Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Tidal Erosion And Upstream Sediment Trapping Modulate Records Of Land-Use Change In A Formerly Glaciated New England Estuary, Justin L. Shawler, Christopher J. Hein, Elizabeth A. Canuel, Et Al
Tidal Erosion And Upstream Sediment Trapping Modulate Records Of Land-Use Change In A Formerly Glaciated New England Estuary, Justin L. Shawler, Christopher J. Hein, Elizabeth A. Canuel, Et Al
VIMS Articles
Land clearing, river impoundments, and other human modifications to theupland landscape and within estuarine systems can drive coastal change at local to regionalscales. However, as compared with mid-latitude coasts, the impacts of human modificationsalong sediment-starved formerly glaciated coastal landscapes are relatively understudied.To address this gap, we present a late-Holocene record of changing sediment accumulationrates and sediment sources from sediment cores collected across a tidal flat in theMerrimack River estuary (Mass., USA). We pairsedimentology, geochronology, bulk- andstable-isotope organic geochemistry, and hydrodynamic simulations with historical datato evaluate human and natural impacts on coastal sediment fluxes. During the 17th to19th centuries, accumulation rates …
Asynchronous Nitrogen Supply And Demand Produce Nonlinear Plant Allocation Responses To Warming And Elevated Co2, Genevieve L. Noyce, Matthew L. Kirwan, Roy L. Rich, J. Patrick Megonigal
Asynchronous Nitrogen Supply And Demand Produce Nonlinear Plant Allocation Responses To Warming And Elevated Co2, Genevieve L. Noyce, Matthew L. Kirwan, Roy L. Rich, J. Patrick Megonigal
VIMS Articles
Terrestrial ecosystem responses to climate change are mediated by complex plant–soil feedbacks that are poorly understood, but often driven by the balance of nutrient supply and demand. We actively increased aboveground plant-surface temperature, belowground soil temperature, and atmospheric CO2 in a brackish marsh and found nonlinear and nonadditive feedbacks in plant responses. Changes in root-to-shoot allocation by sedges were nonlinear, with peak belowground allocation occurring at +1.7 °C in both years. Above 1.7 °C, allocation to root versus shoot production decreased with increasing warming such that there were no differences in root biomass between ambient and +5.1 °C plots …
Scientific Considerations For Acidification Monitoring In The Us Mid-Atlantic Region, Ka Goldsmith, S Lau, Et Al, Eh Shadwick, Et Al
Scientific Considerations For Acidification Monitoring In The Us Mid-Atlantic Region, Ka Goldsmith, S Lau, Et Al, Eh Shadwick, Et Al
VIMS Articles
Coastal and ocean acidification has the potential to cause significant environmental and societal impacts. Monitoring carbonate chemistry parameters over spatial and temporal scales is challenging, especially with limited resources. A lack of monitoring data can lead to a limited understanding of real-world conditions. Without such data, robust experimental and model design is challenging, and the identification and understanding of episodic acidification events is nearly impossible. We present considerations for resource managers, academia, and industry professionals who are currently developing acidification monitoring programs in the Mid-Atlantic region. We highlight the following considerations for deliberation: 1) leverage existing infrastructure to include multiple …
Tidal Variation In Cohesive Sediment Distribution And Sensitivity To Flocculation And Bed Consolidation In An Idealized, Partially Mixed Estuary, Danielle R.N. Tarpley, Courtney K. Harris, Carl Friedrichs, Christopher T. Sherwood
Tidal Variation In Cohesive Sediment Distribution And Sensitivity To Flocculation And Bed Consolidation In An Idealized, Partially Mixed Estuary, Danielle R.N. Tarpley, Courtney K. Harris, Carl Friedrichs, Christopher T. Sherwood
VIMS Articles
Particle settling velocity and erodibility are key factors that govern the transport of sediment through coastal environments including estuaries. These are difficult to parameterize in models that represent mud, whose properties can change in response to many factors, including tidally varying suspended sediment concentration (SSC) and shear stress. Using the COAWST (Coupled Ocean-Atmosphere-Wave-Sediment Transport) model framework, we implemented bed consolidation, sediment-induced stratification, and flocculation formulations within an idealized two-dimensional domain that represented the longitudinal dimension of a micro-tidal, muddy, partially mixed estuary. Within the Estuarine Turbidity Maximum (ETM), SSC and median floc diameter varied by a factor of four over …
Validating An Operational Flood Forecast Model Using Citizen Science In Hampton Roads, Va, Usa, Jon Derek Loftis, Molly Mitchell, Daniel Schatt, David R. Forrest, Harry V. Wang, David Mayfield, William A. Stiles
Validating An Operational Flood Forecast Model Using Citizen Science In Hampton Roads, Va, Usa, Jon Derek Loftis, Molly Mitchell, Daniel Schatt, David R. Forrest, Harry V. Wang, David Mayfield, William A. Stiles
VIMS Articles
Changes in the eustatic sea level have enhanced the impact of inundation events in the coastal zone, ranging in significance from tropical storm surges to pervasive nuisance flooding events. The increased frequency of these inundation events has stimulated the production of interactive web-map tracking tools to cope with changes in our changing coastal environment. Tidewatch Maps, developed by the Virginia Institute of Marine Science (VIMS), is an effective example of an emerging street-level inundation mapping tool. Leveraging the Semi-implicit Cross-scale Hydro-science Integrated System Model (SCHISM) as the engine, Tidewatch operationally disseminates 36-h inundation forecast maps with a 12-h update frequency. …
A Hydrodynamic Model For Galveston Bay And The Shelf In The Northern Gulf Of Mexico, Jiabi Du, Kyeong Park, Jian Shen, Yinglong J. Zhang, Xin Yu, Fei Ye, Zhengui Wang, Nancy N. Rabalais
A Hydrodynamic Model For Galveston Bay And The Shelf In The Northern Gulf Of Mexico, Jiabi Du, Kyeong Park, Jian Shen, Yinglong J. Zhang, Xin Yu, Fei Ye, Zhengui Wang, Nancy N. Rabalais
VIMS Articles
A 3-D unstructured-grid hydrodynamic model for the northern Gulf of Mexico was developed, with a hybrid s–z vertical grid and high-resolution horizontal grid for the main estuarine systems along the Texas–Louisiana coast. This model, based on the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM), is driven by the observed river discharge, reanalysis atmospheric forcing, and open boundary conditions from global HYCOM output. The model reproduces the temporal and spatial variation of observed water level, salinity, temperature, and current velocity in Galveston Bay and on the shelf. The validated model was applied to examine the remote influence of neighboring …
Field Experiments And Meta-Analysis Reveal Wetland Vegetation As A Crucial Element In The Coastal Protection Paradigm, Brian R. Silliman, Qiang He, Christine Angelini, Carter S. Smith, Matthew L. Kirwan, Et Al
Field Experiments And Meta-Analysis Reveal Wetland Vegetation As A Crucial Element In The Coastal Protection Paradigm, Brian R. Silliman, Qiang He, Christine Angelini, Carter S. Smith, Matthew L. Kirwan, Et Al
VIMS Articles
Increasing rates of sea-level rise and wave actionthreaten coastal populations. Defense of shorelinesby protection and restoration of wetlands has beeninvoked as a win-win strategy for humans and na-ture, yet evidence from field experiments supportingthe wetland protection function is uncommon, as isthe understanding of its context dependency. Herewe provide evidence from field manipulationsshowing that the loss of wetland vegetation, regard-less of disturbance size, increases the rate oferosion on wave-stressed shorelines. Vegetationremoval (simulated disturbance) along the edge ofsalt marshes reveals that loss of wetland plants ele-vates the rate of lateral erosion and that extensiveroot systems, rather than aboveground biomass,are primarily responsible for …
Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays, Sr Signorini, A Mannino, Marjorie A.M. Friedrichs, Pierre St-Laurent, Et Al, F Da, Et Al
Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays, Sr Signorini, A Mannino, Marjorie A.M. Friedrichs, Pierre St-Laurent, Et Al, F Da, Et Al
VIMS Articles
This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by …
Sea-Level Driven Land Conversion And The Formation Of Ghost Forests, Matthew L. Kirwan, Keryn B. Gedan
Sea-Level Driven Land Conversion And The Formation Of Ghost Forests, Matthew L. Kirwan, Keryn B. Gedan
VIMS Articles
Ghost forests created by the submergence of low-lying land are one of the most striking indicators of climate change along the Atlantic coast of North America. Although dead trees at the margin of estuaries were described as early as 1910, recent research has led to new recognition that the submergence of terrestrial land is geographically widespread, ecologically and economically important, and globally relevant to the survival of coastal wetlands in the face of rapid sea level rise. This emerging understanding has in turn generated widespread interest in the physical and ecological mechanisms influencing the extent and pace of upland to …
Shoreline Dynamics Along A Developed River Mouth Barrier Island: Multi-Decadal Cycles Of Erosion And Event-Driven Mitigation, Christopher J. Hein, Andrrew R. Fallon, Peter Rosen, Et Al
Shoreline Dynamics Along A Developed River Mouth Barrier Island: Multi-Decadal Cycles Of Erosion And Event-Driven Mitigation, Christopher J. Hein, Andrrew R. Fallon, Peter Rosen, Et Al
VIMS Articles
Human modifications in response to erosion have altered the natural transport of sediment to and across the coastal zone, thereby potentially exacerbating the impacts of future erosive events. Using a combination of historical shoreline-change mapping, sediment sampling, three-dimensional beach surveys, and hydrodynamic modeling of nearshore and inlet processes, this study explored the feedbacks between periodic coastal erosion patterns and associated mitigation responses, focusing on the open-ocean and inner-inlet beaches of Plum Island and the Merrimack River Inlet, Massachusetts, United States. Installation of river-mouth jetties in the early 20th century stabilized the inlet, allowing residential development in northern Plum Island, but …
Citizen-Science For The Future: Advisory Case Studies From Around The Globe, C Simoniello, J Jencks, Fm Lauro, Jon Derek Loftis, K Deja, David R. Forrest, Et At
Citizen-Science For The Future: Advisory Case Studies From Around The Globe, C Simoniello, J Jencks, Fm Lauro, Jon Derek Loftis, K Deja, David R. Forrest, Et At
VIMS Articles
The democratization of ocean observation has the potential to add millions of observations every day. Though not a solution for all ocean monitoring needs, citizen scientists offer compelling examples showcasing their ability to augment and enhance traditional research and monitoring. Information they are providing is increasing the spatial and temporal frequency and duration of sampling, reducing time and labor costs for academic and government monitoring programs, providing hands-on STEM learning related to real-world issues and increasing public awareness and support for the scientific process. Examples provided here demonstrate the wide range of people who are already dramatically reducing gaps in …
Reconstructing Coastal Sediment Budgets From Beach‐ And Foredune‐Ridge Morphology: A Coupled Field And Modeling Approach, Dj Ciarletta, Jl Shawler, C Tenebruso, Christopher J. Hein, J Lorenzo‐Trueba
Reconstructing Coastal Sediment Budgets From Beach‐ And Foredune‐Ridge Morphology: A Coupled Field And Modeling Approach, Dj Ciarletta, Jl Shawler, C Tenebruso, Christopher J. Hein, J Lorenzo‐Trueba
VIMS Articles
Preserved beach and foredune ridges may serve as proxies for coastal change, reflecting alterations in sea level, wave energy, or past sediment fluxes. In particular, time‐varying shoreface sediment budgets have been inferred from the relative size of foredune ridges through application of radiocarbon and optically stimulated luminescence dating to these systems over the last decades. However, geochronological control requires extensive field investigation and analysis. Purely field‐based studies might also overlook relationships between the mechanics of sediment delivery to the shoreface and foredune ridges, missing insights about sensitivity to changes in sediment budget. We therefore propose a simple geomorphic model of …
Sea Ice Meltwater And Circumpolar Deep Water Drive Contrasting Productivity In Three Antarctic Polynyas, S Moreau, D Lannuzel, J Janssens, Mc Arroyo, Et Al
Sea Ice Meltwater And Circumpolar Deep Water Drive Contrasting Productivity In Three Antarctic Polynyas, S Moreau, D Lannuzel, J Janssens, Mc Arroyo, Et Al
VIMS Articles
In the Southern Ocean, polynyas exhibit enhanced rates of primary productivity and represent large seasonal sinks for atmospheric CO2. Three contrasting east Antarctic polynyas were visited in late December to early January 2017: the Dalton, Mertz, and Ninnis polynyas. In the Mertz and Ninnis polynyas, phytoplankton biomass (average of 322 and 354mg chlorophyll a (Chl a)/m(2), respectively) and net community production (5.3 and 4.6mol C/m(2), respectively) were approximately 3 times those measured in the Dalton polynya (average of 122mg Chl a/m(2) and 1.8mol C/m(2)). Phytoplankton communities also differed between the polynyas. Diatoms were thriving in the Mertz and Ninnis polynyas …
A Data-Driven Modeling Approach For Simulating Algal Blooms In The Tidal Freshwater Of James River In Response To Riverine Nutrient Loading, Jian Shen, Qubin Qin, Ya Wang, Mac Sisson
A Data-Driven Modeling Approach For Simulating Algal Blooms In The Tidal Freshwater Of James River In Response To Riverine Nutrient Loading, Jian Shen, Qubin Qin, Ya Wang, Mac Sisson
VIMS Articles
Algal blooms often occur in the tidal freshwater (TF) of the James River estuary, a tributary of the Chesapeake Bay. The timing of algal blooms correlates highly to a summer low-flow period when residence time is long and nutrients are available. Because of complex interactions between physical transport and algal dynamics, it is challenging to predict interannual variations of bloom correctly using a complex eutrophication model without having ahigh-resolution model gridto resolve complexgeometryand anaccurate estimate of nutrientloading to drive the model. In this study, an approach using long-term observational data (from 1990 to 2013) and the Support vector machine (LS-SVM) …
Advancing Marine Biogeochemical And Ecosystem Reanalyses And Forecasts As Tools For Monitoring And Managing Ecosystem Health, K Fennel, M Gehlen, P Brasseur, Cw Brown, C Ciavatta, G Cossarini, A Crise, Ca Edwards, D Ford, Marjorie A.M. Friedrichs, Et Al
Advancing Marine Biogeochemical And Ecosystem Reanalyses And Forecasts As Tools For Monitoring And Managing Ecosystem Health, K Fennel, M Gehlen, P Brasseur, Cw Brown, C Ciavatta, G Cossarini, A Crise, Ca Edwards, D Ford, Marjorie A.M. Friedrichs, Et Al
VIMS Articles
Ocean ecosystems are subject to a multitude of stressors, including changes in ocean physics and biogeochemistry, and direct anthropogenic influences. Implementation of protective and adaptive measures for ocean ecosystems requires a combination of ocean observations with analysis and prediction tools. These can guide assessments of the current state of ocean ecosystems, elucidate ongoing trends and shifts, and anticipate impacts of climate change and management policies. Analysis and prediction tools are defined here as ocean circulation models that are coupled to biogeochemical or ecological models. The range of potential applications for these systems is broad, ranging from reanalyses for the assessment …
Ocean Circulation Causes Strong Variability In The Mid-Atlantic Bight Nitrogen Budget, Marjorie A.M. Friedrichs, Pierre St-Laurent, Yongjin Xiao, Et Al
Ocean Circulation Causes Strong Variability In The Mid-Atlantic Bight Nitrogen Budget, Marjorie A.M. Friedrichs, Pierre St-Laurent, Yongjin Xiao, Et Al
VIMS Articles
Portions of the ocean adjacent to land masses play a particularly important role in global nutrient cycling; however, strong spatial and temporal variability in these shallow regions of the ocean make it difficult to quantify nitrogen fluxes from observations alone. Here we use a computer simulation to estimate the fluxes and transformations of inorganic and organic nitrogen in Mid-Atlantic U.S. coastal waters. The coastal circulation flows southward providing roughly two thirds of the inorganic nitrogen to this region, with the remaining third entering from rivers and estuaries. Nitrogen transport across the continental slope is highly variable, directed into the system …
High-Frequency Co2-System Variability Over The Winter-To-Spring Transition In A Large Coastal Plain Estuary, Elizabeth H. Shadwick, Marjorie A.M. Friedrichs, Raymond G. Najjar, Olivia A. De Meo, Jaclyn R. Friedman, Fei Da, W. G. Reay
High-Frequency Co2-System Variability Over The Winter-To-Spring Transition In A Large Coastal Plain Estuary, Elizabeth H. Shadwick, Marjorie A.M. Friedrichs, Raymond G. Najjar, Olivia A. De Meo, Jaclyn R. Friedman, Fei Da, W. G. Reay
VIMS Articles
Understanding the vulnerability of estuarine ecosystems to anthropogenic impacts requires a quantitative assessment of the dynamic drivers of change to the carbonate (CO2) system. Here we present new high‐frequency pH data from a moored sensor. These data are combined with discrete observations to create continuous time series of total dissolved inorganic carbon (TCO2), CO2 partial pressure (pCO2), and carbonate saturation state. We present two deployments over the winter‐to‐spring transition in the lower York River (where it meets the Chesapeake Bay mainstem) in 2016/2017 and 2017/2018. TCO2 budgets with daily resolution are constructed, …
Summer Carbonate Chemistry In The Dalton Polynya, East Antarctica, Mc Arroyo, Eh Shadwick, B Tilbrook
Summer Carbonate Chemistry In The Dalton Polynya, East Antarctica, Mc Arroyo, Eh Shadwick, B Tilbrook
VIMS Articles
The carbonate chemistry in the Dalton Polynya in East Antarctica (115°–123°E) was investigated in summer 2014/2015 using high‐frequency underway measurements of CO2 fugacity (fCO2) and discrete water column measurements of total dissolved inorganic carbon (TCO2) and total alkalinity. Air‐sea CO2 fluxes indicate this region was a weak net source of CO2 to the atmosphere (0.7 ± 0.9 mmol C m−2 day−1) during the period of observation, with the largest degree of surface water supersaturation (ΔfCO2 = +45 μatm) in ice‐covered waters near the Totten Ice Shelf (TIS) as compared to the ice‐free surface waters in the Dalton Polynya. The seasonal …