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Biophysical Controls Of Marsh Soil Shear Strength Along An Estuarine Salinity Gradient, Megan N. Gillen, Tyler C. Messerschmidt, Matthew L. Kirwan Jan 2021

Biophysical Controls Of Marsh Soil Shear Strength Along An Estuarine Salinity Gradient, Megan N. Gillen, Tyler C. Messerschmidt, Matthew L. Kirwan

VIMS Articles

Sea-level rise, saltwater intrusion, and wave erosion threaten coastal marshes, but the influence of salinity on marsh erodibility remains poorly understood. We measured the shear strength of marsh soils along a salinity and biodiversity gradient in the York River estuary in Virginia to assess the direct and indirect im-pacts of salinity on potential marsh erodibility. We found that soil shear strength was higher in monospecific salt marshes (5–36 kPa) than in biodiverse freshwater marshes (4–8 kPa), likely driven by differences in below ground biomass. However, we also found that shear strength at the marsh edge was controlled by sediment characteristics, …


On The Human Appropriation Of Wetland Primary Production, James E. Cloern, Samuel M. Safran, Lydia Smith Vaughn, (...), Elizabeth A. Canuel, J.Letitia Grenier Jan 2021

On The Human Appropriation Of Wetland Primary Production, James E. Cloern, Samuel M. Safran, Lydia Smith Vaughn, (...), Elizabeth A. Canuel, J.Letitia Grenier

VIMS Articles

Humans are changing the Earth's surface at an accelerating pace, with significant consequences for ecosystems and their biodiversity. Landscape transformation has far-reaching implications including reduced net primary production (NPP) available to support ecosystems, reduced energy supplies to consumers, and disruption of ecosystem services such as carbon storage. Anthropogenic activities have reduced global NPP available to terrestrial ecosystems by nearly 25%, but the loss of NPP from wetland ecosystems is unknown. We used a simple approach to estimate aquatic NPP from measured habitat areas and habitat-specific areal productivity in the largest wetland complex on the USA west coast, comparing historical and …


Diatom Hotspots Driven By Western Boundary Current Instability, Hilde Oliver, Weifeng G. Zhang, Walker O. Smith Jr., Et Al Jan 2021

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

VIMS Articles

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


Onset Of Runaway Fragmentation Of Salt Marshes, Orencio Duran Vinent, Ellen R. Herbert, Daniel J. Coleman, Joshua D. Himmelstein, Matthew L. Kirwan Jan 2021

Onset Of Runaway Fragmentation Of Salt Marshes, Orencio Duran Vinent, Ellen R. Herbert, Daniel J. Coleman, Joshua D. Himmelstein, Matthew L. Kirwan

VIMS Articles

Salt marshes are valuable but vulnerable coastal ecosystems that adapt to relative sea level rise (RSLR) by accumulating organic matter and inorganic sediment. The natural limit of these processes defines a threshold rate of RSLR beyond which marshes drown, resulting in ponding and conversion to open waters. We develop a simplified formulation for sediment transport across marshes to show that pond formation leads to runaway marsh fragmentation, a process characterized by a self-similar hierarchy of pond sizes with power-law distributions. We find the threshold for marsh fragmentation scales primarily with tidal range and that sediment supply is only relevant where …


Long-Term Trends In Chesapeake Bay Remote Sensing Reflectance: Implications For Water Clarity, Jessica S. Turner, Carl T. Friedrichs, Marjorie A.M. Friedrichs Jan 2021

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

VIMS Articles

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


Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan Jan 2021

Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan

VIMS Articles

The impacts of climate change on ecosystems are manifested in how organisms respond to episodic and continuous stressors. The conversion of coastal forests to salt marshes represents a prominent example of ecosystem state change, driven by the continuous stress of sea-level rise (press), and episodic storms (pulse). Here, we measured the rooting dimension and fall direction of 143 windthrown eastern red cedar (Juniperus virginiana) trees in a rapidly retreating coastal forest in Chesapeake Bay (USA). We found that tree roots were distributed asymmetrically away from the leading edge of soil salinization and towards freshwater sources. The length, number, …


Experimental Tree Mortality Does Not Induce Marsh Transgression In A Chesapeake Bay Low-Lying Coastal Forest, David C. Walters, Joel A. Carr, (...), Matthew L. Kirwan, Et Al Jan 2021

Experimental Tree Mortality Does Not Induce Marsh Transgression In A Chesapeake Bay Low-Lying Coastal Forest, David C. Walters, Joel A. Carr, (...), Matthew L. Kirwan, Et Al

VIMS Articles

Transgression into adjacent uplands is an important global response of coastal wetlands to accelerated rates of sea level rise. “Ghost forests” mark a signature characteristic of marsh transgression on the landscape, as changes in tidal inundation and salinity cause bordering upland tree mortality, increase light availability, and the emergence of tidal marsh species due to reduced competition. To investigate these mechanisms of the marsh migration process, we conducted a field experiment to simulate a natural disturbance event (e.g., storm-induced flooding) by inducing the death of established trees (coastal loblolly pine, Pinus taeda) at the marsh-upland forest ecotone. After this simulated …


Sea Ice Suppression Of Co2 Outgassing In The West Antarctic Peninsula: Implications For The Evolving Southern Ocean Carbon Sink, E.H. Shadwick, O.A. De Meo, S. Schroeter, M.C. Arroyo, D.G. Martinson, H. Ducklow Jan 2021

Sea Ice Suppression Of Co2 Outgassing In The West Antarctic Peninsula: Implications For The Evolving Southern Ocean Carbon Sink, E.H. Shadwick, O.A. De Meo, S. Schroeter, M.C. Arroyo, D.G. Martinson, H. Ducklow

VIMS Articles

The Southern Ocean plays an important role in the uptake of atmospheric CO2. In seasonally ice-covered regions, estimates of air-sea exchange remain uncertain in part because of a lack of observations outside the summer season. Here we present new estimates of air-sea CO2 flux in the West Antarctic Peninsula (WAP) from an autonomous mooring on the continental shelf. In summer, the WAP is a sink for atmospheric CO2 followed by a slow return to atmospheric equilibrium in autumn and winter. Outgassing is almost entirely suppressed by ice cover from June through October, resulting in a modest …


Sea Level-Driven Marsh Migration Results In Rapid Net Loss Of Carbon, Alexander J. Smith, Matthew L. Kirwan Jan 2021

Sea Level-Driven Marsh Migration Results In Rapid Net Loss Of Carbon, Alexander J. Smith, Matthew L. Kirwan

VIMS Articles

Sea level rise alters coastal carbon cycling by driving the rapid migration of coastal ecosystems, salinization of freshwater systems, and replacement of terrestrial forests with tidal wetlands. Wetland soils accumulate carbon (C) at faster rates than terrestrial soils, implying that sea level rise may lead to enhanced carbon accumulation. Here, we show that carbon stored in tree biomass greatly exceeds carbon stored in adjacent marsh soils so that marsh migration reduces total carbon stocks by 50% in less than 100years. Continued marsh soil carbon accumulation may eventually offset forest carbon loss, but we estimate that the time for replacement is …


Sea-Ice Microbial Communities In The Central Arctic Ocean: Limited Responses To Short-Term Pco(2) Perturbations, Anders Torstensson, Andrew R. Margolin, Gordon M. Showalter, Walker O. Smith Jr., Elizabeth H. Shadwick, Et Al Jan 2021

Sea-Ice Microbial Communities In The Central Arctic Ocean: Limited Responses To Short-Term Pco(2) Perturbations, Anders Torstensson, Andrew R. Margolin, Gordon M. Showalter, Walker O. Smith Jr., Elizabeth H. Shadwick, Et Al

VIMS Articles

The Arctic Ocean is more susceptible to ocean acidification than other marine environments due to its weaker buffering capacity, while its cold surface water with relatively low salinity promotes atmospheric CO 2 uptake. We studied how sea-ice microbial communities in the central Arctic Ocean may be affected by changes in the carbonate system expected as a consequence of ocean acidification. In a series of four experiments during late summer 2018 aboard the icebreaker Oden, we addressed microbial growth, production of dissolved organic carbon (DOC) and extra- cellular polymeric substances (EPS), photosynthetic activity, and bacterial assemblage structure as sea-ice microbial communities …


The Importance Of Organic Content To Fractal Floc Properties In Estuarine Surface Waters: Insights From Video, Lisst, And Pump Sampling, Kelsey A. Fall, Carl T. Friedrichs, Grace M. Massey, David G. Bowers, S. Jarrell Smith Jan 2021

The Importance Of Organic Content To Fractal Floc Properties In Estuarine Surface Waters: Insights From Video, Lisst, And Pump Sampling, Kelsey A. Fall, Carl T. Friedrichs, Grace M. Massey, David G. Bowers, S. Jarrell Smith

VIMS Articles

To better understand the nature of flocs of varying organic content in estuarine surface waters, Laser in situ Scattering and Transmissometry, video settling, and pump sampling were deployed in the York River estuary. A new in situ method was developed to simultaneously solve the floc fractal dimension (F), primary particle size (d p ), and primary particle density (ρ p ) by fitting a simple fractal model to observations of effective floc density (∆ρ) as a function of floc diameter (d f ), while ensuring that the integrated particle size distribution was consistent with measurements of bulk apparent density (ρ …


Exchange Flow And Material Transport Along The Salinity Gradient Of A Long Estuary, Jilian Xiong, Jian Shen, Qubin Qin Jan 2021

Exchange Flow And Material Transport Along The Salinity Gradient Of A Long Estuary, Jilian Xiong, Jian Shen, Qubin Qin

VIMS Articles

Most estuaries are characterized by non-uniform axial topography with shallow shoals near the mouth. Previous studies have addressed the impacts of the axial topographic variations on mixing and estuarine circulations yet seldom on material transport and retention. This study investigates the longitudinal structure and mechanisms of exchange flow and material transport of Chesapeake Bay (CB), featuring a shallow sill in the lower bay, by applying total exchange flow (TEF) algorithm, tracer experiments, and partial residence time (PRT) using a validated 32-years numerical model simulation. A retention coefficient was adopted to quantify the material retention rate using two characteristic PRTs: with …


Global Blue Carbon Accumulation In Tidal Wetlands Increases With Climate Change, Faming Wang, Christian J. Sanders, (...), Matthew L. Kirwan, Et Al Jan 2021

Global Blue Carbon Accumulation In Tidal Wetlands Increases With Climate Change, Faming Wang, Christian J. Sanders, (...), Matthew L. Kirwan, Et Al

VIMS Articles

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52–59.01) Tg C yr−1, which is∼30% of the organic C buried on the …


A Modeling Study On The Influence Of Sea-Level Rise And Channel Deepening On Estuarine Circulation And Dissolved Oxygen Levels In The Tidal James River, Virginia, Usa, Ya Wang, Jian Shen Nov 2020

A Modeling Study On The Influence Of Sea-Level Rise And Channel Deepening On Estuarine Circulation And Dissolved Oxygen Levels In The Tidal James River, Virginia, Usa, Ya Wang, Jian Shen

VIMS Articles

The impact of channel deepening and sea-level rise on the environmental integrity of an estuary is investigated using a three-dimensional hydrodynamic-eutrophication model. The model results show that dissolved oxygen (DO) only experienced minor changes, even when the deep channel was deepened by 3 m in the mesohaline and polyhaline regions of the James River. We found that vertical stratification decreased DO aeration while the estuarine gravitational circulation increased bottom DO exchange. The interactions between these two processes play an important role in modulating DO. The minor change in DO due to channel deepening indicates that the James River is unique …


A Database Of Ocean Primary Productivity From The 14c Method, J. F. Marra, R. T. Barber, (...), Walker O. Smith Jr., L. Zoffli Nov 2020

A Database Of Ocean Primary Productivity From The 14c Method, J. F. Marra, R. T. Barber, (...), Walker O. Smith Jr., L. Zoffli

VIMS Articles

The database on ocean primary productivity comprises over two decades (1985–2008) of data that the authors have participated in collecting, using the assimilation of inorganic 14C through photosynthesis, in incubations carried out in situ. The dataset is perhaps unique in that it uses, overwhelmingly, consistent methodology while covering a wide geographic range. Ancillary data are included. Using the database, it is hoped that investigators can test for the relationships among the environmental drivers for ocean productivity, the meaning of the 14C method in terms of phytoplankton physiology and the dynamics in the water column, and as a resource …


Ocean_Data_Tools: A Matlab Toolbox For Interacting With Bulk Freely-Available Oceanographic Data, Laur Ferris Oct 2020

Ocean_Data_Tools: A Matlab Toolbox For Interacting With Bulk Freely-Available Oceanographic Data, Laur Ferris

VIMS Articles

ocean_data_tools simplifies the process of extracting, formatting, and visualizing freely-available oceanographic data. A wealth of oceanographic data (from research cruises, autonomous floats, global ocean models, etc.) is accessible online. However, many oceanographers and environmental scientists (particularly those from subdisciplines not accustomed to working with large datasets) can be dissuaded from utilizing this data because of the overhead associated with determining how to batch download data and format it into easily-manipulable data structures. ocean_data_tools solves this problem by allowing the user to transform common oceanographic data sources into uniform structure arrays, call general functions on these structure arrays, perform custom calculations, …


Climate-Induced Variability In South Atlantic Wave Direction Over The Past Three Millennia, A. P. Silva, A. H. F. Klein, A. F. H. Fetter-Filho, Christopher J. Hein, Et Al Oct 2020

Climate-Induced Variability In South Atlantic Wave Direction Over The Past Three Millennia, A. P. Silva, A. H. F. Klein, A. F. H. Fetter-Filho, Christopher J. Hein, Et Al

VIMS Articles

Through alteration of wave-generating atmospheric systems, global climate changes play a fundamental role in regional wave climate. However, long-term wave-climate cycles and their associated forcing mechanisms remain poorly constrained, in part due to a relative dearth of highly resolved archives. Here we use the morphology of former shorelines preserved in beach-foredune ridges (BFR) within a protected embayment to reconstruct changes in predominant wave directions in the Subtropical South Atlantic during the last ~ 3000 years. These analyses reveal multi-centennial cycles of oscillation in predominant wave direction in accordance with stronger (weaker) South Atlantic mid- to high-latitudes mean sea-level pressure gradient …


How Old Are Marshes On The East Coast, Usa? Complex Patterns In Wetland Age Within And Among Regions, Anna E. Braswell, James B. Heffernan, Matthew L. Kirwan Oct 2020

How Old Are Marshes On The East Coast, Usa? Complex Patterns In Wetland Age Within And Among Regions, Anna E. Braswell, James B. Heffernan, Matthew L. Kirwan

VIMS Articles

Sea‐level dynamics, sediment availability, and marine energy are critical drivers of coastal wetland formation and persistence, but their roles as continental‐scale drivers remain unknown. We evaluated the timing and spatial variability of wetland formation from new and existing cores collected along the Atlantic and Gulf coasts of the United States. Most basal peat ages occurred after sea‐level rise slowed (after ~4,000 years before present), but predominance of sea‐level rise studies may skew age estimates toward older sites. Near‐coastal sites tended to be younger, indicating creation of wetlands through basin infilling and overwash events. Age distributions differed among regions, with younger …


A Continental Shelf Pump For Co2 On The Adélie Land Coast, East Antarctica, Mar C. Arroyo, Elizabeth H. Shadwick, Stephen R. Rintoul, Kazuya Kusahara Oct 2020

A Continental Shelf Pump For Co2 On The Adélie Land Coast, East Antarctica, Mar C. Arroyo, Elizabeth H. Shadwick, Stephen R. Rintoul, Kazuya Kusahara

VIMS Articles

We quantify the transport of inorganic carbon from the continental shelf to the deep ocean in Dense Shelf Water (DSW) from the Mertz and Ninnis Polynyas along the Adélie Land coast in East Antarctica. For this purpose, observations of total dissolved inorganic carbon (TCO2) from two summer hydrographic surveys in 2015 and 2017 were paired with DSW volume transport estimates derived from a coupled ocean‐sea ice‐ice shelf model to examine the fate of inorganic carbon in DSW from Adélie Land. Transports indicate a net outflow of 227 ± 115 Tg C yr−1 with DSW in the postglacial …


Estuarine Forecasts At Daily Weather To Subseasonal Time Scales, Andrew C. Ross, Charles A. Stock, Keith W. Dixon, Marjorie A.M. Friedrichs, Et Al Oct 2020

Estuarine Forecasts At Daily Weather To Subseasonal Time Scales, Andrew C. Ross, Charles A. Stock, Keith W. Dixon, Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Most present forecast systems for estuaries predict conditions for only a few days into the future. However, there are many reasons to expect that skillful estuarine forecasts are possible for longer time periods, including increasingly skillful extended atmospheric forecasts, the potential for lasting impacts of atmospheric forcing on estuarine conditions, and the predictability of tidal cycles. In this study, we test whether skillful estuarine forecasts are possible for up to 35 days into the future by combining an estuarine model of Chesapeake Bay with 35-day atmospheric forecasts from an operational weather model. When compared with both a hindcast simulation from …


Coastal Marsh Degradation Into Ponds Induces Irreversible Elevation Loss Relative To Sea Level In A Microtidal System, Lennert Schepers, Patrick Brennand, Matthew L. Kirwan, Glenn Guntenspergen, Stijn Temmerman Sep 2020

Coastal Marsh Degradation Into Ponds Induces Irreversible Elevation Loss Relative To Sea Level In A Microtidal System, Lennert Schepers, Patrick Brennand, Matthew L. Kirwan, Glenn Guntenspergen, Stijn Temmerman

VIMS Articles

Coastal marshes and their valuable ecosystem services are feared to be lost by sea level rise, yet the mechanisms of marsh degradation into ponds and potential recovery are poorly understood. We quantified and analyzed elevations of marsh surfaces and pond bottoms along a marsh loss gradient (Blackwater River, Maryland, USA). Our analyses show that ponds deepen with increasing tidal channel width connecting the ponds to the river, indicating a new feedback mechanism where channels lead to enhanced tidal export of pond bottom material. Pond elevations also decrease with increasing pond size, consistent with previous work identifying a positive feedback between …


Modeling Marsh‐Forest Boundary Transgression In Response To Storms And Sea‐Level Rise, J. Carr, G. Guntenspergen, Matthew L. Kirwan Sep 2020

Modeling Marsh‐Forest Boundary Transgression In Response To Storms And Sea‐Level Rise, J. Carr, G. Guntenspergen, Matthew L. Kirwan

VIMS Articles

The lateral extent and vertical stability of salt marshes experiencing rising sea levels depend on interacting drivers and feedbacks with potential for nonlinear behaviors. A two‐dimensional transect model was developed to examine changes in marsh and upland forest lateral extent and to explore controls on marsh inland transgression. Model behavior demonstrates limited and abrupt forest retreat with long‐term upland boundary migration rates controlled by slope, sea‐level rise (SLR), high water events, and biotic‐abiotic interactions. For low to moderate upland slopes the landward marsh edge is controlled by the interaction of these inundation events and forest recovery resulting in punctuated transgressive …


A Machine‐Learning‐Based Model For Water Quality In Coastal Waters, Taking Dissolved Oxygen And Hypoxia In Chesapeake Bay As An Example, Xin Yu, Jian Shen, Jiabi Du Aug 2020

A Machine‐Learning‐Based Model For Water Quality In Coastal Waters, Taking Dissolved Oxygen And Hypoxia In Chesapeake Bay As An Example, Xin Yu, Jian Shen, Jiabi Du

VIMS Articles

Hypoxia is a big concern in coastal waters as it affects ecosystem health, fishery yield, and marine water resources. Accurately modeling coastal hypoxia is still very challenging even with the most advanced numerical models. A data‐driven model for coastal water quality is proposed in this study and is applied to predict the temporal‐spatial variations of dissolved oxygen (DO) and hypoxic condition in Chesapeake Bay, the largest estuary in the United States with mean summer hypoxic zone extending about 150 km along its main axis. The proposed model has three major components including empirical orthogonal functions analysis, automatic selection of forcing …


Data-Driven, Multi-Model Workflow Suggests Strong Influence From Hurricanes On The Generation Of Turbidity Currents In The Gulf Of Mexico, Courtney K. Harris, Jaia Syvitski, H. G. Arango, Et Al Aug 2020

Data-Driven, Multi-Model Workflow Suggests Strong Influence From Hurricanes On The Generation Of Turbidity Currents In The Gulf Of Mexico, Courtney K. Harris, Jaia Syvitski, H. G. Arango, Et Al

VIMS Articles

Turbidity currents deliver sediment rapidly from the continental shelf to the slope and beyond; and can be triggered by processes such as shelf resuspension during oceanic storms; mass failure of slope deposits due to sediment- and wave-pressure loadings; and localized events that grow into sustained currents via self-amplifying ignition. Because these operate over multiple spatial and temporal scales, ranging from the eddy-scale to continental-scale; coupled numerical models that represent the full transport pathway have proved elusive though individual models have been developed to describe each of these processes. Toward a more holistic tool, a numerical workflow was developed to address …


Sediment Delivery To A Tidal Marsh Platform Is Minimized By Source Decoupling And Flux Convergence, Daniel J. Coleman, Neil K. Ganju, Matthew L. Kirwan Jul 2020

Sediment Delivery To A Tidal Marsh Platform Is Minimized By Source Decoupling And Flux Convergence, Daniel J. Coleman, Neil K. Ganju, Matthew L. Kirwan

VIMS Articles

Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. However, understanding sediment transport across the marsh itself remains limited by discontinuous measurements of SSC over individual tidal cycles. Here, we use an array of optical turbidity sensors to build a long‐term, continuous record of SSC across a marsh platform and adjacent tidal channel. We find that channel and marsh concentrations are correlated (i.e., coupled) within tidal cycles but are largely decoupled over longer time scales. We also find that …


The Impact Of Winter Storms On Sediment Transport Through A Narrow Strait, Bohai, China, Chenghao Wang, Zhiqiang Liu, Courtney K. Harris, Et Al May 2020

The Impact Of Winter Storms On Sediment Transport Through A Narrow Strait, Bohai, China, Chenghao Wang, Zhiqiang Liu, Courtney K. Harris, Et Al

VIMS Articles

The Yellow River is one of the most significant sources of terrestrial sediment to the global seas, and the Bohai Strait is the only pathway that delivers Yellow River‐derived sediments from the shallow Bohai Sea to the Yellow Sea. To investigate sediment transport processes through the strait under the influence of storms (strong northerly winds) that frequently occur in winter, we deployed two sets of observing platforms equipped with Acoustic Doppler Current Profilers (ADCP) and a suite of other sensors in the strait in January 2018. Aided by a system of high‐resolution models, we reconstructed sediment dynamics in response to …


Representing The Function And Sensitivity Of Coastal Interfaces In Earth System Models, Nd Ward, Jp Megonigal, B Bond-Lamberty, Vl Bailey, D Butman, Elizabeth A. Canuel, Et Al May 2020

Representing The Function And Sensitivity Of Coastal Interfaces In Earth System Models, Nd Ward, Jp Megonigal, B Bond-Lamberty, Vl Bailey, D Butman, Elizabeth A. Canuel, Et Al

VIMS Articles

Between the land and ocean, diverse coastal ecosystems transform, store, and transport material. Across these interfaces, the dynamic exchange of energy and matter is driven by hydrological and hydrodynamic processes such as river and groundwater discharge, tides, waves, and storms. These dynamics regulate ecosystem functions and Earth's climate, yet global models lack representation of coastal processes and related feedbacks, impeding their predictions of coastal and global responses to change. Here, we assess existing coastal monitoring networks and regional models, existing challenges in these efforts, and recommend a path towards development of global models that more robustly reflect the coastal interface. …


Providential Tides: The Double Low Water Of Narragansett Bay, D. G. Bowers, J. M. Brubaker May 2020

Providential Tides: The Double Low Water Of Narragansett Bay, D. G. Bowers, J. M. Brubaker

VIMS Articles

We investigate a mechanism for producing double-lows and double-highs in the semi-diurnal tide by selective amplification of higher harmonics in a resonant gulf. A double low water is observed at Providence, RI, near the head of Narragansett Bay on days when there is a flattening of the low water tidal curve at Newport, at the mouth of the bay. The flattening is caused by an unusually large quarter-diurnal component to the tide at Newport. The quarter diurnal component has the right phase (a maximum close to the time of the minimum in the semi-diurnal tide) to produce a prolonged flattening …


Massive Pollutants Released To Galveston Bay During Hurricane Harvey: Understanding Their Retention And Pathway Using Lagrangian Numerical Simulations, Jiabi Du, Kyeong Park, Xin Yu, Yinglong J. Zhang, Fei Ye Feb 2020

Massive Pollutants Released To Galveston Bay During Hurricane Harvey: Understanding Their Retention And Pathway Using Lagrangian Numerical Simulations, Jiabi Du, Kyeong Park, Xin Yu, Yinglong J. Zhang, Fei Ye

VIMS Articles

Increasing frequency of extreme precipitation events under the future warming climate makes the storm-related pollutant release more and more threatening to coastal ecosystems. Hurricane Harvey, a 1000-year extreme precipitation event, caused massive pollutant release from the Houston metropolitan area to the adjacent Galveston Bay. 0.57 × 106 tons of raw sewage and 22,000 barrels of oil, refined fuels and chemicals were reportly released during Harvey, which would likely deteriorate the water quality and damage the coastal ecosystem. Using a Lagrangian particle-tracking method coupled with a validated 3D hydrodynamic model, we examined the retention, pathway, and fate of the released …


Response Of Stratification Processes To Tidal Current Alteration Due To Channel Narrowing And Deepening, Lei Zhu, Qing He, Jian Shen Feb 2020

Response Of Stratification Processes To Tidal Current Alteration Due To Channel Narrowing And Deepening, Lei Zhu, Qing He, Jian Shen

VIMS Articles

Stratification in estuaries has received much focus due to its importance in estuarine hydrodynamics and material transport. By utilizing a well‐calibrated numerical model, in this work we investigate the changes in stratification in the deepened and narrowed North Passage of the Changjiang Estuary. Before channel narrowing and deepening, lateral straining, generated by the interaction between vertical shear in lateral flow and transverse salinity gradient, is the dominant factor that controls stratification. A two‐layer structure of the lateral flow strains the isopycnal transversely, resulting in rapid stratification from late flood to early ebb tide. Thus, maximum stratification occurs during the early …