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Full-Text Articles in Physical Sciences and Mathematics

Relationships Among Estuarine Floc Size, Optical Properties, Organic Content, And Settling Velocity: Insights Gained From Combining Lisst And A Particle Imaging Camera System, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, D.G. Bowers Oct 2016

Relationships Among Estuarine Floc Size, Optical Properties, Organic Content, And Settling Velocity: Insights Gained From Combining Lisst And A Particle Imaging Camera System, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, D.G. Bowers

Presentations

No abstract provided.


Self-Burial Of Objects On Sandy Beds By Wave- And Current-Induced Scour, Carl Friedrichs, S.E. Rennie, A. Brandt Sep 2016

Self-Burial Of Objects On Sandy Beds By Wave- And Current-Induced Scour, Carl Friedrichs, S.E. Rennie, A. Brandt

Presentations

When an object sitting on the bed extends above the surrounding bed roughness, the object will alter the local flow pattern relative to the far field boundary layer. Such perturbations increase the velocities and stresses impinging on sediment immediately adjacent to the object. Nearby grains tend to be dispersed, resulting in a scour pit that deepens until the tendency for sediment to be dispersed is balanced by a tendency for sediment to fall back into the pit. The difference in pressure at the bed upstream and downstream of the object may also drive seepage flow which can cause piping and …


Comt Chesapeake Bay Hypoxia Modeling, M.A.M. Friedrichs, Carl T. Friedrichs, M. Scully, I. Irby, Comt Estaurine Hypoxia Team Aug 2016

Comt Chesapeake Bay Hypoxia Modeling, M.A.M. Friedrichs, Carl T. Friedrichs, M. Scully, I. Irby, Comt Estaurine Hypoxia Team

Presentations

No abstract provided.


Comparison Of Modeled And Observed Bed Erodibility In The York River Estuary, Virginia, Over Varying Time Scale, Danielle Tarpley, Courtney Harris, Carl Friedrichs Jun 2016

Comparison Of Modeled And Observed Bed Erodibility In The York River Estuary, Virginia, Over Varying Time Scale, Danielle Tarpley, Courtney Harris, Carl Friedrichs

Presentations

In general, the availability of sediment for transport increases with the magnitude of bed shear stress, which varies over various temporal and spatial scales. However, in a muddy setting, consolidation or swelling of the bed also contributes to fluctuations in sediment mobility. One such environment is the York River estuary, a partiallymixed tidal tributary of the Chesapeake Bay, USA. The York River often has a Secondary Turbidity Maximum (STM) mid-estuary at the transition from a shallower, less stratified section upstream to a deeper, more stratified section downstream. Since 2006 various instrument arrays have been deployed as part of the Multidisciplinary …


Us-Ioos/Comt Estuarine Hypoxia Nowcast/Forecast Product: Identification And Feedback, Carl T. Friedrichs, Marjorie A.M. Friedrichs, David R. Forrest, R.R. Hood Jun 2016

Us-Ioos/Comt Estuarine Hypoxia Nowcast/Forecast Product: Identification And Feedback, Carl T. Friedrichs, Marjorie A.M. Friedrichs, David R. Forrest, R.R. Hood

Presentations

The Estuarine Hypoxia component of the U.S. Integrated Ocean Observing System (US-IOOS) Coastal and Ocean Modeling Testbed (COMT) is evaluating existing hydrodynamic and water quality models used or likely to be used for operations and/or for regulation in the Chesapeake Bay and other, similar estuarine environments. The outcomes of this work are expected to help with the development of operational hypoxia forecast capabilities for the Bay. As a proof-of-concept, the ChesROMS hydrodynamic model, linked to a 1-term constant respiration equation for dissolved oxygen (DO), is presently being used to produce realtime now-casts and shortterm (3-day) forecasts of DO for the …


Consolidation And Stratification Within A Muddy, Partially Mixed Estuary: A Comparison Between Idealized And Realistic Models For Sediment Transport In The York River Estuary, Virginia, Danielle Tarpley, Courtney Harris, Carl Friedrichs May 2016

Consolidation And Stratification Within A Muddy, Partially Mixed Estuary: A Comparison Between Idealized And Realistic Models For Sediment Transport In The York River Estuary, Virginia, Danielle Tarpley, Courtney Harris, Carl Friedrichs

Presentations

The York River estuary is a partially mixed semi-diurnal tidal tributary of the Chesapeake Bay with salinities ranging from 0 to 26 psu and an ~0.8 m tidal range. Sediment within many estuaries, including the York River, Virginia, is dominated by mixtures of mud. Due to its cohesive nature, estimating sediment fluxes for mud is a complex problem that can be addressed using numerical models such as the Community Sediment Transport Modeling System (CSTMS), which incorporates suspended sediment transport, erosion, and deposition within the hydrodynamic Regional Ocean Modeling System (ROMS). One version of the CSTMS accounts for cohesive processes via …


Identification Of Suspended Resilient Pellets In Particles Tracked By A Particle Image Camera System (Pics) In A Muddy Estuary, Grace M. Massey, Kelsey Fall, Carl Friedrichs, S.J. Smith Apr 2016

Identification Of Suspended Resilient Pellets In Particles Tracked By A Particle Image Camera System (Pics) In A Muddy Estuary, Grace M. Massey, Kelsey Fall, Carl Friedrichs, S.J. Smith

Presentations

No abstract provided.


Hypoxia Forecasts As A Tool For Chesapeake Bay Fisheries, Marjorie A.M. Friedrichs, Carl T. Friedrichs, David R. Forrest, R.R. Hood Apr 2016

Hypoxia Forecasts As A Tool For Chesapeake Bay Fisheries, Marjorie A.M. Friedrichs, Carl T. Friedrichs, David R. Forrest, R.R. Hood

Presentations

No abstract provided.


Examining Spring-Neap Cycle Variation In Bed Erodibility In The York River Estuary, Va: A Numerical Study, Danielle Tarpley, Courtney Harris, Carl Friedrichs Mar 2016

Examining Spring-Neap Cycle Variation In Bed Erodibility In The York River Estuary, Va: A Numerical Study, Danielle Tarpley, Courtney Harris, Carl Friedrichs

Presentations

The York River estuary is categorized as micro-tidal with a tidal range ~0.8 m; however, periodically produce enough shear stress to erode sediment from the bed and redistribute it along the estuary. However, the supply of mobile sediment differs over various temporal and spatial scales. The primary focus here is to examine the tidal variation in bed mobility by comparing variations in bed erodibility over the spring-neap cycle. To accomplish this goal, the Community Sediment Transport Modeling System (CSTMS) is implemented in a three-dimensional domain using the Regional Ocean Modeling System (ROMS). This version of the CSTMS accounts for suspended …


Influence Of Suspended Particle Properties On Optical Properties And Resultant Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Usa, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, David Bowers Mar 2016

Influence Of Suspended Particle Properties On Optical Properties And Resultant Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Usa, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, David Bowers

Presentations

The Chesapeake Bay and its associated tidal tributaries are among the many coastal systems where degraded water clarity is a major concern. Despite long-term decreases in sediment input, water clarity has continued to deteriorate, especially in the southern Bay. Here it is proposed that the disconnect between water clarity and sediment input is related to the dynamic nature of locally suspended estuarine particles, as well as the interaction between suspended organic particles and inorganic solids. Typical estuarine particles are not single solid particles, but clusters of inorganic and organic particles and water (i.e., flocs). Floc properties (such as size, composition, …


What Controls Bed Erodibility In Muddy, Partially-Mixed Estuaries? Insights From The York River, Virginia, Carl Friedrichs, Grace M. Cartwright, P.J. Dickhudt, Kelsey Fall Mar 2016

What Controls Bed Erodibility In Muddy, Partially-Mixed Estuaries? Insights From The York River, Virginia, Carl Friedrichs, Grace M. Cartwright, P.J. Dickhudt, Kelsey Fall

Presentations

Appropriate parameterization of time-dependent erodibility of muddy seabeds is a significant barrier to improved understanding and accurate modeling of sediment dynamics in estuaries and other coastal regions. In an effort to better understand controls on muddy seabed erodibility, bed erodibility and associated bed sediment properties have been measured by our group on cores collected on dozens of cruises over the last decade in the York Estuary. We have also inferred time-varying erodibility indirectly in the York Estuary over several years by vertically integrating observations of tidally-varying suspended sediment concentration. This presentation synthesizes the results of these long-term observations in this …


Controls On Suspended Particle Properties And Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, David Bowers Feb 2016

Controls On Suspended Particle Properties And Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Kelsey Fall, Carl Friedrichs, Grace M. Cartwright, David Bowers

Presentations

The Chesapeake Bay and its associated tidal tributaries, which together form one of the United States’ largest and most important estuaries, are among the many coastal systems where degraded water clarity is a major concern. Despite long-term decreases in sediment input, water clarity has continued to deteriorate in the southern Bay. Paradoxically, clarity has declined less in the northern Bay where riverine sediment load has recently increased. Here it is proposed that the disconnect between water clarity and sediment input is related to the dynamic nature of locally suspended estuarine particles, as well as the interaction between suspended organic particles …


What Controls Bed Erodibility In Muddy, Partially-Mixed Estuaries? Insights From The York River, Virginia, Carl Friedrichs, Grace M. Cartwright, P.J. Dickhudt, Kelsey Fall Feb 2016

What Controls Bed Erodibility In Muddy, Partially-Mixed Estuaries? Insights From The York River, Virginia, Carl Friedrichs, Grace M. Cartwright, P.J. Dickhudt, Kelsey Fall

Presentations

Appropriate parameterization of time-dependent erodibility of muddy seabeds is a significant barrier to improved understanding and accurate modeling of sediment dynamics in estuaries and other coastal regions. In an effort to better understand controls on muddy seabed erodibility, bed erodibility and associated bed sediment properties have been measured by our group on cores collected on dozens of cruises over the last decade in the York Estuary. We have also inferred time-varying erodibility indirectly in the York Estuary over several years by vertically integrating observations of tidally-varying suspended sediment concentration. This presentation synthesizes the results of these long-term observations in this …


Evaluating The Effects Of Cohesive Processes On Sediment Distribution In An Idealized, Partially-Mixed Estuary Using A Numerical Model, Danielle Tarpley, Courtney Harris, Carl Friedrichs Feb 2016

Evaluating The Effects Of Cohesive Processes On Sediment Distribution In An Idealized, Partially-Mixed Estuary Using A Numerical Model, Danielle Tarpley, Courtney Harris, Carl Friedrichs

Presentations

An idealized two-dimensional model is designed to represent a longitudinal section of a partially-mixed estuary, accounting for a freshwater source, tides, and estuarine circulation, but neglecting across-channel variations. The Community Sediment Transport Modeling System (CSTMS) is used to simulate suspended transport, erosion, and deposition within the Regional Ocean Modeling System (ROMS). This version of the model also includes cohesive processes such as consolidation and swelling of the sediment bed; sediment-induced stratification; and variable settling velocities. To better understand the processes controlling fine-grained sediment transport in the York River, VA, the primary features of the idealized estuary mimic that system, and …


Challenges Associated With Modeling Low-Oxygen Waters In Chesapeake Bay: A Multiple Model Comparison, I.D. Irby, M. A.M. Friedrichs, Carl T. Friedrichs, Comt Estuarine Hypoxia Team Feb 2016

Challenges Associated With Modeling Low-Oxygen Waters In Chesapeake Bay: A Multiple Model Comparison, I.D. Irby, M. A.M. Friedrichs, Carl T. Friedrichs, Comt Estuarine Hypoxia Team

Presentations

As ecosystem and water quality models are becoming more frequently used for operational forecasts and scenario-based management decisions, it is important to understand the relative strengths and limitations of existing models of varying complexity. To this end, simulations of the Chesapeake Bay from eight threedimensional coupled hydrodynamic-oxygen models have been statistically compared to each other and to two years of historical monitoring data. Results show that although models have difficulty resolving the variables typically thought to be the main drivers of dissolved oxygen variability (stratification, nutrients, and chlorophyll), all eight models have significant skill in reproducing the mean and seasonal …


Panel Presentation On The Power Dialog, Mary Ellen Mallia, John Pumilio Jan 2016

Panel Presentation On The Power Dialog, Mary Ellen Mallia, John Pumilio

Presentations

Presented at the State of NY Sustainability Conference.


Sustainability Across The Curriculum, Mary Ellen Mallia Jan 2016

Sustainability Across The Curriculum, Mary Ellen Mallia

Presentations

Presented at the State of NY Sustainability Conference.


Street-Level Predictive Modeling Of Nuisance Flooding Verified Via Crowdsourced App Data In Norfolk, Va, J. D. Loftis, H. V. Wang, D R. Forrest Nov 2015

Street-Level Predictive Modeling Of Nuisance Flooding Verified Via Crowdsourced App Data In Norfolk, Va, J. D. Loftis, H. V. Wang, D R. Forrest

Presentations

No abstract provided.


Estuarine Sediment Dynamics, C. T. Friedrichs Oct 2015

Estuarine Sediment Dynamics, C. T. Friedrichs

Presentations

No abstract provided.


Re-Emergence Of The Harmful Algal Bloom Species Alexandrium Monilatum In The Chesapeake Bay: Assessing Bloom Dynamics And Potential Health Impacts, Sarah K.D. Pease, Kimberly S. Reece, Wolfgang K. Vogelbein Oct 2015

Re-Emergence Of The Harmful Algal Bloom Species Alexandrium Monilatum In The Chesapeake Bay: Assessing Bloom Dynamics And Potential Health Impacts, Sarah K.D. Pease, Kimberly S. Reece, Wolfgang K. Vogelbein

Presentations

Effective management of harmful algal blooms (HABs) within a region requires an understanding of species-specific HAB spatial and temporal distributions, bloom dynamics, as well as potential health impacts. In 2007, the southern Chesapeake Bay witnessed its first blooms of the HAB species Alexandrium monilatum. Since then, A. monilatum has bloomed in the region almost annually. A. monilatum produces the toxin ‘goniodomin A’ and is suspected in local mass mortalities of oyster larvae (Crassostrea virginica) grown for aquaculture and restoration projects. Representatives from Virginia’s multimillion dollar oyster aquaculture industry recently expressed great concern over A. monilatum impacts to their businesses; field …


Diel Vertical Distribution Patterns Of Zooplankton Along The Western Antarctic Peninsula, Patricia S. Thibodeau, John A. Conroy, Deborah K. Steinberg Oct 2015

Diel Vertical Distribution Patterns Of Zooplankton Along The Western Antarctic Peninsula, Patricia S. Thibodeau, John A. Conroy, Deborah K. Steinberg

Presentations

The Western Antarctic Peninsula (WAP) is a region that has undergone significant change over the past several decades due to unprecedented increases sea surface temperature and decreases in sea ice cover. The ongoing Palmer Antarctica Long-Term Ecological Research (PAL LTER) study shows that these environmental changes are significantly affecting the marine pelagic ecosystem along the WAP. The goal of this study was to analyze diel vertical distribution patterns of zooplankton along the WAP.


Effects Of Commercial Clam Aquaculture On Biogeochemical Cycling In Shallow Coastal Ecosystems, Annie E. Murphy, Iris C. Anderson, Mark W. Luckenbach Oct 2015

Effects Of Commercial Clam Aquaculture On Biogeochemical Cycling In Shallow Coastal Ecosystems, Annie E. Murphy, Iris C. Anderson, Mark W. Luckenbach

Presentations

The bivalve aquaculture industry is expanding worldwide; sustainability requires improved understanding of its interactions with the environment. As suspension feeders, bivalves, such as clams, reduce primary production through feeding, and thus dampen eutrophication. Additionally, enhanced rates of denitrification, the microbial removal of reactive nitrogen, have been reported in bivalve sediments due to increased organic matter supply through biodeposition; another potential, yet indirect, control on eutrophication. Simultaneously, bivalves can influence local ‘bottom-up’ effects on production by enhancing nutrient regeneration through excretion and microbial mineralization of biodeposits. At clam aquaculture sediments, respiration and nutrient regeneration rates were significantly higher compared to uncultivated …


Informing Social Decision Making: Physical Vulnerability To Sea Level Rise, Alexander D. Renaud, Karinna Nunez, Molly Mitchell, Carl Hershner Oct 2015

Informing Social Decision Making: Physical Vulnerability To Sea Level Rise, Alexander D. Renaud, Karinna Nunez, Molly Mitchell, Carl Hershner

Presentations

Social indices on census tract and other geopolitical levels are increasingly being considered to inform decision making. In a flooding and sea level rise context, the likelihood of an area flooding is an important component of adaptation and the decision-making framework, however it is frequently modeled on a continuous scale. In our work, we have developed an index of physical vulnerability to flooding on a census tract scale, specifically designed to complement social vulnerability indices.


The Role Of Oyster In Nitrous Oxide Emissions From Oyster Reefs, Anne Arfkin, Ashley Smyth, Bongkeun Song Oct 2015

The Role Of Oyster In Nitrous Oxide Emissions From Oyster Reefs, Anne Arfkin, Ashley Smyth, Bongkeun Song

Presentations

Oyster microbiomes may play a significant role in the biogeochemical N cycle and N2O emissions in estuarine and coastal ecosystems. Rates of denitrification and N2O production were measured from live oysters and oyster shells collected at a coastal lagoon and a tidal estuary in the Chesapeake Bay. Live oysters had the highest rates of denitrification and N2O production in both study sites. This indicates that oysters are an import N remover and a N2O source in coastal ecosystems.


Quantifying Finfish And Blue Crab Use Of Created Oyster Reefs In The Lower Chesapeake Bay, Bruce W. Pfirrmann, Rochelle D. Seitz Oct 2015

Quantifying Finfish And Blue Crab Use Of Created Oyster Reefs In The Lower Chesapeake Bay, Bruce W. Pfirrmann, Rochelle D. Seitz

Presentations

Structurally complex reefs created by the eastern oyster Crassostrea virginica provide a host of ecosystem services yet have experienced significant declines, prompting extensive restoration efforts. We investigate the use of created oyster reefs in the lower Bay by mobile finfish and blue crabs with field surveys and diet analysis. The results of this study provide insight into how restoration activities influence estuarine community dynamics and the provision of ecosystem services.


Structural Complexity And Location Affect The Habitat Value Of Restored Oyster Reefs, Melissa Karp, Rochelle Seitz Oct 2015

Structural Complexity And Location Affect The Habitat Value Of Restored Oyster Reefs, Melissa Karp, Rochelle Seitz

Presentations

Oyster reefs provide a suite of valuable ecosystem services, such as water filtration, nitrogen sequestration, and provision of habitat and foraging grounds. The global decline of these habitats has had negative economic and ecological impacts to coastal waters worldwide. In the Chesapeake Bay, < 1% of the historic oyster population remains and efforts to restore oyster populations and the services they provide have been increasing. Building reefs that successfully provide specific ecosystem services may require different techniques then previously used, and success may depend on reef morphology, location, and environmental conditions. Settling trays were embedded into previously restored oyster reefs that varied in their structural complexity (rugosity) in multiple rivers in the lower Chesapeake Bay. Trays were collected after 7-weeks, sorted, and species identified and weighed (ash-free dry weight) to obtain species diversity, abundance, and biomass. Species composition data was analyzed using nMDS plots, which showed that salinity was an important driver of differences in species composition. Results of an ANOVA analysis found that species diversity was significantly greater on reefs in the high-salinity rivers compared to reefs in low-salinity rivers. Total organism abundance and biomass were positively correlated with reef structural complexity measures, such as rugosity, oyster clump volume, and oyster biomass. These results suggest that more complex oyster reefs in higher salinity locations may support more diverse and productive benthic communities. This study provides insight into the driving factors that structure oyster reef communities and has important implications for oyster reef restoration design and management.


The Relationship Between Reproduction And Mortality In Triploid Crassostrea Virginica: A Matter Of Economic Importance, Joseph L. Matt, Standish K. Allen Oct 2015

The Relationship Between Reproduction And Mortality In Triploid Crassostrea Virginica: A Matter Of Economic Importance, Joseph L. Matt, Standish K. Allen

Presentations

The goal of this project is to maximize survival for commercially produced triploid Crassostrea virginica oysters in Virginia. Over the last few years, commercial oyster growers in Virginia have reported significant mortality events of triploid oysters during the spring and summer months. The summer of 2014 was the worst yet, as growers across the state reported summer mortality, most severe on the Eastern shore and in some cases as high as 85% of the crop (Karen Hudson, personal communication). Surviving oysters from some of these mortality events were sent to the Virginia Institute of Marine Science and several of the …


Tidal Flat Morphodynamics: A Synthesis, C. T. Friedrichs Sep 2015

Tidal Flat Morphodynamics: A Synthesis, C. T. Friedrichs

Presentations

No abstract provided.


Controls On Suspended Particle Properties And Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Usa, K. A. Fall, C. T. Friedrichs, G. M. Cartwright, D. G. Bowers Sep 2015

Controls On Suspended Particle Properties And Water Clarity Along A Partially-Mixed Estuary, York River, Virginia, Usa, K. A. Fall, C. T. Friedrichs, G. M. Cartwright, D. G. Bowers

Presentations

The Chesapeake Bay and its associated tidal tributaries, which together form one of the United States’ largest and most important estuaries, are among the many coastal systems where degraded water clarity is a major concern. Despite long-term decreases in sediment input, water clarity over the last 20 years has continued to deteriorate in the Bay and its tributaries (Williams et al., 2010). Analysis of long-term monitoring data (Wang et al., 2010) found that the concentration of total suspended solids (TSS), the regulatory indicator of ‘suspended sediment pollution’, is about as likely to be positively or negatively correlated to sediment loads …


Identification Of Suspended Resilient Pellets In Particles Tracked By A Particle Image Camera System (Pics) In A Muddy Estuary, Grace M. Cartwright, Kelsey A. Fall, Carl T. Friedrichs Sep 2015

Identification Of Suspended Resilient Pellets In Particles Tracked By A Particle Image Camera System (Pics) In A Muddy Estuary, Grace M. Cartwright, Kelsey A. Fall, Carl T. Friedrichs

Presentations

The Particle Imaging Camera System (PICS) was designed to allow for the measurement of the settling velocity of individual particles in situ by using the smaller particles (< density < 1800kg/m3 ). This classification system, while adequate for suspended dredge plumes, needs to be revisited when the PICS is used in a muddy estuary, such as the York River Estuary, Virginia. Figure 1B shows the settling velocities of particles tracked within a video captured 2.5m from the surface in the Clay Bank region of the York River, plotted against their equivalent spherical diameters. While most of the particles are classified as flocs, as indicated by the blue dots in Figure 1C and the peak in the relative number of particles in Figure 1E, there is still a large number of particles classified as “bed aggregates” (red dots). This number of higher density particles may be unexpected, as this video was captured 4.25m over a “muddy bed” in a natural system with a flood current of 40cm/s. However, biologically compacted mud in the form of resilient pellets (see Figure 2) may be the answer. Bed sediments from five sediment cruises during this study period (Aug 2012 – Nov 2014) were found to be comprised of 86-96% mud (Figure 3A). However, 9-14% of the mud was packaged as resilient pellets (Figure 3B). Sediment captured 38cm above the bed by traps deployed on tripods were found to have 92-98% mud, with 4-14% of the mud packaged as resilient pellets (Figures 3A and B). Pellets isolated from the Apr to Jul 2014 trap were sampled with the PICS to determine the distribution of settling velocities (Ws), particle densities, and the ratio of the long and short axis of the particles. This will be used to identify the pellets in PICS videos captured during the five 6h anchor stations (black lines in Figure 3) where three depths were sampled each hour.