Now showing items 349-368 of 769

  • Impact of variable air-sea O2 and CO2 fluxes on atmospheric potential oxygen (APO) and land-ocean carbon sink partitioning 

    Nevison, Cynthia D.; Mahowald, Natalie M.; Doney, Scott C.; Lima, Ivan D.; Cassar, Nicolas (Copernicus Publications on behalf of the European Geosciences Union, 2008-06-02)
    A three dimensional, time-evolving field of atmospheric potential oxygen (APO ~O2/N2+CO2) was estimated using surface O2, N2 and CO2 fluxes from the WHOI ocean ecosystem model to force the MATCH atmospheric transport model. ...
  • The impact on atmospheric CO2 of iron fertilization induced changes in the ocean's biological pump 

    Jin, X.; Gruber, Nicolas; Frenzel, H.; Doney, Scott C.; McWilliams, James C. (Copernicus Publications on behalf of the European Geosciences Union, 2008-03-18)
    Using numerical simulations, we quantify the impact of changes in the ocean's biological pump on the air-sea balance of CO2 by fertilizing a small surface patch in the high-nutrient, low-chlorophyll region of the eastern ...
  • Impacts of increasing anthropogenic soluble iron and nitrogen deposition on ocean biogeochemistry 

    Krishnamurthy, Aparna; Moore, J. Keith; Mahowald, Natalie M.; Luo, Chao; Doney, Scott C.; Lindsay, Keith; Zender, Charles S. (American Geophysical Union, 2009-08-28)
    We present results from transient sensitivity studies with the Biogeochemical Elemental Cycling (BEC) ocean model to increasing anthropogenic atmospheric inorganic nitrogen (N) and soluble iron (Fe) deposition over the ...
  • Impacts of temporal CO2 and climate trends on the detection of ocean anthropogenic CO2 accumulation 

    Goodkin, Nathalie F.; Levine, Naomi M.; Doney, Scott C.; Wanninkhof, Rik (American Geophysical Union, 2011-09-21)
    A common approach for estimating the oceanic uptake of anthropogenic carbon dioxide (Canthro) depends on the linear approximation of oceanic dissolved inorganic carbon (DIC) from a suite of physical and biological ocean ...
  • Impacts of the Fukushima nuclear power plants on marine radioactivity 

    Buesseler, Ken O.; Aoyama, Michio; Fukasawa, Masao (American Chemical Society, 2011-10-20)
    The impacts on the ocean of releases of radionuclides from the Fukushima Dai-ichi nuclear power plants remain unclear. However, information has been made public regarding the concentrations of radioactive isotopes of iodine ...
  • Importance of passive diffusion in the uptake of polychlorinated biphenyls by phagotrophic protozoa 

    Kujawinski, Elizabeth B.; Farrington, John W.; Moffett, James W. (American Society for Microbiology, 2000-05)
    Unicellular protozoan grazers represent a size class of organisms where a transition in the mechanism of chlorobiphenyl (CB) introduction, from diffusion through surface membranes to ingestion of contaminated prey, could ...
  • An improvement in the small-volume technique for determining thorium-234 in seawater 

    Cai, Pinghe; Dai, Minhan; Lv, Dongwei; Chen, Weifang (2005-06-09)
    The recently developed 2‐5 L small‐volume MnO2 coprecipitation method for determining 234Th in seawater has provided a new way to substantially increase, both temporally and spatially, the sampling resolution of 234Th ...
  • Improvements to 232-thorium, 230-thorium, and 231- protactinium analysis in seawater arising from GEOTRACES intercalibration 

    Auro, Maureen E.; Robinson, Laura F.; Burke, Andrea; Bradtmiller, Louisa I.; Fleisher, Martin Q.; Anderson, Robert F. (Association for the Sciences of Limnology and Oceanography, 2012-07)
    The GEOTRACES program requires the analysis of large numbers of seawater samples for 232Th, 230Th, and 231Pa. During the GEOTRACES international intercalibration exercise, we encountered unexpected difficulties with recovery ...
  • Incidence of lesions on Fungiidae corals in the eastern Red Sea is related to water temperature and coastal pollution 

    Furby, Kathryn A.; Apprill, Amy; Cervino, J. M.; Ossolinski, J. E.; Hughen, Konrad A. (2014-03)
    As sea surface temperatures rise and the global human population increases, large-scale field observations of marine organism health and water quality are increasingly necessary. We investigated the health of corals from ...
  • Increase in mercury in Pacific yellowfin tuna 

    Drevnick, Paul E.; Lamborg, Carl H.; Horgan, Martin J. (2015-01)
    Mercury is a toxic trace metal that can accumulate to levels that threaten human and environmental health. Models and empirical data suggest that humans are responsible for a great deal of the mercury actively cycling ...
  • Increased accumulation of sulfur in lake sediments of the high Arctic 

    Drevnick, Paul E.; Muir, Derek C. G.; Lamborg, Carl H.; Horgan, Martin J.; Canfield, Donald E.; Boyle, John F.; Rose, Neil L. (2010-08-31)
    We report a synchronous increase in accumulation of reduced inorganic sulfur since c. 1980 in sediment cores from eight of nine lakes studied in the Canadian Arctic and Svalbard (Norway). Sediment incubations and detailed ...
  • Influence of protozoan grazing on the marine geochemistry of particle reactive trace metals 

    Barbeau, Katherine A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-05)
    Planktonic protozoan grazers have the potential to significantly affect the chemistry of particle-associated trace metals. This is due both to the importance of protists as consumers of bacterial-sized particles, and to ...
  • Influences on the oceanic biogeochemical cycling of the hybrid-type metals : cobalt, iron, and manganese 

    Noble, Abigail E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-02)
    Trace metal cycling is one of many processes that influence ocean ecosystem dynamics. Cobalt, iron, and manganese are redox active trace metal micronutrients with oceanic distributions that are influenced by both biological ...
  • An inland sea high nitrate-low chlorophyll (HNLC) region with naturally high pCO2 

    Murray, James W.; Roberts, Emily; Howard, Evan M.; O'Donnell, Michael; Bantam, Cory; Carrington, Emily; Foy, Mike; Paul, Barbara; Fay, Amanda (John Wiley & Sons, 2015-02-19)
    We present a time series of data for temperature, salinity, nitrate, and carbonate chemistry from September 2011 to July 2013 at the University of Washington's Friday Harbor Laboratories. Samples were collected at the ...
  • Inorganic carbon speciation and fluxes in the Congo River 

    Wang, Zhaohui Aleck; Bienvenu, Dinga Jean; Mann, Paul J.; Hoering, Katherine A.; Poulsen, John R.; Spencer, Robert G. M.; Holmes, Robert M. (John Wiley & Sons, 2013-02-14)
    Seasonal variations in inorganic carbon chemistry and associated fluxes from the Congo River were investigated at Brazzaville-Kinshasa. Small seasonal variation in dissolved inorganic carbon (DIC) was found in contrast ...
  • Insights into vitamin B12 production, acquisition, and use by marine microbes 

    Bertrand, Erin M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-02)
    The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the ...
  • Insights on geochemical cycling of U, Re and Mo from seasonal sampling in Boston Harbor, Massachusetts, USA 

    Morford, Jennifer L.; Martin, William R.; Kalnejais, Linda H.; Francois, Roger; Bothner, Michael H.; Karle, Ida-Maja (2006-10-23)
    This study examined the removal of U, Mo, and Re from seawater by sedimentary processes at a shallow-water site with near-saturation bottom water O2 levels (240-380 μmol O2/L), very high organic matter oxidation rates ...
  • Insights to magmatic–hydrothermal processes in the Manus back-arc basin as recorded by anhydrite 

    Craddock, Paul R.; Bach, Wolfgang (2010-06-16)
    Microchemical analyses of rare earth element (REE) concentrations and Sr and S isotope ratios of anhydrite are used to identify sub–seafloor processes governing the formation of hydrothermal fluids in the convergent ...
  • IntCal04 terrestrial radiocarbon age calibration, 0-26 cal kyr BP 

    Reimer, Paula J.; Baillie, Mike G. L.; Bard, Edouard; Bayliss, Alex; Beck, J. Warren; Bertrand, Chanda J. H.; Blackwell, Paul G.; Buck, Caitlin E.; Burr, George S.; Cutler, Kirsten B.; Damon, Paul E.; Edwards, R. Lawrence; Fairbanks, Richard G.; Friedrich, Michael; Guilderson, Thomas P.; Hogg, Alan G.; Hughen, Konrad A.; Kromer, Bernd; McCormac, Gerry; Manning, Sturt; Ramsey, C. Bronk; Reimer, Ron W.; Remmele, Sabine; Southon, John R.; Stuiver, Minze; Talamo, Sahra; Taylor, F. W.; van der Plicht, Johannes; Weyhenmeyer, Constanze E. (Dept. of Geosciences, University of Arizona, 2004)
    A new calibration curve for the conversion of radiocarbon ages to calibrated (cal) ages has been constructed and internationally ratified to replace IntCal98, which extended from 0–24 cal kyr BP (Before Present, 0 cal BP ...
  • IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP 

    Reimer, Paula J.; Baillie, Mike G. L.; Bard, Edouard; Bayliss, Alex; Beck, J. Warren; Blackwell, Paul G.; Ramsey, C. Bronk; Buck, Caitlin E.; Burr, George S.; Edwards, R. Lawrence; Friedrich, Michael; Grootes, P. M.; Guilderson, Thomas P.; Hajdas, Irka; Heaton, T. J.; Hogg, Alan G.; Hughen, Konrad A.; Kaiser, K. F.; Kromer, Bernd; McCormac, F. G.; Manning, S. W.; Reimer, Ron W.; Richards, D. A.; Southon, John R.; Talamo, Sahra; Turney, C. S. M.; van der Plicht, Johannes; Weyhenmeyer, Constanze E. (Dept. of Geosciences, University of Arizona, 2009-12)
    The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available ...