Preprints
Filtering by Subject: Oceanography
Structure Function Sampling Uncertainty: A Gaussian-Increment Reference Framework
Published: 2026-10-28
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology
Structure functions (SFs) are widely used to characterize scale-dependent variability in geophysical fields, but their sampling uncertainty is difficult to quantify because pairwise increments are generally dependent. Dependence arises from both shared observations and spatial covariance of the underlying field, so pair counts alone do not determine uncertainty. The sampling variance is governed [...]
Decompression, self-leveling, and wobble decay of bubble rings released by scuba divers
Published: 2026-10-28
Subjects: Dynamic Systems, Fluid Dynamics, Oceanography, Ordinary Differential Equations and Applied Dynamics
Scuba divers blow bubble rings, hollow vortex rings with a gas core that expands as the ring rises because the water pressure drops with every meter of ascent. Classical theory keeps the gas volume fixed and treats only level rings, and the one earlier estimate of the expansion, for a laboratory tank, found it small. Here the ring is modeled as a thin hollow vortex ring with a core that obeys [...]
SCI-DEM: A Method for Generating Digital Beach Surfaces from Tide and Waterline Timeseries
Published: 2026-10-27
Subjects: Environmental Monitoring, Geomorphology, Oceanography
We present SCI-DEM, a method for deriving Digital Elevation Models (DEMs) of intertidal beach surfaces, profiles and beach widths from time-series waterlines using low-cost coastal CCTV cameras and modelled water levels. SCI-DEM builds on two established components: a waterline extraction method built on a semantic segmentation model, and a camera-pose-estimated homography, used to georeference [...]
The ocean’s gravity-driven carbon flux from serendipitous particle traps
Published: 2026-10-24
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Particles sinking into the ocean’s interior are a food source for deep-sea ecosystems and sequester carbon from the atmosphere. Yet, measurements of the sinking flux are sparse, leaving substantial uncertainties in its magnitude and variability. We demonstrate how a fleet of Argo floats has serendipitously measured the sinking flux for the last decade because particles settled onto the floats [...]
antasena: A Python Library for Nitrox Diving Calculations
Published: 2026-10-24
Subjects: Dynamic Systems, Fluid Dynamics, Numerical Analysis and Computation, Oceanography
We present antasena, an open-source Python library for calculations that underlie diving with nitrox, oxygen-nitrogen mixtures richer in oxygen than air. It computes depth limits, equivalent depths, inert-gas uptake, no-decompression limits, staged decompression schedules, central-nervous-system and pulmonary oxygen exposure, real-gas cylinder contents, and partial-pressure blending, and its [...]
Settling-driven Rayleigh–Taylor instability in a pre-existing turbulent field
Published: 2026-10-24
Subjects: Fluid Dynamics, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
Vertical particle transport controls environmental processes ranging from sediment deposition and the export of organic material and microplastics to the fate of minerals released for carbon dioxide removal. When a particle-laden layer overlies denser water, particles destabilize the interface and descend collectively as convective plumes, far faster than individual settling. Yet this mechanism [...]
Relationship between Meteorological Parameters and Temporal Variations of Microseismic Processes at the Belarusian Antarctic Research Station
Published: 2026-10-23
Subjects: Geophysics and Seismology, Meteorology, Oceanography
This study involved an analysis of seismic data acquired in the surrounding area of the Belarusian Antarctic research station “Mount Vechernyaya” in February, 2023 to identify a possible relationship between the seismic noises and local meteorological parameters. Probability density functions of power spectral densities histograms were constructed using the ObsPy framework based on the source [...]
Interior-fold and endpoint transitions in finite-depth capillary-gravity ship wakes
Published: 2026-10-23
Subjects: Fluid Dynamics, Oceanography
We study how finite water depth changes the principal stern caustics and wave patterns of linear capillary-gravity waves generated by a steadily moving pressure source on an inviscid fluid of uniform depth. Using the dispersion relation and ray directions relative to the source, we determine the conditions for caustic formation. Let H denote the water depth divided by the capillary length. No [...]
Reconstructing Significant Wave Height Fields from Sparse Observations Using Virtual Observation Augmentation
Published: 2026-10-23
Subjects: Oceanography
Real-time, high-precision significant wave height (SWH) fields are essential for ocean forecasting, disaster mitigation, and marine applications. However, extremely sparse observational coverage in vast ocean regions limits accurate reconstruction, as traditional spatial interpolation often produces overly smoothed fields that fail to capture fine-scale structures and sharp gradients. This study [...]
Random-split validation overstates the skill of machine-learning models of global coral bleaching severity
Published: 2026-10-21
Subjects: Climate, Environmental Indicators and Impact Assessment, Marine Biology, Oceanography, Statistical Methodology
Global compilations of coral bleaching surveys are increasingly used to train machine-learning models of bleaching severity, but such models are often evaluated with random train–test splits that ignore duplicated records, spatial dependence and differences among contributing survey programmes. We re-examined an earlier analysis of the Global Coral Bleaching Database (BCO-DMO dataset 773466) that [...]
Municipal exposure to sea-level-rise inundation in Connecticut: a reproducible screening analysis of NOAA inundation-extent data and its sensitivity to methodological choices
Published: 2026-10-21
Subjects: Environmental Indicators and Impact Assessment, Geographic Information Sciences, Oceanography, Physical and Environmental Geography
Municipal tabulations of sea-level-rise exposure are widely used in coastal planning, but they are sensitive to processing choices that are rarely reported. We tabulated NOAA Office for Coastal Management ocean-connected inundation-extent rasters for Connecticut (0.5–10 ft above mean higher high water, MHHW; ~3 m resolution from 2023 statewide lidar) for all 169 municipalities, using 2020 Census [...]
Ecosystem community structure shapes carbon dynamics in the ocean
Published: 2026-10-19
Subjects: Climate, Marine Biology, Oceanography, Physical Sciences and Mathematics
Understanding how marine ecosystems influence air–sea CO2 flux under climate change remains a major uncertainty in ocean carbon-cycle projections. Progress is hampered by insufficient representation of ecosystem complexity in climate models and insufficient observations for developing and calibrating complex marine ecosystem models. We present a novel three-branch ensemble of the PlankTOM12 [...]
Using Global Climate Models to Inform Multi-Driver Biological Ocean Experiments
Published: 2026-10-15
Subjects: Biogeochemistry, Oceanography
This century, widespread shifts in temperature and CO2-driven acidification are projected for the surface ocean. Determining how ocean biota will respond to these changes requires scaling multiple drivers together because biological responses to one driver often depend on the conditions of the others. However, ocean temperature and carbonate chemistry vary across regions, seasons, and emissions [...]
Feature-Relative Deployment Optimisation of Ice-Tethered Buoy Arrays in the Southern Ocean
Published: 2026-10-13
Subjects: Oceanography, Physical Sciences and Mathematics
The Southern Ocean marginal ice zone is critical for climate dynamics and sea-ice model validation, yet remains severely undersampled due to costly deployment and short buoy lifetimes. The sea-ice edge shifts by hundreds of kilometres between years, so fixed-coordinate optimisation fails when future ice conditions are unknown. This paper presents a robust multi-objective framework that encodes [...]
Wave-Driven Sliding, Ratcheting, and Overturning of Coral Transplant Units: An Idealized Nonsmooth Contact Model
Published: 2026-10-11
Subjects: Environmental Monitoring, Marine Biology, Numerical Analysis and Computation, Numerical Analysis and Scientific Computing, Oceanography, Systems Biology
Coral transplantation attaches fragments to a structure placed on the seabed, and that structure must stay put long enough for the fragments to fuse to it. We examine that requirement with an idealized model in which a transplant unit is a planar rigid body on a rigid bed under two unilateral frictional contacts, loaded through a Morison description of near-bed wave kinematics and integrated by a [...]