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Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Sediment Transport Model Including Short-Lived Radioisotopes: Model Description And Idealized Test Cases, Justin J. Birchler,, Courtney K. Harris, Christopher R Sherwood, Tara A. Kniskern
Sediment Transport Model Including Short-Lived Radioisotopes: Model Description And Idealized Test Cases, Justin J. Birchler,, Courtney K. Harris, Christopher R Sherwood, Tara A. Kniskern
VIMS Articles
Geochronologies derived from sediment cores in coastal locations are often used to infer event bed characteristics such as deposit thicknesses and accumulation rates. Such studies commonly use naturally occurring, short-lived radioisotopes, such as Beryllium-7 (Be-7) and Thorium-234 (Th-234), to study depositional and post-depositional processes. These radioisotope activities, however, are not generally represented in sediment transport models that characterize coastal flood and storm deposition with grain size patterns and deposit thicknesses. We modified the Community Sediment Transport Modeling System (CSTMS) to account for reactive tracers and used this capability to represent the behavior of these short-lived radioisotopes on the sediment bed. …
Symbiotic Unicellular Cyanobacteria Fix Nitrogen In The Arctic Ocean, K. Harding, K. A. Turk-Kubo, Rachel E. Sipler, M. M. Mills, D. A. Bronk
Symbiotic Unicellular Cyanobacteria Fix Nitrogen In The Arctic Ocean, K. Harding, K. A. Turk-Kubo, Rachel E. Sipler, M. M. Mills, D. A. Bronk
VIMS Articles
Biological dinitrogen (N2) fixation is an important source of nitrogen (N) in low-latitude open oceans. The unusual N2-fixing unicellular cyanobacteria (UCYN-A)/haptophyte symbiosis has been found in an increasing number of unexpected environments, including northern waters of the Danish Straight and Bering and Chukchi Seas. We used nanoscale secondary ion mass spectrometry (nanoSIMS) to measure 15N2 uptake into UCYN-A/haptophyte symbiosis and found that UCYN-A strains identical to low-latitude strains are fixing N2 in the Bering and Chukchi Seas, at rates comparable to subtropical waters. These results show definitively that cyanobacterial N2 fixation is not constrained to subtropical waters, challenging paradigms and …
Stormsense: A Blueprint For Coastal Flood Forecast Information & Automated Alert Messaging Systems, Jon Derek Loftis, Sridhar Katragadda, Sokwoo Rhee, Cuong Nguyen
Stormsense: A Blueprint For Coastal Flood Forecast Information & Automated Alert Messaging Systems, Jon Derek Loftis, Sridhar Katragadda, Sokwoo Rhee, Cuong Nguyen
VIMS Articles
Increased availability of low-cost water level sensors communicating through the Internet of Things (IoT) has expanded the horizons of publicly-ingestible data streams available to modern smart cities. StormSense is an IoT-enabled inundation forecasting research initiative and an active participant in the Global City Teams Challenge seeking to enhance flood preparedness in the smart cities of Hampton Roads, VA for flooding resulting from storm surge, rain, and tides. In this study, we present the a blueprint and series of applicable protocols through the use of the new StormSense water level sensors to help establish a regional resilience monitoring network. In furtherance …
Effects Of Density‐Driven Flows On The Long‐Term Morphodynamic Evolution Of Funnel‐Shaped Estuaries, Matiane Olabarrieta, W. Rockwell Geyer, Giovanni Coco, Carl T. Friedrichs
Effects Of Density‐Driven Flows On The Long‐Term Morphodynamic Evolution Of Funnel‐Shaped Estuaries, Matiane Olabarrieta, W. Rockwell Geyer, Giovanni Coco, Carl T. Friedrichs
VIMS Articles
Subtidal flows driven by density gradients affect the tide‐averaged sediment transport in estuaries and, therefore, can influence their long‐term morphodynamic evolution. The three‐dimensional Coupled Ocean‐Atmosphere‐Wave‐Sediment Transport modeling system is applied to numerically analyze the effects of baroclinicity and Earth's rotation on the long‐term morphodynamic evolution of idealized funnel‐shaped estuaries. The morphodynamic evolution in all the analyzed cases reproduced structures identified in many tide‐dominated estuaries: a meandering region in the fluvial‐tidal transition zone, a tidal maximum area close to the head, and a turbidity maxima region in the brackish zone. As the morphology of the estuaries evolved, the tidal propagation (including …
Impact Of Seabed Resuspension On Oxygen And Nitrogen Dynamics In The Northern Gulf Of Mexico: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Marjorie A.M. Friedrichs, Katja Fennel, Kehui Xu
Impact Of Seabed Resuspension On Oxygen And Nitrogen Dynamics In The Northern Gulf Of Mexico: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Marjorie A.M. Friedrichs, Katja Fennel, Kehui Xu
VIMS Articles
Resuspension affects water quality in coastal environments by entraining seabed organic matter into the water column, which can increase remineralization, alter seabed fluxes, decrease water clarity, and affect oxygen and nutrient dynamics. Nearly all numerical models of water column biogeochemistry, however, simplify seabed and bottom boundary layer processes and neglect resuspension. Here we implemented HydroBioSed, a coupled hydrodynamic-sediment transport-biogeochemical model to examine the role of resuspension in regulating oxygen and nitrogen dynamics on timescales of a day to a month. The model was implemented for the northern Gulf of Mexico, where the extent of summertime hypoxia is sensitive to seabed …
Overcoming Early Career Barriers To Interdisciplinary Climate Change Research, Christopher J. Hein, John E. Ten Hoeve, Sathya Gopalakrishnan, Et Al
Overcoming Early Career Barriers To Interdisciplinary Climate Change Research, Christopher J. Hein, John E. Ten Hoeve, Sathya Gopalakrishnan, Et Al
VIMS Articles
Climate-change impacts are among the most serious and complex challenges facing society, affecting both natural and social systems. Addressing these requires a new paradigm of interdisciplinary collaboration which incorporates tools, techniques, and insights from across the social, natural, and engineering sciences. Yet, a wide range of intrinsic and extrinsic hurdles need to be overcome to conduct successful, integrated interdisciplinary research. The results of a bibliometric analysis and survey of early to mid-career scientists from 56 countries who were involved with the interdisciplinary DISsertations initiative for the advancement of Climate Change ReSearch (DISCCRS) emphasize the particular challenges faced by early career …
Future Response Of Global Coastal Wetlands To Sea-Level Rise, M. Schuerch, T. Spencer, S. Temmerman, Matthew L. Kirwan, Et Al
Future Response Of Global Coastal Wetlands To Sea-Level Rise, M. Schuerch, T. Spencer, S. Temmerman, Matthew L. Kirwan, Et Al
VIMS Articles
The response of coastal wetlands to sea-level rise during the twenty-first century remains uncertain. Global-scale projections suggest that between 20 and 90 per cent (for low and high sea-level rise scenarios, respectively) of the present-day coastal wetland area will be lost, which will in turn result in the loss of biodiversity and highly valued ecosystem services(1-3). These projections do not necessarily take into account all essential geomorphological(4-7) and socio-economic system feedbacks(8). Here we present an integrated global modelling approach that considers both the ability of coastal wetlands to build up vertically by sediment accretion, and the accommodation space, namely, the …
Stoichiometric N:P Ratios, Temperature, And Iron Impact Carbon And Nitrogen Uptake By Ross Sea Microbial Communities, Jl Spackeen, Da Bronk, Rachel E. Sipler, Em Bertrand, Da Hutchins, Ae Allen
Stoichiometric N:P Ratios, Temperature, And Iron Impact Carbon And Nitrogen Uptake By Ross Sea Microbial Communities, Jl Spackeen, Da Bronk, Rachel E. Sipler, Em Bertrand, Da Hutchins, Ae Allen
VIMS Articles
The Southern Ocean is one of the most biologically important ecosystems on our planet. Microscopic plants, called phytoplankton, form the base of the food web in the Southern Ocean and play a direct role in regulating how much and how fast elements like nitrogen and carbon are cycled throughout the world ocean. The goal of this research was to determine how predicted changes in the environment will impact how fast phytoplankton use these elements. The conditions that we tested included elevated temperature, addition of iron, and the proportion of nitrogen to phosphorus in the seawater. These parameters were selected because …
Estimating Hypoxic Volume In The Chesapeake Bay Using Two Continuously Sampled Oxygen Profiles, Aaron J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, Malcolm E. Scully
Estimating Hypoxic Volume In The Chesapeake Bay Using Two Continuously Sampled Oxygen Profiles, Aaron J. Bever, Marjorie A.M. Friedrichs, Carl T. Friedrichs, Malcolm E. Scully
VIMS Articles
Low levels of dissolved oxygen (DO) occur in many embayments throughout the world and have numerous detrimental effects on biota. Although measurement of in situ DO is straightforward with modern instrumentation, quantifying the volume of water in a given embayment that is hypoxic (hypoxic volume (HV)) is a more difficult task; however, this information is critical for determining whether management efforts to increase DO are having an overall impact. This paper uses output from a three‐dimensional numerical model to demonstrate that HV in Chesapeake Bay can be estimated well with as few as two vertical profiles. In addition, the cumulative …
Role Of Sediment Resuspension On Estuarine Suspended Particulate Mercury Dynamics, Ea Seelen, Grace M. Massey, Rp Mason
Role Of Sediment Resuspension On Estuarine Suspended Particulate Mercury Dynamics, Ea Seelen, Grace M. Massey, Rp Mason
VIMS Articles
Coastal sediments are an important site for transient and long-term mercury (Hg) storage, and they foster a geochemical environment optimal for Hg methylation. Therefore, efforts have been taken to constrain the role of sediments as a source of methylmercury (MeHg) to the estuarine water column. This study employed the Gust Microcosm Erosion Core system capable of quantifying particle removal from undisturbed cores under measurable shear stress conditions to assess particulate Hg and MeHg exchange between sediments and the water column. Samples were collected from organic-rich and organic-poor sediment types from the mid- and lower Delaware Bay. It was found that …
A 3d Unstructured-Grid Model For Chesapeake Bay: Importance Of Bathymetry, Fei Ye, Yinglong J. Zhang, Harry V. Wang, Marjorie A.M. Friedrichs, Isaac D. Irby, Eli Alteljevich, Arnaldo Valle-Levinson, Zhengui Wang, Hai Huang, Jian Shen, Jiabi Du
A 3d Unstructured-Grid Model For Chesapeake Bay: Importance Of Bathymetry, Fei Ye, Yinglong J. Zhang, Harry V. Wang, Marjorie A.M. Friedrichs, Isaac D. Irby, Eli Alteljevich, Arnaldo Valle-Levinson, Zhengui Wang, Hai Huang, Jian Shen, Jiabi Du
VIMS Articles
We extend the 3D unstructured-grid model previously developed for the Upper Chesapeake Bay to cover the entire Bay and its adjacent shelf, and assess its skill in simulating saltwater intrusion and the coastal plume. Recently developed techniques, including a flexible vertical grid system and a 2nd-order, monotone and implicit transport solver are critical in successfully capturing the baroclinic responses. Most importantly, good accuracy is achieved through an accurate representation of the underlying bathymetry, without any smoothing. The model in general exhibits a good skill for all hydrodynamic variables: the averaged root-mean-square errors (RMSE‟s) in the Bay are 9 cm for …
Role Of Baroclinic Processes On Flushing Characteristics In A Highly Stratified Estuarine System, Mobile Bay, Alabama, Jiabi Du, Kyeong Park, Jian Shen, Et Al
Role Of Baroclinic Processes On Flushing Characteristics In A Highly Stratified Estuarine System, Mobile Bay, Alabama, Jiabi Du, Kyeong Park, Jian Shen, Et Al
VIMS Articles
Flushing of an estuary quantifies the overall water exchange between the estuary and coastal ocean and is crucially important for water quality as well as biological and geochemical processes within the system. Flushing times and freshwater age in Mobile Bay were numerically calculated under realistic and various controlled forcing conditions. Their responses to external forcing were explained by the three‐dimensional characteristics of general circulation in the system. The flushing time ranges from 10 to 33 days under the 25th–75th percentile river discharges, nearly half of the previous estimates based on barotropic processes only, suggesting the important contribution of baroclinic processes. …
Effects Of Marsh Edge Erosion In Coupled Barrier Island-Marsh Systems And Geometric Constraints On Marsh Evolution, Rebecca Lauzon, A Brad Murray, Laura J Moore, David C. Walters, Matthew L. Kirwan, Sergio Fagherazzi,
Effects Of Marsh Edge Erosion In Coupled Barrier Island-Marsh Systems And Geometric Constraints On Marsh Evolution, Rebecca Lauzon, A Brad Murray, Laura J Moore, David C. Walters, Matthew L. Kirwan, Sergio Fagherazzi,
VIMS Articles
Sand washed across barrier islands during storms (called overwash) provides sediment for salt marshes behind those islands, and can allow a marsh which otherwise would drown to grow vertically fast enough to keep up with sea level. We use a barrier island-marsh evolution model (GEOMBEST+) to see what effect marsh edge erosion by waves has on overwash-supported marshes. Consistent with previous research, we find that wave erosion can make marshes more resilient by freeing sediment that can be used elsewhere on the marsh surface. We add that horizontal erosion of the marsh edge provides more sediment per volume eroded than …
Tidal Response To Sea-Level Rise In Different Types Of Estuaries: The Importance Of Length, Bathymetry, And Geometry, Jb Du, Jian Shen, Yinglong J. Zhang, Fei Ye, Z Liu, Zg Wang, Yp Wang, X Yu, M Sisson, Harry V. Wang
Tidal Response To Sea-Level Rise In Different Types Of Estuaries: The Importance Of Length, Bathymetry, And Geometry, Jb Du, Jian Shen, Yinglong J. Zhang, Fei Ye, Z Liu, Zg Wang, Yp Wang, X Yu, M Sisson, Harry V. Wang
VIMS Articles
Tidal response to sea-level rise (SLR) varies in different coastal systems. To provide a generic pattern of tidal response to SLR, a systematic investigation was conducted using numerical techniques applied to idealized and realistic estuaries, with model results cross-checked by analytical solutions. Our results reveal that the response of tidal range to SLR is nonlinear, spatially heterogeneous, and highly affected by the length and bathymetry of an estuary and weakly affected by the estuary convergence with an exception of strong convergence. Contrary to the common assumption that SLR leads to a weakened bottom friction, resulting in increased tidal amplitude, we …
Integrated Ocean, Earth, And Atmospheric Observations For Resilience Planning In Hampton Roads, Virginia, Jon Derek Loftis, Molly Mitchell, Larry Atkinson, Ben Hamlington, Thomas R. Allen, David R. Forrest, Et Al
Integrated Ocean, Earth, And Atmospheric Observations For Resilience Planning In Hampton Roads, Virginia, Jon Derek Loftis, Molly Mitchell, Larry Atkinson, Ben Hamlington, Thomas R. Allen, David R. Forrest, Et Al
VIMS Articles
Building flood resilience in coastal communities requires a precise understanding of the temporal and spatial scales of inundation and the ability to detect and predict changes in flooding. In Hampton Roads, the Intergovernmental Pilot Project's Scientific Advisory Committee recommended an integrated network of ocean, earth, and atmospheric data collection from both private and public sector organizations that engage in active scientific monitoring and observing. Since its establishment, the network has grown to include monitoring of water levels, land subsidence, wave measurements, current measurements, and atmospheric conditions. High-resolution land elevation and land cover data sets have also been developed. These products …
Stormsense: A New Integrated Network Of Iot Water Level Sensors In The Smart Cities Of Hampton Roads, Va, Jon Derek Loftis, David R. Forrest, Sridhar Katragadda, Kyle Spencer, Tammie Organski, Cuong Nguyen, Sokwoo Rhee
Stormsense: A New Integrated Network Of Iot Water Level Sensors In The Smart Cities Of Hampton Roads, Va, Jon Derek Loftis, David R. Forrest, Sridhar Katragadda, Kyle Spencer, Tammie Organski, Cuong Nguyen, Sokwoo Rhee
VIMS Articles
Propagation of cost-effective water level sensors powered through the Internet of Things (IoT) has expanded the available offerings of ingestible data streams at the disposal of modern smart cities. StormSense is an IoT-enabled inundation forecasting research initiative and an active participant in the Global City Teams Challenge, seeking to enhance flood preparedness in the smart cities of Hampton Roads, VA, for flooding resulting from storm surge, rain, and tides. In this study, we present the results of the new StormSense water level sensors to help establish the “regional resilience monitoring network” noted as a key recommendation from the Intergovernmental Pilot …
Massive Upland To Wetland Conversion Compensated For Historical Marsh Loss In Chesapeake Bay, Usa, Nathalie W. Schieder, David C. Walters, Matthew L. Kirwan
Massive Upland To Wetland Conversion Compensated For Historical Marsh Loss In Chesapeake Bay, Usa, Nathalie W. Schieder, David C. Walters, Matthew L. Kirwan
VIMS Articles
Sea level rise leads to coastal transgression, and the survival of ecosystems depends on their ability to migrate inland faster than they erode and submerge. We compared marsh extent between nineteenth-century maps and modern aerial photographs across the Chesapeake Bay, the largest estuary in North America, and found that Chesapeake marshes have maintained their spatial extent despite relative sea level rise rates that are among the fastest in the world. In the mapped region (i.e., 25% of modern Chesapeake Bay marshland),94 km2of marsh was lost primarily to shoreline erosion,whereas 101 km2of marsh was created by upland drowning.Simple projections over the …
Multi-Decadal Trends And Variability In Temperature And Salinity In The Mid-Atlantic Bight, Georges Bank, And Gulf Of Maine, Elizabeth J. Wallace, Lev B. Looney, Donglai Gong
Multi-Decadal Trends And Variability In Temperature And Salinity In The Mid-Atlantic Bight, Georges Bank, And Gulf Of Maine, Elizabeth J. Wallace, Lev B. Looney, Donglai Gong
VIMS Articles
Increasing attention is being placed on the regional impact of climate change. This study focuses on the decadal scale variabilities of temperature and salinity in the Mid-Atlantic Bight (MAB), Georges Bank (GB), and Gulf of Maine (GOM) from 1977 to 2016 using hydrographic survey data from the National Oceanic and Atmospheric Administration (NOAA) Northeast Fisheries Science Center. The MAB (as defined by the shelf regions from Cape Hatteras to Cape Cod) experienced warming rates of 0.57 ◦C per decade during the Winter/Spring season (Jan–Apr) and 0.47 ◦C per decade during the Fall/Winter season (Sep–Dec). The GOM and GB, on the …