Ellen R M Druffel

Biographic Data

ID5597674
NAMEEllen R M Druffel
GIVEN NAMESEllen R M
FAMILY NAMEDruffel
SIGNATUREDRUFFEL E R M
AFFILIATIONSWoods Hole Oceanographic Institution
ORCID0000-0002-7139-1075
VERIFIEDYes
TOTAL WORKS32
TOTAL CITATIONS87
AUTHOR COUNT32
EDITOR COUNT0
FIRST PUBLICATION YEAR1984
LATEST PUBLICATION YEAR2024
H-INDEX6

  • Time Series of Surface Water Dissolved Inorganic Carbon Isotopes From the Southern California Bight

    Open AccessNiels E Hauksson, X Xu et al.ARTICLERadiocarbon2024References: 33

    Dissolved inorganic carbon (DIC) in ocean water is a major sink of fossil fuel derived CO 2 . Carbon isotopes in DIC serve as tracers for oceanic water masses, biogeochemical processes, and air-sea gas exchange. We present a timeseries of surface DIC δ 13 C and Δ 14 C values from 2011 to 2022 from Newport Beach, California. This is a continuation of previous timeseries (Hinger et al. 2010; Santos et al. 2011) that together provide an 18-year reco…

  • Marine Organic Carbon and Radiocarbon—present and Future Challenges

    Open AccessEllen R M Druffel, Steven R Beaupré et al.ARTICLERadiocarbon2022References: 109

    We discuss present and developing techniques for studying radiocarbon in marine organic carbon (C). Bulk DOC (dissolved organic C) Δ 14 C measurements reveal information about the cycling time and sources of DOC in the ocean, yet they are time consuming and need to be streamlined. To further elucidate the cycling of DOC, various fractions have been separated from bulk DOC, through solid phase extraction of DOC, and ultrafiltration of high and low…

  • UV Photochemical Oxidation and Extraction of Marine Dissolved Organic Carbon at UC Irvine

    Open AccessBrett D Walker, Steven R Beaupré et al.ARTICLERadiocarbon2019Cited by: 2References: 16

    The first ultraviolet photochemical oxidation (UVox) extraction method for marine dissolved organic carbon (DOC) as CO 2 gas was established by Armstrong and co-workers in 1966. Subsequent refinement of the UVox technique has co-evolved with the need for high-precision isotopic (Δ 14 C, δ 13 C) analysis and smaller sample size requirements for accelerator mass spectrometry radiocarbon (AMS 14 C) measurements. The UVox line at UC Irvine was establ…

  • Uptake of Carbon for Cellulose Production in a White Oak from Western Oregon, USA

    Open AccessWilliam F Cain, Sheila Griffin et al.ARTICLERadiocarbon2018Cited by: 4References: 13

    We report ∆ 14 C measurements of cellulose extracted from near monthly tree ring growth for the 1960s of a white oak that grew in western Oregon, USA. Comparison with ∆ 14 C measurements of atmospheric CO 2 reveals that the tree ring ∆ 14 C values were equal to or lower than those in atmospheric CO 2 at the time of ring formation. We suggest that the low tree ring ∆ 14 C values during the period 1962–1963 were caused by the presence of an atmosph…

  • Large Variability of Dissolved Inorganic Radiocarbon in the Kuroshio Extension of the Northwest North Pacific

    Open AccessLing Ding, Tiantian Ge et al.ARTICLERadiocarbon2018References: 38

    Radiocarbon ( 14 C) in dissolved inorganic carbon (DIC) was measured for water samples collected from six deep stations in the Kuroshio Extension (KE) region in the northwestern North Pacific in April–May 2015. Vertical profiles of Δ 14 C-DIC indicate that bomb-produced 14 C was present from the surface to ~1500 m water depth. Large variations in Δ 14 C-DIC values (300‰) were observed at 500 m water depth among the stations and the differences we…

  • Obituary

    Open AccessEllen R M Druffel, Sheila Griffin et al.ARTICLERadiocarbon2018References: 3

    where he served as department chair, chair of the faculty senate, and a valuable mentor to many undergraduate students. Bill was six feet, eight inches tall (just over 2 meters), with a deep voice and a quick wit

  • Temporal Variability of Dissolved Organic Radiocarbon in the Deep North Pacific Ocean

    Open AccessEllen R M Druffel, Sheila Griffin et al.ARTICLERadiocarbon2018References: 31

    We report marine dissolved organic carbon (DOC) ∆ 14 C from seawater collected from the North central Pacific Ocean (NCP) in 2015. These measurements show DOC ∆ 14 C values averaged –235±5‰ ( n =3) in the mixed layer (24–81 m) and –544±5‰ ( n =5) in the deep water (1500–5139 m). A comparison of these data with two previously published DOC ∆ 14 C profiles from the NCP in 1985 and 1987 reveals that deep DOC ∆ 14 C values have decreased. We discuss …

  • Effect of Acidified Versus Frozen Storage on Marine Dissolved Organic Carbon Concentration and Isotopic Composition

    Open AccessBrett D Walker, Sheila Griffin et al.ARTICLERadiocarbon2017Cited by: 1References: 23

    The standard procedure for storing/preserving seawater dissolved organic carbon (DOC) samples after field collection is by freezing (–20°C) until future analysis can be made. However, shipping and receiving large numbers of these samples without thawing presents a significant logistical problem and large monetary expense. Access to freezers can also be limited in remote field locations. We therefore test an alternative method of preserving and st…

  • Upwelling of Pacific Intermediate Water in the South China Sea Revealed by Coral Radiocarbon Record

    Open AccessAnnette Bolton, Nathalie F Goodkin et al.ARTICLERadiocarbon2016Cited by: 2References: 58

    Annual radiocarbon from a massive Porites lutea coral collected from Hon Tre Island, Vietnam, South China Sea (SCS) was analyzed over a ~100-yr-long period from AD 1900 to 1986. The pre-bomb results from 1900–1953 show a steady Δ 14 C value of –54.4±1.8‰ ( n =60). These values are similar to coral records located in the central and southern SCS and from Indonesian waters, but are lower than those from Japan. Following the input of anthropogenic b…

  • Extraneous Carbon Assessments in Radiocarbon Measurements of Black Carbon in Environmental Matrices

    Alysha I Coppola, Alysha Coppola et al.ARTICLERadiocarbon2013Cited by: 2References: 18

    Extraneous carbon (C ex ) added during chemical processing and isolation of black carbon (BC) in environmental matrices was quantified to assess its impact on compound specific radiocarbon analysis (CSRA). Extraneous carbon is added during the multiple steps of BC extraction, such as incomplete removal of solvents, and carbon bleed from the gas chromatographic and cation columns. We use 2 methods to evaluate the size and Δ 14 C values of C ex in …

  • Total Uncertainty of Radiocarbon Measurements of Marine Dissolved Organic Carbon and Methodological Recommendations

    Open AccessEllen R M Druffel, Ellen Druffel et al.ARTICLERadiocarbon2013Cited by: 4References: 6

    We report results of duplicate measurements of dissolved organic carbon concentrations ([DOC] as μM) and Δ 14 C in seawater in order to assess the total uncertainty of reported [DOC] and Δ 14 C measurements via the UV oxidation method. In addition, pure International Atomic Energy Agency standards analyzed over a 4-yr period are evaluated. We find the total uncertainty of Δ 14 C measurements to be ±4.0. However, in samples that were thawed, subsa…

  • Variability of Dissolved Inorganic Radiocarbon at a Surface Site in the Northeast Pacific Ocean

    Open AccessEllen R M Druffel, Steven Beaupré et al.ARTICLERadiocarbon2010Cited by: 1References: 13

    We report radiocarbon measurements of dissolved inorganic carbon (DIC) in surface water samples collected daily during 12 cruises to Station M in the northeast Pacific off central California. Individual surface Δ 14 C values ranged from 22‰ to 70‰ over 10 yr. Variability of average cruise values is highest during winter likely due to increased mixing. A general decrease of Δ 14 C values was observed at a rate of about 3‰ per year between 1994 and…

  • Carbon Isotope Measurements of Surface Seawater from a Time-Series Site Off Southern California

    Open AccessElise N Hinger, Guaciara M Santos et al.ARTICLERadiocarbon2010Cited by: 5References: 18

    We report carbon isotope abundances of dissolved inorganic carbon (DIC) in surface seawater collected from a time-series site off the Newport Beach Pier in Orange County, California. These data represent the first time series of Δ 14 C data for a coastal southern California site. From a suite of samples collected daily from 16 October to 11 November 2004, Δ 14 C values averaged 32.1 ± 4.4‰. Freshwater input from the Santa Ana River to our site ca…

  • Compound-Specific Radiocarbon Analyses of Phospholipid Fatty Acids and N -Alkanes in Ocean Sediments

    Open AccessEllen R M Druffel, Dachun Zhang et al.ARTICLERadiocarbon2010Cited by: 7References: 18

    We report compound-specific radiocarbon analyses of organic matter in ocean sediments from the northeast Pacific Ocean. Chemical extractions and a preparative capillary gas chromatograph (PCGC) were used to isolate phospholipid fatty acids (PLFA) and n -alkanes from 3 cores collected off the coast of California, USA. Mass of samples for accelerator mass spectrometry (AMS) 14 C analysis ranged from 13–100 μg C. PLFA extracted from anaerobic sedime…

  • An Alternate Method of Diluting Dissolved Organic Carbon Seawater Samples for 14 C Analysis

    Open AccessSheila Griffin, Steven R Beaupré et al.ARTICLERadiocarbon2010Cited by: 7References: 3

    We present a time-saving modification to the ultraviolet (UV) oxidation method for analyzing dissolved organic carbon (DOC) concentration, Δ 14 C, and δ 13 C measurements in seawater and standard materials. A low background (∼0.2 ± 0.2 μM) was reported for pre-irradiated Milli-Q (MQ) water that was used to dilute samples for DOC 14 C analysis (Beaupré et al. 2007). We use MQ water without pre-irradiation (background ∼0.9 ± 0.2 μM) to dilute the s…

  • Ultra small-mass AMS 14C sample preparation and analyses at KCCAMS/UCI Facility

    Open AccessGuaciara M Santos, John Southon et al.ARTICLENuclear Instruments and Methods…2007

  • Variability of Monthly Radiocarbon During the 1760S in Corals from the Galapagos Islands

    Open AccessEllen R M Druffel, Sheila Griffin et al.ARTICLERadiocarbon2004Cited by: 6References: 12

    Radiocarbon (Δ 14 C) measurements of monthly samples from a Galapagos surface coral are among the first data sets from the new Keck Carbon Cycle Accelerator Mass Spectrometry laboratory at the University of California, Irvine. An average Δ 14 C value of −62 is obtained for 144 measurements of samples from monthly coral bands that lived from about AD 1760–1771 (±6 yr). High Δ 14 C values were found during January through March, when upwelling was …

  • Changes of Subtropical North Pacific Radiocarbon and Correlation with Climate Variability

    Open AccessEllen R M Druffel, S Griffin et al.ARTICLERadiocarbon2001Cited by: 7References: 38

    We show that high-precision radiocarbon (Δ 14 C) measurements from annual bands of a Hawaiian surface coral decreased by 7‰ from AD 1893 to 1952. This decrease is coincident with the Suess Effect, which is mostly due to the dilution of natural levels of 14 C by 14 C-free fossil fuel CO 2 . This decrease is equal to that expected in surface waters of the subtropical gyres, and indicates that the surface waters of the North Pacific were in steady s…

  • Preparation of Inorganic and Organic Carbon for 14 C Analysis from a Single Marine Sample

    Open AccessSheila Griffin, Ellen R M DruffelARTICLERadiocarbon1997References: 8

    We have developed a technique using a single apparatus to recover the inorganic and organic carbon from a small (few milligrams) aliquot of dried marine material for radiocarbon analysis. The main advantages of using a single apparatus are: 1) less sample is required, 2) decreased handling reduces contamination, and 3) less time and materials are used. Blank values of ∼5 μg and 19–44 μg are obtained for the inorganic and organic carbon extraction…

  • Post-Bomb Radiocarbon Records of Surface Corals from the Tropical Atlantic Ocean

    Open AccessEllen R M DruffelARTICLERadiocarbon1996Cited by: 4References: 16

    Δ 14 C records are reported for post-bomb corals from three sites in the tropical Atlantic Ocean. In corals from 18°S in the Brazil Current, Δ 14 C values increased from ca . −58% in the early 1950s to +138% by 1974, then decreased to 110‰ by 1982. Shorter records from 8oS off Brazil and from the Cape Verde Islands (17°N) showed initially higher Δ 14 C values before 1965 than those at 18oS, but showed lower rates of increase of Δ 14 C during the …

  • Radiocarbon in Tropospheric CO 2 and Organic Materials from Selected Northern Hemisphere Sites

    Open AccessEllen R M Druffel, Sheila GriffinARTICLERadiocarbon1995Cited by: 3References: 8

    Radiocarbon was measured in atmospheric CO 2 from La Jolla, California and in living organic materials from six sites in the northern hemisphere. Atmospheric CO 2 ∆ 14 C values from La Jolla agreed with those previously published records from China Lake, California (Berger et al. 1987) and Vermunt, Austria (Levin et al. 1985). ∆ 14 C values of fruit and grain samples that grew during 1980 agreed with the atmospheric CO 2 ∆ 14 C measurements. Most…

  • Intercomparison of High-Precision ∆ 14 C Analyses Using Gas Counting and AMS

    Open AccessEllen R M Druffel, Douglas J Donahue et al.ARTICLERadiocarbon1995References: 7

    We report results of a three-year intercomparison experiment between the WHOI Radiocarbon Laboratory (now at University of California, Irvine) and the NSF-University of Arizona AMS Laboratory. The purpose of this study was to compare high-precision measurements of samples obtained routinely using gas proportional counting techniques with results obtained using AMS techniques. Three sets of annually banded, modern coral samples were used for the i…

  • Regional Variability of Surface Ocean Radiocarbon from Southern Great Barrier Reef Corals

    Open AccessEllen R M Druffel, Sheila GriffinARTICLERadiocarbon1995Cited by: 11References: 16

    High-precision ∆ 14 C and stable isotope (∆ 18 O and ∆ 13 C) records are reported for post-bomb corals from three sites off the eastern Australian coast. We observe that ∆ 14 C values increased from ca. −50′ in the early 1950s to +130‰ by 1974, then decreased to 110‰ by 1991. There is general agreement between the coral results and ∆ 14 C of dissolved inorganic carbon (DIC) in seawater measured previously for locations in the South Pacific. ∆ 14 …

  • A Large Drop in Atmospheric 14 C/ 12 C and Reduced Melting in the Younger Dryas, Documented with 230 Th Ages of Corals

    Open AccessR Lawrence Edwards, J Warren Beck et al.ARTICLEScience1993

    Paired carbon-14 ( 14 C) and thorium-230( 230 Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the 14 C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the 14 C and 230 Th ages suggests that the atmospheric 14 C/ 12 C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This promi…

  • Radiocarbon Updates

    Open AccessRobert Kahn, Ellen R M Druffel et al.ARTICLERadiocarbon1993

    This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries