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Full-Text Articles in Physical Sciences and Mathematics

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl Dec 2019

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl

OES Faculty Publications

Optical instruments can rapidly determine numbers and characteristics of water column particles with high sensitivity. Here we show the usefulness of optically assessed total particle volume below the main pycnocline to estimate carbon export in two systems: the open subarctic North Atlantic and the Ross Sea, Antarctica. Both regions exhibit seasonally high phytoplankton production and efficient export (i.e., a strong biological pump). Total particle volumes in the mesopelagic (200-300 m) were significantly correlated with those in the overlying surface mixed layer (50-60 m), indicating that most particles at depth reflect export from the surface. This connectivity, however, is modulated by …


Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon Dec 2019

Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon

Civil & Environmental Engineering Faculty Publications

Coastal economies are often supported by activities that rely on commercial or recreational vessels to move people or goods, such as shipping, transportation, cruising, and fishing. Unintentionally, frequent or intense vessel traffic can contribute to erosion of coastlines; this can be particularly evident in sheltered systems where shoreline erosion should be minimal in the absence of boat waves. We reviewed the state of the science of known effects of boat waves on shoreline stability, examined data on erosion, turbidity, and shoreline armoring patterns for evidence of a response to boat waves in Chesapeake Bay, and reviewed existing management and policy …


Can The Us And Europe Contain Russian Power In The European Energy Market? A Game Theoretic Approach, Jesse Richman, Nurullah Ayyilmaz Nov 2019

Can The Us And Europe Contain Russian Power In The European Energy Market? A Game Theoretic Approach, Jesse Richman, Nurullah Ayyilmaz

Political Science & Geography Faculty Publications

The Russian history of politicization of natural gas supplies led Europe to seek alternatives. US LNG is considered to be a viable alternative for Europe, which positioned the US as a strong competitor against Russia. In a game theoretic approach, we model this strategic decision-making process in simultaneous-move and sequential games. Our findings indicate a mixed strategy equilibrium: Europe cannot commit to diversify in the face of Russian advantages, and Russia cannot fully resist the temptation to politicize its supplies to Europe. The US might attempt to intervene in the European commitment problem through implementing sanctions on Russian gas sales. …


Mercury Concentrations In Bat Guano From Caves And Bat Houses In Florida And Georgia, Amy E. Edwards, Jenise L. Swall, Charles H. Jagoe Oct 2019

Mercury Concentrations In Bat Guano From Caves And Bat Houses In Florida And Georgia, Amy E. Edwards, Jenise L. Swall, Charles H. Jagoe

Virginia Journal of Science

Previous studies have indicated that several pollutants are bioaccumulating in insectivorous bats, including the heavy metal mercury. This has resulted in an increased presence of mercury in bat waste (guano). In this study, we collected bat guano from ten caves in Florida and Georgia and two bat houses in Florida and analyzed the samples for mercury concentrations (ppm). Since the predominant bat species using caves (Myotis austroriparius) versus bat houses (Tadarida braziliensis) were different, the objective of this study was to make statistical comparisons of the mercury concentrations among caves, between caves and bat houses, and between …


Catalytic Transfer Hydrogenation Reactions Of Lipids, Alexander Asiedu Oct 2019

Catalytic Transfer Hydrogenation Reactions Of Lipids, Alexander Asiedu

Civil & Environmental Engineering Theses & Dissertations

Catalytic transfer hydrogenation (CTH) of lipids was investigated using 2-propanol as hydrogen donor for producing liquid hydrocarbons, e.g. jet fuels. The main sources of lipids selected in this study were waste cooking oil (WCO) and oil-laden algae-derived biofuel intermediate (BI). Two different catalysts were employed in this study, namely activated carbon and trimetallic-doped zeolite.

The CTH reaction was between WCO and 2-propanol in a continuous flow reactor over a packed-bed activated carbon at near atmospheric pressure. Results revealed a high level of alkenes and aromatics compounds, which are not stable and are not environmentally unfriendly. To reduce these compounds in …


Global Conservation Status And Threat Patterns Of The World’S Most Prominent Forage Fishes (Teleostei, Clupeiformes), Tiffany L. Birge Oct 2019

Global Conservation Status And Threat Patterns Of The World’S Most Prominent Forage Fishes (Teleostei, Clupeiformes), Tiffany L. Birge

Biological Sciences Theses & Dissertations

Conserving biodiversity is one of the greatest ethical responsibilities and challenges humans face. Understanding the conservation status of taxonomic groups provides a systematic way to prioritize efforts to combat biodiversity loss. The 405 species within the order Clupeiformes are the herrings, shads, sardines, anchovies, menhadens and relatives that include many of the most important marine forage fishes. These small, schooling fishes are economically, ecologically and culturally significant globally. Despite their contribution to global fisheries and our increasing reliance on these fishes for food and industrial commodities, they are generally poorly known with limited information regarding basic biology and population trends. …


Fostering University Collaboration And Building Capacity To Respond To Coastal Resilience Challenges In Virginia: Findings From The Rotating Resilience Roundtables Workshop Spring 2019, Wie Yusuf, Michelle Covi, Anamaria Bukvic, Tom Allen, Taiwo Oguntuyo Apr 2019

Fostering University Collaboration And Building Capacity To Respond To Coastal Resilience Challenges In Virginia: Findings From The Rotating Resilience Roundtables Workshop Spring 2019, Wie Yusuf, Michelle Covi, Anamaria Bukvic, Tom Allen, Taiwo Oguntuyo

Presentations, Lectures, Posters, Reports

[from Background and Overview]

Communities in coastal Virginia, particularly in the urban region of Hampton Roads and the rural Eastern Shore peninsula, are experiencing the impacts of climate change as part of everyday life. Among the most apparent impacts are sea level rise and associated flooding, but increasingly residents of the region are observing changing ecosystems, health impacts and complex social challenges are made more difficult. The region is experiencing the fastest rate of relative sea level rise on the U.S. east coast due to interactions between ocean currents, global sea level rise, high-water tables and ground subsidence (Adapt Virginia …


Detecting Change: Observations Of Temperature And Precipitation Across Virginia’S Climate Divisions, Jeremy S. Hoffman, Michael J. Allen, Christopher F. Labosier Apr 2019

Detecting Change: Observations Of Temperature And Precipitation Across Virginia’S Climate Divisions, Jeremy S. Hoffman, Michael J. Allen, Christopher F. Labosier

Virginia Journal of Science

Modern global climate change is primarily attributable to human activities and the release of greenhouse gases into the atmosphere. Climate change impacts span a range of sectors, including agriculture, forestry, public health, and water resource management. The Commonwealth of Virginia has already and will continue to deal with many of these impacts, yet lacks concentrated effort to detect, document, and adapt to local climate changes. This study documents observed changes in temperature and precipitation across Virginia’s six climate divisions. Mean seasonal anomalies of minimum temperature, maximum temperature, and precipitation from 1986 to 2016 are examined relative to a long-term 1895-2000 …


Variables Associated With Thermal Emittance Of Wall Mural Art In Richmond, Virginia, Sarah Kwon, Eugene G. Maurakis Apr 2019

Variables Associated With Thermal Emittance Of Wall Mural Art In Richmond, Virginia, Sarah Kwon, Eugene G. Maurakis

Virginia Journal of Science

The objectives of this research are to determine the factors associated with the minimum, maximum, and average thermal emittance temperatures of wall murals in Richmond, Virginia, and make recommendations for color and location of wall murals. Data for 17 parameters were collected for 64 art murals in downtown Richmond, VA from 28 June 2018 – 19 July 2018. Date, time, solar exposure duration, solar elevation, latitude, longitude, air temperature (C), lux, color, solar cardinal minutes, cardinal direction, minimum, maximum, and average surface thermal emittance temperatures of mural face were recorded for each mural. We reject the hypothesis that minimum, maximum, …


Precipitation Trends Across The Commonwealth Of Virginia (1947 – 2016), Michael J. Allen, Thomas R. Allen Apr 2019

Precipitation Trends Across The Commonwealth Of Virginia (1947 – 2016), Michael J. Allen, Thomas R. Allen

Virginia Journal of Science

Water is an important resource for the Commonwealth of Virginia. Too much water increases runoff, disrupt transportation networks, and contributes to school closures. Too little water may adversely impact agricultural operations. To improve climate-related information to Virginia citizens, this study assesses means and changes in precipitation across the Commonwealth of Virginia (1947 – 2016). Using daily station-level precipitation data from the Global Historical Climate Network (GHCN), descriptive statistics were calculated for 43 locations in terms of total precipitation (inches decade-1), precipitation days (x>0”), and heavy precipitation days (x>1.0”). On average, locations showed an overall increase in …


The Effect Of Evapotranspiration On The Groundwater Dome And Past Drought Conditions At Cape Henry, Virginia, Bryce Omar Shoup Apr 2019

The Effect Of Evapotranspiration On The Groundwater Dome And Past Drought Conditions At Cape Henry, Virginia, Bryce Omar Shoup

OES Theses and Dissertations

First Landing State Park, located in Virginia Beach, is a cuspate foreland developed from a succession of erosional and progradational events forming a series of dunes and interdunal swales. Low-lying swales dominate the southern portion of the park forming many wetlands, but the northern portion of the park has fewer wetlands. An asymmetric groundwater dome has been observed on Cape Henry, cresting north of the geographic center of the cuspate foreland. The purpose of this study was to determine if the wetlands that dominate the southern portion of the park are the major driver of the asymmetric groundwater dome and …


Cryptic Herbivorous Invertebrates Restructure The Composition Of Degraded Coral Reef Communities In The Florida Keys, Florida, Usa, Angelo Jason Spadaro Apr 2019

Cryptic Herbivorous Invertebrates Restructure The Composition Of Degraded Coral Reef Communities In The Florida Keys, Florida, Usa, Angelo Jason Spadaro

Biological Sciences Theses & Dissertations

Coral reefs have been on a trajectory of decline for nearly a century due to a variety of factors that have contributed to the shift in these communities away from dominance by reef-building corals, with commensurate changes on community composition and function. Florida’s reefs are a compelling example of a degraded system that has undergone a phase shift, and thus offered an excellent model system for my study of the effects of grazing by cryptic herbivores on community composition and their potential restoration value. I had four major objectives: (1) determine the suitability of Maguimithrax spinosissimus for manipulating grazing intensity …


Change Detection Using Landsat And Worldview Images, Chiman Kwan, Bryan Chou, Leif Hagen, Daniel Perez, Yuzhong Shen, Jiang Li, Krzysztof Koperski Jan 2019

Change Detection Using Landsat And Worldview Images, Chiman Kwan, Bryan Chou, Leif Hagen, Daniel Perez, Yuzhong Shen, Jiang Li, Krzysztof Koperski

Computational Modeling & Simulation Engineering Faculty Publications

This paper presents some preliminary results using Landsat and Worldview images for change detection. The studied area had some significant changes such as construction of buildings between May 2014 and October 2015. We investigated several simple, practical, and effective approaches to change detection. For Landsat images, we first performed pansharpening to enhance the resolution to 15 meters. We then performed a chronochrome covariance equalization between two images. The residual between the two equalized images was then analyzed using several simple algorithms such as direct subtraction and global Reed-Xiaoli (GRX) detector. Experimental results using actual Landsat images clearly demonstrated that the …


Does Helping-At-The-Nest Help? The Case Of The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters, Sahas Barve Jan 2019

Does Helping-At-The-Nest Help? The Case Of The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters, Sahas Barve

Biological Sciences Faculty Publications

Cooperative breeding groups often involve "helpers-at-the-nest"; indeed, such behavior typically defines this intriguing breeding system. In few cases, however, has it been demonstrated that feeding nestlings by helpers, rather than some other behavior associated with helpers' presence, leads to greater reproductive success. One prediction of the hypothesis that feeding behavior per se is responsible for the fitness benefits conferred by helpers is that there should be close congruence between the patterns of helping-at-the-nest and the fitness effects of helpers. Here we look for such a relationship in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus) in order to begin …


Natural Resources Governance Employing Blockchain-Based Decision-Making, Farinaz Sabz Ali Pour, Adrian Gheorghe Jan 2019

Natural Resources Governance Employing Blockchain-Based Decision-Making, Farinaz Sabz Ali Pour, Adrian Gheorghe

Engineering Management & Systems Engineering Faculty Publications

Natural resources are essential structures of socio-economic systems which shape the well-being of humanity, environment, and the economy. Human actions have become the critical responsibility for environmental changes and pressuring many planetary boundaries. Having a systematic approach can provide a governance platform including the inherent characteristics of the resource, the historically established form of use, and transaction costs. A natural resource governance framework is developed by applying Blockchain technology as the primary goal of this study to regulate and manage the extraction and trades. Blockchain technology provides a distributed concurrency monitoring system for sustainable resource management. Persistent and pervasive cooperation …


Mid-Atlantic Oil Spill Workshop: Are We Ready? A Regional Workshop As Part Of The National Academies And Sea Grant Collaborative Workshop Series, G. Walker, M. Covi Jan 2019

Mid-Atlantic Oil Spill Workshop: Are We Ready? A Regional Workshop As Part Of The National Academies And Sea Grant Collaborative Workshop Series, G. Walker, M. Covi

OES Faculty Publications

(First paragraph) In 2017, the Gulf Research Program (GRP) and the Health and Medical Division of the National Academies of Sciences, Engineering, and Medicine hosted a workshop to prepare for and respond to major marine oil spills. To address gaps identified at the workshop, GRP reached out to the Sea Grant Oil Spill Science Outreach Program to host a series of regional workshops. The Sea Grant Oil Spill team, based in the Gulf, partnered with state Sea Grant programs across the country to plan and deliver regional workshops in 2018-2019. The goals of the workshops were to raise awareness of …


Spatial Structuring And Life History Connectivity Of Antarctic Silverfish Along The Southern Continental Shelf Of The Weddell Sea, Jilda Alicia Caccavo, Julian R. Ashford, Svenja Ryan, Chiara Papetti, Michael Schröder, Lorenzo Zane Jan 2019

Spatial Structuring And Life History Connectivity Of Antarctic Silverfish Along The Southern Continental Shelf Of The Weddell Sea, Jilda Alicia Caccavo, Julian R. Ashford, Svenja Ryan, Chiara Papetti, Michael Schröder, Lorenzo Zane

OES Faculty Publications

A multi-disciplinary approach was employed to examine a physical-biological population hypothesis for a critical forage species, the Antarctic silverfish Pleuragramma antarctica. Caccavo et al. (2018; Sci Rep 8:17856) had shown strong gene flow along the westward Antarctic Slope Current, in addition to spatially recurring length modes that provided evidence for episodic connectivity. In this paper, otolith nucleus chemistry from a subset of fish collected in the southern Weddell Sea as part of a hydrographic survey of the Filchner Trough system was used to test between connectivity scenarios. Nucleus chemistry, which reflects environmental exposure during early life, showed significant …


An Introduction To The 'Oceans And Society: Blue Planet' Initiative, Emily A. Smail, Paul M. Digiacomo, Sophie Seeyave, Samy Djavidnia, Louis Celliers, Pierre-Yves Le Traon, Jeremy Gault, Elva Escobar-Briones, Hans-Peter Plag, Christine Pequignet, Lenore Bajona, Li Zhang, Jay Pearlman, Andy Steven, Jonathan Hodge, Marie-Fanny Racault, Curt Storlazzi, William Skirving, Ron Hoeke, John Marra, Ap Van Dongeren, Frank Muller-Karger, Douglas Cripe, Daniel Takaki Jan 2019

An Introduction To The 'Oceans And Society: Blue Planet' Initiative, Emily A. Smail, Paul M. Digiacomo, Sophie Seeyave, Samy Djavidnia, Louis Celliers, Pierre-Yves Le Traon, Jeremy Gault, Elva Escobar-Briones, Hans-Peter Plag, Christine Pequignet, Lenore Bajona, Li Zhang, Jay Pearlman, Andy Steven, Jonathan Hodge, Marie-Fanny Racault, Curt Storlazzi, William Skirving, Ron Hoeke, John Marra, Ap Van Dongeren, Frank Muller-Karger, Douglas Cripe, Daniel Takaki

OES Faculty Publications

We live on a blue planet, and Earth’s waters benefit many sectors of society. The future of our blue planet is increasingly reliant on the services delivered by marine, coastal and inland waters and on the advancement of effective, evidence-based decisions on sustainable development. ‘Oceans and Society: Blue Planet’ is an initiative of the Group on Earth Observations (GEO) that aims to ensure the sustained development and use of ocean and coastal observations for the benefit of society. The initiative works to advance and exploit synergies among the many observational programmes devoted to ocean and coastal waters; to improve engagement …


Recommended Priorities For Research On Ecological Impacts Of Ocean And Coastal Acidification In The U.S. Mid-Atlantic, Grace K. Saba, Kaitlin A. Goldsmith, Sarah R. Cooley, Daniel Grosse, Shannon L. Meseck, A. Whitman Miller, Beth Phelan, Matthew Poach, Robert Rheault, Kari St. Laurent, Jeremy M. Testa, Judith S. Weis, Richard Zimmerman Jan 2019

Recommended Priorities For Research On Ecological Impacts Of Ocean And Coastal Acidification In The U.S. Mid-Atlantic, Grace K. Saba, Kaitlin A. Goldsmith, Sarah R. Cooley, Daniel Grosse, Shannon L. Meseck, A. Whitman Miller, Beth Phelan, Matthew Poach, Robert Rheault, Kari St. Laurent, Jeremy M. Testa, Judith S. Weis, Richard Zimmerman

OES Faculty Publications

The estuaries and continental shelf system of the United States Mid-Atlantic are subject to ocean acidification driven by atmospheric CO2, and coastal acidification caused by nearshore and land-sea interactions that include biological, chemical, and physical processes. These processes include freshwater and nutrient input from rivers and groundwater; tidally-driven outwelling of nutrients, inorganic carbon, alkalinity; high productivity and respiration; and hypoxia. Hence, these complex dynamic systems exhibit substantial daily, seasonal, and interannual variability that is not well captured by current acidification research on Mid-Atlantic organisms and ecosystems. We present recommendations for research priorities that target better understanding of the …