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Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan
Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan
VIMS Articles
Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater …
Introduction To Special Section On The U.S. Ioos Coastal And Ocean Modeling Testbed, Richard A. Luettich Jr, L. Donelson Wright, Richard Signell, Carl T. Friedrichs, Marjorie A.M. Friedrichs, John Harding, Katja Fennel, Eoin Howlett, Sara Graves, Elizabeth Smith, Gary Crane, Rebecca Baltes
Introduction To Special Section On The U.S. Ioos Coastal And Ocean Modeling Testbed, Richard A. Luettich Jr, L. Donelson Wright, Richard Signell, Carl T. Friedrichs, Marjorie A.M. Friedrichs, John Harding, Katja Fennel, Eoin Howlett, Sara Graves, Elizabeth Smith, Gary Crane, Rebecca Baltes
VIMS Articles
Strong and strategic collaborations among experts from academia, federal operational centers, and industry have been forged to create a U.S. IOOS Coastal and Ocean Modeling Testbed (COMT). The COMT mission is to accelerate the transition of scientific and technical advances from the coastal and ocean modeling research community to improved operational ocean products and services. This is achieved via the evaluation of existing technology or the development of new technology depending on the status of technology within the research community. The initial phase of the COMT has addressed three coastal and ocean prediction challenges of great societal importance: estuarine hypoxia …
Us Ioos Coastal And Ocean Modeling Testbed: Inter-Model Evaluation Of Tides, Waves, And Hurricane Surge In The Gulf Of Mexico, Pc Kerr, As Donahue, Jj Westerliink, Ra Luettich, Ly Zheng, Rh Weisberg, Y Huang, Harry V. Wang, Y Teng, David R. Forrest, Et Al
Us Ioos Coastal And Ocean Modeling Testbed: Inter-Model Evaluation Of Tides, Waves, And Hurricane Surge In The Gulf Of Mexico, Pc Kerr, As Donahue, Jj Westerliink, Ra Luettich, Ly Zheng, Rh Weisberg, Y Huang, Harry V. Wang, Y Teng, David R. Forrest, Et Al
VIMS Articles
A Gulf of Mexico performance evaluation and comparison of coastal circulation and wave models was executed through harmonic analyses of tidal simulations, hindcasts of Hurricane Ike (2008) and Rita (2005), and a benchmarking study. Three unstructured coastal circulation models (ADCIRC, FVCOM, and SELFE) validated with similar skill on a new common Gulf scale mesh (ULLR) with identical frictional parameterization and forcing for the tidal validation and hurricane hindcasts. Coupled circulation and wave models, SWAN+ADCIRC and WWMII+SELFE, along with FVCOM loosely coupled with SWAN, also validated with similar skill. NOAA's official operational forecast storm surge model (SLOSH) was implemented on local …
West Antarctic Peninsula: An Ice-Dependent Coastal Marine Ecosystem In Transition, Hugh Ducklow, William R. Fraser, Michael P. Meredith, Sharon E. Stammerjohn, Scott C. Doney, Douglas G. Martinson, Sevrine F. Sailley, Oscar M. Schofield, Deborah K. Steinberg, Hugh Venables, Charles Amsler
West Antarctic Peninsula: An Ice-Dependent Coastal Marine Ecosystem In Transition, Hugh Ducklow, William R. Fraser, Michael P. Meredith, Sharon E. Stammerjohn, Scott C. Doney, Douglas G. Martinson, Sevrine F. Sailley, Oscar M. Schofield, Deborah K. Steinberg, Hugh Venables, Charles Amsler
VIMS Articles
The extent, duration, and seasonality of sea ice and glacial discharge strongly influence Antarctic marine ecosystems. Most organisms' life cycles in this region are attuned to ice seasonality The annual retreat and melting of sea ice in the austral spring stratifies the upper ocean, triggering large phytoplankton blooms. The magnitude of the blooms is proportional to the winter extent of ice cover, which can act as a barrier to wind mixing. Antarctic krill, one of the most abundant metazoan populations on Earth, consume phytoplankton blooms dominated by large diatoms. Krill, in turn, support a large biomass of predators, including penguins, …
Progress Of Regional Oceanography Study Associated With Western Boundary Current In The South China Sea, Dongxiao Wang, Qinyan Liu, Qiang Xie, Zhigang He, Wei Zhuang, Yeqiang Shu, Xianjun Xiao, Bo Hong, Xiangyu Wu, Dandan Sui
Progress Of Regional Oceanography Study Associated With Western Boundary Current In The South China Sea, Dongxiao Wang, Qinyan Liu, Qiang Xie, Zhigang He, Wei Zhuang, Yeqiang Shu, Xianjun Xiao, Bo Hong, Xiangyu Wu, Dandan Sui
VIMS Articles
Recent progress of physical oceanography in the South China Sea (SCS) associated with the western boundary current (WBC) and eddies is reviewed in this paper. It includes Argo observations of the WBC, eddy detection in the WBC based on satellite images, cross-continental shelf exchange in the WBC, eddy-current interaction, interannual variability of the WBC, air-sea interaction, the SCS throughflow (SCSTF), among others. The WBC in the SCS is strong, and its structure, variability and dynamic processes on seasonal and interannual time scales are yet to be fully understood. In this paper, we summarize progresses on the variability of the WBC, …
Photochemical And Microbial Alteration Of Dissolved Organic Matter In Temperate Headwater Streams Associated With Different Land Use, Yuehan Lu, James E. Bauer, Elizabeth A. Canuel, Youhei Yamashita, Randy Chambers, Rudolf Jaffe
Photochemical And Microbial Alteration Of Dissolved Organic Matter In Temperate Headwater Streams Associated With Different Land Use, Yuehan Lu, James E. Bauer, Elizabeth A. Canuel, Youhei Yamashita, Randy Chambers, Rudolf Jaffe
VIMS Articles
Photochemical and microbial transformations of DOM were evaluated in headwater streams draining forested and human-modified lands (pasture, cropland, and urban development) by laboratory incubations. Changes in DOC concentrations, DOC isotopic signatures, and DOM fluorescence properties were measured to assess the amounts, sources, ages, and properties of reactive and refractory DOM under the influence of photochemistry and/or bacteria. DOC in streams draining forest-dominated watersheds was more photoreactive than in streams draining mostly human-modified watersheds, possibly due to greater contributions of terrestrial plant-derived DOC and lower amounts of prior light exposure in forested streams. Overall, the percentage of photoreactive DOC in stream …
Using Timescales To Interpret Dissolved Oxygen Distributions In The Bottom Waters Of Chesapeake Bay, Jian Shen, B Hong, Ay Kuo
Using Timescales To Interpret Dissolved Oxygen Distributions In The Bottom Waters Of Chesapeake Bay, Jian Shen, B Hong, Ay Kuo
VIMS Articles
A simplified conceptual model based on timescales of gravitational circulation, vertical exchange, and total oxygen consumption rate of the biochemical processes is presented to provide insight into the relationships between estuarine dynamics and bottom water dissolved oxygen (DO). Two dimensionless parameters are introduced to diagnose the relationship between the vertical exchange process and the biochemical DO consumption and the influence of gravitational circulation on replenishment of bottom DO. The relative magnitudes of these timescales provide a linkage between the physical and biochemical processes. The hypoxic and anoxic conditions in deep waters of Chesapeake Bay are successfully interpreted with these three …
Improved Method For Quantifying The Air-Sea Flux Of Volatile And Semi-Volatile Organic Carbon, Ej Hauser, Rm Dickhut, R Falconer, As Wozniak
Improved Method For Quantifying The Air-Sea Flux Of Volatile And Semi-Volatile Organic Carbon, Ej Hauser, Rm Dickhut, R Falconer, As Wozniak
VIMS Articles
A method for quantifying the diffusive air-sea exchange of gaseous organic carbon (OC) was developed. OC compounds were separated into two operational pools-those that were kinetically air limited in diffusion across the air-sea interface and those that were water limited-during simultaneous air/water sampling. The method separates OC compounds into low Henry's law constant (low-H) semivolatile OC (SOC) and high Henry's law constant (high-H) volatile OC (VOC) pools that can be categorized by relating diffusion kinetic parameters to Henry's Law constant. Air limited (low-H; H << similar to 0.1 L atm mol(-1)) compounds were collected in pure water traps and were quantified as dissolved OC, whereas water limited (high-H; H >> similar to 0.1 L atm mol-1) compounds were collected on solid sorbent tubes downstream from the …
Trichodesmium-Derived Dissolved Organic Matter Is A Source Of Nitrogen Capable Of Supporting The Growth Of Toxic Red Tide Karenia Brevis, Rachel E. Sipler, Deborah A. Bronk, Sybil P. Seitzinger, Ronald J. Lauck, Lora R. Mcguinness, Gary J. Kirkpatrick, Cynthia A. Heil, Lee J. Kerkhof, Oscar M. Schofield
Trichodesmium-Derived Dissolved Organic Matter Is A Source Of Nitrogen Capable Of Supporting The Growth Of Toxic Red Tide Karenia Brevis, Rachel E. Sipler, Deborah A. Bronk, Sybil P. Seitzinger, Ronald J. Lauck, Lora R. Mcguinness, Gary J. Kirkpatrick, Cynthia A. Heil, Lee J. Kerkhof, Oscar M. Schofield
VIMS Articles
Dissolved organic nitrogen (DON) produced by the nitrogen-fixer Trichodesmium sp. has the potential to serve as a nitrogen source for the red tide dinoflagellate Karenia brevis. Dissolved organic matter (DOM) from laboratory cultures of Trichodesmium sp. was isolated, concentrated and then supplied as a nutrient source to K. brevis cells collected from the Gulf of Mexico. K. brevis abundance increased immediately after Trichodesmium sp. cellular exudate (TCE) addition, allowing the population to double within the first 24 h. There was rapid and complete utilization of the TCE DON as well as ~89% of the TCE dissolved organic phosphorus (DOP). Additionally, …
Fluid Driven By Tangential Velocity And Shear Stress: Mathematical Analysis, Numerical Experiment, And Implication To Surface Flow, H. S. Tang, L. Z. Zhang, J. P. -Y. Maa, H. Li, C.B. Jiang, R. Hussain
Fluid Driven By Tangential Velocity And Shear Stress: Mathematical Analysis, Numerical Experiment, And Implication To Surface Flow, H. S. Tang, L. Z. Zhang, J. P. -Y. Maa, H. Li, C.B. Jiang, R. Hussain
VIMS Articles
This paper investigates behaviors of flows driven by tangential velocity and shear stress on their boundaries such as solid walls and water surfaces. In a steady flow between two parallel plates with one of them in motion, analytic solutions are the same when a velocity and a shear stress boundary condition are applied on the moving plate. For an unsteady, impulsively started flow, however, analysis shows that solutions for velocity profiles as well as energy transferring and dissipation are different under the two boundary conditions. In an air-water flow, if either a velocity or a stress condition is imposed at …
Simulated Tsunami Inundation For A Range Of Cascadia Megathrust Earthquake Scenarios At Bandon, Oregon, Usa, Rc Witter, Yinglong J. Zhang, Kl Wang, Gr Priest, C Goldfinger
Simulated Tsunami Inundation For A Range Of Cascadia Megathrust Earthquake Scenarios At Bandon, Oregon, Usa, Rc Witter, Yinglong J. Zhang, Kl Wang, Gr Priest, C Goldfinger
VIMS Articles
Characterizations of tsunami hazards along the Cascadia subduction zone hinge on uncertainties in megathrust rupture models used for simulating tsunami inundation. To explore these uncertainties, we constructed 15 megathrust earthquake scenarios using rupture models that supply the initial conditions for tsunami simulations at Bandon, Oregon. Tsunami inundation varies with the amount and distribution of fault slip assigned to rupture models, including models where slip is partitioned to a splay fault in the accretionary wedge and models that vary the updip limit of slip on a buried fault. Constraints on fault slip come from onshore and offshore paleoseismological evidence. We rank …
Regression Modeling Of The North East Atlantic Spring Bloom Suggests Previously Unrecognized Biological Roles For V And Mo, Nj Klein, Aj Beck, Da Hutchins, Sa Sanudo-Wilhelmy
Regression Modeling Of The North East Atlantic Spring Bloom Suggests Previously Unrecognized Biological Roles For V And Mo, Nj Klein, Aj Beck, Da Hutchins, Sa Sanudo-Wilhelmy
VIMS Articles
In order to identify the biogeochemical parameters controlling pCO(2), total chlorophyll a, and dimethyl sulfide (DMS) concentrations during the North East Atlantic Spring Bloom (NASB), we used previously unpublished particulate and dissolved elemental concentrations to construct several linear regression models; first by hypothesis testing, and then with exhaustive stepwise linear regression followed by leave-one-out cross-validation. The field data was obtained along a latitudinal transect from the Azores Islands to the North Atlantic, and best-fit models (determined by lowest predictive error) of up to three variables are presented. Total chlorophyll a is predicted best by biomass (POC, PON) parameters and by …
Microphytobenthos And Benthic Macroalgae Determine Sediment Organic Matter Composition In Shallow Photic Sediments, Ak Hardison, Elizabeth A. Canuel, Iris C. Anderson, C. R. Tobias, B. Veuger, M. N. Waters
Microphytobenthos And Benthic Macroalgae Determine Sediment Organic Matter Composition In Shallow Photic Sediments, Ak Hardison, Elizabeth A. Canuel, Iris C. Anderson, C. R. Tobias, B. Veuger, M. N. Waters
VIMS Articles
Microphytobenthos and benthic macroalgae play an important role in system metabolism within shallow coastal bays. However, their independent and interactive influences on sediment organic matter (SOM) are not well understood. We investigated the influence of macroalgae and microphytobenthos on SOM quantity and quality in an experimental mesocosm system using bulk and molecular level (total hydrolyzable amino acids, THAA; phospholipid linked fatty acids, PLFA; pigment) analyses. Our experiment used an incomplete factorial design made up of two factors, each with two levels: (1) light (ambient vs. dark) and (2) macroalgae (presence vs. absence of live macroalgae). Over the course of the …
Linking Dynamics Of Transport Timescale And Variations Of Hypoxia In The Chesapeake Bay, Bo Hong, Jian Shen
Linking Dynamics Of Transport Timescale And Variations Of Hypoxia In The Chesapeake Bay, Bo Hong, Jian Shen
VIMS Articles
Dissolved oxygen (DO) replenishment in the bottom waters of an estuary depends on physical processes that are significantly influenced by external forcings. The vertical exchange time (VET) is introduced in this study to quantify the physical processes that regulate the DO replenishment in the Chesapeake Bay. A 3-D numerical model was applied to simulate the circulation, VET, and DO. Results indicate that VET is a suitable parameter for evaluating the bottom DO condition over both seasonal and interannual timescales. The VET is negatively correlated with the bottom DO. Hypoxia (DO L-1) will develop in the Bay when VET is greater …
Extratropical Storm Inundation Testbed: Intermodel Comparisons In Scituate, Massachusetts, Changsheng Chen, Et Al., Harry V. Wang
Extratropical Storm Inundation Testbed: Intermodel Comparisons In Scituate, Massachusetts, Changsheng Chen, Et Al., Harry V. Wang
VIMS Articles
The Integrated Ocean Observing System Super-regional Coastal Modeling Testbed had one objective to evaluate the capabilities of three unstructured-grid fully current-wave coupled ocean models (ADCIRC/SWAN, FVCOM/SWAVE, SELFE/WWM) to simulate extratropical storm-induced inundation in the US northeast coastal region. Scituate Harbor (MA) was chosen as the extratropical storm testbed site, and model simulations were made for the 24-27 May 2005 and 17-20 April 2007 (Patriot's Day Storm) nor'easters. For the same unstructured mesh, meteorological forcing, and initial/boundary conditions, intermodel comparisons were made for tidal elevation, surface waves, sea surface elevation, coastal inundation, currents, and volume transport. All three models showed similar …
Longitudinal Variability Of Size-Fractionated N-2 Fixation And Don Release Rates Along 24.5 Degrees N In The Subtropical North Atlantic, Mar Benavides, Deborah A. Bronk, Nona S.R. Agawin, M. Dolores Perez-Hernandez, Alonso Hernandez-Guerra, Javier Aristegui
Longitudinal Variability Of Size-Fractionated N-2 Fixation And Don Release Rates Along 24.5 Degrees N In The Subtropical North Atlantic, Mar Benavides, Deborah A. Bronk, Nona S.R. Agawin, M. Dolores Perez-Hernandez, Alonso Hernandez-Guerra, Javier Aristegui
VIMS Articles
Dinitrogen (N-2) fixation and dissolved organic nitrogen (DON) release rates were measured on fractionated samples (>10 mu m and m) along 24.5 degrees N in the subtropical North Atlantic. Net N-2 fixation rates (N-2 assimilation into biomass) ranged from 0.01 to 0.4 nmol N L-1 h(-1), and DON release rates ranged from 0.001 to 0.09 nmol N L-1 h(-1). DON release represented approximate to 14% and approximate to 23% of >10 mu m and (assimilation into biomass plus DON release), respectively. This implies that by overlooking DON release, N-2 fixation rates are underestimated. Net N-2 fixation rates were higher …
Distribution And Sources Of Organic Matter In Surface Marine Sediments Across The North American Arctic Margin, Miguel A. Goni, Alison E. O'Connor, Zou Zou Kyzyk, Mark B. Yunker, Charles Gobeil, Robie W. Macdonald
Distribution And Sources Of Organic Matter In Surface Marine Sediments Across The North American Arctic Margin, Miguel A. Goni, Alison E. O'Connor, Zou Zou Kyzyk, Mark B. Yunker, Charles Gobeil, Robie W. Macdonald
VIMS Articles
As part of the International Polar Year research program, we conducted a survey of surface marine sediments from box cores along a section extending from the Bering Sea to Davis Strait via the Canadian Archipelago. We used bulk elemental and isotopic compositions, together with biomarkers and principal components analysis, to elucidate the distribution of marine and terrestrial organic matter in different regions of the North American Arctic margin. Marked regional contrasts were observed in organic carbon loadings, with the highest values (1 mg C m(-2) sediment) found in sites along Barrow Canyon and the Chukchi and Bering shelves, all of …