Now showing items 67-86 of 976

    • Biogeochemistry of dissolved free amino acids in marine sediments 

      Henrichs, Susan M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-08)
      Dissolved free amino acids (DFAA) were measured in interstitial water samples squeezed from sediments collected in a variety of depositional environments. These sediments were further characterized by measurements of ...
    • The biogeochemistry of lipid derived infochemical signals in the ocean 

      Edwards, Bethanie R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2016-02)
      The role of oxylipins in ocean biogeochemistry was investigated using microcosm amendment experiments, environmental lipidomics, and culture based studies. Oxylipins are a bioactive class of secondary metabolites produced ...
    • The biogeochemistry of marine nitrous oxide 

      Frame, Caitlin H. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-06)
      Atmospheric nitrous oxide N2O concentrations have been rising steadily for the past century as a result of human activities. In particular, human perturbation of the nitrogen cycle has increased the N2O production rates ...
    • The biogeochemistry of marine particulate trace metals 

      Ohnemus, Daniel C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2014-02)
      Marine particles include living and non-living solid components of seawater, representing a dynamic and chemically diverse mixture of phases. Through a combination of method development, basin-scale particulate collection ...
    • The biogeography of the Plastisphere : implications for policy 

      Amaral-Zettler, Linda A.; Zettler, Erik R.; Slikas, Beth; Boyd, Gregory D.; Melvin, Donald W.; Morrall, Clare E.; Proskurowski, Giora; Mincer, Tracy J. (Ecological Society of America, 2015-12)
      Microplastics (particles less than 5 mm) numerically dominate marine debris and occur from coastal waters to mid-ocean gyres, where surface circulation concentrates them. Given the prevalence of plastic marine debris (PMD) ...
    • Biological consumption of carbon monoxide in Delaware Bay, NW Atlantic and Beaufort Sea 

      Xie, Huixiang; Zafiriou, Oliver C.; Umile, Thomas P.; Kieber, David J. (Inter-Research, 2005-04-13)
      Microbial consumption is the dominant sink of oceanic carbon monoxide (CO), one of the major carbon-containing photoproducts of chromophoric dissolved organic matter in marine waters. This study presents first-order microbial ...
    • Biosynthesis of coral settlement cue tetrabromopyrrole in marine bacteria by a uniquely adapted brominase-thioesterase enzyme pair 

      El Gamal, Abrahim; Agarwal, Vinayak; Diethelm, Stefan; Rahman, Imran; Schorn, Michelle A.; Sneed, Jennifer M.; Louie, Gordon V.; Whalen, Kristen E.; Mincer, Tracy J.; Noel, Joseph P.; Paul, Valerie J.; Moore, Bradley S. (2016-02)
      Halogenated pyrroles (halopyrroles) are common chemical moieties found in bioactive bacterial natural products. The halopyrrole moieties of mono- and di- halopyrrole-containing compounds arise from a conserved mechanism ...
    • Blank assessment for ultra-small radiocarbon samples : chemical extraction and separation versus AMS 

      Santos, Guaciara M.; Southon, John R.; Drenzek, Nicholas J.; Ziolkowski, Lori A.; Druffel, Ellen R. M.; Xu, Xiaomei; Zhang, Dachun; Trumbore, Susan E.; Eglinton, Timothy I.; Hughen, Konrad A. (Dept. of Geosciences, University of Arizona, 2010-08)
      The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ~0.001 mg of carbon (C). Mass-balance background corrections for ...
    • A bottom-up view of the biological pump : modeling source funnels above ocean sediment traps 

      Siegel, David A.; Fields, E.; Buesseler, Ken O. (2007-10-21)
      The sinking of particles that make up the biological pump is not vertical, but nearly horizontal. This means that the locations where the particles are formed may be distant from their collection in a sediment trap. This ...
    • Building a window to the sea : Ocean Research Interactive Observatory Networks (ORION) 

      Schofield, Oscar M. E.; Tivey, Margaret K. (Oceanography Society, 2004-06)
      For centuries, oceanographers have relied on data and observations about the ocean and the seafloor below gathered from ships during cruises of limited duration. This expeditionary research approach has resulted in ...
    • Bulk organic geochemistry of sediments from Puyehue Lake and its watershed (Chile, 40°S) : implications for paleoenvironmental reconstructions 

      Bertrand, Sebastien; Sterken, Mieke; Vargas-Ramirez, Lourdes; De Batist, Marc; Vyverman, Wim; Lepoint, Gilles; Fagel, Nathalie (2009-03-04)
      Since the last deglaciation, the mid-latitudes of the southern Hemisphere have undergone considerable environmental changes. In order to better understand the response of continental ecosystems to paleoclimate changes in ...
    • Cadmium and phosphate in coastal Antarctic seawater : implications for Southern Ocean nutrient cycling 

      Hendry, Katharine R.; Rickaby, Rosalind E. M.; de Hoog, Jan C. M.; Weston, Keith; Rehkamper, Mark (2008-09)
      Cadmium is a biologically important trace metal that co-varies with phosphate (PO43- or Dissolved Inorganic Phosphate, DIP) in seawater. However, the exact nature of Cd uptake mechanisms and the relationship with phosphate ...
    • Cadmium isotope variations in the Southern Ocean 

      Xue, Zichen; Rehkamper, Mark; Horner, Tristan J.; Abouchami, Wafa; Middag, Rob; van de Flierdt, Tina; de Baar, Hein J. W. (2013-09-09)
      Cadmium concentrations and isotope compositions were determined for 47 seawater samples from the high nutrient low chlorophyll (HNLC) zone of the Atlantic sector of the Southern Ocean. The samples include 13 surface ...
    • Cadmium isotopic composition in the ocean 

      Lacan, Francois; Francois, Roger; Ji, Yongcheng; Sherrell, Robert M. (2006-06-29)
      The oceanic cycle of cadmium is still poorly understood, despite its importance for phytoplankton growth and paleoceanographic applications. As for other elements that are biologically recycled, variations in isotopic ...
    • Capturing dynamics of marine inorganic carbon fluxes from diurnal to decadal timescales 

      Chu, Sophie N. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2017-02)
      The marine carbon cycle plays an important role in regulating Earth’s climate. The vastness of the open ocean and the large variability in the coastal ocean provide obstacles to accurately quantify storage and transport ...
    • Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene 

      Doney, Scott C.; Schimel, David S. (2007-05-29)
      The global carbon and climate systems are closely intertwined, with biogeochemical processes responding to and driving climate variations. Over a range of geological and historical time-scales, warmer climate conditions ...
    • A carbon budget for a naturally iron fertilized bloom in the Southern Ocean 

      Morris, Paul J.; Sanders, Richard J. (American Geophysical Union, 2011-07-08)
      Subantarctic islands in the high-nutrient, low-chlorophyll (HNLC) Southern Ocean are natural sources of iron and stimulate blooms in their proximity, such as the one observed close to the Crozet Islands (52°E, 46°S). During ...
    • Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt 

      Rosengard, Sarah Z.; Lam, Phoebe J.; Balch, William M.; Auro, Maureen E.; Pike, Steven M.; Drapeau, David T.; Bowler, Bruce C. (Copernicus Publications on behalf of the European Geosciences Union, 2015-07-02)
      Sequestration of carbon by the marine biological pump depends on the processes that alter, remineralize, and preserve particulate organic carbon (POC) during transit to the deep ocean. Here, we present data collected from ...
    • Carbon fluxes and pelagic ecosystem dynamics near two western Antarctic Peninsula Adélie penguin colonies : an inverse model approach 

      Sailley, Sevrine F.; Ducklow, Hugh W.; Moeller, Holly V.; Fraser, William R.; Schofield, Oscar M. E.; Steinberg, Deborah K.; Garzio, Lori M.; Doney, Scott C. (Inter-Research, 2013-10-31)
      An inverse food-web model for the western Antarctic Peninsula (WAP) pelagic food web was constrained with data from Palmer Long Term Ecological Research (PAL-LTER) project annual austral summer sampling cruises. Model ...
    • Carbon isotope composition of organic compounds produced by abiotic synthesis under hydrothermal conditions 

      McCollom, Thomas M.; Seewald, Jeffrey S. (2006-01-12)
      Although it is widely believed that production of organic compounds by Fischer-Tropsch synthesis and related processes occurs in many geologic environments, unambiguous identification of compounds with an abiotic origin ...