@article {1943, title = {Incorporation of aged dissolved organic carbon (DOC) onto oceanic particulate organic carbon (POC): an experimental approach using carbon isotopes}, journal = {Marine Chemistry}, volume = {98}, year = {2006}, note = {id: 682}, month = {2006}, pages = {315-322}, author = {Hwang, J. and Druffel, E. R. M. and Bauer, J. E.} } @article {1942, title = {Quantifying archaeal community autotrophy in the mesopelogic ocean using natural radiocarbon}, journal = {Proc. Natl. Acad. Sci. USA}, volume = {103}, year = {2006}, note = {id: 502}, month = {2006}, pages = {6442-6447}, author = {Ingalls, A. E. and Shah, S. R. and Hansman, R. L. and Aluwihare, L. I. and Santos, G. M. and Druffel, E. R. M. and Pearson, A.} } @article {2003, title = {Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean}, journal = {Geochemistry Geophysics Geosystems}, volume = {6}, year = {2005}, note = {909pwTimes Cited:17 Cited References Count:21 }, month = {Mar 18}, abstract = {We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC D 14 C results revealed postbomb carbon in river and ocean waters, with slightly higher values at the river mouth. The low DIC delta(13)C signature of the river end-member (-11\%) demonstrates that about half of the DIC originated from the remineralization of terrestrially derived organic matter. A linear relationship between DIC and salinity indicates that DIC was mixed nearly conservatively in the transition zone from the river mouth to the open ocean, though there was a small amount (<= 10\%) of organic matter remineralization in the mesohaline region. The POC Delta(14)C values in the river mouth were markedly lower than those values from the western Amazon region (Hedges et al., 1986). We conclude that the dominant source of POC near the river mouth and in the inner Amazon plume during November 1991 was aged, resuspended material of significant terrestrial character derived from shelf sediments, while the outer plume contained mainly marine-derived POC.}, keywords = {accumulation, amazon, C-14, carbon cycling, CO2, continental-shelf, poc, radiocarbon, river system, Sediment, total co(2), water}, isbn = {1525-2027}, doi = {10.1029/2004GC000842}, author = {Druffel, E. R. M. and Bauer, J. E. and Griffin, S.} } @article {628, title = {Variable ageing and storage of dissolved organic components in the open ocean}, journal = {Nature}, volume = {430}, year = {2004}, note = {847daTimes Cited:93Cited References Count:30}, month = {Aug 19}, pages = {877-881}, abstract = {Seawater dissolved organic matter (DOM) is the largest reservoir of exchangeable organic carbon in the ocean, comparable in quantity to atmospheric carbon dioxide(1,2). The composition, turnover times and fate of all but a few planktonic constituents of this material are, however, largely unknown(3,4). Models of ocean carbon cycling are thus limited by the need for information on temporal scales of carbon storage in DOM subcomponents, produced via the {\textquoteright}biological pump{\textquoteright}, relative to their recycling by bacteria(3,4). Here we show that carbohydrate- and protein-like substances in the open Atlantic and Pacific oceans, though often significantly aged, comprise younger fractions of the DOM, whereas dissolved lipophilic material exhibits up to similar to90 per cent fossil character. In contrast to the millennial mean ages of DOM observed throughout the water column, weighted mean turnover times of DOM in the surface ocean are only decadal in magnitude. An observed size-age continuum further demonstrates that small dissolved molecules are the most highly aged forms of organic matter, cycling much more slowly than larger, younger dissolved and particulate precursors, and directly links oceanic organic matter age and size with reactivity(3,5).}, issn = {0028-0836}, doi = {10.1038/nature02780}, author = {Loh, A. N. and Bauer, J. E. and Druffel, E. R. M.} } @article {2079, title = {Decadal timescale shift in the 14C record of a central equatorial Pacific coral}, journal = {Radiocarbon}, volume = {45}, year = {2003}, note = {id: 1130}, month = {2003}, pages = {91-99}, author = {Grottoli, A. G. and Gille, S. T. and Druffel, E. R. M. and Dunbar, R. B.} } @article {2083, title = {Penetration of anthropogenic carbon into organic particles of the deep ocean}, journal = {Geophysical Research Letters}, volume = {30}, year = {2003}, note = {709dpTimes Cited:12 Cited References Count:29 }, month = {Jul 23}, pages = {1744}, abstract = {[1] In the late 1980s, bomb C-14 was present in suspended particulate organic carbon (POC) from the North Central Pacific (NCP) and Sargasso Sea ( SS) throughout most of the water column, demonstrating that deep POC had exchanged with atmospheric CO2 in the past 30 years. Upon reoccupation of these sites in 1999 and 2000, respectively, we observed that the delta(13)C values of suspended POC were lower than those measured a decade earlier. This demonstrates that anthropogenic CO2 from fossil fuel and biomass burning has penetrated a major organic matter pool in the deep ocean. Delta(14)C measured in the suspended POC showed similar or higher values in the deep Sargasso Sea and decreased values in the deep NCP compared to those measured previously. We use a box model to show that the differences in the radiocarbon results are likely due to the presence of resuspended sediment that is laterally advected from the continental margin to the deep Sargasso Sea.}, keywords = {bomb radiocarbon, C-14, CO2, delta-c-13, MATTER, NORTH PACIFIC-OCEAN, SARGASSO SEA, Sediment, variability, water}, isbn = {0094-8276}, doi = {10.1029/2003GL017423}, author = {Druffel, E. R. M. and Bauer, J. E. and Griffin, S. and Hwang, J.} } @conference {1768, title = {Radiocarbon in a Fanning Island coral: Inter-decadal variability in waters upwelling in the central equatorial Pacific from 1922-1955}, booktitle = {ALSO/AGU Ocean Sciences Meeting}, year = {2002}, note = {id: 658}, month = {2002}, address = {Honolulu, HI}, author = {Grottoli, A. G. and Gille, S. T. and Druffel, E. R. M. and Dunbar, R. B.} } @article {1010, title = {Temporal and regional variability in sources and cycling of DOC and POC in the northwest Atlantic continental shelf and slope}, journal = {Deep-Sea Research II}, volume = {49}, year = {2002}, note = {id: 685}, pages = {4419}, chapter = {4387}, doi = {10.1016/S0967-0645(02)00123-6}, author = {Bauer, J. E. and Druffel, E. R. M. and Wolgast, D. M. and Griffin, S.} } @article {770, title = {Carbon isotope geochemistry of the Santa Clara River}, journal = {Global Biogeochemical Cycles}, volume = {15}, year = {2001}, note = {441mbTimes Cited:116Cited References Count:34}, month = {Jun}, pages = {407-416}, abstract = {The Santa Clara River is a prototypical small mountainous river, with a headwater height greater than 1000 m and a basin area smaller than 10,000 m(2). Although individual small mountainous rivers export trivial amounts of sediment and carbon to the ocean, as a group these rivers may export a major fraction las much as 50\%) of the total global river sediment flux [Milliman and Syvitski, 1992], making their geochemistry relevant the study of the ocean{\textquoteright}s carbon cycle. In addition, many small rivers export sediment in a few high flux events, causing massive, sporadic discharge of carbon onto coastal shelves, discharge conditions very different from those of large rivers. This class of rivers is an end-member of the river-ocean carbon exchange system, opposite the Earth{\textquoteright}s largest river, the Amazon. The carbon mass and isotopic properties of the Santa Clara River are significantly different from previously studied large rivers. During the 1997-1998 winter, all Santa Clara carbon pools were old, with flux-weighted average Delta (14)C values of -428 +/- 76 parts per thousand for particulate organic carbon, -73 +/- 31 parts per thousand for dissolved organic carbon, and -644 +/- 58 parts per thousand for black carbon. The age of exported carbon is primarily due to the deep erosion of old soils and not to inclusion of fossil fuel carbon. Additionally, the delta (13)C signatures of exported carbon pools were high relative to terrestrial carbon, bearing a signature quite similar to marine carbon (average particulate organic carbon (POC) delta (13)C = -22.2 +/- 0.8 parts per thousand). The Santa Clara{\textquoteright}s estuary is small and drains onto the narrow eastern Pacific coastal margin, exporting this old soil organic matter directly into the ocean. If the Santa Clara export patterns are representative of this class of rivers, they may be a significant source of refractory terrestrial carbon to the ocean.}, issn = {0886-6236}, doi = {10.1029/2000gb001290}, author = {Masiello, C. A. and Druffel, E. R. M.} } @article {2146, title = {Radiocarbon in a Fanning Island Coral: Inter-decadal Variability in Waters Upwelling in the Central Equatorial Pacific from 1922 - 1955}, journal = {EOS}, year = {2001}, note = {id: 1399}, month = {2001}, author = {Grottoli, A. G. and Gille, S. T. and Druffel, E. R. M. and Dunbar, R. B.} } @article {2196, title = {Identification of Seasonal-to-Decadal Timescale Variations in the Zonal Currents of the Central Equatorial Pacific Prior to 1955 Using A14C in Coral}, journal = {EOS}, volume = {81}, year = {2000}, note = {id: 254}, month = {2000}, abstract = {F767}, author = {Grottoli, A. G. and Druffel, E. R. M. and Gille, S. T. and Dunbar, R. B.} } @conference {1651, title = {Identification of seasonal-to-decadal timescale variations in the zonal currents of the central equatorial Pacific}, booktitle = {International Coral Reef Symposium}, year = {2000}, note = {id: 1401}, month = {2000}, address = {Bali}, author = {Grottoli, A. G. and Druffel, E. R. M. and Gille, S. T. and Dunbar, R. B.} } @article {800, title = {Physical controls on dissolved inorganic radiocarbon variability in the California Current}, journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography}, volume = {45}, year = {1998}, note = {102ttTimes Cited:21Cited References Count:43}, pages = {617-642}, abstract = {We present depth profiles of Delta(14)C and delta(13)C Of dissolved inorganic carbon (DIC) at Station M in the Eastern North Pacific. Several seasonal profiles are presented for the time period between 1991 and 1996. Comparison with GEOSECS data clearly shows changes in ocean radiocarbon profiles since 1973. The Delta(14)C Of DIC shows the most variability at depths of 450, 85, and 25 m, and the lowest variability at depths of 1600 and 2500 m. The largest variability in DIC Delta(14)C occurs at 450 m, a depth marked by large fluctuations in the radiocarbon signatures of the source waters. The likely controls of DIC Delta(14)C variability are physical changes in the circulation of the California Current System. A simple two-box model is used to show the importance of wind driven mixing at the surface. We discuss the likely effects of mesoscale eddies and ENSO on the DIC Delta(14)C values at this site. We also show that remineralization of organic carbon (dissolved or particulate) is not responsible for the variability in the Delta(14)C Of DIC observed at Station M. (C) 1998 Elsevier Science Ltd. All rights reserved.}, issn = {0967-0645}, doi = {10.1016/S0967-0645(97)00096-9}, author = {Masiello, C. A. and Druffel, E. R. M. and Bauer, J. E.} } @article {745, title = {Variability in radiocarbon ages of individual organic compounds from marine sediments}, journal = {Science}, volume = {277}, year = {1997}, note = {Xq247Times Cited:175Cited References Count:37}, month = {Aug 8}, pages = {796-799}, abstract = {Organic carbon (OC) from multiple sources can be delivered contemporaneously to aquatic sediments. The influence of different OC inputs on carbon-14-based sediment chronologies is illustrated in the carbon-14 ages of purified, source-specific (biomarker) organic compounds from near-surface sediments underlying two contrasting marine systems, the Black Sea and the Arabian Sea, In the Black Sea, isotopic heterogeneity of n-alkanes indicated that OC was contributed from both fossil and contemporary sources. Compounds reflecting different source inputs to the Arabian Sea exhibit a 10,000-year range in conventional carbon-14 ages. Radiocarbon measurements of biomarkers of marine photoautotrophy enable sediment chronologies to be constructed independent of detrital OC influences.}, issn = {0036-8075}, doi = {10.1126/science.277.5327.796}, author = {Eglinton, T. I. and BenitezNelson, B. C. and Pearson, A. and McNichol, A. P. and Bauer, J. E. and Druffel, E. R. M.} } @article {2337, title = {Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis--A Novel Approach}, journal = {Radiocarbon}, volume = {38}, year = {1996}, note = {id: 1650}, month = {1996}, pages = {26}, author = {Eglinton, T. I. and McNichol, A. P. and Benitez-Nelson, B. C. and Pearson, A. and von Reden, K. F. and Schneider, R. J. and Bauer, J. E. and Druffel, E. R. M.} } @conference {1658, title = {Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis -- A Novel Approach}, booktitle = {7th International Conference on Accelerator Mass Spectrometry}, volume = {38}, year = {1996}, note = {id: 1800; 1}, month = {1996}, pages = {26}, publisher = {Radiocarbon}, organization = {Radiocarbon}, address = {Tucson, AZ}, author = {Eglinton, T. I. and McNichol, A. P. and Benitez-Nelson, B. C. and Pearson, A. and von Reden, K. F. and Schneider, R. J. and Bauer, J. E. and Druffel, E. R. M.} } @article {2340, title = {Post-bomb radiocarbon records of surface corals from the tropical Atlantic Ocean}, journal = {Radiocarbon}, volume = {38}, year = {1996}, note = {Xd080Times Cited:25 Cited References Count:20 }, month = {1996}, pages = {563-572}, abstract = {Delta(14)C records are reported for post-bomb corals from three sites in the tropical Atlantic Ocean. In corals from 18 degrees S in the Brazil Current, Delta(14)C values increased from ca.-58 parts per thousand in the early 1950s to +138 parts per thousand by 1974, then decreased to 110 parts per thousand by 1982 Shorter records from 8 degrees S off Brazil and from the Cape Verde Islands (17 degrees N) showed initially higher Delta(14)C values before 1965 than those at 18 degrees S, but showed lower rates of increase of Delta(14)C during the early 1960s. There is general agreement between the coral results and Delta(14)C of dissolved inorganic carbon (DIC) measured in seawater previously for locations in the tropical Atlantic Ocean. Delta(14)C values at our tropical ocean sites increased at a slower rate than those observed previously in the temperate North Atlantic (Florida and Bermuda), owing to the latter{\textquoteright}s proximity to the bomb C-14 input source in the northern hemisphere. Model results show that from 1960-1980 the Cape Verde coral and selected DIC Delta(14)C values from the North Equatorial Current agree with that calculated for the North Atlantic based on an isopycnal mixing model with a constant water mass renewal rate between surface and subsurface waters. This is in contrast to Delta(14)C values in Bermuda corals that showed higher post-bomb values than those predicted using a constant water mass renewal rate, hence indicating that ventilation in the western north Atlantic Ocean had decreased by a factor of 3 during the 1960s and 1970s (Druffel 1989).}, keywords = {atmosphere, banded corals, bermuda, C-14, pacific, rings, ventilation}, isbn = {0033-8222}, author = {Druffel, E. R. M.} } @article {2338, title = {Preparative capillary gas chromatographic isolation of individual compounds from complex matrices for radiocarbon dating}, journal = {Analytical Chemistry}, volume = {68}, year = {1996}, note = {id: 1340}, month = {1996}, pages = {904-912}, author = {Eglinton, T. I. and Aluwihare, L. I. and Bauer, J. E. and Druffel, E. R. M. and McNichol, A. P.} } @article {1364, title = {Radiocarbon Studies of Particulate Organic Carbon in the Eastern North Pacific Ocean}, year = {1994}, note = {id: 907}, month = {1994}, author = {Druffel, E. R. M. and Griffin, S. and Bauer, J. E. and Williams, P. M. and Wolgast, D. M. and Lee, C.} } @conference {1770, title = {Radiocarbon studies of particulate organic carbon in the eastern North Pacific Ocean}, booktitle = {1994 ocean sciences meeting}, volume = {75}, year = {1994}, note = {id: 1240; 3}, month = {1994}, pages = {236}, address = {San Diego, CA}, author = {Druffel, E. R. M. and Bauer, J. E. and Williams, P. M. and Griffin, S. and Wolgast, C. Lee and Wakeham, S. G.}, editor = {University of California at Irvine, Department of Geosciences} } @article {2403, title = {Variability of the delta13C of dissolved inorganic carbon at a site in the North Pacific Ocean}, journal = {Geochimica et Cosmochimica Acta}, volume = {56}, year = {1992}, note = {id: 1746}, month = {1992}, pages = {3589-3592}, author = {McNichol, A. P. and Druffel, E. R. M.} } @inbook {1440, title = {Carbon cycling in coastal sediments: 2. An investigation of the sources of CO2 to pore water using carbon isotopes}, booktitle = {Organic Substances and Sediments in Water, Processes and Analytical}, volume = {2}, year = {1991}, note = {id: 1743}, month = {1991}, pages = {249-272}, publisher = {CRC Press}, organization = {CRC Press}, address = {Boca Raton, FL}, author = {McNichol, A. P. and Druffel, E. R. M. and Lee, C.}, editor = {Baker, R. A.} }