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Full-Text Articles in Physical Sciences and Mathematics

Modeling Distinct Vertical Biogeochemical Structure Of The Black Sea: Dynamical Coupling Of The Oxic, Suboxic, And Anoxic Layers, T Oguz, Hw Ducklow, P Malanotte-Rizzoli Nov 2000

Modeling Distinct Vertical Biogeochemical Structure Of The Black Sea: Dynamical Coupling Of The Oxic, Suboxic, And Anoxic Layers, T Oguz, Hw Ducklow, P Malanotte-Rizzoli

VIMS Articles

A one-dimensional, vertically resolved, physical-biogeochemical model is used to provide a unified representation of the dynamically coupled oxic-suboxic-anoxic system for the interior Black Sea. The model relates the annual cycle of plankton production in the form of a series of successive phytoplankton, mesozooplankton, and higher consumer blooms to organic matter generation and to the remineralization-ammonification-nitrification-dentrification chain of the nitrogen cycle as well as to anaerobic sulfide oxidation in the suboxic-anoxic interface zone. The simulations indicate that oxygen consumption during remineralixation and nitrification, together with a lack of ventilation of subsurface waters due to the presence of strong stratification, are the …


Environmental Survey Of Potential Sand Resource Sites, Offshore Delaware And Maryland : Final Report, Virginia Institute Of Marine Science Aug 2000

Environmental Survey Of Potential Sand Resource Sites, Offshore Delaware And Maryland : Final Report, Virginia Institute Of Marine Science

Reports

  • Technical summary / Carl H. Hobbs
  • Non-technical summary / Carl H. Hobbs
  • Part. 1. Benthic mapping and resource evaluation of potential sand mining areas, offshore Mayland and Delaware, 1998-1999 / G.R. Cutter and R.J. Diaz
  • Part. 2. Transitory species (vertebrate nekton) / John A. Musick
  • Part. 3. Literature survey of reproductive finfish and ichthyoplankton present in proposed sand mining locations within the Middle Atlantic Bight / John Olney, Donna Marie Bilkovic
  • Part. 4. Potential modifications to waves due to dredging and other oceanographic considerations / Jerome P.-Y. Maa, Sung C. Kim
  • Part. 5. Maryland-Delaware shoreline : long-term trends and short-term …


Radiocarbon Distributions In Southern Ocean Dissolved And Particulate Organic Matter, Erm Druffel, Je Bauer May 2000

Radiocarbon Distributions In Southern Ocean Dissolved And Particulate Organic Matter, Erm Druffel, Je Bauer

VIMS Articles

Dissolved organic carbon (DOC) is the largest actively exchanging pool of organic carbon in the ocean, yet its sources and sinks are not well constrained. The average C-14 ages of DOC in the deep N. Atlantic and N. Pacific Oceans are 4,000 [Bauer et al., 1992; Druffel et al., 1992] and 6,000 years [Williams and Druffel, 1987], respectively, and represent the beginning and end of the deep ocean conveyor [Broecker, 1991]. Here we report that the deep Southern Ocean DOC has a C-14 age (5,600 y) much closer to that of the deep N. Pacific, but its concentration in seawater …


A Stable Isotopic Study To Determine Carbon And Nitrogen Cycling In A Disturbed Southern Californian Forest Ecosystem, S Korontzi, Sa Macko, Iris C. Anderson Mar 2000

A Stable Isotopic Study To Determine Carbon And Nitrogen Cycling In A Disturbed Southern Californian Forest Ecosystem, S Korontzi, Sa Macko, Iris C. Anderson

VIMS Articles

This study utilized isotope analyses to contrast nitrogen and carbon dynamics at four sites located along an air pollution gradient in the San Bernardino National Forest in southern California. Natural N-15 and C-13 abundances along with nutritional and edaphic properties were determined in soil, litter, and vegetation samples. Mean bulk nitrogen delta(15)N values of soil and vegetation at Camp Paivika (CP), the most polluted site, were at least 1.7 parts per thousand more enriched than the other, less polluted sites. Mean soil delta(15)NH(4)(+) was also significantly enriched in N-15 at CP compared to Barton Flats (BF), the least polluted site, …


Organic Matter Composition Of Sediments And The History Of Eutrophication And Anoxia In The Mesohaline Chesapeake Bay, Andrew R. Zimmerman Jan 2000

Organic Matter Composition Of Sediments And The History Of Eutrophication And Anoxia In The Mesohaline Chesapeake Bay, Andrew R. Zimmerman

Dissertations, Theses, and Masters Projects

To evaluate the effects of anthropogenic alteration of the Chesapeake Bay (CB) watershed since European settlement, the historical progression of eutrophication and anoxia in the mesohaline region of CB was reconstructed. Lipid biomarker and carbon and nitrogen stable isotopic and elemental composition of CB surficial sediments were examined seasonally in order to identify the present sources of organic matter to CB sediments and the processes controlling their distribution. Temporal variability in surficial sediment composition could be linked to seasonal changes in phytoplankton community composition and biomass while spatial variation was dominated by the delivery of alloclithonous versus autochthonous sources of …


Sand- And Clay-Size Mineralogy Of The Ganges And Brahmaputra Rivers: Records Of River Switching And Late-Quaternary Climate Change, David Carlson Heroy Jan 2000

Sand- And Clay-Size Mineralogy Of The Ganges And Brahmaputra Rivers: Records Of River Switching And Late-Quaternary Climate Change, David Carlson Heroy

Dissertations, Theses, and Masters Projects

No abstract provided.


Carbon Dynamics In A Tidal Freshwater Marsh, Scott C. Neubauer Jan 2000

Carbon Dynamics In A Tidal Freshwater Marsh, Scott C. Neubauer

Dissertations, Theses, and Masters Projects

The sources and fates of carbon in a tidal freshwater marsh (Sweet Hall marsh; Pamunkey River, Virginia) were determined to understand the role that these marshes play with respect to estuarine carbon cycling. A carbon gas flux model, based on measured carbon dioxide and methane fluxes, was developed to calculate annual rates of macrophyte and microalgal photosynthesis and community and belowground respiration. Because carbon fluxes out of marsh sediments may underestimate true belowground respiration if sediment-produced gases are transported through plant tissues, gross nitrogen mineralization was used as a proxy for belowground carbon respiration. Annual community respiration exceeded gross photosynthesis, …


Supplemental Data: Environmental Survey Of Potential Sand Resource Sites Offshore Delaware And Maryland, Virginia Institute Of Marine Science Jan 2000

Supplemental Data: Environmental Survey Of Potential Sand Resource Sites Offshore Delaware And Maryland, Virginia Institute Of Marine Science

Data

The APR file "mdde_habitat" and the directories "gisdata", "images", and "temp" together are an appendix to Part 1, "Benthic Habit Mapping and Resource Evaluation of Potential Sand Mining Areas Offshore Maryland and Delaware, 1998-1999" that was created with and must be read with "ArcView" (tm) software with the "Spatial Analyst" extension. To view the project, start the ArcView program and open the project file, mmde-habitat.apr, when prompted. The project should enable the necessary extensions. It is a very large file and may take 5 to 10 minutes to load.