Preprints
Filtering by Subject: Oceanography
Energy and Momentum of a Density-Driven Overflow in the Samoan Passage
Published: 2022-10-22
Subjects: Oceanography
The energy and momentum balance of an abyssal overflow across a major sill in the Samoan Passage is estimated from two highly resolved towed sections, set 16 months apart, and results from a two-dimensional numerical simulation. Driven by the density anomaly drop across the sill, the flow is relatively steady. The system gains energy from divergence of horizontal pressure work O(5) kW/m and flux [...]
Trait-based modeling revealed higher microbial diversity leads to greater ecological resilience in response to an ecosystem disturbance
Published: 2022-10-15
Subjects: Biogeochemistry, Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Microbiology, Oceanography, Oil, Gas, and Energy, Physical Sciences and Mathematics, Sustainability, Terrestrial and Aquatic Ecology
To quantitatively understand the ecological resilience of an ecosystem with specialized habitats, we focused on deep-sea microbial communities and simulated the response of diverse microbes in specialized habitats to a pulse ecosystem disturbance - the Deepwater Horizon Oil Spill in the Gulf of Mexico. Two microbial communities with equivalent metabolic libraries were acclimated to the presence [...]
Tsunami Early Warning from Global Navigation Satellite System Data using Convolutional Neural Networks
Published: 2022-09-29
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Oceanography
We investigate the potential of using Global Navigation Satellite System (GNSS) observations to directly forecast full tsunami waveforms in real time. We train convolutional neural networks (CNNs) to use less than 9 minutes of GNSS data to forecast the full tsunami waveforms over 6 hours at select locations, and obtain accurate forecasts on a test dataset. Our training and test data consists of [...]
Improved estimation of phytoplankton abundance and fine-scale water quality features via simultaneous discrete and semi-continuous surveys
Published: 2022-08-06
Subjects: Biogeochemistry, Environmental Monitoring, Fresh Water Studies, Oceanography, Water Resource Management
The abundance and distribution of phytoplankton is driven by light and nutrient availability which in turn is controlled by larger-scale regional processes such as climatic variability and global teleconnections. However, such estimates are largely built on evidence gathered from coarse (on the order of kilometers), discrete grab sampling networks where the overall set of measured parameters is [...]
Efficient Probabilistic Prediction and Uncertainty Quantification of Hurricane Surge and Inundation
Published: 2022-05-31
Subjects: Atmospheric Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study proposes a methodology for efficient probabilistic prediction of near-landfall hurricane-driven storm surge, tide, and inundation. We perturb forecasts of hurricane track, intensity, and size according to quasi-random low-discrepancy Korobov sequences of historical forecast errors with assumed Gaussian and uniform statistical distributions. These perturbations are run in an ensemble of [...]
How to drain a megalake: Comments on a study by Palcu et al. (2021) Scientific Reports 11, Art. Nr.: 11471.
Published: 2022-05-27
Subjects: Earth Sciences, Geology, Oceanography, Paleobiology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
In a recent paper by Palcu et al. (2021: Scientific Reports 11, Art. Nr.: 11471), the Cape Panagia section on the Taman peninsula (Russian Black Sea) was dated using magnetostratigraphy, in order to calibrate the timing of previously published regressions of the Paratethys megalake. The authors of the paper claim that this “largest megalake in the geological record” experienced four major [...]
Using Lagrangian filtering to remove waves from the ocean surface velocity field
Published: 2022-05-19
Subjects: Oceanography
The Surface Water and Ocean Topography (SWOT) satellite will measure altimetry on scales down to about 15km: at these scales, the sea-surface-height signature of inertia-gravity waves, including barotropic tides and internal tides, will be visible. However, tides and inertia-gravity waves have little impact on tracer transport. Recent work has shown that Lagrangian filtering can be used to [...]
Data from the drain: a sensor framework that captures multiple drivers of chronic coastal floods
Published: 2022-04-02
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tide gauge water levels are commonly used as a proxy for flood incidence on land. These proxies are useful for projecting how sea-level rise (SLR) will increase the frequency of coastal flooding. However, tide gauges do not account for land-based sources of coastal flooding and therefore flood thresholds and the proxies derived from them likely underestimate the current and future frequency of [...]
Deep submarine infiltration of altered geothermal groundwater on the south Chilean Margin
Published: 2022-01-25
Subjects: Earth Sciences, Geochemistry, Geology, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics
Submarine groundwater discharge is increasingly recognized as an important component of the oceanic geochemical budget, but knowledge of the distribution of this phenomenon is limited. To date, reports of meteoric inputs to marine sediments are typically limited to shallow shelf and coastal environments, whereas contributions of freshwater along deeper sections of tectonically active margins like [...]
Diapycnal Displacement, Diffusion, and Distortion of Tracers in the Ocean
Published: 2022-01-07
Subjects: Applied Mathematics, Fluid Dynamics, Non-linear Dynamics, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Small-scale mixing drives the diabatic upwelling that closes the abyssal ocean overturning circulation. Indirect microstructure measurements of in situ turbulence suggest that mixing is bottom enhanced over rough topography, implying downwelling in the interior and stronger upwelling in a sloping bottom boundary layer. Tracer release experiments (TREs), in which inert tracers are purposefully [...]
Quantifying the environmental impact of a major coal mine project on the adjacent Great Barrier Reef ecosystems
Published: 2021-12-23
Subjects: Environmental Indicators and Impact Assessment, Environmental Sciences, Oceanography, Oil, Gas, and Energy
A major coal mine project in Queensland, Australia, is currently under review. It is planned to be located about 10 km away from the Great Barrier Reef World Heritage Area (GBRWHA). Sediment dispersal patterns and their impact on marine ecosystems have not been properly assessed yet. Here, we simulate the dispersal of different sediment types with a high-resolution ocean model, and derive their [...]
Components and Tidal Modulation of the Wave Field in a Semi-Enclosed Shallow Bay
Published: 2021-12-10
Subjects: Environmental Engineering, Geomorphology, Oceanography
The wave field in coastal bays is comprised of waves generated by far-off storms and waves generated locally by winds inside the bay and regionally outside the bay. The resultant wave field varies spatially and temporally and is expected to control morphologic features, such as beaches in estuaries and bays (BEBs). However, neither the wave field nor the role of waves in shaping BEBs have been [...]
Sedimentological data-driven bottom friction parameter estimation in modelling Bristol Channel tidal dynamics
Published: 2021-11-09
Subjects: Oceanography, Physical Sciences and Mathematics
Accurately representing the bottom friction effect is a significant challenge in numerical tidal models. Bottom friction effects are commonly defined via parameter estimation techniques. However, the bottom friction coefficient (BFC) can be related to the roughness of the sea bed. Therefore, sedimentological data can be beneficial in estimating BFCs. Taking the Bristol Channel and Severn Estuary [...]
GESLA Version 3: A major update to the global higher-frequency sea-level dataset
Published: 2021-11-05
Subjects: Oceanography
This paper describes a major update to the quasi-global, higher-frequency sea-level dataset known as GESLA (Global Extreme Sea Level Analysis). Versions 1 (released 2009) and 2 (released 2016) of the dataset have been used in many published studies, across a wide range of oceanographic and coastal engineering-related investigations concerned with evaluating tides, storm surges, extreme sea levels [...]
Seismic and Acoustic Monitoring of Submarine Landslides: Ongoing Challenges, Recent Successes and Future Opportunities
Published: 2021-10-04
Subjects: Geology, Geophysics and Seismology, Oceanography, Sedimentology
Submarine landslides pose a hazard to coastal communities due to the tsunamis they can generate, and can damage critical seafloor infrastructure, such as the network of cables that underpin global data transfer and communications. These mass movements can be orders of magnitude larger than their onshore equivalents and are found on all of the world’s continental margins; from coastal zones to [...]