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Ephemeral Surface Chlorophyll Enhancement At The New England Shelf Break Driven By Ekman Restratification, H. Oliver, W. G. Zhang, K. M. Hirzel, Walker O. Smith Jr., Et Al Jan 2022

Ephemeral Surface Chlorophyll Enhancement At The New England Shelf Break Driven By Ekman Restratification, H. Oliver, W. G. Zhang, K. M. Hirzel, Walker O. Smith Jr., Et Al

VIMS Articles

The Mid-Atlantic Bight (MAB) hosts a large and productive marine ecosystem supported by high phytoplankton concentrations. Enhanced surface chlorophyll concentrations at the MAB shelf-break front have been detected in synoptic measurements, yet this feature is not present in seasonal means. To understand why, we assess the conditions associated with enhanced surface chlorophyll at the shelf break. We employ in-situ and remote sensing data, and a 2-dimensional model to show that Ekman restratification driven by upfront winds drives ephemerally enhanced chlorophyll concentrations at the shelf-break front in spring. Using 8-day composite satellite-measured surface chlorophyll concentration data from 2003–2020, we constructed a …


Simple Relationships Between Residence Time And Annual Nutrient Retention, Export, And Loading For Estuaries, Jian Shen, Jiabi Du, Lisa V. Lucas Jan 2022

Simple Relationships Between Residence Time And Annual Nutrient Retention, Export, And Loading For Estuaries, Jian Shen, Jiabi Du, Lisa V. Lucas

VIMS Articles

Simple mathematical models are derived from mass balances for water and transported substance to provide insight into the relationships between import, export, transport, and internal removal for nonconservative sub-stances in an estuary. Extending previous work, our models explicitly include water and substance inputs from the ocean and are expressed in terms of timescales (i.e., mean residence time and the timescale for net removal). Steady-state, timescale-based expressions for ratios of export to import, retention to import, and net export to loading, as well as for loading and annually averaged concentration, are provided. The net export:loading model explains the underlying mechanisms for …


Multi-Biomarker Analysis For Identifying Organic Matter Sources In Small Mountainous River Watersheds: A Case Study Of The Yuba River Watershed, Christina R. Pondell, Elizabeth A. Canuel Jan 2022

Multi-Biomarker Analysis For Identifying Organic Matter Sources In Small Mountainous River Watersheds: A Case Study Of The Yuba River Watershed, Christina R. Pondell, Elizabeth A. Canuel

VIMS Articles

Organic matter in soils and sediments derives from a mixture of biological origins, often making it difficult to determine inputs from individual sources. Complicating the determination of source inputs to soil and sedimentary organic matter (OM) is the fact that physical and microbial processes have likely modified the initial composition of these sources. This study focused on identifying the composition of watershed-derived OM to better understand inputs to inland waters and improve our ability to resolve between terrigenous and aquatic sources in downstream systems, such as estuaries and coasts. We surveyed OM sources from the Yuba River watershed in northern …


Following The Sand Grains, Duncan M. Fitzgerald, Zoe J. Hughes, Alice Staro, Christopher J. Hein, Et Al Jan 2022

Following The Sand Grains, Duncan M. Fitzgerald, Zoe J. Hughes, Alice Staro, Christopher J. Hein, Et Al

VIMS Articles

When longshore transport systems encounter tidal inlets, complex mechanisms are involved in bypassing sand to downdrift barriers. Here, this process is examined at Plum Island Sound and Essex Inlets, Massachusetts, USA. One major finding from this study is that sand is transferred along the coast—especially at tidal inlets—by parcels, in discrete steps, and over decadal-scale periods. The southerly orientation of the main-ebb channel at Plum Island Sound, coupled with the landward migration of bars from the ebb delta to the central portion of the downdrift Castle Neck barrier island, have formed a beach protuberance. During the constructional phase, sand is …


A Cycle Of Wind-Driven Canyon Upwelling And Downwelling At Wilmington Canyon And The Evolution Of Canyon-Upwelled Dense Water On The Mab Shelf, Haixing Wang, Donglai Gong, Marjorie A.M. Friedrichs, Courtney K. Harris, Travis Miles, Hao-Cheng Yu, Yinglong J. Zhang Jan 2022

A Cycle Of Wind-Driven Canyon Upwelling And Downwelling At Wilmington Canyon And The Evolution Of Canyon-Upwelled Dense Water On The Mab Shelf, Haixing Wang, Donglai Gong, Marjorie A.M. Friedrichs, Courtney K. Harris, Travis Miles, Hao-Cheng Yu, Yinglong J. Zhang

VIMS Articles

Submarine canyons provide a conduit for shelf-slope exchange via topographically induced processes such as upwelling and downwelling. These processes in the Wilmington Canyon, located along the shelf-break of the Mid-Atlantic Bight (MAB), have not been previously studied, and the associated hydrographic variability inside the canyon and on the adjacent shelf are largely unknown. Observations from an underwater glider deployed in Wilmington Canyon (February 27 - March 8, 2016), along with wind and satellite altimetry data, showed evidence for a wind-driven canyon upwelling event followed by a subsequent downwelling event. Next, a numerical model of the MAB was developed to more …


Spreading And Accumulation Of River-Borne Sediments In The Coastal Ocean After The Environmental Disaster At The Doce River In Brazil, Angleo T. Lemos, Alexander Osadchiev, Piero L. F. Mazzini, Et Al Jan 2022

Spreading And Accumulation Of River-Borne Sediments In The Coastal Ocean After The Environmental Disaster At The Doce River In Brazil, Angleo T. Lemos, Alexander Osadchiev, Piero L. F. Mazzini, Et Al

VIMS Articles

This study is focused on the fate of a large volume of mine slurry discharged from the Doce River (DR) to the coastal ocean after the worst environmental disaster in Brazilian which occurred in November 2015. We used Eulerian (ROMS) and Lagrangian (STRiPE) numerical models, as well as satellite remote sensing data, to study the spreading and seafloor accumulation of fine river-borne sediments during the initial six months following the disaster. We show that the regions of intense sediment accumulation were determined by spreading patterns of the surface-advected DR plume. The river discharge rate governed the plume surface area, while …


Status, Change, And Futures Of Zooplankton In The Southern Ocean, Nadine M. Johnston, Eugene J. Murphy, (...), Walker O. Smith Jr., Deborah K. Steinberg, Et Al Jan 2022

Status, Change, And Futures Of Zooplankton In The Southern Ocean, Nadine M. Johnston, Eugene J. Murphy, (...), Walker O. Smith Jr., Deborah K. Steinberg, Et Al

VIMS Articles

In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary and secondary producers, and are prey for fishes, cephalopods, seabirds, and marine mammals. In providing the link between microbes, primary production, and higher trophic levels these taxa influence energy flows, biological production and biomass, biogeochemical cycles, carbon flux and food web interactions thereby modulating the structure and functioning of ecosystems. Additionally, Antarctic …


Quantifying Seasonal Particulate Organic Carbon Concentrations And Export Potential In The Southwestern Ross Sea Using Autonomous Gliders, Meredith G. Meyer, Randolph G. Jones, Walker O. Smith Jr. Jan 2022

Quantifying Seasonal Particulate Organic Carbon Concentrations And Export Potential In The Southwestern Ross Sea Using Autonomous Gliders, Meredith G. Meyer, Randolph G. Jones, Walker O. Smith Jr.

VIMS Articles

To assess the temporal biological and hydrographic features of the southwestern Ross Sea, we deployed a glider in a spatially restricted, ice-free area during the austral summer (1 December–6 February), and quantified from sensor measurements the particulate organic carbon (POC; via particulate backscatter) concentrations, their changes through time, and net community production (NCP; via dissolved O2 concentrations). The POC levels could be divided into three distinct phases (I, II, and III, respectively) characterized by changes in NCP, surface-layer POC concentrations, remineralization, and export. Surface POC concentrations increased from 215 mg C m−3 in early December to a peak …


The Spatio-Temporal Distribution And Transport Of Suspended Sediment In Laizhou Bay: Insights From Hydrological And Sedimentological Investigations, Bo Xie, Rui Bao, Dongxiao Yin, Et Al Jan 2022

The Spatio-Temporal Distribution And Transport Of Suspended Sediment In Laizhou Bay: Insights From Hydrological And Sedimentological Investigations, Bo Xie, Rui Bao, Dongxiao Yin, Et Al

VIMS Articles

Suspended sediment transport and deposition are crucial physical processes controlling the geomorphological evolution of estuaries and bays. Specially, under the context of worldwide coastal erosion, knowledge of the spatio-temporal distribution of suspended sediment concentration (SSC) and its associated sediment load have become increasingly important for bay management. However, our understanding of the mechanisms of suspended sediment dynamics continues to be hampered by the lack of high-resolution observations. Here, we present a study of the transport mechanisms and controlling factors of suspended sediment over Laizhou Bay. For this, we conducted continuous measurements of SSC, salinity, temperature, and flow velocity at nine …


Seasonal Controls On Nearshore Dissolved Oxygen Variability And Hypoxia In A Coastal Embayment, Ryan K. Walter, Stephen A. Huie, (...), Piero L.F. Mazzini, Ian Robbins Jan 2022

Seasonal Controls On Nearshore Dissolved Oxygen Variability And Hypoxia In A Coastal Embayment, Ryan K. Walter, Stephen A. Huie, (...), Piero L.F. Mazzini, Ian Robbins

VIMS Articles

Declining dissolved oxygen (DO) is emerging as an increasingly important stressor in nearshore ecosystems, and there is a growing need to better understand DO dynamics and hypoxia risk in this highly variable environment. In this study, we collected data from monthly cruises on the inner shelf, continuous nearshore moorings inside and outside a small coastal upwelling embayment (San Luis Obispo Bay in Central California), and weekly phytoplankton measurements inside the bay during the upwelling season. Nearshore DO was generally dominated by low-frequency synoptic variability, with increased DO variance near the surface relative to the bottom and inside the bay compared …


A Numerical Investigation Of Hurricane Florence-Induced Compound Flooding In The Cape Fear Estuary Using A Dynamically Coupled Hydrological-Ocean Model, Daoyang Bao, Z. George Xue, John C. Warner, Melissa Moulton, Dongxiao Yin, Et Al Jan 2022

A Numerical Investigation Of Hurricane Florence-Induced Compound Flooding In The Cape Fear Estuary Using A Dynamically Coupled Hydrological-Ocean Model, Daoyang Bao, Z. George Xue, John C. Warner, Melissa Moulton, Dongxiao Yin, Et Al

VIMS Articles

Hurricane-induced compound flooding is a combined result of multiple processes, including overland runoff, precipitation, and storm surge. This study presents a dynamical coupling method applied at the boundary of a processes-based hydrological model (the hydrological modeling extension package of the Weather Research and Forecasting model) and the two-dimensional Regional Ocean Modeling System on the platform of the Coupled-Ocean-Atmosphere-Wave-Sediment Transport Modeling System. The coupled model was adapted to the Cape Fear River Basin and adjacent coastal ocean in North Carolina, United States, which suffered severe losses due to the compound flood induced by Hurricane Florence in 2018. The model's robustness was …


Dynamical Controls Of The Eastward Transport Of Overwintering Calanus Finmarchicus From The Lofoten Basin To The Continental Slope, Huizi Dong, Meng Zhou, Walker O. Smith Jr., Et Al Jan 2022

Dynamical Controls Of The Eastward Transport Of Overwintering Calanus Finmarchicus From The Lofoten Basin To The Continental Slope, Huizi Dong, Meng Zhou, Walker O. Smith Jr., Et Al

VIMS Articles

Diapausing populations of Calanus finmarchicus at depth in the Lofoten Basin (LB) return to the continental shelf and slope off the Lofoten-Vesterålen Islands during the phytoplankton spring bloom to feed and spawn, forming surface swarms with a great abundance. To study how overwintering populations of C. finmarchicus move with the deep currents and return to the shelf, Lagrangian transport characteristics of particles in deep water between 2008 and 2019 were analyzed using Global Ocean Reanalysis and Simulation re-analysis data and Lagrangian Coherent Structures (LCSs). Our analyses revealed that persistent eastward transport of diapausing C. finmarchicus between LB and continental slope …


The Middle Atlantic Outer Continental Shelf Environmental Studies: Data Files, Gary F. Anderson Jan 2022

The Middle Atlantic Outer Continental Shelf Environmental Studies: Data Files, Gary F. Anderson

Data

During the oil embargo in the mid-1970’s, the U.S. Government proposed exploring the mid-Atlantic continental shelf for oil leasing to increase production. The Virginia Institute of Marine Science was contracted by the Bureau of Land Management (BLM) to conduct baseline surveys of the biological, geological, chemical, and physical nature of the environment being considered for lease, and its sensitivity to prolonged exposure to contaminants derived from development activities. Surveys were conducted off the coast, from Virginia to New Jersey, four times a year (summer, fall, spring, winter) for two years beginning summer of 1975 through spring of 1977, resulting in …


Uncrewed Ocean Gliders And Saildrones Support Hurricane Forecasting And Research, Travis N. Miles, Dongxiao Zhang, Gregory R. Foltz, (...), Donglai Gong, Et Al Jan 2022

Uncrewed Ocean Gliders And Saildrones Support Hurricane Forecasting And Research, Travis N. Miles, Dongxiao Zhang, Gregory R. Foltz, (...), Donglai Gong, Et Al

VIMS Articles

In the United States alone, hurricanes have been responsible for thousands of deaths and over US$1 trillion in damages since 1980 (https://www.ncdc.noaa.gov/billions/). These impacts are significantly greater globally, particularly in regions with limited hurricane early warning systems and where large portions of the population live at or near sea level. The high socioeconomic impacts of tropical cyclones will increase with a changing climate, rising sea level, and increasing coastal populations. To mitigate these impacts, efforts are underway to improve hurricane track and intensity forecasts, which drive storm surge models and evacuation orders and guide coastal preparations. Hurricane track forecasts have …


Freshwater Transport In The Scotian Shelf And Its Impacts On The Gulf Of Maine Salinity, Z. Wang, D. Li, H. Xue, A. C. Thomas, Yinglong J. Zhang, F. Chai Jan 2022

Freshwater Transport In The Scotian Shelf And Its Impacts On The Gulf Of Maine Salinity, Z. Wang, D. Li, H. Xue, A. C. Thomas, Yinglong J. Zhang, F. Chai

VIMS Articles

A 3D unstructured-grid ocean circulation model covering the continental shelf and coastal seas around New England is used to investigate freshwater transport (FWT) on the Scotian Shelf (SS) and its impact on the salinity in the Gulf of Maine (GoME). The model was first validated using observed elevation, velocity, temperature, and salinity at multiple locations, demonstrating generally high model skills. Intraseasonal variabilities of freshwater fluxes in 2017 and 2018 were then analyzed across different transects around SS and Browns Bank (BB). These indicated that the flow pattern in SS during 2017 was consistent with previous understanding: low salinity water flows …


Bifurcate Responses Of Tidal Range To Sea-Level Rise In Estuaries With Marsh Evolution, Xun Cai, Qubin Qin, Jian Shen, Yinglong J. Zhang Jan 2022

Bifurcate Responses Of Tidal Range To Sea-Level Rise In Estuaries With Marsh Evolution, Xun Cai, Qubin Qin, Jian Shen, Yinglong J. Zhang

VIMS Articles

The response of tidal range in tidal marshes under sea-level rise (SLR) is essential to the marsh resilience, but how tidal ranges respond to different marsh evolutions remains unclear. Here, we show the existence of bifurcate responses of tidal range to SLR using both numerical model and theoretical analyses. The tidal range tends to increase if marsh accretion keeps pace with SLR; otherwise, the tidal range tends to decrease. As tidal range plays the key role in marsh evolution, the interactions between changing tidal range and marsh evolution lead to positive feedback on marsh resilience. If the marsh accretion can …


Adcp Observations Of Currents And Suspended Sediment In The Macrotidal Gulf Of Martaban, Myanmar, Courtney K. Harris, Jacob T. Wacht, Matthew J. Fair, Jessica M. Cote Jan 2022

Adcp Observations Of Currents And Suspended Sediment In The Macrotidal Gulf Of Martaban, Myanmar, Courtney K. Harris, Jacob T. Wacht, Matthew J. Fair, Jessica M. Cote

VIMS Articles

The Ayeyarwady and Thanlwin Rivers, which drain Myanmar, together form one of the largest point sources of freshwater and sediment to the global ocean. Combined, these rivers annually deliver an estimated 485 Mt of sediment to the northern Andaman Sea. This sediment contributes to a perennially muddy zone within the macro-tidal Gulf of Martaban, but little is known about the processes that dominate dispersal and trapping of sediment there, as very few water column observations are available. A research cruise in December 2017 provided a rare opportunity to obtain Acoustic Doppler Current Profiler (ADCP) data along transects from the Gulf …


Water Circulation Driven By Cold Fronts In The Wax Lake Delta (Louisiana, Usa), Q. Zhang, C. Li, W. Huang, Et Al Jan 2022

Water Circulation Driven By Cold Fronts In The Wax Lake Delta (Louisiana, Usa), Q. Zhang, C. Li, W. Huang, Et Al

VIMS Articles

: Atmospheric cold fronts can periodically generate storm surges and affect sediment transport in the Northern Gulf of Mexico (NGOM). In this paper, we evaluate water circulation spatiotemporal patterns induced by six atmospheric cold front events in the Wax Lake Delta (WLD) in coastal Louisiana using the 3-D hydrodynamic model ECOM-si. Model simulations show that channelized and inter-distributary water flow is significantly impacted by cold fronts. Water volume transport throughout the deltaic channel network is not just constrained to the main channels but also occurs laterally across channels accounting for about a quarter of the total flow. Results show that …


Contamination Of Finescale Strain Estimates Of Turbulent Kinetic Energy Dissipation By Frontal Physics, Laur Ferris, Donglai Gong, Sophia Merrifield, Louis St. Laurent Jan 2022

Contamination Of Finescale Strain Estimates Of Turbulent Kinetic Energy Dissipation By Frontal Physics, Laur Ferris, Donglai Gong, Sophia Merrifield, Louis St. Laurent

VIMS Articles

Finescale strain parameterization (FSP) of turbulent kinetic energy dissipation rate has become a widely used method for observing ocean mixing, solving a coverage problem where direct turbulence measurements are absent but CTD profiles are available. This method can offer significant value, but there are limitations in its broad application to the global ocean. FSP often fails to produce reliable results in frontal zones where temperature–salinity (T/S) intrusive features contaminate the CTD strain spectrum, as well as where the aspect ratio of the internal wave spectrum is known to vary greatly with depth, as frequently occurs in …


Surface Chlorophyll Anomalies Induced By Mesoscale Eddy-Wind Interactions In The Northern Norwegian Sea, Huizi Dong, Meng Zhou, Roshin P. Raj, Walker O. Smith Jr., Et Al Jan 2022

Surface Chlorophyll Anomalies Induced By Mesoscale Eddy-Wind Interactions In The Northern Norwegian Sea, Huizi Dong, Meng Zhou, Roshin P. Raj, Walker O. Smith Jr., Et Al

VIMS Articles

The substantial productivity of the northern Norwegian Sea is closely related to its strong mesoscale eddy activity, but how eddies affect phytoplankton biomass levels in the upper ocean through horizontal and vertical transport-mixing has not been well quantified. To assess mesoscale eddy induced ocean surface chlorophyll-a concentration (CHL) anomalies and modulation of eddy-wind interactions in the region, we constructed composite averaged CHL and wind anomalies from 3,841 snapshots of anticyclonic eddies (ACEs) and 2,727 snapshots of cyclonic eddies (CEs) over the period 2000-2020 using satellite altimetry, scatterometry, and ocean color products. Results indicate that eddy pumping induces negative (positive) CHL …


A Multi-Decadal Analysis Of River Discharge And Suspended Sediment Load In Three Texas Coastal Rivers In Relation To Hurricanes, Seasonal Rainfall, And Enso, Qiang Yao, Sanjeev Joshi, Kam-Biu Liu, Erika Rodrigues, Dongxiao Yin Jan 2022

A Multi-Decadal Analysis Of River Discharge And Suspended Sediment Load In Three Texas Coastal Rivers In Relation To Hurricanes, Seasonal Rainfall, And Enso, Qiang Yao, Sanjeev Joshi, Kam-Biu Liu, Erika Rodrigues, Dongxiao Yin

VIMS Articles

Coastal river discharge and sediment load exert major influence on the sustainability of coastal systems. Controlled by various hydroclimatic/hydrometeorological agents, they exhibit distinct trend/variability at different time scales. Coastal Texas, while being a major target for tropical cyclones over the past 6 decades, has been experiencing drought and flood cycles associated with ENSO in the long term. However, it is still unclear the temporal variability of river discharge and the associated sediment delivery over this area at different time scales, and the controlling factors behind it. In this study, a 58-years (1960–2017) dataset is compiled to analyze the influence of …


Primary Productivity Measurements In The Ross Sea, Antarctica: A Regional Synthesis, Walker O. Smith Jr. Jan 2022

Primary Productivity Measurements In The Ross Sea, Antarctica: A Regional Synthesis, Walker O. Smith Jr.

VIMS Articles

Polar systems are undersampled due to the difficulty of sampling remote and challenging environments; however, these systems are critical components of global biogeochemical cycles. Measurements on primary productivity in specific areas can quantify the input of organic matter to food webs and so are of critical ecological importance as well. However, long-term measurements using the same methodology are available only for a few polar systems. Primary productivity measurements using 14C-uptake incubations from the Ross Sea, Antarctica, are synthesized, along with chlorophyll concentrations at the same depths and locations. A total of 19 independent cruises were completed and 449 stations …


Clarifying Water Clarity: A Call To Use Metrics Best Suited To Corresponding Research And Management Goals In Aquatic Ecosystems, Jessica S. Turner, Kelsey A. Fall, Carl T. Friedrichs Jan 2022

Clarifying Water Clarity: A Call To Use Metrics Best Suited To Corresponding Research And Management Goals In Aquatic Ecosystems, Jessica S. Turner, Kelsey A. Fall, Carl T. Friedrichs

VIMS Articles

Water clarity is a subjective term and can be measured multiple ways. Different metrics such as light attenuation and Secchi depth vary in effectiveness depending on the research or management application. In this essay, we argue that different questions merit different water clarity metrics. In coastal and inland waters, empirical relationships to estimate light attenuation can yield clarity estimates that either under- or overestimate the underwater light climate for restoration goals, such as potential habitat available for submerged aquatic vegetation. Best practices in reporting water clarity measurements include regionally specific, temporally representative calibrations and communicating the metric that was actually …


Vertical Transport Timescale Of Surface-Produced Particulate Material In The Chesapeake Bay, Jilian Xiong, Jian Shen Jan 2022

Vertical Transport Timescale Of Surface-Produced Particulate Material In The Chesapeake Bay, Jilian Xiong, Jian Shen

VIMS Articles

Accumulation and remineralization of surface-produced particulate organic matter (POM) in the water column and seabed link closely to hypoxia and the health of aquatic ecosystems. The POM retention time provides a key timescale to interpret biochemical reaction processes. In this study, we investigated the spatiotemporal variations in the vertical particulate age (VPA) of surface-produced POM, which is the mean time elapsed since the particulates last contact the surface, by incorporating major physical processes including sinking, resuspension, and deposition in the Chesapeake Bay. It was found that the vertical transport time for the particulates (i.e., VPA) is much longer than the …


Across-Scale Energy Transfer In The Southern Ocean, Laur Ferris Jan 2022

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 Jan 2022

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 …


Roles Of Hydrodynamics And Topographies On The Transport Of Dissolved Material, Particulates, And Harmful Algae In Chesapeake Bay, Jilian Xiong Jan 2022

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 Jan 2022

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 Jan 2022

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 Jan 2022

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 …