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Showing 1 to 11 of 11 for “"Δ14C"”.
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Radiocarbon (Δ14C) and Stable Carbon (δ13C) Isotopic Composition of Dissolved Inorganic Carbon (DIC) in Baffin Bay
… aging and residence times. However, very few DIC Δ14C and d13C data have been reported in the Arctic Ocean, comprising only a handful of stations in the Eurasian Basin, Canadian Basin, and Beaufort Sea. With this goal in mind, we conducted a study in which DIC samples were collected aboard the …
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Tracking nuclear generating station emissions and fossil fuel contributions using tree rings in southern Ontario, Canada
… southern Ontario. This study analyzes tree-ring Δ14C (the amount of 14C in a particular sample) as a proxy for atmospheric Δ14C by isolating tree-ring alpha cellulose and using accelerator mass spectrometry (AMS). Results indicate that Δ14C tree-ring signatures from white spruce (Picea glauca) …
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A radiocarbon method and multi-tracer approach to quantifying groundwater discharge to coastal waters
… discharge. The natural radiocarbon content (Δ14C) of dissolved inorganic carbon (DIC) was developed as a tracer of fresh, terrestrially driven fluxes from confined aquifers. This Δ14C method was tested during five sampling periods from November 1999 to April 2002 in two small estuaries in …
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An inverse modeling approach to investigate deep ocean ventilation from radiocarbon records
… benthic foraminifera and deep-sea corals (paleo-Δ14C data). Here, we combine a global compilation of paleo-Δ14C data for the past 40 kyrs with a 16-box model of the world ocean (except the Arctic Ocean) to address two key questions: (1) To what extent can the paleo-Δ14C data be explained by …
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High molecular weight (HMW) dissolved organic matter (DOM) in seawater : chemical structure, sources and cycling
… by which APS is delivered to the deep ocean the Δ14C value of APS in the deep ocean was compared to the Δ14C value of the dissolved inorganic carbon (DIC) at the same depth. If the formation of deep water is the dominant mode of transport then both the DIC and APS will have similar Δ14C values. …
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Biogeochemical applications of compound-specific radiocarbon analysis
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 phytoplanktonic, zooplanktonic, bacterial, archaeal, terrestrial, and fossil carbon …
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Age, movements, and feeding ecology of northwest Atlantic white sharks estimated from ecogeochemical profiles in vertebrae
… vertebrae. I generate the first radiocarbon (Δ14C) age estimates for adult white sharks, dramatically extending the maximum age and longevity compared to earlier age studies. Δ14C results also verify a lack of reworking of vertebral material and hint at possible sexual dimorphism in growth …
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Development and application of the mollusc Arctica islandica as a paleoceanographic tool for the North Atlantic ocean
… dissolved inorganic carbon's (DIC) radiocarbon (Δ14C) concentration and accurately reflects the ambient temperature in its stable oxygen isotope (δ180) composition. However, the stable carbon isotope (δ13C) composition of the A. islandica shell likely is not a good recorder of ambient DIC δl3C, …
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Molecular and isotopic records of combustion inputs to the environment over the last 250 years
… substantially during the 20th century. δ13C and Δ14C measurements were also used to constrain the relative importance of combustion versus in situ production as sources of perylene. In addition, a comparison of the down-core concentration and isotopic profiles of black carbon (BC) generated by a …
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Chemical characterization of dissolved organic matter (DOM) in seawater : structure, cycling, and the role of biology
… analysis. These amino acids had a range of Δ14C values, from 121% to 454%. The final section investigates biological controls on the dissolved organic nitrogen (DON) pool. Total hydrolyzable amino acids (THAA), and nucleic acids were measured for four incubations: a control incubation, a …
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Quantifying biophysical and biogeochemical influence on northern high latitudes greenhouse gases dynamics
… soil organic carbon (SOC). I also implemented Δ14C to estimate SOC turnover time, a critical determinant of SOC stocks, sequestration potential, and the carbon cycle feedback under changing atmospheric CO2 concentration [CO2] and climate. ISAM accounted for the vertical movement of SOC caused …