Preprints
Filtering by Subject: Physical Sciences and Mathematics
Annual mean methane emissions from individual oil-gas point sources worldwide inferred from multi-satellite plume-imaging observations
Published: 2026-09-30
Subjects: Physical Sciences and Mathematics
Plume-imaging satellite instruments routinely reveal large methane point source emissions from oil and gas systems. But the observations are for instantaneous plumes, and the instruments have limited detection and revisit capabilities, making it challenging to infer time-averaged emission rates as needed for emission inventories and reporting. Here we develop a general method to infer the [...]
Fit for purpose evapotranspiration measurements: A multi-site comparison of lower-cost approaches across croplands and shrublands
Published: 2026-09-29
Subjects: Physical Sciences and Mathematics
Evapotranspiration (ET) links the water and energy cycles, yet research-grade eddy covariance (EC) systems may not be the best option to deploy operationally for water management. Emerging lower-cost ET approaches may expand fit-for-purpose observations, but their reliability across contrasting ecosystems, climates, and instrumentation configurations remains uncertain. Here, we evaluate [...]
Forecasting the moisture content of live forest fuels with a transformer machine learning model and Sentinel-2 satellite data
Published: 2026-09-29
Subjects: Ecology and Evolutionary Biology, Environmental Monitoring, Forest Biology, Forest Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Other Plant Sciences, Physical Sciences and Mathematics, Planetary Hydrology, Planetary Sciences, Plant Sciences, Terrestrial and Aquatic Ecology
Live fuel moisture content (LFMC) provides an indicator of vegetation flammability, the potential for canopy dieback from drought, and habitat quality for arboreal fauna. Recent advances in artificial intelligence have increased the potential in meteorological forecasts for Earth surface forecasting. Combining weather forecasts with remotely sensed LFMC offers a promising avenue for short and [...]
Propagation of the Storegga tsunami in the southeastern North Sea
Published: 2026-09-28
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Numerical simulations of the 8150 BP Storegga slide event in the Norwegian Sea are necessary for understanding both landslide dynamics and tsunami propagation. Here we focus on the southern North Sea, South East of Dogger Bank, and the shores of Denmark and Germany where there have been reports of Storegga tsunami deposits. We simulate the slide using a recently developed cohesive landslide model [...]
Physics, Ecology, Mathematics and Engineering of the Negawatt Economy: A Formal Architecture for Verified Energy Conservation
Published: 2026-09-26
Subjects: Engineering, Physical Sciences and Mathematics
The contribution is a formal issuance architecture for verified energy conservation. The Negawatt (NWT) is the registry denomination of that conservation: one NWT equals one megawatt-hour (1 MWh) accepted under Proof of Conservation. In this paper, energy conservation means measured and verified avoided energy use relative to an adjusted baseline; it does not mean the First-Law [...]
Hidden periodicity in LiDAR point-count rasters
Published: 2026-09-26
Subjects: Computer Sciences, Earth Sciences, Geophysics and Seismology, Numerical Analysis and Scientific Computing, Other Earth Sciences, Physical Sciences and Mathematics
LiDAR point-count rasters can contain regular stripes that are not present in the surveyed scene. They arise when the fixed step on which LAS files store coordinates, often 1 cm, interacts with the grid used to count points. We identify three mechanisms, grid mismatch, floating-point boundary rounding and uneven filling of stored positions, predict where each pattern appears and how strong it is, [...]
Transient Events: A Rapid-Response, Multi-Platform Observing Strategy for Detecting and Understanding Abrupt Change in Aquatic Ecosystems
Published: 2026-09-25
Subjects: Biochemistry, Biodiversity, Biogeochemistry, Earth Sciences, Marine Biology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Extremes, not average conditions, increasingly govern the state of aquatic ecosystems and the risks they carry for people. Events far outside normal variability can reshape ecosystem structure and function within hours to weeks, and both the observational record and climate projections indicate such extremes are growing more frequent, more intense, and longer lasting. Whether an extreme becomes a [...]
Carbon and the Elements of Life: Integrated Observing and Modeling of Marine Biological Carbon Cycles
Published: 2026-09-25
Subjects: Atmospheric Sciences, Biodiversity, Biogeochemistry, Biology, Climate, Earth Sciences, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The global ocean acts as a massive reservoir for carbon dioxide, establishing ocean biogeochemistry as a primary driver of global carbon distributions [1-3]. This dynamic system is mediated by living organisms that cycle carbon and other elements through the ocean interior and air-sea interface, and is already being altered by warming, acidification, deoxygenation, and shifting nutrient supply [...]
Rare deglacial-aged corals point to weaker El Niño in a colder world
Published: 2026-09-24
Subjects: Physical Sciences and Mathematics
Extreme El Niño events, the warm phase of the El Niño–Southern Oscillation (ENSO), have increased in frequency since the late 20th century, intensifying concerns about ENSO’s response to a changing climate and its far-reaching impacts on global weather. Yet climate model projections of future ENSO behaviour remain divergent, and simulations under past glacial boundary conditions likewise lack [...]
A brief history of equifinality in hydrological modelling: from GST to GLUE to ML
Published: 2026-09-24
Subjects: Education, Engineering, Physical Sciences and Mathematics
AbstractEquifinality has shaped hydrological modelling for five decades. The equifinality thesis rejects the concept of an “optimal” model in favour of the possibility that different model structures or parameter sets can provide similarly acceptable representations of a system when uncertainties in the forcing and evaluation data are considered, especially when those data are subject to [...]
Deep seismo-volcanic tremors constrain the magma supply from the mantle
Published: 2026-09-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Volcanic eruptions are driven by magma supplied from the mantle, yet deep magmatic flux remains poorly constrained. Here we propose to quantify it based on deep seismic tremors. We adopt a model of tremor generation by rapid growth of gas bubbles in response to magma decompression and establish a physical relationship between the cumulative seismic moment and the volume of the ascending magma. By [...]
Subvolcanic magma pathways in transtensional regimes; AMS and structural evidence from SE Iceland
Published: 2026-09-24
Subjects: Physical Sciences and Mathematics
This study presents an integrated analysis of magmatic and tectonic strain data recorded within and around the Reyðarártindur intrusion, southeast Iceland, combining anisotropy of magnetic susceptibility (AMS) with UAV-based fracture mapping. Thermomagnetic experiments and petrography confirm AMS fabrics capture magmatic-state strain, defining a consistent NNE–SSW magnetic lineation with [...]
A Probabilistic Framework for Site-Specific Tropical Cyclone Loss Quantification and Reinsurance Optimization
Published: 2026-09-24
Subjects: Computational Engineering, Earth Sciences, Engineering, Environmental Sciences, Physical Sciences and Mathematics
Quantifying the financial risk posed by landfalling tropical cyclones requires statistical methods that extend beyond the limits of a short and non-stationary historical observational record. This paper explores techniques for improving site-specific loss estimation in tropicalcyclone catastrophe risk, an area of ongoing interest to insurance and reinsurance pricingand solvency capital [...]
Ambient Noise Surface-Wave Polarization in Anisotropic Media: Theory, Measurement, and Interpretation
Published: 2026-09-24
Subjects: Physical Sciences and Mathematics
We develop an adiabatic theory and practical methodology for measuring quasi-Rayleigh and quasi-Love polarization from the complete ambient noise cross-correlation tensor. The formulation allows the polarization parameters at both stations of a pair to be estimated jointly and, under sufficiently adiabatic propagation, interpreted in terms of local anisotropic structure at those locations. A new [...]
Hydrogeology and Water Quality of the Unconsolidated Aquifer System in the Lower Fall Creek Valley, Tompkins County, New York
Published: 2026-09-24
Subjects: Earth Sciences, Physical Sciences and Mathematics
The U.S. Geological Survey, in cooperation with Tompkins County and the Town of Dryden, conducted a hydrogeologic investigation of the lower Fall Creek unconsolidated aquifer system in Tompkins County, New York. This study is part of an ongoing effort to characterize major valley-fill aquifers in the region to support sustainable groundwater management. The lower Fall Creek valley, encompassing [...]