Physical Sciences and Mathematics Commons^™

Water Quality In Accomack County Freshwater Streams, Richard A. Snyder, Paige G. Ross

Reports

Expansion of poultry house operations and use of litter as a soil amendment in Accomack County Virginia has raised concerns for water quality impacts both seaside and bayside of the Eastern Shore of Virginia (ESVA). This ongoing investigation is examining freshwater stream water quality in Accomack Virginia to identify water quality impairments from poultry operation storm water runoff. Sampling in 2019 followed two inch rainfall events covering 83 streams at road crossings in southern and northern Accomack County. Estimates of land cover in the drainages for these streams were used to determine correlations between stream water nutrient levels and the …

Seasonal Variability Of The Co2 System In A Large Coastal Plain Estuary, Jaclyn R. Friedman, Elizabeth H. Shadwick, Marjorie A.M. Friedrichs, Raymond G. Najjar, Olivia A. De Meo, Fei Da, Juliette L. Smith

VIMS Articles

The Chesapeake Bay, a large coastal plain estuary, has been studied extensively in terms of its water quality, and yet, comparatively less is known about its carbonate system. Here we present discrete observations of dissolved inorganic carbon (DIC) and total alkalinity from four seasonal cruises in 2016–2017. These new observations are used to characterize the regional CO₂ system and to construct a DIC budget of the mainstem. In all seasons, elevated DIC concentrations were observed at the mouth of the bay associated with inflowing Atlantic Ocean waters, while minimum concentrations of DIC were associated with fresher waters at the …

Saildrone: Adaptively Sampling The Marine Environment, C. L. Gentemann, Joel P. Scott, Piero L. F. Mazzini, Cassia Pianca, Et Al

VIMS Articles

From 11 April to 11 June 2018 a new type of ocean observing platform, the Saildrone surface vehicle, collected data on a round-trip, 60-day cruise from San Francisco Bay, down the U.S. and Mexican coast to Guadalupe Island. The cruise track was selected to optimize the science team’s validation and science objectives. The validation objectives include establishing the accuracy of these new measurements. The scientific objectives include validation of satellite-derived fluxes, sea surface temperatures, and wind vectors and studies of upwelling dynamics, river plumes, air–sea interactions including frontal regions, and diurnal warming regions. On this deployment, the Saildrone carried 16 …

2020 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2020 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2020 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2020 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

A Model Archive For A Coupled Hydrodynamic-Sediment Transport-Biogeochemistry Model For The Chesapeake Bay, Usa, Julia Moriarty, Marjorie A.M. Friedrichs, Courtney K. Harris

Data

No abstract provided.

Comparison Of Electropolishing Of Aluminum In A Deep Eutectic Medium And Acidic Electrolyte, Tarek M. Abdel-Fattah, Jon Derek Loftis

VIMS Articles

Research advances in electropolishing, with respect to the field of metalworking, have afforded significant improvements in the surface roughness and conductivity properties of aluminum polished surfaces in ways that machine polishing and simple chemical polishing cannot. The effects of a deep eutectic medium as an acid-free electrolyte were tested to determine the potential energy thresholds during electropolishing treatments based upon temperature, experiment duration, current, and voltage. Using voltammetry and chronoamperometry tests during electropolishing to supplement representative recordings via atomic force microscopy (AFM), surface morphology comparisons were performed regarding the electropolishing efficiency of phosphoric acid and acid-free ionic liquid treatments for …

Impacts Of Muddy Bed Aggregates On Sediment Transport And Management In The Tidal James River, Va, David W. Perkey, S. Jarrell Smith, Kelsey A. Fall, Grace M. Massey, Carl T. Friedrichs, Emmalynn M. Hicks

VIMS Articles

Aggregation state significantly influences the size, density and transport characteristics of fine sediment. Understanding sediment transport and deposition processes in the nation’s navigable waterways is a primary mission for the US Army Corps of Engineers (USACE), particularly when it comes to infilling of navigation channels. In this study, a newly developed camera system was used to evaluate the aggregation state of eroded sediment from cores collected in the tidal James River, VA. Results showed that bed sediments were composed mostly of mud, but that erosion predominately occurred in the form of aggregates with median sizes 50-270x larger than the disaggregated …

Microplastics Affect Sedimentary Microbial Communities And Nitrogen Cycling, Meredith E. Seeley, Bk Song, Renia Passie, Robert C. Hale

VIMS Articles

Microplastics are ubiquitous in estuarine, coastal, and deep sea sediments. The impacts of microplastics on sedimentary microbial ecosystems and biogeochemical carbon and nitrogen cycles, however, have not been well reported. To evaluate if microplastics influence the composition and function of sedimentary microbial communities, we conducted a microcosm experiment using salt marsh sediment amended with polyethylene (PE), polyvinyl chloride(PVC), polyurethane foam (PUF) or polylactic acid (PLA) microplastics. We report that the presence of microplastics alters sediment microbial community composition and nitrogen cycling processes. Compared to control sediments without microplastic, PUF- and PLA-amended sediments promote nitrification and denitrification, while PVC amendment inhibits …

Extraordinary Human Energy Consumption And Resultant Geological Impacts Beginning Around 1950ce Initiated The Proposed Anthropocene Epoch, Jaia Syvitsk, Colin N. Waters, John Day, John D. Milliman, Et Al

VIMS Articles

Growth in fundamental drivers—energy use, economic productivity and population—can provide quantitative indications of the proposed boundary between the Holocene Epoch and the Anthropocene. Human energy expenditure in the Anthropocene, ~22 zetajoules (ZJ),exceeds that across the prior 11,700 years of the Holocene (~14.6 ZJ), largely through combustion of fossil fuels. The global warming effect during the Anthropocene is more thanan order of magnitude greater still. Global human population, their productivity and energy consumption, and most changes impacting the global environment, are highly correlated. This extraordinary outburst of consumption and productivity demonstrates how the Earth System has departed from its Holocene state …

Simulating Storm Surge And Compound Flooding Events With A Creek-To-Ocean Model: Importance Of Baroclinic Effects, Fei Ye, Yinglong J. Zhang, Haocheng Yu, Weiling Sun, Saeed Moghimi, Edward Myers, Karinna Nunez, Ruoyin Zhang, Harry V. Wang, Aron Roland, Kevin Martins, Xavier Bertin, Jiabi Du, Zhou Liiu

VIMS Articles

We present a creek-to-ocean 3D baroclinic model based on unstructured grids that aims to unite traditional hydrologic and ocean models in a single modeling platform, by taking full advantage of the polymorphism (i.e. a single model grid can seamlessly morph between full 3D, 2DV, 2DH and quasi-1D configurations). Using Hurricane Irene (2011)'s impact on the Delaware Bay as an example, a seamless 2D-3D model grid is implemented to include the entire US East Coast and Gulf of Mexico with a highly resolved Delaware Bay (down to 20-m resolution). The model is forced by flows from a hydrological model (National Water …

Investigating Economic Costs Of Derelict Blue Crab Callinectes Sapidus Pots And Preferred Mitigation Solutions In The Chesapeake Bay, James Delbene

Dissertations, Theses, and Masters Projects

Derelict fishing gear, particularly pots or traps, occupy waters worldwide and cause negative ecological and economic impacts. Derelict pots persist throughout Chesapeake Bay, the largest estuary in the U.S., that supports a valuable commercial fishery for the blue crab Callinectes sapidus. Chesapeake Bay is responsible for 30-40% of U.S. commercial blue crab harvests. Yet, few studies have quantified the impacts of derelict pots on harvest or the perceptions of commercial fishers on derelict pot mitigation activities in this predominantly pot fishery. This thesis examined the impacts of derelict pots on harvest in a field experiment and worked with commercial fishers …

A Global Perspective On Microplastics, Robert Hale, Meredith E. Seeley, Mark J. La Guardia, Lei Mai, Eddy Y. Zeng

VIMS Articles

Society has become increasingly reliant on plastics since commercial production began in about 1950. Their versatility, stability, light weight, and low production costs have fueled global demand. Most plastics are initially used and discarded on land. Nonetheless, the amount of microplastics in some oceanic compartments is predicted to double by 2030. To solve this global problem, we must understand plastic composition, physical forms, uses, transport, and fragmentation into microplastics (and nanoplastics). Plastic debris/microplastics arise from land disposal, wastewater treatment, tire wear, paint failure, textile washing, and at‐sea losses. Riverine and atmospheric transport, storm water, and disasters facilitate releases. In surface …

Potential Physical Impacts Of Sea-Level Rise On The Pearl River Estuary, China, Bo Hong, Zhonghui Liu, Jian Shen, Hui Wu, Wenping Gong, Hongzhou Xu, Dongxiao Wang

VIMS Articles

The response of a coastal region to sea-level rise depends on the local physical features, which should therefore be evaluated locally to provide an accurate vulnerability assessment. In this study, we conducted comprehensive analyses of the potential impacts of sea-level rise on the Pearl River Estuary (PRE), China with the aid of a fully calibrated three-dimensional hydrodynamic model. We found that in general, the salinity, stratification and tidal range will increase as the sea-level rises. Clear spatial variations were apparent in the response of these parameters, with different patterns occurring in different seasons. The strongest salinity increase was mostly at …

Secchi Disk Measurements In Turbid Water, D. G. Bowers, E M. Roberts, A. M. Hoguane, K A. Fall, Grace M. Massey, Carl T. Friedrichs

VIMS Articles

In the classical theory of the Secchi disk depth, diffuse sunlight falling on the disk is reflected back to the observer’s eye along the most direct route, as a beam. The disappearance depth, ZSD, of the disk is then expected to vary inversely with the sum of the beam and diffuse attenuation coefficients: c+KD. Observations presented here show that, in the most turbid waters sampled, the Secchi disk is visible at greater depths (by a factor of up to 4) than predicted by this theory. In these conditions, the disk appears blurry and it seems likely that some of the …

Role Of Delta-Front Erosion In Sustaining Salt Marshes Under Sea-Level Rise And Fluvial Sediment Decline, Shi Lun Yang, Xiangxin Luo, Stijn Temmerman, Matthew L. Kirwan, Et Al

VIMS Articles

Accelerating sea-level rise and decreasing riverine sediment supply are widely considered to lead to global losses of deltaic marshes and their valuable ecosystem services. However, little is known about the degree to which the related erosion of the seaward delta front can provide sediments to sustain salt marshes. Here, we present dataf rom the mesomacrotidal Yangtze Delta demonstrating that marshes have continued to accrete vertically and laterally, despite rapid relative sea-level rise (approx.10 mm yr−1) and a > 70% decrease in the Yangtze River sediment supply. Marsh progradation has decelerated at a lower rate than fluvial sediment reduction, suggesting an additional …

Hurricane Sandy Effects On Coastal Marsh Elevation Change, Alice G. Yeates, James B. Grace, Et Al, Scott Lerberg, James C. Lynch, Nichole Maher, J.Patrick Megonigal, W. G. Reay

VIMS Articles

High-magnitude storm events such as Hurricane Sandy are powerful agents of geomorphic change in coastal marshes, potentially altering their surface elevation trajectories. But how do a storm’s impacts vary across a large region spanning a variety of wetland settings and storm exposures and intensities. We determined the short-term impacts of Hurricane Sandy at 223 surface elevation table–marker horizon stations in estuarine marshes located across the northeast region of the United States by comparing post- storm surface elevation change with pre-storm elevation trends. We hypothesized that the storm’s effect on marsh elevation trends would be influenced by position relative to landfall …

Annual And Seasonal Surface Circulation Over The Mid-Atlantic Bight Continental Shelf Derived From A Decade Of High Frequency Radar Observations, Hugh Roarty, Scott Glenn, Et Al, Haixing Wang, Donglai Gong

VIMS Articles

A decade (2007–2016) of hourly 6-km-resolution maps of the surface currents across the Mid-Atlantic Bight (MAB) generated by a regional scale High Frequency Radar network are used to reveal new insights into the spatial patterns of the annual and seasonal mean surface flows. Across the 10-year time series, temporal means and interannual and intra-annual variability are used to quantify the variability of spatial surface current patterns. The 10-year annual mean surface flows are weaker and mostly cross-shelf near the coast, increasing in speed and rotating to more alongshore directions near the shelfbreak, and increasing in speed and rotating to flow …

Gis & Middle Earth, Robert A. Rose

Arts & Sciences Open Educational Resources

Did Frodo take the best path to destroy the One Ring?

With the right spatial data layers and utilizing the power of a geographic information system, a least cost path analysis could reveal whether there was a better route that Frodo could have taken from the Shire to Mount Doom to destroy the ring of power.

After several years of development, the Center for Geospatial Analysis at William & Mary, has developed an extensive list of GIS layers of Middle Earth, including a 50 meter elevation model, roads, rivers, realms and many others. These data formed the basis for an …

Secchi Disk Measurements In Turbid Water: Supporting Data, D. G. Bowers, E. M. Roberts, A. M. Hoguane, K. A. Fall, Grace M. Massey, Carl T. Friedrichs

Data

No abstract provided.

Co2-System Observations From A Mooring On The West Antarctic Peninsula Continental Shelf, Elizabeth H. Shadwick, Olivia A. De Meo

Data

These are CO₂-system data from a mooring deployed on the continental shelf of the West Antarctic Peninsula (latitude: 66.5S, longitude: 69.9W), at station 300.100 of the Palmer Long-Term Ecological Research (PAL-LTER) sampling grid (https://pal.lternet.edu). Temperature, salinity, and pH were acquired by using an SBE SeapHOx sensor ~18m below the surface with 3-hourly resolution from January 2018 to January 2019. Sensor data were averaged to 24-hour resolution. The salinity sensor failed in May 2018, and mean value between the start of the deployment and the last observation is used to populate the remainder of the record. The pH data …

Composition And Bioavailability Of Effluent Dissolved Organic Nitrogen, Quinn Nicole Roberts

Dissertations, Theses, and Masters Projects

Cultural eutrophication, the overproduction of phytoplankton biomass in response to increased nutrient inputs directly associated with human activities, is a major threat to the health of Chesapeake Bay. Strict regulations, which require a reduction in nutrient loading from all sources, have been a key component to restoration efforts. Water reclamation facilities (WRFs), which discharge effluent containing nitrogen (N) and other nutrients into receiving waters, have implemented upgrades in an effort to comply with regulations. These improvements have decreased the concentration of highly labile dissolved inorganic N (DIN), leaving behind significant concentrations of dissolved organic N (DON) whose bioavailability, and therefore …

Hardware-Assisted Security Mechanisms On Arm-Based Multi-Core Processors, Shengye Wan

Dissertations, Theses, and Masters Projects

During the last decade, Trusted Execution Environment (TEE) provided by ARM TrustZone had become one of the most popular techniques to build security on mobile devices. On a TrustZone-enabled system, the software can execute in either Secure World (trusted) and Normal World (untrusted). Meanwhile, along with the expeditious development of TrustZone technology, the security of TEE is also challenged by dealing with more and more on-board hardware and in-TEE applications. In this dissertation, we explicitly study the security of ARM TrustZone technology with the latest ARM architecture in three aspects. First, we study the security of the TrustZone-assisted asynchronous introspection. …

Design And Analysis Of Memory Management Techniques For Next-Generation Gpus, Haonan Wang

Dissertations, Theses, and Masters Projects

Graphics Processing Unit (GPU)-based architectures have become the default accelerator choice for a large number of data-parallel applications because they are able to provide high compute throughput at a competitive power budget. Unlike CPUs which typically have limited multi-threading capability, GPUs execute large numbers of threads concurrently to achieve high thread-level parallelism (TLP). While the computation of each thread requires its corresponding data to be loaded from or stored to the memory, the key to supporting the high TLP of GPUs lies in the high bandwidth provided by the GPU memory system. However, with the continuous scaling of GPUs, the …

Efficacy And Unintended Outcomes Of Spatial Property Rights For Fisheries And Aquaculture Management In Chile And In Virginia, U.S.A., Jennifer Beckensteiner

Dissertations, Theses, and Masters Projects

Marine spatial property rights reduce many common pool externalities that plague wild capture fisheries and incentivize productive use for aquaculture. Specifically, Territorial Use Rights for Fisheries (TURFs) are a management tool whereby individuals or groups are granted exclusive access to harvest resources within an area, and are the prevailing management of coastal fisheries in Chile. Additionally, secured spatial property rights appear inherently obligatory for aquaculture development; i.e., private leases in Virginia, where submerged grounds granted to an individual or a company for oyster production are considered a form of TURF. Although the number and extent of spatially managed areas are …

Inorganic Carbon Chemistry In East Antarctic Coastal Polynyas, Mar C. Arroyo

Dissertations, Theses, and Masters Projects

Polynyas are large areas of open water or reduced sea ice coverage that persistently form in polar environments and often experience enhanced rates of physical, chemical, and biological processes that impact ocean dynamics on local to global scales. Polynyas that form adjacent to the coast, known as coastal polynyas, play an important role in the global carbon cycle by regulating the exchange of CO2 between the ocean and atmosphere in the high latitudes. Because of their importance to the global carbon cycle, there is a particular interest to better characterize CO2 system processes in Antarctic coastal polynyas. In this study, …

Dietary Monitoring Through Sensing Mastication Dynamics, Shuangquan Wang

Dissertations, Theses, and Masters Projects

Unhealthy dietary habits (such as eating disorders, eating too fast, excessive energy intake, and chewing side preference) are major causes of some chronic diseases, including obesity, heart disease, digestive system disease, and diabetes. Dietary monitoring is necessary and important for patients to change their unhealthy diet and eating habits. However, the existing monitoring methods are either intrusive or not accurate enough. In this dissertation, we present our efforts to use wearable motion sensors to sense mastication dynamics for continuous dietary monitoring. First, we study how to detect a subject's eating activity and count the number of chews. We observe that …

Competing And Cooperating Orders In The Three-Band Hubbard Model: A Comprehensive Quantum Monte Carlo And Generalized Hartree-Fock Study, Adam Chiciak

Dissertations, Theses, and Masters Projects

Significant progress has been made in studying strongly correlated electronic systems with major focus on understanding high-temperature superconductivity. At the center of these studies are the so-called cuprates, which are characterized by a quasi-2D Copper-Oxide plane in which superconductivity is believed to arise. From the theoretical point of view, the complex electronic structure of these materials makes a fully ab initio many-body computation a formidable task, so we are forced to focus on minimal models that can reproduce the physics, the most well known of which is known as the Hubbard Model, which relies on the Zhang-Rice singet notion to …