Preprints
Filtering by Subject: Physical Sciences and Mathematics
Seismic Evidence for an Ultralow Velocity Zone Beneath the Cape Verde Hotspot
Published: 2026-06-17
Subjects: Physical Sciences and Mathematics
Mega ultralow velocity zones (mega-ULVZs), thin patches of strongly reduced seismic velocity with large horizontal extent just above the core-mantle boundary (CMB), are increasingly found beneath deep mantle plumes, suggesting a link to hotspot volcanism. The Cape Verde hotspot is thought to overlie a deep plume, but whether a ULVZ exists at its base has remained unknown. We present [...]
Tropical cyclones intensify mesoscale eddy variability and accelerate Western Boundary Current instability
Published: 2026-06-17
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tropical cyclones strongly disrupt the upper ocean, yet their influence on mesoscale variability in western boundary current systems remains poorly quantified. The Gulf of Mexico, where the Loop Current regularly sheds large warm-core eddies, offers an ideal setting to examine how hurricanes reshape mesoscale dynamics. Using a high-resolution ocean model and hurricane-denial experiments, we [...]
ENSO-Driven Modulation of the Caribbean Subsurface Salinity Maximum
Published: 2026-06-16
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study identifies El Niño–Southern Oscillation (ENSO) as the primary driver of interannual subsurface salinity variability in the Caribbean Sea. Using 30 years of high-resolution, data-assimilative ocean reanalysis (1993–2022), we show that the Subsurface Salinity Maximum (SSM) closely tracks ENSO cycles: El Niño events correspond to a saltier and deeper SSM, while La Niña drives a fresher [...]
Internal Processes Driving the Slow-to-Fast Transition of a Rockslide
Published: 2026-06-16
Subjects: Physical Sciences and Mathematics
Landslides may creep slowly for decades to centuries under external influences such as rainfall or seismic shaking. Predicting when and how they transition into catastrophic acceleration remains a major challenge because the internal processes driving failure occur at depth and are often not evident from surface observations alone. Here, we combine local seismic and geodetic measurements to [...]
Why the Earth Exhibits Interhemispheric Albedo Symmetry: Erosion–formation asymmetry of low-cloud responses to circulation reorganization.
Published: 2026-06-16
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Earth exhibits a striking near symmetry in interhemispheric mean albedo despite substantial asymmetries in surface properties, aerosols, and geography. Whether this symmetry is coincidental or dynamically constrained remains unresolved. Here we present a minimal theoretical framework showing that a moist atmosphere provides a physically constrained, but bounded, tendency to oppose [...]
Samoa Basin Abyssal Mapping: Box Coring Leg
Published: 2026-06-15
Subjects: Physical Sciences and Mathematics
This cruise report describes work from leg three of the NOAA American Samoa Abyssal Mapping effort, OPR-T900-KR-26. Leg one preceded this effort and collected ship-based acoustic data. Leg two collected autonomous underwater vehicle (AUV) data and began before, continued contemporaneously, and finished subsequently to leg three. The USGS field activity number assigned to this expedition is [...]
Condensation Radiation of Water Vapor Drives Diurnal Temperature Range Patterns
Published: 2026-06-15
Subjects: Physical Sciences and Mathematics
The global distribution and variation of the Diurnal Temperature Range (DTR) remain “an essential knowledge gap” in our understanding of climate dynamics in IPCC assessment reports. This study introduces the radiative mechanism of water vapor condensation as a novel physical driver of DTR dynamics. Contrary to classical heat conduction theory, which assumes latent heat transfers via temperature [...]
Deglacial reconstruction of the spatial extent and intensity of the North Atlantic Subtropical High
Published: 2026-06-13
Subjects: Climate, Physical Sciences and Mathematics
Rainfall-related hazards are growing in southeastern North America (SENA) but well-documented climate-model biases cast doubt on projected rainfall changes. The North Atlantic Subtropical High (NASH) supplies the moisture that drives extreme rainfall in SENA, so reconstructing its past behavior offers a test of model fidelity. Using the hydrogen-isotope composition of leaf-wax biomarkers (δDwax) [...]
Warming above, cooling below: First model-based quantitative thermal- regime assessment and subsurface thermal evolution of Nivlisen Ice Shelf, East Antarctica, revealing non-equilibrium thermal adjustment and progressive thermal preconditioning
Published: 2026-06-13
Subjects: Physical Sciences and Mathematics
We present the first quantitative thermal characterisation of Nivlisen Ice Shelf, central Dronning Maud Land, East Antarctica, using a one-dimensional heat-transfer model forced by ERA5 surface skin temperatures (1940–2025). For the primary scenario (H = 312 m), the steady-state solution yields a mid-column temperature of −4.89 °C, Péclet number Pe = 4 (intermediate conduction–advection regime), [...]
PIKART Version 1.1: Release Notes
Published: 2026-06-12
Subjects: Physical Sciences and Mathematics
The PIK Atmospheric River Trajectories (PIKART) catalog is a global, high-resolution catalog of atmospheric rivers (ARs). Version 1.1 (v1.1) addresses two algorithmic bugs present in version 1.0 (v1.0): a boundary artifact at 30°E emerging during the extraction of the background component of the integrated vapor transport (IVT), and an error in the AR tracking algorithm that affected the [...]
Novel Data-driven High-Frequency Mass Change Models from GRACE orbit residuals
Published: 2026-06-11
Subjects: Climate, Earth Sciences, Fresh Water Studies, Glaciology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We present a fully data-driven framework for transforming residual K-band range-rate (KBRR) data from GRACE into 5-day mass change models expressed in Equivalent Water Height (EWH). The approach first derives residual range and Line-of-Sight Gravity Differences (LGDs) from monthly post-fit residual range-rates and combines them with 5-day post-fit residuals. A hybrid formulation, merging LGD- and [...]
Seeing Cities in Depth: Subsurface Urban Expansion and the Case for Volumetric Monitoring and Accountability
Published: 2026-06-10
Subjects: Physical Sciences and Mathematics, Social and Behavioral Sciences
Urban science can measure surface and aboveground change with increasing precision. Satellites, building-footprint datasets, and emerging three-dimensional products now track urban land, building height, and built volume. Yet these tools still struggle to capture urbanization below ground. This Perspective defines subsurface urban expansion as the extension of urbanization below the local ground [...]
A Rotating Air-Ring Model for Atmospheric Vortices and a Peripheral Drag Concept for Tornado Mitigation
Published: 2026-06-10
Subjects: Education, Engineering, Physical Sciences and Mathematics
This study introduces Latent Angular Momentum (LAM) as a heuristic parameter for understanding the intensification of rotating atmospheric vortices. Using a simplified air-ring model based on the conservation of angular momentum, we derive an analytical expression for tangential wind speed as a function of radial contraction and latitude. Model predictions yield physically plausible initial radii [...]
A Unified Treatment of SKS Splitting and Surface-Wave Anisotropy for Media with Arbitrary Elastic Symmetry
Published: 2026-06-09
Subjects: Physical Sciences and Mathematics
Observations of SKS splitting and surface-wave azimuthal anisotropy are two of the primary geophysical constraints on crust and upper-mantle anisotropy, yet the two methods often yield apparently inconsistent inferences about the strength and vertical extent of anisotropy. Here we show that neglecting anisotropy parameters associated with Rayleigh-Love coupling is an important and largely [...]
High-resolution pavement material data can improve estimates of water supply from precipitation to street trees
Published: 2026-06-09
Subjects: Physical Sciences and Mathematics
Impervious surfaces in urban landscapes strongly influence how precipitation supplies water to trees. Most data on imperviousness are satellite derived restricting our ability to analyze impacts of imperviousness at the scale of single tree catchments: the area covering tree roots. To address this challenge, we compiled a high-resolution dataset for Berlin, Germany, that specifies pavement [...]