hours and is (seasonally) diurnally driven, which immediately raises questions about the statistical characteristics of its extreme daily accumulations in general. Atop this is layered troubling context: during the historical period of these [...]
Misalignments between national mangrove monitoring capacities and climate policy ambitions
Published: 2025-12-13
Subjects: Ecology and Evolutionary Biology, Environmental Studies, Forest Sciences, Geography, Life Sciences, Social and Behavioral Sciences
Ambitious global targets for mangrove conservation have advanced rapidly in recent years, yet the implementation of these commitments depends largely on national monitoring systems and policy processes. Despite widespread reliance on country-reported data for setting and evaluating targets, little is known about how national mangrove statistics are generated or how they interact with climate [...]
A Multidisciplinary Data Synthesis for Environmentally-Relevant Beta-Emitting Radionuclides in the Back-End Nuclear Fuel Cycle
Published: 2025-12-14
Subjects: Chemistry, Environmental Sciences, Other Physical Sciences and Mathematics
This study synthesizes multidisciplinary information—from nuclear physics and environmental science—related to environmentally relevant beta-emitting radionuclides in the back-end nuclear fuel cycle: H-3, C-14, Cl-36, Se-79, Sr-90, Tc-99, and I-129. First, our synthesis shows that these radionuclides are the key contaminants and dominant dose contributors, both in the high-level radioactive waste [...]
National scale sub-meter time series mangrove mapping using Landsat imagery and deep transfer learning
Published: 2025-12-15
Subjects: Geography, Remote Sensing
Current mangrove time-series products are constrained to 25 m resolution, hindering precise delineation of boundaries, small patches, and internal structures, thus compromising area estimates and ecological assessments. Key barriers are the paucity of historical high-resolution imagery and high-quality labeled samples. To this end, we developed the Sub-meter Mangrove Transfer Learning Mapping [...]
A Rapid Analytical Method for Predicting Injection Rates in Heterogeneous Reservoirs
Published: 2025-12-16
Subjects: Engineering
Maximum injection rate is a key criterion when screening subsurface hydrocarbon reservoirs or aquifers for possible EOR schemes or storage of hydrocarbon gas, hydrogen or carbon dioxide. It has to be high enough to achieve desired rates without risking the formation fracturing. Screening requires evaluation of thousands or millions of potential injection sites to identify those with favourable [...]
Gutenberg-Richter-type earthquake size distributions: maximum likelihood estimation, unbiased estimation, and Bayesian forecasting
Published: 2025-12-18
Subjects: Geophysics and Seismology
Characterizing earthquake size distributions using the Gutenberg-Richter (GR) law is ubiquitous in seismology. According to the GR law, earthquake magnitudes follow an exponential distribution, with a rate parameter commonly represented by the b-value. For many applications, including seismic hazard and risk assessment, estimating the b-value is therefore a common procedure. However, the [...]
Heat stress as an emerging constraint on global dairy systems: global gridded CMIP6 projections and national-scale milk loss exposure
Published: 2025-12-17
Subjects: Agriculture, Animal Sciences
Dairy production is a key component of global food systems, providing essential nutrients and supporting rural livelihoods, but it is increasingly exposed to heat stress under climate change. Here, we present a spatially explicit global assessment of heat-stress exposure and potential milk-yield losses using bias-corrected CMIP6 climate projections at 0.25° resolution combined with gridded [...]
Resource expansion with uncertainty quantification of regolith-hosted REE deposits using radiometric data
Published: 2025-12-17
Subjects: Earth Sciences, Physical Sciences and Mathematics, Statistics and Probability
Rare earth elements (REE) are critical raw materials due to their essential role in modern technologies. In regolith-hosted REE (RH-REE) deposits a substantial fraction of the REE is present as ionically adsorbed, exchangeable cations on secondary clay minerals and amenable to mild extraction routes potentially being less environmentally disruptive than conventional hard-rock REE operations. [...]
South Atlantic abyssal temperature variability and trends at 34.5°S
Published: 2025-12-16
Subjects: Physical Sciences and Mathematics
Warming of abyssal waters in the South Atlantic has been reported in recent years. However, the variability of bottom temperatures and its implications for assessing linear trends have received limited attention. In addition to confirming positive temperature trends, this study documents substantial bottom-temperature variability, from tidal to annual time scales, captured by bottom moorings [...]
The impact of extreme temperatures on respiratory mortality in Brazil: evaluating regional adaptations to different thermal environments
Published: 2025-12-19
Subjects: Public Health
We conducted a nationwide ecological time-series study to quantify the association between ambient temperature and respiratory mortality across Brazil's diverse climates. Using data from 520 municipalities (population ≥50,000) from 2010 to 2020, we analysed 1,008,157 respiratory deaths (ICD-10 J00–J99) using distributed-lag non-linear models (lags 0–21 days) with quasi-Poisson regression, [...]