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Multiplatform, Multidisciplinary Investigations Of The Impacts Of Modified Circumpolar Deep Water In The Ross Sea, Antarctica, Walker O. Smith Jr., Kt Goetz, De Kaufman, By Queste, V Asper, Dp Costa, Ms Dinniman, Mam Friedrichs, Et Al
Multiplatform, Multidisciplinary Investigations Of The Impacts Of Modified Circumpolar Deep Water In The Ross Sea, Antarctica, Walker O. Smith Jr., Kt Goetz, De Kaufman, By Queste, V Asper, Dp Costa, Ms Dinniman, Mam Friedrichs, Et Al
VIMS Articles
In 2010-2011, three projects combined to characterize the temporal and spatial distributions of Modified circumpolar Deep Water (MCDW) in the Ross Sea using icebreaker-based sampling, gliders, instrumented seals, and hindcasts from a numerical circulation model. The fieldwork cearly identified MCDW throughout the Ross Sea, and the lata were used to determine its influence on potential heat.md nutrient inputs and biotic distributions. Furthermore, the numerical simulations confirm its apparent trajectory and location. Substantial small-scale variability in oceanographic and biological distributions suggests that such variability may play an important role in biogeochemical cycles. Data from the three projects provide a view of …
The Storm Surge And Sub-Grid Inundation Modeling In New York City During Hurricane Sandy, Harry V. Wang, Jon Derek Loftis, Zhou Liu, David R. Forrest, Yinglong J. Zhang
The Storm Surge And Sub-Grid Inundation Modeling In New York City During Hurricane Sandy, Harry V. Wang, Jon Derek Loftis, Zhou Liu, David R. Forrest, Yinglong J. Zhang
VIMS Articles
Hurricane Sandy inflicted heavy damage in New York City and the New Jersey coast as the second costliest storm in history. A large-scale, unstructured grid storm tide model, Semi-implicit Eulerian Lagrangian Finite Element (SELFE), was used to hindcast water level variation during Hurricane Sandy in the mid-Atlantic portion of the U.S. East Coast. The model was forced by eight tidal constituents at the model’s open boundary, 1500 km away from the coast, and the wind and pressure fields from atmospheric model Regional Atmospheric Modeling System (RAMS) provided by Weatherflow Inc. The comparisons of the modeled storm tide with the NOAA …
Reducing Wave-Induced Microwave Water-Level Measurement Error With A Least Squares-Designed Digital Filter, John D. Boon
Reducing Wave-Induced Microwave Water-Level Measurement Error With A Least Squares-Designed Digital Filter, John D. Boon
VIMS Articles
A microwave water-level sensor, the Design Analysis model H-3611i, will soon enter service at tide stations operated by the National Oceanic and Atmospheric Administration's Center for Operational Oceanographic Products and Services (CO-OPS) as part of the National Water Level Observation Network. CO-OPS tests include a multisensor deployment at the U.S. Army Corps of Engineers Field Research Facility at Duck, North Carolina, to evaluate microwave water-level measurement error over a wide range of Atlantic Ocean sea states. In situ precision and accuracy of processed (6-min average) water level is found to depend on sea state in addition to data processing methods …
The Vertical Structure Of The Circulation And Dynamics In Hudson Shelf Valley, Steven J. Lentz, Bradford Butman, Courtney K. Harris
The Vertical Structure Of The Circulation And Dynamics In Hudson Shelf Valley, Steven J. Lentz, Bradford Butman, Courtney K. Harris
VIMS Articles
Hudson Shelf Valley is a 20-30 m deep, 5-10 km wide v-shaped submarine valley that extends across the Middle Atlantic Bight continental shelf. The valley provides a conduit for cross-shelf exchange via along-valley currents of 0.5 m s(-1) or more. Current profile, pressure, and density observations collected during the winter of 1999-2000 are used to examine the vertical structure and dynamics of the flow. Near-bottom along-valley currents having times scales of a few days are driven by cross-shelf pressure gradients setup by wind stresses, with eastward (westward) winds driving onshore (offshore) flow within the valley. The along-valley momentum balance in …
Coastal Response To Late-Stage Transgression And Sea-Level Highstand, C J. Hein, Dm Fitzgerald, Jt De Menezes, Wj Cleary, Ahf Klein
Coastal Response To Late-Stage Transgression And Sea-Level Highstand, C J. Hein, Dm Fitzgerald, Jt De Menezes, Wj Cleary, Ahf Klein
VIMS Articles
Coastal morphologic features associated with past shoreline transgressions and sea-level highstands can provide insight into the rates and processes associated with coastal response to the modern global rise in sea level. Along the eastern and southern Brazilian coasts of South America, 6000 years of sea-level fall have preserved late-stage transgressive and sea-level highstand features 1-4 m above present mean sea level and several kilometers landward of modern shorelines. GPS with real-time kinematics data, ground-penetrating radar, stratigraphy, and radiocarbon dating within a 2-3-km-wide river-associated strandplain in central Santa Catarina (southern Brazil) uncovered a diverse set of late-stage transgressive and highstand deposits. …
Ocean Processes At The Antarctic Continental Slope, Kj Heywood, S Schmidtko, C Heuze, J Kaiser, Td Jickells, Walker O. Smith, Et Al.
Ocean Processes At The Antarctic Continental Slope, Kj Heywood, S Schmidtko, C Heuze, J Kaiser, Td Jickells, Walker O. Smith, Et Al.
VIMS Articles
The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. …
Effect Of Temperature On Rates Of Ammonium Uptake And Nitrification In The Western Coastal Arctic During Winter, Spring, And Summer, Se Baer, Tl Connelly, Rachel E. Sipler, Pl Yager, Da Bronk
Effect Of Temperature On Rates Of Ammonium Uptake And Nitrification In The Western Coastal Arctic During Winter, Spring, And Summer, Se Baer, Tl Connelly, Rachel E. Sipler, Pl Yager, Da Bronk
VIMS Articles
Biogeochemical rate processes in the Arctic are not currently well constrained, and there is very limited information on how rates may change as the region warms. Here we present data on the sensitivity of ammonium (NH4+) uptake and nitrification rates to short-term warming. Samples were collected from the Chukchi Sea off the coast of Barrow, Alaska, during winter, spring, and summer and incubated for 24h in the dark with additions of (NH4+)-N-15 at -1.5, 6, 13, and 20 degrees C. Rates of NH4+ uptake and nitrification were measured in conjunction with bacterial production. In all seasons, NH4+ uptake rates were …
Earth Is (Mostly) Flat: Apportionment Of The Flux Of Continental Sediment Over Millennial Time Scales Comment, Ja Warrick, Jd Milliman, De Walling, Rj Wasson, Jpm Syvitski, Re Aalto
Earth Is (Mostly) Flat: Apportionment Of The Flux Of Continental Sediment Over Millennial Time Scales Comment, Ja Warrick, Jd Milliman, De Walling, Rj Wasson, Jpm Syvitski, Re Aalto
VIMS Articles
No abstract provided.
Inner-Shelf Circulation And Sediment Dynamics On A Series Of Shoreface-Connected Ridges Offshore Of Fire Island, Ny, Jc Warner, Jh List, Wc Schwab, G Voulgaris, B Armstrong, N Marshall
Inner-Shelf Circulation And Sediment Dynamics On A Series Of Shoreface-Connected Ridges Offshore Of Fire Island, Ny, Jc Warner, Jh List, Wc Schwab, G Voulgaris, B Armstrong, N Marshall
VIMS Articles
Locations along the inner-continental shelf offshore of Fire Island, NY, are characterized by a series of shoreface-connected ridges (SFCRs). These sand ridges have approximate dimensions of 10 km in length, 3 km spacing, and up to similar to 8 m ridge to trough relief and are oriented obliquely at approximately 30 degrees clockwise from the coastline. Stability analysis from previous studies explains how sand ridges such as these could be formed and maintained by storm-driven flows directed alongshore with a key maintenance mechanism of offshore deflected flows over ridge crests and onshore in the troughs. We examine these processes both …
Urea Uptake And Carbon Fixation By Marine Pelagic Bacteria And Archaea During The Arctic Summer And Winter Seasons, Tl Connelly, Se Baer, Jt Cooper, Da Bronk, B Wawrik
Urea Uptake And Carbon Fixation By Marine Pelagic Bacteria And Archaea During The Arctic Summer And Winter Seasons, Tl Connelly, Se Baer, Jt Cooper, Da Bronk, B Wawrik
VIMS Articles
How Arctic climate change might translate into alterations of biogeochemical cycles of carbon (C) and nitrogen (N) with respect to inorganic and organic N utilization is not well understood. This study combined N-15 uptake rate measurements for ammonium, nitrate, and urea with N-15-and C-13-based DNA stable-isotope probing (SIP). The objective was to identify active bacterial and archeal plankton and their role in N and C uptake during the Arctic summer and winter seasons. We hypothesized that bacteria and archaea would successfully compete for nitrate and urea during the Arctic winter but not during the summer, when phytoplankton dominate the uptake …
Model Behavior And Sensitivity In An Application Of The Cohesive Bed Component Of The Community Sediment Transport Modeling System For The York River Estuary, Va, Usa, Kelsey A. Fall, Courtney K. Harris, Carl T. Friedrichs, J. Paul Rineheimer, Christopher R. Sherwood
Model Behavior And Sensitivity In An Application Of The Cohesive Bed Component Of The Community Sediment Transport Modeling System For The York River Estuary, Va, Usa, Kelsey A. Fall, Courtney K. Harris, Carl T. Friedrichs, J. Paul Rineheimer, Christopher R. Sherwood
VIMS Articles
The Community Sediment Transport Modeling System (CSTMS) cohesive bed sub-model that accounts for erosion, deposition, consolidation, and swelling was implemented in a three-dimensional domain to represent the York River estuary, Virginia. The objectives of this paper are to (1) describe the application of the three-dimensional hydrodynamic York Cohesive Bed Model, (2) compare calculations to observations, and (3) investigate sensitivities of the cohesive bed sub-model to user-defined parameters. Model results for summer 2007 showed good agreement with tidal-phase averaged estimates of sediment concentration, bed stress, and current velocity derived from Acoustic Doppler Velocimeter (ADV) field measurements. An important step in implementing …
A Hydrodynamic And Sediment Transport Model For The Waipaoa Shelf, New Zealand: Sensitivity Of Fluxes To Spatially-Varying Erodibility And Model Nesting, Julia M. Moriarty, Courtney K. Harris, Mark G. Hadfield
A Hydrodynamic And Sediment Transport Model For The Waipaoa Shelf, New Zealand: Sensitivity Of Fluxes To Spatially-Varying Erodibility And Model Nesting, Julia M. Moriarty, Courtney K. Harris, Mark G. Hadfield
VIMS Articles
Numerical models can complement observations in investigations of marine sediment transport and depositional processes. A coupled hydrodynamic and sediment transport model was implemented for the Waipaoa River continental shelf offshore of the North Island of New Zealand, to complement a 13-month field campaign that collected seabed and hydrodynamic measurements. This paper described the formulations used within the model, and analyzed the sensitivity of sediment flux estimates to model nesting and seabed erodibility. Calculations were based on the Regional Ocean Modeling System—Community Sediment Transport Modeling System (ROMS-CSTMS), a primitive equation model using a finite difference solution to the equations for momentum …
Interactions Between Barrier Islands And Backbarrier Marshes Affect Island System Response To Sea Level Rise: Insights From A Coupled Model, David C. Walters, Laura J. Moore, Orencio Duran Vincent, Sergio Fagherazzi, Giulio Mariotti
Interactions Between Barrier Islands And Backbarrier Marshes Affect Island System Response To Sea Level Rise: Insights From A Coupled Model, David C. Walters, Laura J. Moore, Orencio Duran Vincent, Sergio Fagherazzi, Giulio Mariotti
VIMS Articles
Interactions between backbarrier marshes and barrier islands will likely play an important role in determining how low-lying coastal systems respond to sea level rise and changes in storminess in the future. To assess the role of couplings between marshes and barrier islands under changing conditions, we develop and apply a coupled barrier island-marsh model (GEOMBEST+) to assess the impact of overwash deposition on backbarrier marsh morphology and of marsh morphology on rates of island migration. Our model results suggest that backbarrier marsh width is in a constant state of change until either the backbarrier basin becomes completely filled or backbarrier …
Temperature Sensitivity Of Organic-Matter Decay In Tidal Marshes, Matthew L. Kirwan, G. R. Guntenspergen, J. A. Langley
Temperature Sensitivity Of Organic-Matter Decay In Tidal Marshes, Matthew L. Kirwan, G. R. Guntenspergen, J. A. Langley
VIMS Articles
Approximately half of marine carbon sequestration takes place in coastal wetlands, including tidal marshes, where organic matter contributes to soil elevation and ecosystem persistence in the face of sea-level rise. The long-term viability of marshes and their carbon pools depends, in part, on how the balance between productivity and decay responds to climate change. Here, we report the sensitivity of labile soil organic-matter decay in tidal marshes to seasonal and latitudinal variations in temperature measured over a 3-year period. We find a moderate increase in decay rate at warmer temperatures (3-6% per degrees C, Q(10) = 1.3-1.5). Despite the profound …
The Effects Of Changing Winds And Temperatures On The Oceanography Of The Ross Sea In The 21st Century, Walker O. Smith, Ms Dinniman, Ee Hofmann, Jm Klinck
The Effects Of Changing Winds And Temperatures On The Oceanography Of The Ross Sea In The 21st Century, Walker O. Smith, Ms Dinniman, Ee Hofmann, Jm Klinck
VIMS Articles
The Ross Sea is critically important in regulating Antarctic sea ice and is biologically productive, which makes changes in the region's physical environment of global concern. We examined the effects of projected changes in atmospheric temperatures and winds on aspects of the ocean circulation likely important to primary production using a high-resolution sea ice-ocean-ice shelf model of the Ross Sea. The modeled summer sea-ice concentrations decreased by 56% by 2050 and 78% by 2100. The duration of shallow mixed layers over the continental shelf increased by 8.5 and 19.2days in 2050 and 2100, and the mean summer mixed layer depths …