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Atlantic Coastal Experiment VI: R/V KNORR cruise, 23 August--11 September 1980, data report

Description: An investigation of the influence of estuaries on the ecosystem of the Mid-Atlantic Bight was undertaken. Data were collected from excursions into the Hudson, Delaware and Chesapeake estuaries, three across-shelf and one along-shelf transects, and two time series stations. In all, 139 stations were occupied and 164 XBT soundings were taken. In addition to standard hydrographic measurements, nutrient , chlorophyll, particulate carbon and nitrogen, 14C, 15N, DNA, particle size, FTD, phytoplankton and zooplankton analyses were made.
Date: January 1, 1983
Creator: Behrens, W. & von Bock, K. (eds)
Partner: UNT Libraries Government Documents Department

A study of sediment motion and bottom boundary layer dynamics over the Middle Atlantic Bight shelf and upper slope. Final report

Description: This report summarizes research on circulation and particle dynamics over the Middle Atlantic Bight shelf and upper slope. It includes an overview of the field experiments conducted in the waters off North Carolina, and gives the principal results from these experiments.
Date: February 14, 2001
Creator: Churchill, James H. & Williams, Albert J.
Partner: UNT Libraries Government Documents Department

On the mass and salt budgets for a region of the continental shelf in the southern Mid-Atlantic Bight

Description: Two field studies were conducted across and along the continental shelf, one from February to May 1996 (deployment 1) and the other from July to October 1996 (deployment 2), in part to determine the mass and salt budgets of shelf water from south of Cape Henry to north of Cape Hatteras, the southernmost portion of the Mid-Atlantic Bight. The temporal means of current meter records indicated that most of the water enters the region across its northern boundary near the shelf break as part of a southward, alongshore current and exits the southeast corner as a southeastward flowing current. Estimates of the volume transports indicated that not all the transport across the northern boundary was accounted for by transport across the southern boundary, and that the remainder occurred as a broad, diffusive flow across the eastern boundary at the shelf break. Time series of volume transport across northern and southern boundaries were very similar and associated with variations in the alongshore wind stress and sea level, indicative of a geostrophic balance. Examination of the individual current meter records indicated these fluctuations were very barotropic even during deployment 2, which included the stratified summer season. Time series of the volume transport across the eastern boundary at the shelf break strongly mirrored the volume transport across the northern boundary minus that across the southern boundary, suggesting that the inferred eastern boundary transport was real and accommodated whatever the southern boundary could not. The turbulent salt flux across each boundary contributes very little to the net respective mass fluxes because the salt fluxes are almost governed by current velocity fields. The instantaneous and mean salt fluxes across each boundary were very well approximated by the instantaneous and mean volume transports across the boundary times the deployment average salinity across that boundary, respectively. The ...
Date: December 1, 2001
Creator: Kim, Yoo Yin; Weatherly, Georges L. & Pietrafesa, Leonard J.
Partner: UNT Libraries Government Documents Department

Atlantic Coastal experiment III, FRV Delaware II cruise, 17-27 May 1977 and R/V ONRUST cruise, 28-30, June 1977. Data report

Description: The DELAWARE II and ONRUST cruises, continuations of Atlantic Coastal Experiment III, were made during May and late June, 1977, to compare seasonal changes in chlorophyll a, nitrogen nutrient, dissolved oxygen and phytoplankton composition within the mid-Atlantic and New York Bights. Data from 106 stations and 3300 km of surface mapping are reported as classical hydrographic listings, areal and/or vertical contours of chlorophyll a, inorganic nitrogen and salinity, and listings of phytoplankton species abun- dance. Temperature profiles from 100 stations are included, as well as res- piration experiments [ETS assay] for the dinoflagellate, Ceratium tripos.
Date: September 1, 1980
Creator: Malloy, S.; Stoddard, A. & von Bock, K. (eds.)
Partner: UNT Libraries Government Documents Department

Carbon transport in the bottom boundary layer. Final report

Description: This report summarizes the activities and findings from a field experiment devised to estimate the rates and mechanisms of transport of carbon across the continental shelves. The specific site chosen for the experiment was the mid-Atlantic Bight, a region off the North Carolina coast. The experiment involved a large contingent of scientists from many institutions. The specific component of the program was the transport of carbon in the bottom boundary layer. The postulate mechanisms of transport of carbon in the bottom boundary layer are: resuspension and advection, downward deposition, and accumulation. The high turbulence levels in the bottom boundary layer require the understanding of the coupling between turbulence and bottom sediments. The specific issues addressed in the work reported here were: (a) What is the sediment response to forcing by currents and waves? (b) What is the turbulence climate in the bottom boundary layer at this site? and (c) What is the rate at which settling leads to carbon sequestering in bottom sediments at offshore sites?
Date: October 5, 1998
Creator: Agrawal, Y.C.
Partner: UNT Libraries Government Documents Department

Sea floor cycling of organic matter in the continental margin of the mid-Atlantic Bight. Final report, May 1, 1995--April 30, 1998

Description: The objective of this project was to examine quantitatively the cycling of organic matter at the sea floor of the mid-Atlantic Bight continental margin. This information would be used to better understand sedimentary geochemical processes and, when used in conjunction with other measurements made within the DOE Ocean Margins Program, would be used to constrain the offshore and surface-to-deep water transport of organic carbon in this region. The latter information is critical in assessing the role of continental margins in the sequestration of anthropogenic carbon dioxide, the dominant greenhouse gas, in the deep ocean. Because the build-up of greenhouse gases in the atmosphere may cause significant changes in climate, this project had major societal importance.
Date: December 31, 1998
Creator: Jahnke, R.A.
Partner: UNT Libraries Government Documents Department

A study of sediment motions and bottom layer dynamics over the Middle Atlantic Bight shelf and upper slope. Final technical report, 1 June 1992--31 May 1995

Description: A study of sediment dynamics over the Middle Atlantic Bight (MAB) in the vicinity of the Cape Hatteras Confluence (CHC), including the mouths of estuaries, the shelf and the slope, was carried out by investigators at North Carolina State University as part of the Department of Energy Ocean Margins Program. Studied were processes effecting sediment motion. In particular, the processes which determine rates of vertical transport of dissolved carbon dioxide and organic matter and particulates to and from the bottom by turbulent mixing resuspension and particulate sinking and vertical motions induced by BBL convergences; especially during periods of storm activity when both surface waves and currents are maxima.
Date: December 31, 1995
Creator: Pietrafesa, L.J.
Partner: UNT Libraries Government Documents Department

Surficial bioturbation and rapid benthic remineralization in the Cape Hatteras shelf/slope region. Final report

Description: This is a final report for the DOE of grant DE-FG02-92ER61464 ''Surficial bioturbation and rapid benthic remineralization in the Cape Hatteras shelf slope region''. Over the past 6 years we have participated in a multidisciplinary field study called the Ocean margins Program (OMP) to examine the importance of continental margins in the global carbon cycle. Specifically, we have focused on the southern portion of the Mid-Atlantic Bight between Cape Hatteras and Chesapeake Bay where a large flux of freshwater and organic carbon enters the North Atlantic Ocean. Additionally, during the first stage of this project, we developed the use of CM-a distributions in sediments as a quantitative indicator of benthic C flux and remineralization rates. The primary objective of our research group has been to understand mechanisms and quantify biogeochemical processes in the seabed that affect cycling, flux, and storage of carbon on the ocean margin of the Mid-Atlantic Bight.
Date: March 17, 1999
Creator: Aller, Robert C.; Aller, Josephine Y.; Lee, C. & Cochran, J. Kirk
Partner: UNT Libraries Government Documents Department

Burial, remineralization and utilization of organic matter at the sea floor under a strong western boundary current. Final report, May 1, 1992--April 30, 1995

Description: The overall goals of this project were to quantify the rates of organic carbon export from the southern mid-Atlantic Bight and to quantify the rates at which carbon is exchanged between the inorganic and organic pools within the bottom sediments. This information is necessary to constrain the role of the oceans in the control of carbon dioxide released to the atmosphere in association with energy production. During this project, in situ benthic flux chamber incubations have been performed at six sites on the continental slope and rise adjacent to Cape Hatteras. Based on the analysis of the time-series samples recovered during each experiment, the sea floor exchange rates of the major biogenic elements, oxygen, carbon, nitrogen, phosphorus and silicon were calculated. From the estimated benthic flux rates and the ancillary pore water and sediment analyses, the deposition, remineralization and burial rates of organic carbon to the sea floor in this area was evaluated. This information has been incorporated into regional and global assessments of organic carbon fluxes to the deep sea.
Date: August 24, 1995
Creator: Jahnke, R.A.
Partner: UNT Libraries Government Documents Department

Final Technical Report: DOE-Biological Ocean Margins Program. Microbial Ecology of Denitrifying Bacteria in the Coastal Ocean.

Description: The focus of our research was to provide a comprehensive study of the bacterioplankton populations off the coast of New Jersey near the Rutgers University marine field station using terminal restriction fragment polymorphism analysis (TRFLP) coupled to 16S rRNA genes for large data set studies. Our three revised objectives to this study became: (1) to describe bacterioplankton population dynamics in the Mid Atlantic Bight using TRFLP analysis of 16S rRNA genes. (2) to determine whether spatial and temporal factors are driving bacterioplankton community dynamics in the MAB using monthly samping along our transect line over a 2-year period. (3) to identify dominant members of a coastal bacterioplankton population by clonal library analysis of 16S rDNA genes and sequencing of PCR product corresponding to specific TRFLP peaks in the data set. Although open ocean time-series sites have been areas of microbial research for years, relatively little was known about the population dynamics of bacterioplankton communities in the coastal ocean on kilometer spatial and seasonal temporal scales. To gain a better understanding of microbial community variability, monthly samples of bacterial biomass were collected in 1995-1996 along a 34-km transect near the Long-Term Ecosystem Observatory (LEO-15) off the New Jersey coast. Surface and bottom sampling was performed at seven stations along a transect line with depths ranging from 1 to 35m (n=178). The data revealed distinct temporal patterns among the bacterioplankton communities in the Mid-Atlantic Bight rather than grouping by sample location or depth (figure 2-next page). Principal components analysis models supported the temporal patterns. In addition, partial least squares regression modeling could not discern a significant correlation from traditional oceanographic physical and phytoplankton nutrient parameters on overall bacterial community variability patterns at LEO-15. These results suggest factors not traditionally measured during oceanographic studies are structuring coastal microbial communities.
Date: January 1, 2013
Creator: Kerkhof, Lee
Partner: UNT Libraries Government Documents Department

Burial, remineralization and utilization of organic matter at the seafloor under a strong western boundary current. Annual progress report, 1 May 1993--30 April 1994

Description: The overall objectives of this project are to quantify the rates of organic carbon export from the southern mid-Atlantic Bight and to quantify the rates at which carbon is exchanged between the inorganic and organic pools within the bottom sediments. The strategy for achieving these goals is to quantify the rates of benthic exchange and burial of bioactive elements including oxidants (such as oxygen, nitrate, sulfate), micronutrient, and carbon system parameters on the continental shelf, slope and rise regions within and adjacent to the south portion of the mid-Atlantic Bight. This information, in conjunction with burial rates provided by others in this program, will be used to determine the locations and rates of export and oxidative loss of organic matter from the shelf. During this past funding period, three expeditions were completed to the study region, successfully conducting 6 in situ benthic flux chamber experiments. The results provide an initial assessment of the magnitude and location of organic matter export from the southern Middle Atlantic Bight shelf and of the importance of this region as a supplier of organic carbon to the North Atlantic Ocean Basin.
Date: December 30, 1993
Creator: Jahnke, R.A.
Partner: UNT Libraries Government Documents Department

Time-series records of pCO{sub 2} and NO{sub 3} during the OMP Field Program: a final report for DOE Grant DE-FG03-96ER62224

Description: The specific goals of this research are to (1) determine daily and seasonal variability of seawater pCO{sub 2} partial pressure of CO{sub 2} and NO{sub 3} in Middle Atlantic Bight (MAB) waters; (2) estimate seasonal CO{sub 2} fluxes between the MAB shelf and the atmosphere; and (3) determine the primary controls of surface seawater pCO{sub 2} in this coastal system. During the first phase of the DOE-OMP (1992-1995) we developed the Submersible Autonomous Moored Instrument for CO{sub 2} (SAMI-CO{sub 2}) which is designed to measure seawater CO{sub 2} on ocean moorings for extended periods.
Date: April 1, 2000
Creator: DeGrandpre, Michael D.
Partner: UNT Libraries Government Documents Department

Circulation and exchange at the continental shelf and slope, SEEP-II

Description: This project is a component of the SEEP-2 program to study shelf-slope exchange in the southern Middle Atlantic bight (MBA). It represents the physical oceanographic portion of the SEEP-2 research at Lamont-Doherty Geological Observatory (L-DGO). Since the work consists of two parts: data analysis and theoretical modeling, this report will be divided into two parts to describe the progress of each activity. It covers work performed during the time interval March to December 1990 and is a sequel to the report submitted in February 1990. 25 figs.
Date: January 1, 1990
Creator: Houghton, R.W. & Ou, Hsien-Wang.
Partner: UNT Libraries Government Documents Department

[Tools for determining health of phytoplankton cells]

Description: The primary purpose of the proposed research is to develop molecular tools for determining the health of marine phytoplankton on an individual cell basis. Since the definition of healthy in phytoplankton cells is elusive, we propose to develop markers for several different metabolic processes indicative of physiological state: photosynthetic activity, esterase activity, membrane permeability, and mitochondrial activity. One underlying motivation is to develop methods which will allow us to evaluate the hypothesis that, while healthy cells release very little dissolved organic carbon (DOC), many phytoplankton communities are comprised of unhealthy or physiologically stressed cells which release a large proportion of total photosynthate directly into the pool of labile DOC. This is proposed to be especially true in continental shelf and coastal environments where zones of productivity are patchy and phytoplankton populations adapted to one regime can be easily transported into waters which differ in salinity, nutrient supply, and/or turbidity. The significance of the work, however, extends beyond this immediate goal since there are presently relatively few methods which allow us to estimate the physiological state of phytoplankton cells.When we evaluate population sizes of phytoplankton in the water column or examine fecal pellets, particulate aggregates, or other material, we generally work in ignorance of the activity of the cells except as the average cell-specific activity is estimated from bulk measurements. This approach effectively hides any differences in the relative contribution of different taxa or individuals to overall productivity eventhough most flux processes are sensitive to physiological and taxonomically determined differences among members of the community.
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department

Simulation analysis of moored fluorometer time series from the Mid-Atlantic Bight during 1987--1990

Description: The goal of the previous research during 1987-1990 within the DOE (Department of Energy) Shelf Edge Exchange Processes (SEEP) program in the Mid-Atlantic Bight was to understand the physical and biogeochemical processes effecting the diffusive exchange of the proxies of energy-related, by-products associated with particulate matter between estuarine, shelf, and slope waters on this continental margin. As originally envisioned in the SEEP program plan, SEEP-III would take place at Cape Hatteras to study the advective exchange of materials by a major boundary current. One problem of continuing interest is the determination of the local assimilative capacity of slope waters and sediments off the eastern seaboard of the US to lengthen the pathway between potentially harmful energy by-products and man. At basin scales, realistic specification of the lateral transport by western boundary currents of particulate matter is a necessary input to global models of carbon/nitrogen cycling. Finally, at these global scales, the generic role of continental margins in cycling greenhouse gases, e.g. CO{sub 2}, CH{sub 4}, and N{sub 2}O, is now of equal interest. This continuing research of model construction and evaluation within the SEEP program focuses on all three questions at local, regional, and basin scales. Results from SEEP-I and II are discussed as well as plans for SEEP-III. 14 figs., 3 tabs.
Date: January 1, 1990
Creator: Walsh, J.J.
Partner: UNT Libraries Government Documents Department