Preprints
Filtering by Subject: Oceanography
Extracting information from ocean color
Published: 2022-12-09
Subjects: Oceanography, Other Oceanography and Atmospheric Sciences and Meteorology
Products derived from remote sensing reflectances ($R_{rs}(\lambda)$), e.g. chlorophyll, phytoplankton carbon, euphotic depth, or particle size, are widely used in oceanography. Problematically, $R_{rs}(\lambda)$ may have fewer degrees of freedom (DoF) than measured wavebands or derived products. A global sea surface hyperspectral $R_{rs}(\lambda)$ dataset has DoF=4. MODIS-like multispectral [...]
Global climate change trends detected in indicators of ocean ecology
Published: 2022-12-07
Subjects: Oceanography
Climate change-driven trends in phytoplankton populations, as viewed by Earth-observing satellites, were thought to be masked by strong natural variability, so that >30 years of continuous data was needed to detect a climate trend. Here we show that climate change trends emerge more rapidly in ocean color (remote sensing reflectance, Rrs), as Rrs is multivariate and some wavebands have low [...]
Atmospheric carbon emissions from benthic trawling depend on water depth and ocean circulation
Published: 2022-10-28
Subjects: Biogeochemistry, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology
Through its vastness, resilience and biogeochemical complexity, the ocean offers humanity some of the largest potential natural pathways for removing carbon dioxide from the atmosphere while avoiding new sources of anthropogenic emissions. In proposing a network of new marine protected areas in service of global ocean conservation, Sala et al. describe a potentially large climate benefit of such [...]
Efficiently Simulating Lagrangian Particles in Large-Scale Ocean Flows – Data Structures and their Impact on Geophysical Applications
Published: 2022-10-26
Subjects: Fluid Dynamics, Numerical Analysis and Scientific Computing, Oceanography
Studying oceanography by using Lagrangian simulations has been adopted for a range of scenarios, such as the determining the fate of microplastics in the ocean, simulating the origin locations of microplankton used for palaeoceanographic reconstructions, for studying the impact of fish aggregation devices on the migration behaviour of tuna. These simulations are complex and represent a [...]
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: 2022-10-14
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 [...]