Oceanography: Recent submissions
Now showing items 61-80 of 152
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Water Column Seismic Images as Maps of Temperature Gradient
(2009-03)Multichannel seismic imaging of ocean water column features is anew interdisciplinary study that may become an accepted oceanographic toot in coming years. We now know that reflectors are associated with water column ... -
Anisotropy in high-frequency broadband acoustic backscattering in the presence of turbulent microstructure and zooplankton
(2012-08)High-frequency broadband (120-600 kHz) acoustic backscattering measurements have been made in the vicinity of energetic internal waves. The transducers on the backscattering system could be adjusted so as to insonify the ... -
Acoustic scattering from density and sound speed gradients: Modeling of oceanic pycnoclines
(Published for the Acoustical Society of America through the American Institute of Physics, 2012-01)A weak-scattering model that allows prediction of acoustic scattering from oceanic pycnoclines (and the accompanying sound speed gradients) based on hydrographic profiles is described. Model predictions, based on profiles ... -
Acoustic scattering from double-diffusive microstructure
(2007-09)Laboratory measurements of high-frequency broadband acoustic backscattering (200-600 kHz) from the diffusive regime of double-diffusive microstructure have been performed. This type of microstructure, which was characterized ... -
Effect of the nonlinearity of the carbonate system on partial pressure of carbon dioxide in the oceans
(1995-04)Partial pressure of CO sub(2) is a nonlinear function of several seawater properties. Due to the nonlinearity in this relationship, the partial pressure of a uniform ocean would be different from that of a nonuniform ocean ... -
A seasonal study of methyl bromide concentrations in the North Atlantic (35 degrees-60 degrees N)
(2006-04)Methyl bromide concentrations in and over the North Atlantic were examined during spring, summer, and fall 2003. The results demonstrate that seasonality plays a great role in controlling methyl bromide fluxes from and ... -
Composite global emissions of reactive chlorine from anthropogenic and natural sources: Reactive Chlorine Emissions Inventory
(1999-04)Emission inventories for major reactive tropospheric Cl species (particulate Cl, HCl, ClNO2, CH3Cl, CHCl3, CH3CCl3, C2Cl4, C2HCl3, CH2Cl2 and CHClF2) were integrated across source types (terrestrial biogenic and oceanic ... -
Methyl-Chloride (Ch3cl) Production in Phytoplankton Cultures
(1995-01)Unialgal nonaxenic cultures of seven species of phytoplankton, including both warm- and cold-water organisms, were examined under halocarbon-clean conditions for the production of CH3Cl. Incubations of all species showed ... -
Carbon disulfide in the North Atlantic and Pacific Oceans
(American Geophysical Union, Washington, DC, 1999-03)No abstract available. -
Methyl iodide in the NW Atlantic: Spatial and seasonal variation
(2009-07)While the global ocean is an important source of atmospheric methyl iodide (CH(3)I), the major producers of CH(3)I within the ocean remain unclear. During a seasonal study in the NW Atlantic, the relationship between CH(3)I ... -
A new measurement of CO sub(2) eddy flux in the nearshore atmospheric surface layer
(1991)Fluxes of CO sub(2) in the atmospheric surface layer have been measured at a shoreline site by the eddy correlation method using a new CO sub(2) sensor with greater sensitivity than the ones used in earlier studies. In ... -
Measurements of methyl chloride in the Northwest Atlantic
(American Geophysical Union, 1994-04)Methyl chloride was measured directly in seawater using a purge and trap system and gas chromatography with electron capture detection. The results indicate that surface waters of the northwest Atlantic are a source of ... -
Aerobic hydrogen production and dinitrogen fixation in the marine cyanobacterium Trichodesmium erythraeum IMS101
(2008-11)Rates of hydrogen production and acetylene reduction were measured in aerobic cultures of the marine cyanobacterium Trichodesmium erythraeum IMS101 grown in a supplemented seawater medium low in combined inorganic nitrogen. ... -
Production of chlorinated hydrocarbons and methyl iodide by the red microalga Porphyridium purpureum
(1999-05)Two experiments were performed using axenic batch cultures of the red microalga Porphyridium purpureum. The cultures were grown in sealed 5-liter glass vessels under a high-purity artificial atmosphere and analyzed for the ... -
Dissolved organic phosphorus concentrations in the northeast subarctic Pacific Ocean
(1992)Shipboard determinations of dissolved organic P (DOP) concentrations were made for NE subarctic Pacific Ocean samples with three different oxidation-hydrolysis methods: UV irradiation, acid persulfate digestion, and a ... -
An isotopic labeling method for determining production of volatile organohalogens by marine microalgae
(2000-12)An isotopic method has been developed to establish the biological production of volatile organohalogens. The marine microalgae Porphyridium purpureum and Dunaliella tertiolecta were grown in seawater medium containing ... -
Ocean-atmosphere exchange of methyl bromide: NW Atlantic and Pacific Ocean studies
(1998-07)Measurements of methyl bromide partial pressure and concentration in surface water and air samples in the NW Atlantic Ocean in July 1995 and the Pacific Ocean in October 1995 are presented, Mean atmospheric mixing ratios ... -
Photochemical Production of Methyl-Iodide in Seawater
(1994-08)It is generally accepted that methyl iodide is a major contributor to the flux of iodine from the ocean to the atmosphere, but its sources in the ocean are largely unknown, an exception being production by certain species ... -
Trichloroethylene and tetrachlorethylene in Atlantic waters
(American Geophysical Union, Washington, DC, 2001-11)No abstract available. -
Bromoperoxidase and iodoperoxidase enzymes and production of halogenated methanes in marine diatom cultures
(1996-09)Halogenated methanes produced in the oceans are important as carriers of chlorine, bromine, and iodine into the atmosphere. There they play roles in the regulation of ozone in the stratosphere and perhaps in the Arctic ...