Oceanography and Atmospheric Sciences and Meteorology Commons^™

Impact Of Canyon Upwelling And Downwelling In The Mid-Atlantic Bight, Haixing Wang

Dissertations, Theses, and Masters Projects

Submarine canyons can impact regional oceanography and provide a conduit for shelf-slope exchanges via topographically induced processes such as canyon upwelling and downwelling. Between Virginia and New York in the Mid-Atlantic Bight (MAB), there are five major shelf-incising canyons (Norfolk, Washington, Baltimore, Wilmington, and Hudson canyons) and four sizable slope-confined canyons (Accomac, Spencer, Lindenkhol, and Toms canyons). Canyon upwelling and downwelling at these canyons have not been well studied. Consequently, the associated hydrographic variability and dynamics inside the canyons and on the adjacent shelf are largely unknown, and the integrated impact of submarine canyons on MAB shelf hydrography and shelf-slope …

Estuarine Microbiomes And Biogeochemistry: Impacts Of Spatiotemporal Variation, Algal Blooms, And Microplastics, Samantha Grace Fortin

Dissertations, Theses, and Masters Projects

Estuaries are biogeochemical hotspots connecting terrestrial and coastal ecosystems. Anthropogenic disturbances, including increased nitrogen loading and plastic pollution, may have significant impacts on estuarine carbon and nitrogen cycling by altering microbiome structure and functions. The overarching goal of this dissertation was to examine how microbiomes and their associated biogeochemical processes are influenced by natural variation and anthropogenic disturbances in the York River Estuary (YRE). In chapter 2, spatial and temporal variation in benthic microbiomes and the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) were examined to determine biotic and abiotic drivers of nitrogen …

Sediment Transport And Trapping On The Ayeyarwady-Martaban Continental Shelf, Matthew Joshua Fair

Dissertations, Theses, and Masters Projects

The Ayeyarwady and Thanlwin Rivers, which primarily drain Myanmar, are together one of the largest point sources of freshwater and sediment to the global ocean. Much of the estimated 600 Mt of river sediment annually carried by the combined Ayeyarwady and Thanlwin River system is delivered to a wide continental shelf in the northern Andaman Sea. Called here the Ayeyarwady-Martaban continental shelf, this area is influenced by strong tides, monsoon conditions, and periodic cyclones; however, the processes that dominate dispersal of fluvial material in the coastal ocean of this system remain poorly understood. The shelf exhibits a dramatic asymmetry of …

Water Clarity And Suspended Particle Dynamics In The Chesapeake Bay: Local Effects Of Oyster Aquaculture, Regional Effects Of Reduced Shoreline Erosion, And Long-Term Trends In Remotely Sensed Reflectance, Jessica Turner

Dissertations, Theses, and Masters Projects

Water clarity is a key indicator of the ecosystem health in the Chesapeake Bay. Estuarine water clarity fluctuates due to external inputs from the watershed as well as processes occurring within the estuary itself, such as sediment resuspension and organic matter production. Therefore, water clarity requires study at multiple spatial and temporal scales and with multiple metrics. One local-scale process potentially influencing water clarity is shellfish aquaculture. One part of this dissertation examined how water quality and hydrodynamics varied among oyster farms as well as inside versus outside the extent of caged areas located in southern Chesapeake Bay. Current speed …

Extent And Causes Of Chesapeake Bay Warming, Kyle E. Hinson, Marjorie A.M. Friedrichs, Pierre St-Laurent, Fei Da, Raymond G. Najjar

VIMS Articles

Coastal environments such as the Chesapeake Bay have long been impacted by eutrophication stressors resulting from human activities, and these impacts are now being compounded by global warming trends. However, there are few studies documenting long-term estuarine temperature change and the relative contributions of rivers, the atmosphere, and the ocean. In this study, Chesapeake Bay warming, since 1985, is quantified using a combination of cruise observations and model outputs, and the relative contributions to that warming are estimated via numerical sensitivity experiments with a watershed–estuarine modeling system. Throughout the Bay’s main stem, similar warming rates are found at the surface …

Light Regulation Of Phytoplankton Growth In San Francisco Bay Studied Using A 3d Sediment Transport Model, Zhengui Wang, Fei Chai, (...), Yinglong J. Zhang, Et Al

VIMS Articles

In San Francisco Bay (SFB), light availability is largely determined by the concentration of suspended particulate matter (SPM) in the water column. SPM exhibits substantial variation with time, depth, and location. To study how SPM influences light and phytoplankton growth, we coupled a sediment transport model with a hydrodynamic model and a biogeochemical model. The coupled models were used to simulate conditions for the year of 2011 with a focus on northern SFB. For comparison, two simulations were conducted with ecosystem processes driven by SPM concentrations supplied by the sediment transport model and by applying a constant SPM concentration of …

Nonlinearity Of Subtidal Estuarine Circulation In The Pearl River Estuary, China, Hongzhou Xu, Jian Shen, Dongxiao Wang, Lin Luo, Bo Hong

VIMS Articles

The Pearl River Estuary (PRE) is a bell-shaped estuary with a narrow deep channel and wide shoals. This unique topographic feature leads to different dynamics of the subtidal estuarine circulation (SEC) in the PRE compared with a narrow and straight estuary. In this study, the nonlinear dynamics of the SEC in the PRE under mean circumstance are analyzed by using a validated 3D numerical model. Model results show that the nonlinear advections reach leading order in the along-channel momentum balance. Modulated by tide, the nonlinear advections show significant temporal variations as they have much larger values during spring tide than …

Impacts Of Multiple Environmental Changes On Long- Term Nitrogen Loading From The Chesapeake Bay Watershed, Shufen Pan, Zihao Bian, (...), Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Excessive nitrogen can enter estuarine and coastal areas from land, disturbing coastal ecosystems and causing serious environmental problems. The Chesapeake Bay is one of the regions that have experienced hypoxia and harmful algal blooms in recent decades. This study estimated nitrogen export from the Chesapeake Bay watershed (CBW) to the estuary from 1900 to 2015 by applying a state-of-the-art numerical model. Nitrogen loading from the CBW continually increased from the 1900s to the 1990s and has declined since then. The key contributors to nitrogen export have shifted from atmospheric nitrogen deposition (before the 1960s) to synthetic nitrogen fertilizer (after the …

Formation Of Oil-Particle-Aggregates: Numerical Model Formulation And Calibration, Linlin Cui, Courtney K. Harris, Danielle R.N. Tarpley

VIMS Articles

When oil spills occur in turbid waters, the oil droplets and mineral grains can combine to form oil-particle aggregates (OPAs). The formation of OPAs impacts the vertical transport of both the oil and the mineral grains; especially increasing deposition of oil to the seabed. Though the coastal oceans can be very turbid, to date, few numerical ocean models have accounted for aggregation processes that form OPAs. However, interactions between oil and mineral aggregates may be represented using techniques developed to account for sediment aggregation. As part of Consortium for Simulation of Oil Microbial Interactions in the Ocean (CSOMIO), we modified …

Vims Ferry Pier Ambient Water Monitoring And Meteorological Data, Six-Minute Data 1986-2003, Gary F. Anderson

Data

Bulk water parameters of Temperature and Salinity were measured at the VIMS Ferry Pier from 1947 to 2003. Initial methods were undocumented but likely automated with an instrument and chart recorder since the data consists of a daily high and low measurement from which a mean value was derived. Beginning in 1986 an Inter-Ocean CTD instrument placed at mid-depth was interfaced to a digital data logger (Campbell Scientific CRJ) that recorded data every six minutes, resulting in 240 measurements per day.

This collection contains only the six-minute data from 1986 through 2003. Weather parameters were also added in 1986 and …

Mechanisms Driving Decadal Changes In The Carbonate System Of A Coastal Plain Estuary: Associated Dataset, Fei Da, Marjorie A.M. Friedrichs, Pierre St-Laurent

Data

This dataset includes model outputs presented in the associated publication (Da et al. 2021, Journal of Geophysical Research: Oceans). This study used a three-dimensional ecosystem model to quantify the relative impacts of multiple anthropogenic drivers on the Chesapeake Bay carbonate system over the past three decades. Model simulations highlight that increased atmospheric CO₂ concentrations and decreased terrestrial nutrient inputs are two primary drivers causing nearly equal reductions in pH in surface waters of the Bay.

Vims Ferry Pier Ambient Water Monitoring Data, Salinity And Temperature, Daily Summary 1947-2003, Gary F. Anderson

Data

Bulk water parameters of Temperature and Salinity were measured at the VIMS Ferry Pier from 1947 to 2003. Initial methods were undocumented but likely automated with an instrument and chart recorder since the data consists of a daily high and low measurement from which a mean value was derived.

Beginning in 1971 an automated instrument recorded continuously from which 2-hour measurements were made and daily minimum and maxima were derived. Beginning in 1986 an Inter-Ocean CTD instrument placed at mid-depth was interfaced to a digital data logger (Campbell Scientific CRJ) that recorded data every six minutes, resulting in 240 measurements …

Development Of The Csomio Coupled Ocean-Oil-Sediment- Biology Model, Dmitry S. Dukhovskoy, Steven L. . Morey, (...), Courtney K. Harris, Et Al

VIMS Articles

The fate and dispersal of oil in the ocean is dependent upon ocean dynamics, as well as transformations resulting from the interaction with the microbial community and suspended particles. These interaction processes are parameterized in many models limiting their ability to accurately simulate the fate and dispersal of oil for subsurface oil spill events. This paper presents a coupled ocean-oil-biology-sediment modeling system developed by the Consortium for Simulation of Oil-Microbial Interactions in the Ocean (CSOMIO) project. A key objective of the CSOMIO project was to develop and evaluate a modeling framework for simulating oil in the marine environment, including its …

A Regional, Early Spring Bloom Of Phaeocystis Pouchetii On The New England Continental Shelf, Walker O. Smith Jr., Weifeng G. Zhang, Andrew Hirzel, Et Al

VIMS Articles

The genus Phaeocystis is distributed globally and has considerable ecological, biogeochemical, and societal impacts. Understanding its distribution, growth and ecological impacts has been limited by lack of extensive observations on appropriate scales. In 2018, we investigated the biological dynamics of the New England continental shelf and encountered a substantial bloom of Phaeocystis pouchetii. Based on satellite imagery during January through April, the bloom extended over broad expanses of the shelf; furthermore, our observations demonstrated that it reached high biomass levels, with maximum chlorophyll concentrations exceeding 16 μg L−1 and particulate organic carbon levels > 95 μmol L−1. Initially, the bloom was …

Effects Of Reduced Shoreline Erosion On Chesapeake Bay Water Clarity, Jessica S. Turner, Pierre St-Laurent, Marjorie A.M. Friedrichs, Carl T. Friedrichs

VIMS Articles

Shoreline erosion supplies sediments to estuaries and coastal waters, influencing water clarity and primary production. Globally, shoreline erosion sediment inputs are changing with anthropogenic alteration of coastlines in populated regions. Chesapeake Bay, a prime example of such a system where shoreline erosion accounts for a large proportion of sediments entering the estuary, serves here as a case study for investigating the effects of changing sediment inputs on water clarity. Long-term increases in shoreline armoring have contributed to decreased erosional sediment inputs to the estuary, changing the composition of suspended particles in surface waters. This study examined the impact of shoreline …

2021 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2021 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2021 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2021 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

Vims Hydrofile: Ambient Water Monitoring And Meteorological Data For Chesapeake Bay And Near Coastal Shelf Waters, 1942-1982, Gary F. Anderson

Data

Historical ambient water quality and meteorologic conditions from cruises conducted by the Virginia Institute of Marine Science in Chesapeake Bay and nearshore coastal shelf waters over a 40-year period through 1982.

Bulk water parameters were routinely measured during cruises conducted in Chesapeake Bay and nearshore coastal waters conducted by VIMS over four decades. Data were punched on 80-character cards known as ‘Form 1’ format by the VIMS central Computer Center. These were later converted to digital files. For this publication the Form 1 files were unpacked into yearly flat files containing two record types:

Station records - Contain surface observations …

Nitrogen Reductions Have Decreased Hypoxia In The Chesapeake Bay: Evidence From Empirical And Numerical Modeling : Data Repository, Luke T. Frankel, Marjorie A.M. Friedrichs

Data

This data repository is a permanent archive of the results presented in the associated publication: Frankel et al., 2022, Nitrogen reductions have decreased hypoxia in the Chesapeake Bay: Evidence from empirical and numerical modeling, Science of the Total Environment, accepted for publication in December 2021.

Quantifying The Increased Resiliency Of Chesapeake Bay Hypoxia To Environmental Conditions: A Benefit Of Nutrient Reductions, Luke Thomas Frankel

Dissertations, Theses, and Masters Projects

Seasonal hypoxia is a characteristic feature of the Chesapeake Bay as a result of anthropogenic eutrophication from agriculture and urban development throughout the watershed. Although in recent years coordinated management efforts have successfully reduced the flux of nutrients into the Bay, the overall goal of sufficient oxygen concentrations below the pycnocline for living resources remains unfulfilled. This was particularly apparent in 2018 and 2019 when the volume of hypoxic water exceeded the long-term (35-year) average due to anomalously high riverine discharge. To quantify the impact of watershed nutrient reductions, conventional statistical methods were employed in concert with a 3-D numerical …

Controls On Estuarine Sediment Bed Erodibility: Insights From The York River Estuary, Cristin Lee Wright

Dissertations, Theses, and Masters Projects

The erodibility of estuarine sediment beds has a number of ecological and societal implications, including alteration of benthic habitats, light-limitation of primary production, and reintroduction of pollutants to the water column, as well as impacts on dredging operations and on the fate of potentially dangerous objects on the seafloor. The objectives of this study are to better understand controls on bed erodibility in estuarine environments, including the roles of sediment grain size, water content, percent organics, and bed fabric, as well as effects of tides, storms, salinity distribution, river discharge, and location within the estuary. An extensive set of erosion …

Improving Observation, Assessment, And Management Of Atlantic Coastal Sharks, Cassidy Dawn Peterson

Dissertations, Theses, and Masters Projects

Coastal sharks represent a group of stocks for which observation, assessment, and management are particularly challenging. Large distributional ranges, complex migratory behavior, low economic value, and relatively few observations in fishery independent surveys hinder relative abundance estimation. Assessing stock status of coastal sharks is encumbered by limited data availability, data quality, and knowledge of life history strategy. Further, coastal sharks are challenging to manage due to their slow intrinsic population growth rates, competing stakeholder interests, history of overexploitation, and in some cases, subjection to international exploitation. This dissertation aimed to improve the capacity to observe relative abundance of coastal sharks. …

Sediment And Terrestrial Organic Carbon Budgets For The Offshore Ayeyarwady Delta: Establishing A Baseline For Future Change, Evan Rose Flynn

Dissertations, Theses, and Masters Projects

Large river deltas serve as globally important archives of terrestrial and shallow marine biogeochemical signatures because of rapid sediment burial, and have the potential to impact global biogeochemical cycling on modern and geologic timescales. This study investigates modern sediment and terrestrial organic carbon (TerrOC) accumulation within the offshore Ayeyarwady Delta in order to determine sediment and TerrOC budgets for this largely understudied mega-delta. The Ayeyarwady is the world’s third largest delta in terms of sediment supply, and remains one of the last long free-flowing rivers in Asia. However, recent increases in regional anthropogenic impacts risk severe alterations to sediment and …

Diatom Hotspots Driven By Western Boundary Current Instability, Hilde Oliver, Weifeng G. Zhang, Walker O. Smith Jr., Et Al

VIMS Articles

Climatic changes have decreased the stability of the Gulf Stream (GS), increasing the frequency at which its meanders interact with the Mid-Atlantic Bight (MAB) continental shelf and slope region. These intrusions are thought to suppress biological productivity by transporting low-nutrient water to the otherwise productive shelf edge region. Here we present evidence of widespread, anomalously intense subsurface diatom hotspots in the MAB slope sea that likely resulted from a GS intrusion in July 2019. The hotspots (at ∼50 m) were associated with water mass properties characteristic of GS water (∼100 m); it is probable that the hotspots resulted from the …

Estuaries As Filters For Riverine Microplastics: Simulations In A Large, Coastal-Plain Estuary, Alexander G. Lopez, Raymond G. Najjar, Marjorie A.M. Friedrichs, Michael A. Hickner, Denice H. Wardrop

VIMS Articles

Public awareness of microplastics and their widespread presence throughout most bodies of water are increasingly documented. The accumulation of microplastics in the ocean, however, appears to be far less than their riverine inputs, suggesting that there is a “missing sink” of plastics in the ocean. Estuaries have long been recognized as filters for riverine material in marine biogeochemical budgets. Here we use a model of estuarine microplastic transport to test the hypothesis that the Chesapeake Bay, a large coastal-plain estuary in eastern North America, is a potentially large filter, or “sink,” of riverine microplastics. The 1-year composite simulation, which tracks …

Anticipating And Adapting To The Future Impacts Of Climate Change On The Health, Security And Welfare Of Low Elevation Coastal Zone (Lecz) Communities In Southeastern Usa, T. Allen, J. Behr, (...), Jon Derek Loftis, Molly Mitchell, Karinna Nunez, Et Al

VIMS Articles

Low elevation coastal zones (LECZ) are extensive throughout the southeastern United States. LECZ communities are threatened by inundation from sea level rise, storm surge, wetland degradation, land subsidence, and hydrological flooding. Communication among scientists, stake-holders, policy makers and minority and poor residents must improve. We must predict processes spanning the ecological, physical, social, and health sciences. Communities need to address linkages of (1) human and socioeconomic vulnerabilities; (2) public health and safety; (3) economic concerns; (4) land loss; (5) wetland threats; and (6) coastal inundation. Essential capabilities must include a network to assemble and distribute data and model code to …

Long-Term Trends In Chesapeake Bay Remote Sensing Reflectance: Implications For Water Clarity, Jessica S. Turner, Carl T. Friedrichs, Marjorie A.M. Friedrichs

VIMS Articles

While ecosystem health is improving in many estuaries worldwide following nutrient reductions, inconsistent trends in water clarity often remain. The Chesapeake Bay, a eutrophic estuary with a highly populated watershed, is a crucial testbed for these concerns. Improved efforts are needed to understand why some measurements of downstream estuarine water clarity appear to be uncorrelated with watershed management actions, and multiple metrics of clarity are needed to address this issue. To complement in situ measurements, satellite remote sensing provides an additional tool with which to assess long-term change in water clarity. In this study, remote sensing reflectance (Rrs) from the …

Mechanisms Driving Decadal Changes In The Carbonate System Of A Coastal Plain Estuary, Fei Da, Marjorie A.M. Friedrichs, Pierre St-Laurent, Elizabeth Shadwick, Raymond G. Najjaar, Kyle E. Hinson

VIMS Articles

Understanding decadal changes in the coastal carbonate system is essential for predicting how the health of these waters responds to anthropogenic drivers, such as changing atmospheric conditions and riverine inputs. However, studies that quantify the relative impacts of these drivers are lacking. In this study, the primary drivers of decadal trends in the surface carbonate system, and the spatiotemporal variability in these trends, are identified for a large coastal plain estuary: the Chesapeake Bay. Experiments using a coupled three-dimensional hydrodynamic-biogeochemical model highlight that, over the past three decades, the changes in the surface carbonate system of Chesapeake Bay have strong …