Now showing items 49-68 of 781

  • Biogeochemical applications of compound-specific radiocarbon analysis 

    Pearson, Ann (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1999-10)
    Compound-specific carbon isotopic (δ13C and Δ14C) data are reported for lipid biomarkers isolated from Santa Monica Basin (SMB) and Santa Barbara Basin (SBB) surface sediments. These organic compounds represent ...
  • Biogeochemical iron budgets of the Southern Ocean south of Australia : decoupling of iron and nutrient cycles in the subantarctic zone by the summertime supply 

    Bowie, Andrew R.; Lannuzel, Delphine; Remenyi, Tomas A.; Wagener, Thibaut; Lam, Phoebe J.; Boyd, Philip W.; Guieu, Cecile; Townsend, Ashley T.; Trull, Thomas W. (American Geophysical Union, 2009-12-31)
    Climate change is projected to significantly alter the delivery (stratification, boundary currents, aridification of landmasses, glacial melt) of iron to the Southern Ocean. We report the most comprehensive suite of ...
  • Biogeochemical relationships between ultrafiltered dissolved organic matter and picoplankton activity in the Eastern Mediterranean Sea 

    Meador, Travis B.; Gogou, Alexandra; Spyres, Georgina; Herndl, Gerhard J.; Krasakopoulou, Evangelia; Psarra, Stella; Yokokawa, Taichi; De Corte, Daniele; Zervakis, Vassilis; Repeta, Daniel J. (2009-12-10)
    We targeted the warm, subsurface waters of the Eastern Mediterranean Sea (EMS) to investigate processes that are linked to the chemical composition and cycling of dissolved organic carbon (DOC) in seawater. The apparent ...
  • Biogeochemical responses to late-winter storms in the Sargasso Sea, III—Estimates of export production using 234Th:238U disequilibria and sediment traps 

    Maiti, Kanchan; Benitez-Nelson, Claudia R.; Lomas, Michael W.; Krause, Jeffrey W. (2009-01)
    Direct measurements of new production and carbon export in the subtropical North Atlantic Ocean appear to be too low when compared to geochemical based estimates. It has been hypothesized that episodic inputs of new ...
  • The biogeochemistry of 210Pb and 210Po in fresh waters and sediments 

    Benoit, Gaboury (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-01)
    The focus of this work was geochemical cycling of 210Pb in lakes, including the water column, sediments, and their interactions with each other. A special goal was to elucidate processes that might influence the distribution ...
  • The biogeochemistry of carbon across a gradient of streams and rivers within the Congo Basin 

    Mann, Paul J.; Spencer, Robert G. M.; Dinga, B. J.; Poulsen, John R.; Hernes, P. J.; Fiske, Gregory J.; Salter, M. E.; Wang, Zhaohui Aleck; Hoering, Katherine A.; Six, J.; Holmes, Robert M. (John Wiley & Sons, 2014-04-30)
    Dissolved organic carbon (DOC) and inorganic carbon (DIC, pCO2), lignin biomarkers, and theoptical properties of dissolved organic matter (DOM) were measured in a gradient of streams and rivers within the Congo Basin, with ...
  • The biogeochemistry of cobalt in the Sargasso Sea 

    Saito, Mak A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2001-02)
    Processes that enable marine phytoplankton to acquire trace metals are fundamental to our understanding of primary productivity and global carbon cycling. This thesis explored the biogeochemistry of cobalt using analytical ...
  • 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 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 ...
  • 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 ...
  • 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 ...
  • 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 ...