Physical Sciences and Mathematics Commons^™

The Importance Of Antarctic Krill In Biogeochemical Cycles, El Cavan, A Belcher, Sl Hill, S Kawaguchi, S Mccormack, B Meyer, S Nicol, K Schmidt, Deborah K. Steinberg, Ga Tarling, Pw Boyd

VIMS Articles

Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins – but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean’s largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval …

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 …

Impacts Of Sea Level Rise On Hypoxia In The Chesapeake Bay: A Model Intercomparison, Pierre St-Laurent, Marjorie A.M. Friedrichs, Ming Li, Wenfei Ni

Reports

Over recent years a number of studies have examined the effects of sea level rise (SLR) on hypoxia in Chesapeake Bay. However, variations in the methodology, the years considered, and the metrics reported made comparisons between these studies difficult. To clarify the effects of SLR on the Bay’s hypoxia, we present an intercomparison between four numerical models following a common methodology. The models share the riverine fluxes, baseline period (1991–1995), and consider the same three scenarios of SLR: an increase in sea level of 0.17m, 0.50m, and 1.00m (representative of years 2025, 2050 and 2100, respectively). SLR is the sole …

James River Water Quality Model Refinement And Scenario Simulations, Jian Shen, Qubin Qin

Reports

This project was part of the Virginia Department of Environmental Quality’s (DEQ) study to evaluate the protectiveness of chlorophyll criteria and consider potential criteria revisions, along with implications for the James River portion of the Chesapeake Bay TMDL.

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 …

The Floodwater Depth Estimation Tool (Fwdet V2.0) For Improved Remote Sensing Analysis Of Coastal Flooding, S Cohen, A Raney, D Munasinghe, Jon Derek Loftis, Et Al

VIMS Articles

Remote sensing analysis is routinely used to map flooding extent either retrospectively or in near-real time. For flood emergency response, remote-sensing-based flood mapping is highly valuable as it can offer continued observational information about the flood extent over large geographical domains. Information about the floodwater depth across the inundated domain is important for damage assessment, rescue, and prioritizing of relief resource allocation, but cannot be readily estimated from remote sensing analysis. The Floodwater Depth Estimation Tool (FwDET) was developed to augment remote sensing analysis by calculating water depth based solely on an inundation map with an associated digital elevation model …

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 …

It’S About Time: A Synthesis Of Changing Phenology In The Gulf Of Maine Ecosystem, Md Staudinger, Ke Mills, Et Al, David S. Johnson, Et Al

VIMS Articles

The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological-human systems; and (d) potential phenology-focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events. The most common response was earlier timing, …

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 …

Collaborative Science To Enhance Coastal Resilience And Adaptation, C. Reid Nichols, Lynn Wright, Arthur Cosby, Alain Henaff, Jon Derek Loftis, Et Al

VIMS Articles

Impacts from natural and anthropogenic coastal hazards are substantial and increasing significantly with climate change. Coasts and coastal communities are increasingly at risk. In addition to short-term events, long-term changes, including rising sea levels, increasing storm intensity, and consequent severe compound flooding events are degrading coastal ecosystems and threatening coastal dwellers. Consequently, people living near the coast require environmental intelligence in the form of reliable short-term and long-term predictions in order to anticipate, prepare for, adapt to, resist, and recover from hazards. Risk-informed decision making is crucial, but for the resulting information to be actionable, it must be effectively and …

Treading Water: Tools To Help Us Coastal Communities Plan For Sea Level Rise Impacts, E A. Smith, W Sweet, Molly Mitchell, R Domingues, C P. Weaver, M Baringer, G Goni, J Haines, Jon Derek Loftis, John D. Boon, David L. Malmquist

VIMS Articles

As communities grapple with rising seas and more frequent flooding events, they need improved projections of future rising and flooding over multiple time horizons, to assist in a multitude of planning efforts. There are currently a few different tools available that communities can use to plan, including the Sea Level Report Card and products generated by a United States. Federal interagency task force on sea level rise. These tools are a start, but it is recognized that they are not necessarily enough at present to provide communities with the type of information needed to support decisions that range from seasonal …

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 …

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 …

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 …

Modeling Iron And Light Controls On The Summer Phaeocystis Antarctica Bloom In The Amundsen Sea Polynya, H Oliver, Pierre St-Laurent, Rm Sherrell, Pl Yager

VIMS Articles

Of all the Antarctic coastal polynyas, the Amundsen Sea Polynya is the most productive per unit area. Observations from the 2010–2011 Amundsen Sea Polynya International Research Expedition (ASPIRE) revealed that both light and iron can limit the growth of phytoplankton (Phaeocystis antarctica), but how these controls manifest over the bloom season is poorly understood, especially with respect to their climate sensitivity. Using a 1‐D biogeochemical model, we examine the influence of light and iron limitation on the phytoplankton bloom and vertical carbon flux at 12 stations representing different bloom stages within the polynya. Model parameters are determined by …

Variability And Change In The West Antarctic Peninsula Marine System: Research Priorities And Opportunities, Sian F. Henley, Oscar M. Schofield, Katherine R. Hendry, Irene R. Schloss, Deborah K. Steinberg, Et Al

VIMS Articles

The west Antarctic Peninsula (WAP) region has undergone significant changes in temperature and seasonal ice dynamics since the mid-twentieth century, with strong impacts on the regional ecosystem, ocean chemistry and hydrographic properties. Changes to these long-term trends of warming and sea ice decline have been observed in the 21st century, but their consequences for ocean physics, chemistry and the ecology of the high-productivity shelf ecosystem are yet to be fully established. The WAP shelf is important for regional krill stocks and higher trophic levels, whilst the degree of variability and change in the physical environment and documented biological and biogeochemical …

Associated Dataset: Modeling The Seasonal Cycle Of Iron And Carbon Fluxes In The Amundsen Sea Polynya, Antarctica, Pierre St-Laurent

Data

This dataset features the results from the numerical simulation described in the associated publication (St-Laurent et al.). The simulation results are in the standard, self-documented NetCDF format (extension .nc); see https://www.unidata.ucar.edu/software/netcdf/ for more information. Files in this format can be manipulated and displayed by a wide range of freely available software. The results from the simulation are divided into monthly files (ocean_avg_0001.nc to ocean_avg_0098.nc). Each file holds 30 days worth of time-averaged daily model fields, from January 2006 to December 2013. The dataset also includes the forcings used in the model calculation (in the same format as above). Detailed information …

Modeling The Seasonal Cycle Of Iron And Carbon Fluxes In The Amundsen Sea Polynya, Antarctica, P. St-Laurent, Pl Yager, Rm Sherrell, H. Oliver, Ms Dinniman, Se Stammerjohn

VIMS Articles

The Amundsen Sea Polynya (ASP) is distinguished by having the highest net primary production per unit area in the coastal Antarctic. Recent studies have related this high productivity to the presence of fast-melting ice shelves, but the mechanisms involved are not well understood. In this study we describe the first numerical model of the ASP to represent explicitly the ocean-ice interactions, nitrogen and iron cycles, and the coastal circulation at high resolution. The study focuses on the seasonal cycle of iron and carbon, and the results are broadly consistent with field observations collected during the summer of 2010–2011. The simulated …

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 …

Impacts Of Physical Transport On Estuarine Phytoplankton Dynamics And Harmful Algal Blooms, Qubin Qin

Dissertations, Theses, and Masters Projects

The spatial and temporal variability of phytoplankton biomass in estuaries is determined by both local processes and transport processes. Local processes include biological processes (e.g., photosynthesis, respiration/excretion, and grazing) and settling, whereas transport processes include advective and diffusive transports. Transport processes have been demonstrated to regulate phytoplankton dynamics significantly by distributing both phytoplankton and other dissolved and particulate substances (e.g., nutrients, salts, sediments, and chromophoric dissolved organic matter). Yet, these transport properties lack a framework that unifies the pieced description of their various effects, and quantification of their importance under various environmental conditions. This dissertation highlights the role of horizontal …

2019 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2019 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2019 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

2019 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

Simulating Storm Surge And Compound Flooding Events With A Creek-To-Ocean Model: Importance Of Baroclinic Effects : Model Files, Fei Ye, Yinglong J. Zhang, Haocheng Yu, Weiling Sun, Saeed Moghimi, Edward Myers, Karinna Nunez, Ruoyin Zhang, Harry V. Wang, Aron Roland, Kevin Martins, Xavier Bertin, Jiabi Du, Zhou Liu

Data

The supplemental material contains the input files for setting up a 3D baroclinic model based on the Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM), supplementing the description of model setup in Ye et al. (2019; associated publication).

The SCHISM version used for the simulation was r5082 in the SCHISM svn repository. A compressed file (setup.tar.gz) is provided, which can be extracted with common zip/unzip software on Unix/Windows/Mac (such as gzip, winzip, 7-zip, etc.). Since the dataset is intended for conducting a SCHISM simulation, readers/users should familiarize themselves with the SCHISM model system first.

The SCHISM manual is at: http://ccrm.vims.edu/schismweb/schism_manual.html; …

High-Frequency Co2-System Observations From A Moored Sensor In The York River, Elizabeth H. Shadwick, Olivia A. De Meo

Data

These are CO₂-system data from a moored sensor in the York River, a tributary of the Chesapeake Bay. Temperature, salinity and pH were acquired hourly over two deployments lasting several months. Sensor data were then averaged to 24-hour resolution. Data were calibrated with discrete dissolved inorganic carbon (TCO₂) and alkalinity samples analyzed at the Virginia Institute of Marine Science, following standard procedures. The pH sensor data were then combined with salinity data, and a relationship between alkalinity and salinity, to compute the remaining CO₂-system parameters (TCO₂, CO₂ partial pressure (pCO_{2 …}

Discrete Co2-System Measurements In The Chesapeake Bay Mainstem Between 2016 And 2018, Elizabeth H. Shadwick, Olivia A. De Meo, Jaclyn R. Friedman

Data

These are discrete observations of total dissolved inorganic carbon (DIC) and alkalinity (TA), and associated computed CO₂-system parameters, from samples collected throughout the Chesapeake Bay mainstem between 2016 and 2018. Samples were collected on board the R/V Kerhin in Maryland and the R/V Fay Slover in Virginia at a subset of fixed stations in collaboration with the Chesapeake Bay Water Quality Monitoring Program. Samples were analyzed following standard procedures at the Virginia Institute of Marine Science. The DIC and TA data were then used to compute the remaining CO₂-system parameters (pH, CO₂ partial pressure (pCO …

A Model Archive For Simulations In A Partially-Mixed Idealized Estuary Using The Coawst System: Model Code And Output, Danielle R.N. Tarpley, Courtney K. Harris, Carl Friedrichs

Data

This dataset includes model input, code and output used in the publication Tarpley et al. (2019, Journal of Marine Science and Engineering), which used a coupled hydrodynamic-sediment transport model to investigate the roles of flocculation, bed consolidation and sediment-induced stratification on changes in fine-grained sediment distribution in an idealized estuarine model. The modeling system used in the development was the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) framework.

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 …

Alkalinity In Tidal Tributaries Of The Chesapeake Bay, R. G. Najjar, M. Herrmann, S. M. Cintrón Del Valle, Jaclyn R. Friedman, Marjorie A.M. Friedrichs, Et Al

VIMS Articles

Despite the important role of alkalinity in estuarine carbon cycling, the seasonal and decadal variability of alkalinity, particularly within multiple tidal tributaries of the same estuary, is poorly understood. Here we analyze more than 25,000 alkalinity measurements, mostly from the 1980s and 1990s,in the major tidal tributaries of the Chesapeake Bay, a large, coastal‐plain estuary of eastern North America.The long‐term means of alkalinity in tidal‐fresh waters vary by a factor of 6 among seven tidal tributaries,reflecting the alkalinity of nontidal rivers draining to these estuaries. At 25 stations, mostly in the Potomac River Estuary, wefind significant long‐term increasing trends that …