Preprints
Filtering by Subject: Oceanography
A comparison of Bayesian inference and gradient-based approaches for friction parameter estimation
Published: 2020-06-29
Subjects: Applied Mathematics, Numerical Analysis and Computation, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Numerical tidal models are essential to the study of a variety of coastal ocean processes, but typically rely on uncertain inputs, including a bottom friction parameter which can in principle be spatially varying. Here we employ an adjoint-capable numerical ocean model, Thetis, and apply it to the Bristol Channel and Severn Estuary, using a spatially varying Manning coefficient within the bottom [...]
Tropical cyclone response to anthropogenic warming as simulated by a mesoscale-resolving global coupled earth system model
Published: 2020-06-19
Subjects: Atmospheric Sciences, Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tropical cyclones (TCs) are extreme storm systems that form over warm tropical oceans. Along their track TCs can mix up cold water which can further impact their development. Due to the adoption of lower ocean model resolutions, previous modeling studies on the TC response to greenhouse warming underestimate such oceanic feedbacks. To address the robustness of TC projections in the presence of [...]
Global wave-driven beach evolution; consequences for observation strategies
Published: 2020-06-12
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Life Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is an illusion to think that one can observe monthly beach behaviour with monthly surveys. Current coastal observation strategies restrict understanding of beach evolution, preventing effective risk mitigation. In this article, we quantify the global spatiotemporal scales of coastal wave changes, which are the known dominant driver of beach evolution. Consequences and recommendations for beach [...]
A novel rules-based shoreface translation model for predicting future coastal change: ShoreTrans
Published: 2020-06-04
Subjects: Earth Sciences, Engineering, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Engineering, Physical Sciences and Mathematics
Predicting change to global shorelines presents an increasing challenge as sea-level rise (SLR) accelerates. Many shoreline prediction models use variations of the ‘Bruun-rule’, failing to account for relevant processes and morphologic complexity. To address this, we introduce a simple rules-based model (ShoreTrans) designed for complex, real-world profiles that predicts change across a wide [...]
Advective sorting of silt by currents: a laboratory study
Published: 2020-05-27
Subjects: Earth Sciences, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accumulations of fine sediments along continental shelf and deep-sea bathymetric contours, known as contourite drifts, form a sedimentary record that is dependent on oceanographic processes such as ocean-basin-scale circulation. A tool used to aid in interpretation of such deposits is the sortable silt hypothesis, which suggests that the mean size of the sortable silt (silt from 10-63 µm) within [...]
Kilometer-scale sound speed structure that affects GNSS-A observation: Case study off the Kii channel
Published: 2020-05-27
Subjects: Earth Sciences, Geophysics and Seismology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Global Navigation Satellite System-Acoustic ranging combination technique (GNSS-A) is a recently developed technology to precisely detect seafloor crustal deformation. This method can also estimate km-scale underwater sound speed structure (SSS) as a by-product of monitoring seafloor crustal deformation. This paper evaluates the validity of the spatial gradient and its temporal variation of [...]
Recent water mass changes reveal mechanisms of ocean warming
Published: 2020-05-19
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Over 90% of the build up of additional heat in the earth system over recent decades is contained in the ocean. Since 2006 new observational programs have revealed heterogeneous patterns of ocean heat content change. It is unclear how much of this heterogeneity is due to heat being added to and mixed within the ocean leading to material changes in water mass properties or due to changes in [...]
Human Health Benefits of the Minamata Convention on Mercury
Published: 2020-05-17
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Environmental Health and Protection, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Minamata Convention is a legally-binding international treaty aimed at reducing the anthropogenic release of mercury, a potent neurotoxin. However, its human health benefit has not been quantified on a global scale. Here we evaluate the Convention’s benefit by a coupled climate-atmosphere-land-ocean-ecosystem model and a human mercury exposure component that considers all food categories. We [...]
Projections of global delta land loss from sea-level rise in the 21st century
Published: 2020-05-06
Subjects: Earth Sciences, Geomorphology, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
River deltas will likely experience significant land loss because of relative sea-level rise (RSLR), but predictions have not been tested against observations. Here, we use global data of RSLR and river sediment supply to build a model of delta response to RSLR for 6,402 deltas, representing 86% of global delta land. We validate this model against delta land area change observations from [...]
Unexpected meteotsunamis prior to the Typhoon Wipha
Published: 2020-03-23
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
On October 15, 2013, unexpected meteotsunamis occurred prior to Typhoon Wipha located the distance of ~1,100 km from the center of the cyclone to the Tokyo bay. The occurrences were observed around the east coast of Japan coincidentally with atmospheric pressure disturbances induced by this typhoon. The observed wave height of meteotsunamis was up to ~0.5 m with the pressure fluctuation of ~2 hPa [...]
Rapid Tidal Marsh Development in Anthropogenic Backwaters
Published: 2020-03-21
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Fresh Water Studies, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sustainability, Water Resource Management
Tidal marsh restoration and creation has been proposed as a tool to build coastal resilience in the face of rising sea level and increasing intensity of coastal storms. However, it is unclear what conditions within constructed settings will lead to the successful establishment of tidal marsh. We used sediment cores and historical geospatial data in the tidal freshwater Hudson River to identify [...]
Drivers of Local Ocean Heat Content Variability in ECCOv4
Published: 2020-02-06
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Variation in upper ocean heat content is a critical factor in understanding global climate variability. By using temperature anomaly budgets in a physically consistent ocean state estimate we describe the balance between atmospheric forcing and ocean transport mechanisms for different depth horizons and at varying temporal and spatial resolutions. The processes controlling local variations in [...]
Centrifugal and symmetric instability during Ekman adjustment of the bottom boundary layer
Published: 2020-02-04
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Flow along isobaths of a sloping lower boundary generates an across-isobath Ekman transport in the bottom boundary layer. When this Ekman transport is down the slope it causes convective mixing --- much like a downfront wind in the surface boundary layer --- destroying stratification and potential vorticity. In this manuscript we show how this can lead to the development of a forced centrifugal [...]
On the potential of linked-basin tidal power plants: an operational and coastal modelling assessment
Published: 2020-02-02
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Environmental Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Single-basin tidal range power plants have the advantage of predictable energy outputs, but feature non-generation periods in every tidal cycle. Linked-basin tidal power systems can reduce this variability and consistently generate power. However, as a concept the latter are under-studied with limited information on their performance relative to single-basin designs. In addressing this, we [...]
Abyssal Circulation Driven By Near-Boundary Mixing: Water Mass Transformations and Interior Stratification
Published: 2020-01-12
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The emerging view of the abyssal circulation is that it is associated with bottom enhanced mixing, which results in downwelling in the stratified ocean interior and upwelling in a bottom boundary layer along the insulating and sloping seafloor. In the limit of slowly-varying vertical stratification and topography, however, boundary layer theory predicts that these up- and down-slope flows largely [...]