Turbulent Mixing In A Strongly Forced Salt Wedge Estuary,
2010
Old Dominion University
Turbulent Mixing In A Strongly Forced Salt Wedge Estuary, David K. Ralston, W. Rockwell Geyer, James A. Lerczak, Malcolm Scully
OES Faculty Publications
Turbulent mixing of salt is examined in a shallow salt wedge estuary with strong fluvial and tidal forcing. A numerical model of the Merrimack River estuary is used to quantify turbulent stress, shear production, and buoyancy flux. Little mixing occurs during flood tides despite strong velocities because bottom boundary layer turbulence is dislocated from stratification elevated in the water column. During ebbs, bottom salinity fronts form at a series of bathymetric transitions. At the fronts, near-bottom velocity and shear stress are low, but shear, stress, and buoyancy flux are elevated at the pycnocline. Internal shear layers provide the dominant source …
Effect Of The Heterotrophic Dinoflagellate Oxyrrhis Marina And The Copepod Acartia Tonsa On Vertical Carbon Flux In And Around Thin Layers Of The Phytoflagellate Isochrysis Galbana,
2010
Old Dominion University
Effect Of The Heterotrophic Dinoflagellate Oxyrrhis Marina And The Copepod Acartia Tonsa On Vertical Carbon Flux In And Around Thin Layers Of The Phytoflagellate Isochrysis Galbana, A. B. Bochdansky, S. M. Bollens, G. C. Rollwagen-Bollens, A. H. Gibson
OES Faculty Publications
Dynamics of material and energy flow through food webs differ when resources are allocated in patches in comparison to situations in which the same resources are distributed evenly throughout the water column. Thin layers of plankton are special cases of such resource patches. While previous studies have predominantly focused on the response of organisms to these layers, we investigated how 2 types of grazers in turn affect thin layers. In an experimental study with tightly controlled environmental conditions, we monitored the redistribution of particulate organic (POC), dissolved organic (DOC) and inorganic (DIC) carbon from thin layers of Isochrysis galbana. …
Role Of Macroscopic Particles In Deep-Sea Oxygen Consumption,
2010
Old Dominion University
Role Of Macroscopic Particles In Deep-Sea Oxygen Consumption, Alexander B. Bochdansky, Hendrik M. Van Aken, Gerhard J. Herndl
OES Faculty Publications
Macroscopic particles (> 500 µg), including marine snow, large migrating zooplankton, and their fast-sinking fecal pellets, represent primary vehicles of organic carbon flux from the surface to the deep sea. In contrast, freely suspended microscopic particles such as bacteria and protists do not sink, and they contribute the largest portion of metabolism in the upper ocean. In bathy- and abyssopelagic layers of the ocean (2,000-6,000 m), however, microscopic particles may not dominate oxygen consumption. In a section across the tropical Atlantic, we show that macroscopic particle peaks occurred frequently in the deep sea, whereas microscopic particles were barely detectable. In …
Determination Of Total Dissolved Cobalt In Uv-Irradiated Seawater Using Flow Injection With Chemiluminescence Detection,
2010
Old Dominion University
Determination Of Total Dissolved Cobalt In Uv-Irradiated Seawater Using Flow Injection With Chemiluminescence Detection, Rachel U. Shelley, Bernhard Zachhuber, Peter N. Sedwick, Paul J. Worsfold, Maeve C. Lohan
OES Faculty Publications
A sensitive flow-injection method with chemiluminescence detection (FI-CL) for the determination of dissolved cobalt in open ocean samples, suitable for shipboard use has been developed. To date, FI methods for dissolved cobalt have been used only in coastal and estuarine waters. Therefore, significant modifications to existing methods were required, including (1) the use of a commercially available iminodiacetate (IDA) resin (Toyopearl AF-chelate 650M) in place of resin immobilized 8-hydroxyquinoline for online preconcentration and matrix removal, (2) the introduction of acidified ammonium acetate (pH 4) as a column-conditioning step before sample loading and rinse steps, and most importantly, (3) UV irradiation …
Causes Of Tropical Atlantic Paleo-Salinity Variation During Periods Of Reduced Amoc,
2010
Old Dominion University
Causes Of Tropical Atlantic Paleo-Salinity Variation During Periods Of Reduced Amoc, Xiuquan Wan, Ping Chang, Matthew W. Schmidt
OES Faculty Publications
During periods of reduced Atlantic meridional overturning circulation (AMOC) associated with a freshening of northern North Atlantic surface water, paleo proxy records indicate a corresponding surface salinity increase over the entire tropical Atlantic. Although latitudinal-shifts in the mean position of the Atlantic Intertropical Convergence Zone (ITCZ) can explain certain features of the paleo salinity reconstructions, this mechanism does not offer an explanation for the reconstructed basin-wide paleo-salinity response to AMOC change. Here, we present new results from general circulation model simulations that suggest the sea surface salinity (SSS) increase in the tropical north Atlantic during periods of weakened AMOC is …
A Seasonal Study Of Dissolved Cobalt In The Ross Sea, Antarctica: Micronutrient Behavior, Absence Of Scavenging, And Relationships With Zd, Cd, And P.,
2010
Old Dominion University
A Seasonal Study Of Dissolved Cobalt In The Ross Sea, Antarctica: Micronutrient Behavior, Absence Of Scavenging, And Relationships With Zd, Cd, And P., M. A. Saito, T. J. Goepfert, A. E. Noble, E. M. Bertrand, Peter N. Sedwick, Giacomo R. Ditullio
OES Faculty Publications
We report the distribution of cobalt (Co) in the Ross Sea polynya during austral summer 2005-2006 and the following austral spring 2006. The vertical distribution of total dissolved Co (dCo) was similar to soluble reactive phosphate (PO(4)(3-)), with dCo and PO(4)(3-) showing a significant correlation throughout the water column (r(2) = 0.87, 164 samples). A strong seasonal signal for dCo was observed, with most spring samples having concentrations ranging from similar to ~ 45-85 pM, whereas summer dCo values were depleted below these levels by biological activity. Surface transect data from the summer cruise revealed concentrations at the low range …
Variations In Synechococcus Cell Quotas Of Phosphorus, Sulfur, Manganese, Iron, Nickel, And Zinc Within Mesoscale Eddies In The Sargasso Sea,
2010
Old Dominion University
Variations In Synechococcus Cell Quotas Of Phosphorus, Sulfur, Manganese, Iron, Nickel, And Zinc Within Mesoscale Eddies In The Sargasso Sea, Benjamin S. Twining, Daliangelis Nunez-Milland, Stefan Vogt, Rodney S. Johnson, Peter N. Sedwick
OES Faculty Publications
The quotas of P, S, Mn, Fe, Ni, and Zn in individual Synechococcus cells collected from the surface and deep chlorophyll maximum (DCM) layer of three mesoscale eddies in the Sargasso Sea were measured using synchrotron X-ray fluorescence microscopy. Cells in a mode-water eddy had significantly higher P (57 +/- 10 amol) and Mn (28 +/- 7 zmol) cell quotas than cells collected from a cyclone (22 +/- 2 amol and 10 +/- 1 zmol, respectively) or anticyclone (25 +/- 3 amol and 18 +/- 3 zmol, respectively). Conversely, Ni and Zn quotas were significantly higher in the cells from …
Temporal Controls On Dissolved Organic Matter And Lignin Biogeochemistry In A Pristine Tropical River, Democratic Republic Of Congo,
2010
Old Dominion University
Temporal Controls On Dissolved Organic Matter And Lignin Biogeochemistry In A Pristine Tropical River, Democratic Republic Of Congo, Robert G. M. Spencer, Peter J. Hernes, Rosmarie Ruf, Andy Baker, Rachael Y. Dyda, Aron Stubbins, Johan Six
Chemistry & Biochemistry Faculty Publications
Dissolved organic carbon (DOC), lignin biomarkers, and the optical properties of dissolved organic matter (DOM) were measured in the Epulu River (northeast Democratic Republic of Congo) with the aim of investigating temporal controls on the quantity and chemical composition of DOM in a tropical rainforest river. Three different periods defined by stages of the hydrologic regime of the region, (1) post dry flushing period, (2) intermediary period, and (3) start of the dry period/post flush, were sampled. Temporal variability in DOM quantity and quality was observed with highest DOC, lignin concentration (Σ8) and carbon‐normalized (Λ8) values …
What Are The Causes, Consequences And Correctives Of Fish Contamination In The Detroit River Aoc That Cause Health Consumption Advisories? (Final Report, Michigan Sea Grant Michu-T-10-001),
2010
Department of Biological Sciences, Wayne State University, Detroit, MI
What Are The Causes, Consequences And Correctives Of Fish Contamination In The Detroit River Aoc That Cause Health Consumption Advisories? (Final Report, Michigan Sea Grant Michu-T-10-001), Donna R. Kashian, Ken G. Drouillard, D. Haffner, Ann E. Krause, Z Liu, Larissa Sano
Environmental Science and Geology Faculty Research Publications
Using an Integrated Assessment (IA) framework, we consolidated and utilized existing data from the Detroit River to develop models that both identify possible drivers of elevated fish contaminant body burdens, and to facilitate a more risk-based approach of tissue trigger-levels for consumption advisories. This integrated assessment approach was particularly useful for consumption advisories as it provided the ability to integrate and organize complex data in a manner that can help inform management decisions. In addition, the IA framework explicitly fosters collaboration and participation of multiple interested groups. We have capitalized on this component of IAs, by seeking the active participation …
Model Of Sprite Luminous Trail Caused By Increasing Streamer Current,
2010
Florida Institute of Technology
Model Of Sprite Luminous Trail Caused By Increasing Streamer Current, Ningyu Liu
Aerospace, Physics, and Space Science Faculty Publications
This study investigates a possible physical mechanism responsible for the occurrence of the luminous trail of sprite streamers, which is also known as "afterglow." According to streamer modeling results, when sprite streamers propagate with expansion, acceleration and brightening, the total current flowing through the streamer body also increases. The increasing current results in the rise of the electric field in the streamer channel far behind the streamer head, which leads to effective production of N₂ excited states by electron impact excitation and then the glowing trail.
Exchange Across The Shelf Break At High Southern Latitudes,
2010
Old Dominion University
Exchange Across The Shelf Break At High Southern Latitudes, J. M. Klinck, M. S. Dinniman
CCPO Publications
Exchange of water across the Antarctic shelf break has considerable scientific and societal importance due to its effects on circulation and biology of the region, conversion of water masses as part of the global overturning circulation and basal melt of glacial ice and the consequent effect on sea level rise. The focus in this paper is the onshore transport of warm, oceanic Circumpolar Deep Water (CDW); export of dense water from these shelves is equally important, but has been the focus of other recent papers and will not be considered here. A variety of physical mechanisms are described which could …
A Spline Kernel Based Smoothing Algorithm : A Comparison Of Methods With A Spatiotemporal Application To Global Climate Fluctuations,
2010
University at Albany, State University of New York
A Spline Kernel Based Smoothing Algorithm : A Comparison Of Methods With A Spatiotemporal Application To Global Climate Fluctuations, Derek Daniel Cyr
Legacy Theses & Dissertations (2009 - 2024)
In statistics, smoothing is a technique that attempts to capture the key patterns or trends in data while leaving out the noise that is obscuring them. Nonparametric techniques are well-suited for smoothing as they do not rely on assumptions that the data arise from a given probability distribution.
Retrieval Of Atmospheric Elemental Carbon Records Using Lake Sediments : Implications In Radiative Forcing,
2010
University at Albany, State University of New York
Retrieval Of Atmospheric Elemental Carbon Records Using Lake Sediments : Implications In Radiative Forcing, Tanveer Ahmed
Legacy Theses & Dissertations (2009 - 2024)
Elemental or black carbon (EC or BC) aerosols produced during incomplete combustion strongly absorb solar radiation and contribute to global warming, and cause cardiopulmonary disease. Long-term atmospheric EC measurements, [EC]atm, are needed to validate global climate models to estimate the impact of EC on earth's temperature. Such data is sparse.
Assessing Replicated Coral Trace Element (Sr/Ca And Mg/Ca) Variability And Skeletal Growth Records From The Tropical Pacific,
2010
University at Albany, State University of New York
Assessing Replicated Coral Trace Element (Sr/Ca And Mg/Ca) Variability And Skeletal Growth Records From The Tropical Pacific, Henry Chun-Yi Wu
Legacy Theses & Dissertations (2009 - 2024)
To gain a more complete history and understanding of the full amplitude of climate variability prior to instrumental records, science must rely on natural proxy archives that are sensitive to fluctuations in key climate parameters. Calcium carbonate skeletons of long-living hermatypic corals in some locations have been shown to be natural archives of surface ocean variability. This study investigated the fidelity and reproducibility of coral derived Sr/Ca time series from Clipperton Atoll, Fiji, and Tonga as accurate proxies of sea surface temperature (SST). The replicated high-resolution Sr/Ca time series record monthly and bimonthly SST changes, though with a greater magnitude …
Effect Of Noise In Principal Component Analysis With An Application To Ozone Pollution,
2010
University at Albany, State University of New York
Effect Of Noise In Principal Component Analysis With An Application To Ozone Pollution, Katerina G. Tsakiri
Legacy Theses & Dissertations (2009 - 2024)
This thesis analyzes the effect of independent noise in principal components of k normally distributed random variables defined by a covariance matrix. We prove that the principal components as well as the canonical variate pairs determined from joint distribution of original sample affected by noise can be essentially different in comparison with those determined from the original sample. However when the differences between the eigenvalues of the original covariance matrix are sufficiently large compared to the level of the noise, the effect of noise in principal components and canonical variate pairs proved to be negligible. The theoretical results are supported …
Tropical Cyclogenesis Associated With Extratropical Precursors In The North Atlantic Basin,
2010
University at Albany, State University of New York
Tropical Cyclogenesis Associated With Extratropical Precursors In The North Atlantic Basin, Thomas J. Galarneau
Legacy Theses & Dissertations (2009 - 2024)
This thesis investigates genesis pathways of tropical cyclones (TCs) over the North Atlantic basin during 2004-2008 with a focus on TCs that form in conjunction with extratropical precursor disturbances. These genesis pathways are nonbaroclinic, low-level baroclinic, trough-induced, transient-trough interaction, weak tropical transition (TT), and strong TT. The transient-trough interaction, trough-induced, weak TT, and strong TT genesis pathways all occur in conjunction with extratropical precursor disturbances. This thesis will assess the physical and dynamical mechanisms relevant to TC genesis among these genesis pathways via composite and case study analyses.
Role Of Equatorial Waves In Tropical Cyclogenesis,
2010
University at Albany, State University of New York
Role Of Equatorial Waves In Tropical Cyclogenesis, Carl J. Schreck, Iii
Legacy Theses & Dissertations (2009 - 2024)
Tropical cyclones typically form within preexisting wavelike disturbances that couple with convection. Using Tropical Rainfall Measuring Mission (TRMM) multisatellite rainfall estimates, this study determines the relative number of tropical cyclones that can be attributed to various wave types, including the Madden-Julian oscillation (MJO), Kelvin waves, equatorial Rossby (ER) waves, mixed Rossby-gravity (MRG) waves, and tropical depression (TD)-type disturbances. Tropical cyclogenesis is attributed to an equatorial wave's convection when the filtered rainfall anomaly exceeds a threshold value at the genesis location.
Developing Performance Indicators To Evaluate The Management Effectiveness Of The Massachusetts Ocean Management Plan,
2010
University of Massachusetts Boston
Developing Performance Indicators To Evaluate The Management Effectiveness Of The Massachusetts Ocean Management Plan, Jack Wiggin, Dan Hellin, Kristin Uiterwyk, Robert E. Bowen, Prassede Vella, John Weber, Stephanie Moura, Nicholas Napoli, Kim Starbuck, Howard Krum
Urban Harbors Institute Publications
In June 2009, the Massachusetts Executive Office of Energy and Environmental Affairs (EEA) released its draft Massachusetts Ocean Management Plan (draft plan) for public comment. The plan is required by the Oceans Act of 2008 to, among other things, be adaptive to evolving knowledge and understanding of the ocean environment. The plan’s Science Framework establishes a blueprint for future research and data acquisition and ensuring that the plan evolves and its management measures adapt to this new and enhanced information. As stated in Chapter 5 of the draft plan, an important part of the science framework is the development and …
Blue Carbon: The Role Of Healthy Oceans In Binding Carbon,
2010
UNEP/GRID-Arendal, Norway
Blue Carbon: The Role Of Healthy Oceans In Binding Carbon, Christian Nellemann, Emily Corcoran, Carlos M. Duarte, Cassandra De Young, Luciano E. Fonseca, Gabriel Grimsdith
Center for Coastal and Ocean Mapping
No abstract provided.
Assessment Of Total Organic Carbon Concentrations In Two Streams Of Northwest Arkansas: Town Branch And Brush Creek,
2010
University of Arkansas, Fayetteville
Assessment Of Total Organic Carbon Concentrations In Two Streams Of Northwest Arkansas: Town Branch And Brush Creek, Abigail N. Washispack, Jason A. Mcginnis, Brian E. Haggard
Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences
Within a stream, changes in flow rate and local environment can affect the total organic content (TOC) concentrations in the stream water and TOC delivery downstream to water supply reservoirs. Disinfection by-products (DBPs) result from various chemical reactions between chlorine, bromine, and organic carbon in raw water during the drinking water treatment process; DBPs are potential carcinogens and are regulated by the U.S. Environmental Protection Agency. In this project, we measured the TOC concentrations in two streams in the Beaver Lake Watershed: Town Branch and Brush Creek. We then compared TOC concentrations between the two streams and to that observed …
