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Full-Text Articles in Life Sciences
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
VIMS Articles
Contamination of oysters with a variety of viruses is one key pathway to trigger outbreaks of massive oyster mortality as well as human illnesses, including gastroenteritis and hepatitis. Much effort has gone into examining the fate of viruses in contaminated oysters, yet the current state of knowledge of nonlinear virus-oyster interactions is not comprehensive because most studies have focused on a limited number of processes under a narrow range of experimental conditions. A framework is needed for describing the complex nonlinear virus-oyster interactions. Here, we introduce a mathematical model that includes key processes for viral dynamics in oysters, such as …
Using Forward And Backward Particle Tracking Approaches To Analyze Impacts Of A Water Intake On Ichthyoplankton Mortality In The Appomattox River, Qubin Qin, Jian Shen, Troy D. Tuckey, Xun Cai, Jilian Xiong
Using Forward And Backward Particle Tracking Approaches To Analyze Impacts Of A Water Intake On Ichthyoplankton Mortality In The Appomattox River, Qubin Qin, Jian Shen, Troy D. Tuckey, Xun Cai, Jilian Xiong
VIMS Articles
Municipal intakes of surface water have various uses, and their impacts on the aquatic environment and ecosystem, such as the impingement and entrainment of ichthyoplankton, are a major concern. A robust assessment of the intake impacts on ichthyoplankton in a system generally requires modeling efforts that can simulate the transport and dispersal pathways of the ichthyoplankton. However, it is challenging to simulate hydrodynamics with a high‐resolution grid at the
scale needed for intake screen sizes in a large system. In this study, a 3D unstructured grid model with a fine resolution grid (<1 >m) was developed to investigate potential impacts …
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
VIMS Articles
As the oyster aquaculture industry grows and becomes incorporated into management practices, it is important to understand its effects on local environments. This study investigated how water quality and hydrodynamics varied among farms as well as inside versus outside the extent of caged grow-out areas located in southern Chesapeake Bay. Current speed and water quality variables (chlorophyll-a fluorescence, turbidity, and dissolved oxygen) were measured along multiple transects within and adjacent to four oyster farms during two seasons. At the scale of individual aquaculture sites, we were able to detect statistically significant differences in current speed and water quality variables between …
The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, Qubin Quin, Jian Shen
The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, Qubin Quin, Jian Shen
VIMS Articles
Although both local processes (photosynthesis, respiration, grazing, and settling), and transport processes (advective transport and diffusive transport) significantly affect local phytoplankton dynamics, it is difficult to separate their contributions and to investigate the relative importance of each process to the local variability of phytoplankton biomass over different timescales. A method of using the transport rate is introduced to quantify the contribution of transport processes. By combining the time-varying transport rate and high-frequency observed chlorophyll a data, we can explicitly examine the impact of local and transport processes on phytoplankton biomass over a range of timescales from hourly to annually. For …
Millennial Soil Retention Of Terrestrial Organic Matter Deposited In The Bengal Fan, Kl French, Christopher J. Hein, N Haghipour, L Wacker, Hr Kudrass
Millennial Soil Retention Of Terrestrial Organic Matter Deposited In The Bengal Fan, Kl French, Christopher J. Hein, N Haghipour, L Wacker, Hr Kudrass
VIMS Articles
The abundance of organic carbon (OC) in vegetation and soils (similar to 2,600 PgC) compared to carbon in the atmosphere (similar to 830 PgC) highlights the importance of terrestrial OC in global carbon budgets. The residence time of OC in continental reservoirs, which sets the rates of carbon exchange between land and atmosphere, represents a key uncertainty in global carbon cycle dynamics. Retention of terrestrial OC can also distort bulk OC- and biomarker-based paleorecords, yet continental storage timescales remain poorly quantified. Using "bomb" radiocarbon (C-14) from thermonuclear weapons testing as a tracer, we model leaf-wax fatty acid and bulk OC …
Predicting Marsh Vulnerability To Sea-Level Rise Using Holocene Relative Sea-Level Data, Bp Horton, I Shennan, Sl Bradley, N Cahill, Matthew L. Kirwan, Re Kopp, Ta Shaw
Predicting Marsh Vulnerability To Sea-Level Rise Using Holocene Relative Sea-Level Data, Bp Horton, I Shennan, Sl Bradley, N Cahill, Matthew L. Kirwan, Re Kopp, Ta Shaw
VIMS Articles
Tidal marshes rank among Earth's vulnerable ecosystems, which will retreat if future rates of relative sea-level rise (RSLR) exceed marshes' ability to accrete vertically. Here, we assess the limits to marsh vulnerability by analyzing >780 Holocene reconstructions of tidal marsh evolution in Great Britain. These reconstructions include both transgressive (tidal marsh retreat) and regressive (tidal marsh expansion) contacts. The probability of a marsh retreat was conditional upon Holocene rates of RSLR, which varied between -7.7 and 15.2 mm/yr. Holocene records indicate that marshes are nine times more likely to retreat than expand when RSLR rates are >= 7.1 mm/yr. Coupling …
Numerical Model Of Geochronological Tracers For Deposition And Reworking Applied To The Mississippi Subaqueous Delta, Jj Birchler, Courtney K. Harris, Ta Kniskern, Cr Sherwood
Numerical Model Of Geochronological Tracers For Deposition And Reworking Applied To The Mississippi Subaqueous Delta, Jj Birchler, Courtney K. Harris, Ta Kniskern, Cr Sherwood
VIMS Articles
Measurements of naturally occurring, short-lived radioisotopes from sediment cores on the Mississippi subaqueous delta have been used to infer event bed characteristics such as depositional thicknesses and accumulation rates. Specifically, the presence of Beryllium-7 (Be-7) indicates recent riverine-derived terrestrial sediment deposition; while Thorium-234 (Th-234) provides evidence of recent suspension in marine waters. Sediment transport models typically represent coastal flood and storm deposition via estimated grain size patterns and deposit thicknesses, however, and do not directly calculate radioisotope activities and profiles, which leads to a disconnect between the numerical model and field observations. Here, observed radioisotopic profiles from the Mississippi subaqueous …
Cross-Scale Baroclinic Simulation Of The Effect Of Channel Dredging In An Estuarine Setting, Fei Ye, Harry V. Wang, H Huang, Zg Wang, Z Liu, X Li
Cross-Scale Baroclinic Simulation Of The Effect Of Channel Dredging In An Estuarine Setting, Fei Ye, Harry V. Wang, H Huang, Zg Wang, Z Liu, X Li
VIMS Articles
Holistic simulation approaches are often required to assess human impacts on a river-estuary-coastal system, due to the intrinsically linked processes of contrasting spatial scales. In this paper, a Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM) is applied in quantifying the impact of a proposed hydraulic engineering project on the estuarine hydrodynamics. The project involves channel dredging and land expansion that traverse several spatial scales on an ocean-estuary-river-tributary axis. SCHISM is suitable for this undertaking due to its flexible horizontal and vertical grid design and, more importantly, its efficient high-order implicit schemes applied in both the momentum and transport calculations. These …
Accuracy And Precision Of Tidal Wetland Soil Carbon Mapping In The Conterminous United States, Jr Holmquist, L Windham-Myers, N Bliss, S Crooks, Jt Morris, W. G. Reay, Et Al.
Accuracy And Precision Of Tidal Wetland Soil Carbon Mapping In The Conterminous United States, Jr Holmquist, L Windham-Myers, N Bliss, S Crooks, Jt Morris, W. G. Reay, Et Al.
VIMS Articles
Tidal wetlands produce long-term soil organic carbon (C) stocks. Thus for carbon accounting purposes, we need accurate and precise information on the magnitude and spatial distribution of those stocks. We assembled and analyzed an unprecedented soil core dataset, and tested three strategies for mapping carbon stocks: applying the average value from the synthesis to mapped tidal wetlands, applying models fit using empirical data and applied using soil, vegetation and salinity maps, and relying on independently generated soil carbon maps. Soil carbon stocks were far lower on average and varied less spatially and with depth than stocks calculated from available soils …
Spatial Distribution And Morphological Responses To Predation In The Salt Marsh Periwinkle, Aj Rietl, Mg Sorrentino, Bj Roberts
Spatial Distribution And Morphological Responses To Predation In The Salt Marsh Periwinkle, Aj Rietl, Mg Sorrentino, Bj Roberts
VIMS Articles
The salt marsh periwinkle (Littoraria irrorata) is a common and often abundant mollusk in marshes of the Gulf and Atlantic coasts of the United States. Several studies have focused on the effects of periwinkles on Spartina alterniflora production and the effects of oil on periwinkle survivability, yet the general ecology of the snail has been underreported. In this study, we measured spatial distributions, biomass, shell repair frequency, and a suite of morphological characteristics of L. irrorata at three sites in each of five regions spanning the southeastern Louisiana Coast between the Atchafalaya and Mississippi rivers. Sampling was conducted along 50 …
Time Trends Of Polybrominated Diphenyl Ethers (Pbdes) In Antarctic Biota, E Markham, Ek Brault, M Khairy, Ar Robuck, Me Goebel, Mg Cantwell, Rm Dickhut, R Lohmann
Time Trends Of Polybrominated Diphenyl Ethers (Pbdes) In Antarctic Biota, E Markham, Ek Brault, M Khairy, Ar Robuck, Me Goebel, Mg Cantwell, Rm Dickhut, R Lohmann
VIMS Articles
Polybrominated diphenyl ethers (PBDEs) are "emerged" contaminants that were produced and used as flame retardants in numerous consumer and industrial applications for decades until banned. They remain ubiquitously present in the environment today. Here, a unique set of >200 biotic samples from the Antarctic was analyzed for PBDEs, including phytoplankton, krill, fish, and fur seal milk, spanning several sampling seasons over 14 years. PBDE-47 and -99 were the dominant congeners determined in all samples, constituting > 60% of total PBDEs. A temporal trend was observed for Sigma 7PBDE concentrations in fur seal milk, where concentrations significantly increased (R-2 = 0.57, p < 0.05) over time (2000-2014). Results for krill and phytoplankton also suggested increasing PBDE concentrations over time. Trends of PBDEs in fur seal milk of individual seals sampled 1 or more years apart showed no clear temporal trends. Overall, there was no indication of PBDEs decreasing in Antarctic biota yet, whereas numerous studies have reported decreasing trends in the northern hemisphere. Similar PBDE concentrations in perinatal versus nonperinatal milk implied the importance of local PBDE sources for bioaccumulation. These results indicate the need for continued assessment of contaminant trends, such as PBDEs, and their replacements, in Antarctica.
Cohesive And Mixed Sediment In The Regional Ocean Modeling System (Roms V3.6) Implemented In The Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (Coawst R1234), Cr Sherwood, Al Aretxabaleta, Courtney K. Harris, Jp Rinehimer, R Verney, B Ferre
Cohesive And Mixed Sediment In The Regional Ocean Modeling System (Roms V3.6) Implemented In The Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (Coawst R1234), Cr Sherwood, Al Aretxabaleta, Courtney K. Harris, Jp Rinehimer, R Verney, B Ferre
VIMS Articles
We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean-Atmosphere-Wave- Sediment Transport Modeling System (COAWST Subversion repository revision 1234). These include the following: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing noncohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to …
The Competing Impacts Of Climate Change And Nutrient Reductions On Dissolved Oxygen In Chesapeake Bay, Id Irby, Marjorie A.M. Friedrichs, F Da, Ke Hinson
The Competing Impacts Of Climate Change And Nutrient Reductions On Dissolved Oxygen In Chesapeake Bay, Id Irby, Marjorie A.M. Friedrichs, F Da, Ke Hinson
VIMS Articles
The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea …
Assimilating Bio-Optical Glider Data During A Phytoplankton Bloom In The Southern Ross Sea, De Kaufman, Marjorie A.M. Friedrichs, Jcp Hemmings, Walker O. Smith Jr.
Assimilating Bio-Optical Glider Data During A Phytoplankton Bloom In The Southern Ross Sea, De Kaufman, Marjorie A.M. Friedrichs, Jcp Hemmings, Walker O. Smith Jr.
VIMS Articles
The Ross Sea is a region characterized by high primary productivity in comparison to other Antarctic coastal regions, and its productivity is marked by considerable variability both spatially (1-50 km) and temporally (days to weeks). This variability presents a challenge for inferring phytoplankton dynamics from observations that are limited in time or space, which is often the case due to logistical limitations of sampling. To better understand the spatio-temporal variability in Ross Sea phytoplankton dynamics and to determine how restricted sampling may skew dynamical interpretations, high-resolution bio-optical glider measurements were assimilated into a one-dimensional biogeochemical model adapted for the Ross …
Early-Holocene Greening Of The Afro-Asian Dust Belt Changed Sources Of Mineral Dust In West Asia, A Sharifi, Ln Murphy, A Pourmand, Ac Clement, Elizabeth A. Canuel
Early-Holocene Greening Of The Afro-Asian Dust Belt Changed Sources Of Mineral Dust In West Asia, A Sharifi, Ln Murphy, A Pourmand, Ac Clement, Elizabeth A. Canuel
VIMS Articles
Production, transport and deposition of mineral dust have significant impacts on different components of the Earth systems through time and space. In modern times, dust plumes are associated with their source region(s) using satellite and land -based measurements and trajectory analysis of air masses through time. Reconstruction of past changes in the sources of mineral dust as related to changes in climate, however, must rely on the knowledge of the geochemical and mineralogical composition of modern and paleodust, and that of their potential source origins. In this contribution, we present a 13,000-yr record of variations in radiogenic Sr-Nd-Hf isotopes and …
Assessing Water Quality Of The Chesapeake Bay By The Impact Of Sea Level Rise And Warming, P Wang, L Linker, Harry V. Wang, G Bhatt, G Yactayo, K Hinson, R Tian
Assessing Water Quality Of The Chesapeake Bay By The Impact Of Sea Level Rise And Warming, P Wang, L Linker, Harry V. Wang, G Bhatt, G Yactayo, K Hinson, R Tian
VIMS Articles
The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9 degrees C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase …
Ensemble Modeling Informs Hypoxia Management In The Northern Gulf Of Mexico, D Scavia, I Bertani, Dr Obenour, Re Turner, David R. Forrest, A Katin
Ensemble Modeling Informs Hypoxia Management In The Northern Gulf Of Mexico, D Scavia, I Bertani, Dr Obenour, Re Turner, David R. Forrest, A Katin
VIMS Articles
A large region of low-dissolved-oxygen bottom waters (hypoxia) forms nearly every summer in the northern Gulf of Mexico because of nutrient inputs from theMississippi River Basin andwater column stratification. Policymakers developed goals to reduce the area of hypoxic extent because of its ecological, economic, and commercial fisheries impacts. However, the goals remain elusive after 30 y of research and monitoring and 15 y of goal-setting and assessment because there has been little change in river nitrogen concentrations. An intergovernmental Task Force recently extended to 2035 the deadline for achieving the goal of a 5,000-km(2) 5-y average hypoxic zone and set …
Lateral Vegetation Growth Rates Exert Control On Coastal Foredune "Hummockiness" And Coalescing Time, Eb Goldstein, Lj Moore, Od Vinent
Lateral Vegetation Growth Rates Exert Control On Coastal Foredune "Hummockiness" And Coalescing Time, Eb Goldstein, Lj Moore, Od Vinent
VIMS Articles
Coastal foredunes form along sandy, low-sloped coastlines and range in shape from continuous dune ridges to hummocky features, which are characterized by alongshore-variable dune crest elevations. Initially scattered dune-building plants and species that grow slowly in the lateral direction have been implicated as a cause of foredune "hummockiness". Our goal in this work is to explore how the initial configuration of vegetation and vegetation growth characteristics control the development of hummocky coastal dunes including the maximum hummockiness of a given dune field. We find that given sufficient time and absent external forcing, hummocky foredunes coalesce to form continuous dune ridges. …
Chemical And Photophysiological Impact Of Terrestrially-Derived Dissolved Organic Matter On Nitrate Uptake In The Coastal Western Arctic, Rachel E. Sipler, Se Baer, Tl Connelly, Me Frischer, Qn Roberts, Pl Yager, Da Bronk
Chemical And Photophysiological Impact Of Terrestrially-Derived Dissolved Organic Matter On Nitrate Uptake In The Coastal Western Arctic, Rachel E. Sipler, Se Baer, Tl Connelly, Me Frischer, Qn Roberts, Pl Yager, Da Bronk
VIMS Articles
The Arctic is warming at a rate nearly twice the global average, leading to thawing permafrost, increased coastal erosion, and enhanced delivery of riverine terrestrially-derived dissolved organic matter (tDOM) to coastal waters. This humic-rich tDOM has the ability to attenuate light required for photosynthesis and stimulate heterotrophic growth by supplying a source of labile organic carbon. Due to tDOM's high carbon to nitrogen (C : N) ratio, additional nitrogen is required for microorganisms to utilize this excess carbon for growth, thus exacerbating competition between autotrophs and heterotrophs for limiting nutrients and potentially reducing primary production. The effect of Arctic tDOM …
Comparisons Of Different Instruments For Measuring Suspended Cohesive Sediment Concentrations, Yy Shao, Jpy Maa
Comparisons Of Different Instruments For Measuring Suspended Cohesive Sediment Concentrations, Yy Shao, Jpy Maa
VIMS Articles
Laboratory experiments were conducted to compare the performances of four different instruments for measuring suspended cohesive sediment concentrations (SSCs). Among these instruments, two were different models of optical backscatter sensor (i.e., OBS3+ and OBS5+), one was an acoustic Doppler velocimeter (MicroADV), and the last was a laser infrared optical sensor developed at Hohai University, China (HHU-LIOS). Sediments collected from the Yangtze River Estuary and a commercially available kaolinite were selected to check the responses of these four instruments. They were placed in an aqueous solution, and the SSCs were changed within a range from about 10 mg/L to 30 g/L …
Seamless Cross-Scale Modeling With Schism, Yinglong J. Zhang, Fei Ye, Ev Stanev, S Grashorn
Seamless Cross-Scale Modeling With Schism, Yinglong J. Zhang, Fei Ye, Ev Stanev, S Grashorn
VIMS Articles
We present a new 3D unstructured-grid model (SCHISM) which is an upgrade from an existing model (SELFE). The new advection scheme for the momentum equation includes an iterative smoother to reduce excess mass produced by higher-order kriging method, and a new viscosity formulation is shown to work robustly for generic unstructured grids and effectively filter out spurious modes without introducing excessive dissipation. A new higher-order implicit advection scheme for transport (TVD2) is proposed to effectively handle a wide range of Courant numbers as commonly found in typical cross-scale applications. The addition of quadrangular elements into the model, together with a …
Using Lidar Elevation Data To Develop A Topobathymetric Digital Elevation Model For Sub-Grid Inundation Modeling At Langley Research Center, Jon Derek Loftis, Harry V. Wang, Rj Deyoung, Wb Ball
Using Lidar Elevation Data To Develop A Topobathymetric Digital Elevation Model For Sub-Grid Inundation Modeling At Langley Research Center, Jon Derek Loftis, Harry V. Wang, Rj Deyoung, Wb Ball
VIMS Articles
Technological progression in light detection and ranging permits the production of highly detailed digital elevation models, which are useful in sub-grid hydrodynamic modeling applications. Sub-grid modeling technology is capable of incorporating these high-resolution lidar-derived elevation measurements into the conventional hydrodynamic modeling framework to resolve detailed topographic features for inclusion in a hydrological transport model for runoff simulations. The horizontal resolution and vertical accuracy of the digital elevation model is augmented via inclusion of these lidar elevation values on a nested 5-m sub-grid within each coarse computational grid cell. This aids in resolving ditches and overland drainage infrastructure at Langley Research …
Levels, Sources And Chemical Fate Of Persistent Organic Pollutants In The Atmosphere And Snow Along The Western Antarctic Peninsula, Ma Khairy, Jl Luek, R Dickhut, R Lohmann
Levels, Sources And Chemical Fate Of Persistent Organic Pollutants In The Atmosphere And Snow Along The Western Antarctic Peninsula, Ma Khairy, Jl Luek, R Dickhut, R Lohmann
VIMS Articles
The Antarctic continent is among the most pristine regions; yet various organic contaminants have been measured there routinely. Air and snow samples were collected during the austral spring (October November, 2010) along the western Antarctic Peninsula and analyzed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) to assess the relative importance of long-range transport versus local primary or secondary emissions. Highest concentrations of PCBs, PBDEs and DDTs were observed in the glacier's snow sample, highlighting the importance of melting glaciers as a possible secondary source of legacy pollutants to the Antarctic. In the atmosphere, contaminants were …
Water Residence Time In Chesapeake Bay For 1980-2012, Jb Du, Jian Shen
Water Residence Time In Chesapeake Bay For 1980-2012, Jb Du, Jian Shen
VIMS Articles
Concerns have grown over the increase of nutrients and pollutants discharged into the estuaries and coastal seas. The retention and export of these materials inside a system depends on the residence time (RT). A long-term simulation of time-varying RT of the Chesapeake Bay was conducted over the period from 1980 to 2012. The 33-year simulation results show that the mean RT of the entire Chesapeake Bay system ranges from 110 to 264 days, with an average value of 180 days. The RT was larger in the bottom layers than in the surface layers due to the persistent stratification and estuarine …
Complex Coastal Change In Response To Autogenic Basin Infilling: An Example From A Sub-Tropical Holocene Strandplain, Christopher J. Hein, Dm Fitzgerald, Lhp De Souza, Iy Georgiou, Iv Buynevich, Et Al.
Complex Coastal Change In Response To Autogenic Basin Infilling: An Example From A Sub-Tropical Holocene Strandplain, Christopher J. Hein, Dm Fitzgerald, Lhp De Souza, Iy Georgiou, Iv Buynevich, Et Al.
VIMS Articles
Thick bay-fill sequences that often culminate in strandplain development serve as important sedimentary archives of land-ocean interaction, although distinguishing between internal and external forcings is an ongoing challenge. This study employs sediment cores, ground-penetrating radar surveys, radiocarbon dates, palaeogeographic reconstructions and hydrodynamic modelling to explore the role of autogenic processes - notably a reduction in wave energy in response to coastal embayment infilling - in coastal evolution and shoreline morphodynamics. Following a regional 2 to 4m highstand at ca 58ka, the 75km(2) Tijucas Strandplain in southern Brazil built from fluvial sediments deposited into a semi-enclosed bay. Holocene regressive deposits are …
Unstructured-Grid Model For The North Sea And Baltic Sea: Validation Against Observations, Yinglong J. Zhang, Ev Stanev, S Grashorn
Unstructured-Grid Model For The North Sea And Baltic Sea: Validation Against Observations, Yinglong J. Zhang, Ev Stanev, S Grashorn
VIMS Articles
A new unstructured grid model and its application to the North Sea and Baltic Sea are described. The research focus is on the dynamics in the two basins and in the multiple straits connecting them and more specifically on how the model replicates the temporal and spatial variability of physical processes. The comparison against observed data indicates the realism in the simulations of the exchange flows. The simulations demonstrated that in contrast to the tidal variability which decreases in the strait, the role of the barotropic forcing due to weather systems increases. In this zone reversal of transport is well …
Overcoming Restoration Paradigms: Value Of The Historical Record And Metapopulation Dynamics In Native Oyster Restoration, Rom Lipcius, Russell P. Burke, Danielle N. Mcculloch, Sebastian J. Schreiber, David M. Schulte, Rochelle D. Seitz, Jian Shen
Overcoming Restoration Paradigms: Value Of The Historical Record And Metapopulation Dynamics In Native Oyster Restoration, Rom Lipcius, Russell P. Burke, Danielle N. Mcculloch, Sebastian J. Schreiber, David M. Schulte, Rochelle D. Seitz, Jian Shen
VIMS Articles
Restoration strategies for native oyster populations rely on multiple sources of information, which often conflict due to time- and space-varying patterns in abundance and distribution. For instance, strategies based on population connectivity and disease resistance can differ, and extant and historical records of abundance and distribution are often at odds, such that the optimal strategy is unclear and valuable restoration sites may be excluded from consideration. This was the case for the Lynnhaven River subestuary of lower Chesapeake Bay, which was deemed unsuitable for Eastern Oyster (Crassostrea virginica) restoration based on physical conditions, disease challenge, and extant oyster …
Source-Age Dynamics Of Estuarine Particulate Organic Matter Using Fatty Acid Delta C-13 And Delta C-14 Composition, Ha Mcintosh, Ap Mcnichol, L Xu, Elizabeth A. Canuel
Source-Age Dynamics Of Estuarine Particulate Organic Matter Using Fatty Acid Delta C-13 And Delta C-14 Composition, Ha Mcintosh, Ap Mcnichol, L Xu, Elizabeth A. Canuel
VIMS Articles
This study used a multiproxy approach to elucidate the source and age composition of estuarine particulate organic matter (POM) using bulk stable isotopes (C-13(POC)), fatty acid (FA) biomarkers, and compound specific isotopic analyses in surface waters along the Delaware River and Bay (Delaware Estuary, hereafter). C-13 values of FA (C-13(FA)) ranged more widely (-30.9 parts per thousand to -21.8 parts per thousand) than C-13(POC) (-27.5 parts per thousand to -23.5 parts per thousand), providing greater insight about POM sources along the estuary. C-13 values of C-16:0 phospholipid FA (primarily, aquatic sources) increased along the salinity gradient (-29.8 parts per thousand …
Image Processing Methods For In Situ Estimation Of Cohesive Sediment Floc Size, Settling Velocity, And Density, Sj Smith, Carl T. Friedrichs
Image Processing Methods For In Situ Estimation Of Cohesive Sediment Floc Size, Settling Velocity, And Density, Sj Smith, Carl T. Friedrichs
VIMS Articles
Recent advances in development of in situ video settling columns have significantly contributed toward fine-sediment dynamics research through concurrent measurement of suspended sediment floc size distributions and settling velocities, which together also allow inference of floc density. Along with image resolution and sizing, two additional challenges in video analysis from these devices are the automated tracking of settling particles and accounting for fluid motions within the settling column. A combination of particle tracking velocimetry (PTV) and particle image velocimetry (PIV) image analysis techniques is described, which permits general automation of image analysis collected from video settling columns. In the fixed …
Iron Supply And Demand In An Antarctic Shelf Ecosystem, Dj Mcgillicuddy, Pn Sedwick, Ms Dinniman, Kr Arrigo, Ts Bibby, Bjw Greenan, Ee Hofmann, Jm Klinck, Walker O. Smith Jr., Sl Mack, Cm Marsay, Bm Sohst, Gl Van Dijken
Iron Supply And Demand In An Antarctic Shelf Ecosystem, Dj Mcgillicuddy, Pn Sedwick, Ms Dinniman, Kr Arrigo, Ts Bibby, Bjw Greenan, Ee Hofmann, Jm Klinck, Walker O. Smith Jr., Sl Mack, Cm Marsay, Bm Sohst, Gl Van Dijken
VIMS Articles
The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …