Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Roles Of Hydrodynamics And Topographies On The Transport Of Dissolved Material, Particulates, And Harmful Algae In Chesapeake Bay, Jilian Xiong
Dissertations, Theses, and Masters Projects
Estuaries are highly productive and characterized by complex shoreline geometry and topography. Multiple materials produced within or transported into estuaries include non-living dissolved/particulate materials and living organisms. Estuarine circulation determines material transport and distributions, which further impact estuarine ecosystem to support abundant fauna/flora and their vulnerability to escalated anthropogenic inputs. Short-term material transport process in Chesapeake Bay (CB) has been studied for years, yet its long-term characteristics and the transport of materials with settling and biological behaviors that interact with physical transport have not been fully studied. This study aims to understand the transport of non-living and non-motile dissolved/particulate materials, …
Barrier-Island Dynamics: Transgression, Regression, And State Changes, Justin Lee Shawler
Barrier-Island Dynamics: Transgression, Regression, And State Changes, Justin Lee Shawler
Dissertations, Theses, and Masters Projects
Barrier islands provide critical habitat for shorebirds and buffer backbarrier and inland coastal habitats and communities from the direct effects of storms and wave energy. Yet, barrier systems are under threat from these very same processes. In particular, whereas long-term barrier behavior and landward migration rate is directly related to the rate of sea-level rise, decadal to centennial barrier-island dynamics are more complicated, and often highly localized. Barrier-island dynamics—including state changes between seaward growth and landward migration—are driven by a complex interplay of forcings and interactions, including changes in longshore and cross-shore sediment fluxes, underlying geology and slope, barrier-marsh and …
Data-Driven Approaches For Water Quality Modeling In Coastal Systems, Xin Yu
Data-Driven Approaches For Water Quality Modeling In Coastal Systems, Xin Yu
Dissertations, Theses, and Masters Projects
Water quality in coastal waters is of great socio-economic concern. Anthropogenic activities along the coast have led to an increasing number of impaired waterbodies and degraded ecosystems. To manage water quality issues, accurately modeling the coastal water quality is vitally important. One traditional way to model water quality is using numerical models. Despite great advances in hydrodynamic modeling over the past few decades, water quality simulation is still challenging as the performance of water quality model depends on how well the complex biogeochemical processes are parameterized. While numerical models are the dominant tool for water quality modeling, there are increasing …
The Role Of Zooplankton Community Composition In Fecal Pellet Carbon Production In The York River Estuary, Chesapeake Bay, Kristen Nicole Sharpe
The Role Of Zooplankton Community Composition In Fecal Pellet Carbon Production In The York River Estuary, Chesapeake Bay, Kristen Nicole Sharpe
Dissertations, Theses, and Masters Projects
The biological pump is a critical component of carbon transformation in aquatic ecosystems, but the role that zooplankton play in carbon production and vertical export is rarely studied in estuaries. Zooplankton produce carbon-rich fecal pellets which sink to depth and can fuel benthic community metabolism. The body size and taxonomic structure of the zooplankton community varies on interannual, seasonal, and diel time scales, and can lead to varying carbon production and export rates. We quantified fecal pellet carbon (FPC) production by the whole mesozooplankton community (> 200 µm) in the York River, a sub-estuary of Chesapeake Bay. Biomass and taxonomic …
Diel, Seasonal, And Interannual Changes In Coastal Antarctic Zooplankton Community Composition And Trophic Ecology, John A. Conroy
Diel, Seasonal, And Interannual Changes In Coastal Antarctic Zooplankton Community Composition And Trophic Ecology, John A. Conroy
Dissertations, Theses, and Masters Projects
Throughout the ocean, zooplankton transfer energy from primary producers to higher predators and transport carbon from surface waters to depth. The efficiency of these processes depends in part upon the taxonomic composition and trophic ecology of the zooplankton community. Zooplankton species abundance and distribution shifted over recent decades along the West Antarctic Peninsula during a period of rapid regional warming and sea-ice decline. Although conducted within the context of long-term change, this dissertation research focuses on zooplankton dynamics at finer temporal scales that have received less attention. I analyzed depth-stratified net samples to investigate zooplankton diel vertical migration during Antarctic …
Across-Scale Energy Transfer In The Southern Ocean, Laur Ferris
Across-Scale Energy Transfer In The Southern Ocean, Laur Ferris
Dissertations, Theses, and Masters Projects
Numerous physics are responsible for forward energy cascade at oceanic fronts but their roles are not fully clear. This dissertation investigates wind-sheared turbulence in the ocean surface boundary layer (OSBL), internal wave interactions in the ocean interior, and instability-driven turbulence in energetic jets; with attention paid to the parameterizations used to quantify them. At the OSBL, meteorological forcing injects turbulent kinetic energy (TKE), mixing the upper ocean and rapidly transforming its density structure. In the absence of direct observations or capability to resolve sub-grid scale turbulence in ocean models, the community relies on boundary layer scalings (BLS) of shear and …
Importance Of Muddy Bed Aggregate Processes In Cohesive Sediment Dynamics Associated With Sediment Management Projects, David Perkey
Importance Of Muddy Bed Aggregate Processes In Cohesive Sediment Dynamics Associated With Sediment Management Projects, David Perkey
Dissertations, Theses, and Masters Projects
The erosion and transport processes of fine sediment is largely impacted by the aggregation state. Understanding fine sediment transport processes is a key component to managing the nation’s navigation channels, ports, and reservoirs. To improve its ability to apply management strategies related to fine sediments, the USACE has undertaken research that focusses on the aggregation state of fine sediment. Of particular interest is the ability to expand the use of fine-grained sediment in projects that seek to beneficially use dredge material. In this study, a newly developed camera system was used to evaluate the aggregation state of eroded sediment from …
The Fate And Transport Of Nitrogen In Subterranean Estuaries, Stephanie J. Wilson
The Fate And Transport Of Nitrogen In Subterranean Estuaries, Stephanie J. Wilson
Dissertations, Theses, and Masters Projects
The subterranean estuary (STE) is a subsurface ecosystem where fresh groundwater mixes with intruding, recirculated seawater at the coastline. Despite being present globally, STEs and their potential impacts as hotspots for biogeochemical processing, or as a source of nutrients to coastal systems, are not well understood. STEs have been recognized as highly reactive zones for biogeochemical reactions, which influence the fate and transport of nutrients, organic matter, and trace metals discharged to the coastal ocean. Biogeochemical processing of nitrogen (N) in STEs influences N in submarine groundwater discharge (SGD) including its availability for use by primary producers and cascading eutrophication. …
Toward A Comprehensive Water Quality Model For The Chesapeake Bay Using Unstructured Grids, Xun Cai
Toward A Comprehensive Water Quality Model For The Chesapeake Bay Using Unstructured Grids, Xun Cai
Dissertations, Theses, and Masters Projects
Chesapeake Bay is one of the most productive ecosystems on the US east coast which supports various living resources and habitat, and therefore has significant impacts on human beings and ecosystem health. Developing the capability of accurately simulating the water quality condition in the Chesapeake Bay, such as seasonal hypoxia, phytoplankton production, and nutrient dynamics, helps to better understand the interactions of hydrodynamical and biochemical processes, and more importantly, to predict conditions under changing climate and human intervention. Currently, most Chesapeake Bay models use structured grids that lack the flexibility for local refinements to fit complex geometry over both large …