Preprints
Filtering by Subject: Physical Sciences and Mathematics
Band ratio to band difference for Chl of oceanic waters: broke a self-imposed no-touch zone
Published: 2025-08-28
Subjects: Education, Physical Sciences and Mathematics
There are many empirical algorithms developed for the remote sensing of chlorophyll-a concentration (Chl) from ocean color measurements, with the blue-green band-ratio type of algorithms dominating these practices. During the phase of algorithm development, which is data-driven, generally the errors of remote sensing reflectance (Rrs) from satellites are ignored until Hu et al. (2012) developed a [...]
Surface Expression of Low Basal Friction Upstream of Antarctic Grounding Lines
Published: 2025-08-27
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Ice sheets leave contact with the bed at grounding lines, beyond which floating ice shelves experience no friction at their base. In places where basal friction begins to decrease upstream of the grounding line, ice sheets respond more strongly to climate forcing. However, the spatial extent of zones of low grounding line friction is poorly constrained by observations. Here, we use a steady-state [...]
Strike-slip restraining screwed fault geometry reconstructed from the 2025 Myanmar earthquake
Published: 2025-08-25
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
We present a fault surface model of the 2025 Mw 7.7 Myanmar earthquake based on the potency density tensor inversion (PDTI) of teleseismic P-waves combined with surface reconstruction from distributed potency tensor solutions. Our source model demonstrates that the earthquake fault is twisted, varying the dip angle along strike. Inferred fault twists are prominent near fault-segment junctions, [...]
Bayesian Estimation of Paleoearthquake Magnitudes in the Central Apennines
Published: 2025-08-22
Subjects: Physical Sciences and Mathematics
Paleoseismic data provide critical constraints on earthquake recurrence where instrumental records are limited, but magnitude estimation from geologic evidence requires careful treatment of measurement uncertainties. We develop a Bayesian method with application to the estimation of paleoearthquake magnitudes in the central Apennines, Italy, by jointly analyzing rupture length (L), slip (S), and [...]
High-Resolution Simulation of the Urban Heat Island Effect in Grenoble During the 2018 Heatwave: Evaluating WRF Model Configurations
Published: 2025-08-22
Subjects: Atmospheric Sciences, Climate, Fluid Dynamics, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
This study investigates the Urban Heat Island (UHI) effect in Grenoble, France, during the August 2018 heatwave, using high-resolution Weather Research and Forecasting (WRF) simulations at 111 meters. The objective is to evaluate at this resolution the capac- ity of different WRF urban parameterizations such as the Building Effect Parameterization (BEP) and Building Energy Model (BEM), to [...]
WRFUP: A Python Package to Enhance Urban Simulations
Published: 2025-08-22
Subjects: Atmospheric Sciences, Databases and Information Systems, Fluid Dynamics, Meteorology, Physical Sciences and Mathematics, Physics
WRFUP is a Python package designed to enhance urban climate modeling in the Weather Research and Forecasting (WRF) model by automating the sourcing and ingestion of high-resolution urban morphology data. This package calculates crucial urban canopy parameters—URB_PARAM and FRC_URB2D—enabling precise simulations for advanced urban canopy parameterizations like SLUCM, BEP, and BEP+BEM. This tool [...]
Megadyke propagation down dynamic topography
Published: 2025-08-22
Subjects: Earth Sciences, Physical Sciences and Mathematics
Magmatic dykes that align vertically and extend laterally for hundreds to thousands of kilometres are known as megadykes. Observations of solidified megadyke swarms indicate that they have a common magma source and a characteristic run-out length. There is no consensus on what determines this length. We develop quantitative predictions to test the hypothesis that run-out length is set by the [...]
An Ice Core Snapshot of Past Atmospheric Chemistry in Mt. Everest’s 'Death Zone'
Published: 2025-08-21
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Glaciology, Other Environmental Sciences, Physical Sciences and Mathematics
We present a unique atmospheric chemistry record from the highest ice core ever recovered (8020 m, South Col Glacier (SCG), Mt. Everest), that captures ~400 years of deposition during the latter half of the first millennium BCE. Due to recent glacier thinning, the upper ~2000 years of accumulation have been lost, however, this is the only ice core record ever recovered from the “Death Zone [...]
Newly discovered active faults in the Wairarapa Valley: Implications for multi-fault rupture and kinematics in the southern North Island, Aotearoa New Zealand
Published: 2025-08-21
Subjects: Physical Sciences and Mathematics
Active fault locations and constraints on the timing and size of earthquakes are important for understanding and mitigating seismic hazard in Aotearoa New Zealand. However, historical and instrumental records are too short to provide these data on most earthquake-generating faults. Light detection and ranging (lidar) data provide us with the ability to locate and describe active faults and [...]
Quantifying the intensity of crystallographic preferred orientation (CPO): some practical considerations and recommended practices
Published: 2025-08-16
Subjects: Earth Sciences, Geology, Mineral Physics, Physical Sciences and Mathematics, Tectonics and Structure
Crystallographic preferred orientations (CPOs) commonly develop during the crystal-plastic deformation of rocks and minerals, and are widely used to infer strain intensity and geometry, reconstruct deformation conditions, and estimate mechanical anisotropy. Although CPO intensity is often quantified using scalar metrics that reduce the full orientation distribution to a single value, these [...]
Best practices for the analyses of CO2 fluids by Raman Spectroscopy
Published: 2025-08-15
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Raman spectroscopy is a key method for determining CO₂ densities in geological fluids, yet acquisition, calibration, and processing methodologies vary widely between laboratories. This study evaluates how these parameters affect precision and accuracy. We show that spectral non-linearity can cause a single instrument to show variable relationships between CO2 density and spectral parameters as [...]
Precipitation-driven typology of storms in the Alps
Published: 2025-08-15
Subjects: Physical Sciences and Mathematics
Numerous advances in precipitation science hinge on our ability to categorize storms into homogeneous classes, for instance to isolate time series with convective- or stratiform-like characteristics. Nonetheless, achieving such classifications remains challenging. Here, we use an Alpine storm typology developed through a straightforward methodology for unsupervised classification based on [...]
Modeling Large Dust Aerosols in the Community Earth System Model Version 2 (CESM2)
Published: 2025-08-15
Subjects: Physical Sciences and Mathematics
Dust aerosols have a wide size distribution from less than 1.0 nm to over 100 μm and dominate the Earth’s atmospheric aerosol mass. However, most Earth system models inadequately represent dust aerosols larger than 10 µm in diameter, limiting the accuracy of dust cycle and climatic impact simulations. Here, we introduce a new modeling framework that captures the observed full-size distribution of [...]
Can spinodal decomposition occur during decompression-induced vesiculation of magma?
Published: 2025-08-15
Subjects: Physical Sciences and Mathematics
Volcanic eruptions are driven by decompression-induced vesiculation of supersaturated volatiles in magma. The initial phase has long been described as a process of nucleation and growth. Recently, it was proposed that spinodal decomposition—an energetically spontaneous phase separation that does not require a distinct interface—may occur during decompression. This idea has attracted attention, [...]
Mutual Gravitational Capture as a Mechanism for Planetary Growth: An Alternative Hypothesis
Published: 2025-08-15
Subjects: Physical Sciences and Mathematics
This study proposes a new hypothesis for the growth of rocky planets through successive events of mutual gravitational capture followed by planetary fusion. The model suggests that collisions resulting from mutual gravitational captures within the Hill sphere occur under initial conditions of zero relative velocity, aligned velocity vectors, and relatively similar mass ratios. Under these [...]