TY - JOUR T1 - Export of submicron particulate organic matter to mesopelagic depth in an oligotrophic gyre JF - Proceedings of the National Academy of Sciences Y1 - 2013 A1 - Close, H. G. A1 - Shah, S. R. A1 - Ingalls, A. E. A1 - Diefendorf, A. F. A1 - Brodie, E. L. A1 - Hansman, R. L. A1 - Freeman, K. H. A1 - Aluwihare, L. I. A1 - Pearson, A. KW - Biogeochemistry KW - biomarkers KW - carbon isotopes KW - Oceanography AB - Sixty percent of the world ocean by area is contained in oligotrophic gyres [Longhurst A (1995) Prog Oceanog 36:77-16], the biomass of which is dominated by picophytoplankton, including cyanobacteria and picoeukaryotic algae, as well as picoheterotrophs. Despite their recognized importance in carbon cycling in the surface ocean, the role of small cells and their detrital remains in the transfer of particulate organic matter (POM) to the deep ocean remains disputed. Because oligotrophic marine conditions are projected to expand under current climate trends, a better understanding of the role of small particles in the global carbon cycle is a timely goal. Here we use the lipid profiles, radiocarbon, and stable carbon isotopic signatures of lipids from the North Pacific Subtropical Gyre to show that in the surface ocean, lipids from submicron POM (here called extra-small POM) are distinct from larger classes of suspended POM. Remarkably, this distinct extra-small POM signature dominates the total lipids collected at mesopelagic depth, suggesting that the lipid component of mesopelagic POM primarily contains the exported remains of small particles. Transfer of submicron material to mesopelagic depths in this location is consistent with model results that claim the biological origin of exported carbon should be proportional to the distribution of cell types in the surface community, irrespective of cell size [Richardson TL, Jackson GA (2007) Science 315:838-840]. Our data suggest that the submicron component of exported POM is an important contributor to the global biological pump, especially in oligotrophic waters. VL - 110 UR - http://www.pnas.org/cgi/doi/10.1073/pnas.1217514110https://syndication.highwire.org/content/doi/10.1073/pnas.1217514110 IS - 31 ER - TY - JOUR T1 - Ultra-microscale analysis of lipids by 14C-AMS: Assessment and correction for sample processing blanks JF - Radiocarbon Y1 - 2007 A1 - Shah, S. R. A1 - Pearson, A. VL - 49 N1 - id: 501 ER - TY - JOUR T1 - Quantifying archaeal community autotrophy in the mesopelogic ocean using natural radiocarbon JF - Proc. Natl. Acad. Sci. USA Y1 - 2006 A1 - Ingalls, A. E. A1 - Shah, S. R. A1 - Hansman, R. L. A1 - Aluwihare, L. I. A1 - Santos, G. M. A1 - Druffel, E. R. M. A1 - Pearson, A. VL - 103 N1 - id: 502 ER - TY - JOUR T1 - Bacterial incorporation of relict carbon in the hydrothermal environment of Guaymas Basin JF - Geochimica Et Cosmochimica Acta Y1 - 2005 A1 - Pearson, A. A1 - Seewald, J. S. A1 - Eglinton, T. I. AB - Radiocarbon analyses of bulk carbon and individual organic compounds are presented for the hydrothermal environment of the Rebecca's Roost vent in the southern trough of the Guaymas Basin hydrothermal field. The Delta(14)C values of CO, and CH4 in the hottest hydrothermal fluids (317 degrees C) are nearly "radiocarbon dead" (-944 parts per thousand and -923 parts per thousand, respectively). In contrast, the Delta(14)C values of sediments and individual fatty acids (-418 parts per thousand to -227 parts per thousand) obtained from a bacterial mat located south of the vent site are similar to values previously reported for hydrothermal petroleum in this environment and are more depleted in C-14 than overlying waters. Hydrothermal fluids moving through the sediments appear to supply C-14 of intermediate age to the bacteria. This carbon may take the form of, or may be supplied by processes similar to, the generation of hydrothermal petroleum. Although the bacterial mat visibly was dominated by Beggiatoa spp., such mats are known to include numerous other species. Individual compound data show that preaged carbon is being consumed by the integrated bacterial assemblage. Values of delta(13)C and Delta(14)C indicate that petroleum-derived carbon is incorporated directly into fresh bacterial biomass. Subsequently, some of this newly synthesized material also is consumed by heterotrophs, as eukaryotic sterols from the same sample also have C-14-depleted values (Delta(14)C = -136 parts per thousand to -110 parts per thousand). Therefore, the entire system may operate as a complex consortium to transform relict carbon back into biomass. Bacterial consumption of relict carbon occurs despite the ample supply of fresh carbon delivered from the productive, overlying water column. Copyright (c) 2005 Elsevier Ltd. VL - 69 IS - 23 N1 - 999tpTimes Cited:36Cited References Count:69 JO - Bacterial incorporation of relict carbon in the hydrothermal environment of Guaymas Basin ER - TY - JOUR T1 - Ten years of compound-specific radiocarbon analysis JF - Oceanography Y1 - 2005 A1 - Ingalls, A. E. A1 - Pearson, A. VL - 18 N1 - id: 504 ER - TY - JOUR T1 - Radiocarbon dating of diatom-bound organic compounds JF - Marine Chemistry Y1 - 2004 A1 - Ingalls, A. E. A1 - Anderson, R. F. A1 - Pearson, A. AB - Here we present a new method for obtaining radiocarbon dates for the organic compounds intrinsic to diatom frustules. This method will improve age models for sediment cores that lack calcium carbonate and improve current interpretations of diatom-based paleoproxies. In preparation for radiocarbon dating by Accelerator Mass Spectrometry, compounds intrinsic to diatom frustules are released from their opal matrix by dissolution in HF and then purified using preparative liquid chromatography-mass spectrometry (LC-MS). The method was applied to one sample from each of three cores (NBP9802 Station 7 GC2; TN057-13 PC4; Ell-2) and a plankton tow (CRS 746, FOODBANCS) collected in the Southern Ocean. In each sample, radiocarbon ages of diatom-bound organic compounds differed from those obtained from foraminiferal CaCO3. Agreement between the foraminifera and compound-specific date was best in cores Ell-2 and TN057-13. In contrast, compound-specific C-14 ages obtained from NBP9802 differed substantially from those measured for foraminiferal CaCO3. The influence of background contamination was assessed throughout all stages of the method and cannot be responsible for the discrepancy observed. Possible reasons for the disagreement between the ages of foraminifera and diatom-bound compounds are discussed in the context of sediment dynamics. These preliminary results suggest that our diatom-based dating method represents a major step forward in our ability interpret sediment records in the Southern Ocean and therefore our understanding of the role of the Southern Ocean in past climate. (C) 2004 Elsevier B.V. All rights reserved. VL - 92 IS - 1-4 N1 - 882iaTimes Cited:34Cited References Count:33 JO - Radiocarbon dating of diatom-bound organic compounds ER - TY - JOUR T1 - A Critical Evaluation of Interlaboratory Data on Total, Elemental, and Isotopic Carbon in the Carbonaceous Particle Reference Material, NIST SRM 1649a JF - J Res Natl Inst Stand Technol Y1 - 2002 A1 - Currie, L. A. A1 - Benner, B. A., Jr. A1 - Kessler, J. D. A1 - Klinedinst, D. B. A1 - Klouda, G. A. A1 - Marolf, J. V. A1 - Slater, J. F. A1 - Wise, S. A. A1 - Cachier, H. A1 - Cary, R. A1 - Chow, J. C. A1 - Watson, J. A1 - Druffel, E. R. A1 - Masiello, C. A. A1 - Eglinton, T. I. A1 - Pearson, A. A1 - Reddy, C. M. A1 - Gustafsson, O. A1 - Quinn, J. G. A1 - Hartmann, P. C. A1 - Hedges, J. I. A1 - Prentice, K. M. A1 - Kirchstetter, T. W. A1 - Novakow, T. A1 - Puxbaum, H. A1 - Schmid, H. AB - Because of increased interest in the marine and atmospheric sciences in elemental carbon (EC), or black carbon (BC) or soot carbon (SC), and because of the difficulties in analyzing or even defining this pervasive component of particulate carbon, it has become quite important to have appropriate reference materials for intercomparison and quality control. The NIST "urban dust" Standard Reference Material((R)) SRM 1649a is useful in this respect, in part because it comprises a considerable array of inorganic and organic species, and because it exhibits a large degree of ((14)C) isotopic heterogeneity, with biomass carbon source contributions ranging from about 2 % (essentially fossil aliphatic fraction) to about 32 % (polar fraction). A primary purpose of this report is to provide documentation for the new isotopic and chemical particulate carbon data for the most recent (31 Jan. 2001) SRM 1649a Certificate of Analysis. Supporting this is a critical review of underlying international intercomparison data and methodologies, provided by 18 teams of analytical experts from 11 institutions. Key results of the intercomparison are: (1) a new, Certified Value for total carbon (TC) in SRM 1649a; (2) (14)C Reference Values for total carbon and a number of organic species, including for the first time 8 individual PAHs; and (3) elemental carbon (EC) Information Values derived from 13 analytical methods applied to this component. Results for elemental carbon, which comprised a special focus of the intercomparison, were quite diverse, reflecting the confounding of methodological-matrix artifacts, and methods that tended to probe more or less refractory regions of this universal, but ill-defined product of incomplete combustion. Availability of both chemical and (14)C speciation data for SRM 1649a holds great promise for improved analytical insight through comparative analysis (e.g., fossil/biomass partition in EC compared to PAH), and through application of the principle of isotopic mass balance. VL - 107 IS - 3 N1 - Currie, L ABenner, B A JrKessler, J DKlinedinst, D BKlouda, G AMarolf, J VSlater, J FWise, S ACachier, HCary, RChow, J CWatson, JDruffel, E R MMasiello, C AEglinton, T IPearson, AReddy, C MGustafsson, OQuinn, J GHartmann, P CHedges, J IPrentice, K MKirchstetter, T WNovakow, TPuxbaum, HSchmid, Heng2002/01/01 00:00J Res Natl Inst Stand Technol. 2002 Jun 1;107(3):279-98. doi: 10.6028/jres.107.022. Print 2002 May-Jun. U2 - PMC4861351 JO - A Critical Evaluation of Interlaboratory Data on Total, Elemental, and Isotopic Carbon in the Carbonaceous Particle Reference Material, NIST SRM 1649a ER - TY - JOUR T1 - Radiocarbon as a tool to apportion the sources of polycyclic aromatic hydrocarbons and black carbon in environmental samples JF - Environmental Science & Technology Y1 - 2002 A1 - Reddy, C. M. A1 - Pearson, A. A1 - Xu, L. A1 - McNichol, A. P. A1 - Benner, B. A. A1 - Wise, S. A. A1 - Klouda, G. A. A1 - Currie, L. A. A1 - Eglinton, T. I. AB - To determine the relative inputs of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) in environmental samples from the combustion of fossil fuels and biomass we have developed two independent analytical methods for determining the C-14 abundance of PAHs and BC. The 5730 yr half-life of C-14 makes it an ideal tracer for identifying combustion products derived from fossil fuels (C-14-free) versus those stemming from modern biomass (contemporary C-14). The C-14 abundance of PAHs in several environmental Standard Reference Materials was measured by accelerator mass spectrometry after extraction and then purification by high-performance liquid chromatography and preparative capillary gas chromatography. This method yields pure compounds that allow for a high degree of confidence in the C-14 results. The PAHs data were then used to compare and evaluate results from an operationally defined thermal oxidation method used to isolate a BC fraction. The C-14 compositions of PAHs and BC were very similar and suggest that the thermal oxidation method employed for isolating BC is robust and free from interferences by non-BC components. In addition, these data indicate that both the PAHs and the BC species derive mostly from fossil fuels and/or their combustion products. VL - 36 IS - 8 N1 - 541gfTimes Cited:133Cited References Count:59 JO - Radiocarbon as a tool to apportion the sources of polycyclic aromatic hydrocarbons and black carbon in environmental samples ER - TY - CHAP T1 - Ocean Process Tracers: Single compound radiocarbon measurements T2 - Encyclopedia of Ocean Sciences Y1 - 2001 A1 - Eglinton, T. I. A1 - Pearson, A. JF - Encyclopedia of Ocean Sciences PB - Academic Press CY - London N1 - id: 1420 ER - TY - JOUR T1 - Origins of lipid biomarkers in Santa Monica Basin surface sediment: A case study using compound-specific D14C analysis JF - Geochimica et Cosmochimica Acta Y1 - 2001 A1 - Pearson, A. A1 - McNichol, A. P. A1 - Benitez-Nelson, B. C. A1 - Hayes, J. M. A1 - Eglinton, T. I. VL - 65 IS - 18 N1 - id: 1419 ER - TY - JOUR T1 - An organic tracer for surface ocean radiocarbon JF - Paleoceanography Y1 - 2000 A1 - Pearson, A. A1 - Eglinton, T. I. A1 - McNichol, A. P. AB - The Delta(14)C of surface water dissolved inorganic carbon (DIC) in the Southern California Eight was compared to Delta(14)C as recorded by the sterols in Santa Monica and Santa Barbara Basin sediments. All of the C-26, C-27, C-28, and C-29 sterols as well as dinosterol had C-14 concentrations equal to surface water DIG, indicating that all of the major sterols were derived from phytoplanktonic production. There is no detectable terrestrial component. Their tracer capability was confirmed by comparing the "bomb C-14"-derived change in surface water Delta(14)C(DIC) With the change in Delta(14)C(sterol). The "prebomb" Delta(14)C(DIC) was similar to 82 parts per thousand, and prebomb sterols averaged -75 +/- 19 parts per thousand. The Delta(14)C value in 1996 was +71 parts per thousand, Eighteen measurements representing eight different sterols from the sediment-water interface of both Santa Monica and Santa Barbara Basins averaged +62 +/- 23 parts per thousand. When three of these values were eliminated because of suspected contamination, the remaining data averaged +71 +/- 12 parts per thousand. The entire compound class could serve as an excellent proxy for the C-14 concentration of ocean surface waters. VL - 15 IS - 5 N1 - 358wyTimes Cited:37Cited References Count:58 JO - An organic tracer for surface ocean radiocarbon ER - TY - JOUR T1 - The origin of n-alkanes in Santa Monica Basin surface sediment: A model based on compount-specific Delta14C and delta13C data JF - Org. Geochem Y1 - 2000 A1 - Pearson, A. A1 - Eglinton, T. I. VL - 31 N1 - id: 364 ER - TY - CHAP T1 - New Developments at the NOSAMS Facility T2 - Proceeding of the International Workshop on Frontiers in Accelerator Mass Spectrometry Y1 - 1999 A1 - von Reden, K. F. A1 - Schneider, R. J. A1 - McNichol, A. P. A1 - Hayes, J. M. A1 - Pearson, A. A1 - Eglinton, T. I. ED - Science, Japan International ED - Technology Exchange, Center JF - Proceeding of the International Workshop on Frontiers in Accelerator Mass Spectrometry PB - National Institute for Environmental Studies, Tsukuba, National Museum of Japanese History CY - Tsukuba, Japan N1 - id: 1723(JISTEC) ER - TY - CONF T1 - New Developments at the NOSAMS Facility T2 - International Workshop on Frontiers in Accelerator Mass Spectrometry Y1 - 1999 A1 - von Reden, K. F. A1 - Schneider, R. J. A1 - McNichol, A. P. A1 - Hayes, J. M. A1 - Pearson, A. A1 - Eglinton, T. I. ED - Shibata, Y. JF - International Workshop on Frontiers in Accelerator Mass Spectrometry PB - National Institute for Environmental Studies Reprot CY - Tsukuba, Japan N1 - id: 1679 ER - TY - CONF T1 - AMS measurement of T2 - Sixteenth International Radiocarbon Conference Y1 - 1998 A1 - von Reden, K. F. A1 - McNichol, A. P. A1 - Pearson, A. A1 - Schneider, R. J. JF - Sixteenth International Radiocarbon Conference CY - Groningen VL - 40(1) N1 - id: 1643 ER - TY - JOUR T1 - AMS Measurement of small samples with high-current system: (Proceedings of the 16th International Radiocarbon Conference, 1997) JF - Radiocarbon Y1 - 1998 A1 - von Reden, K. F. A1 - McNichol, A. A1 - Pearson, A. A1 - Schneider, R. VL - 40 IS - 1 N1 - id: 1815 ER - TY - JOUR T1 - Microscale AMS 14C measurements at NOSAMS JF - Radiocarbon Y1 - 1998 A1 - Pearson, A. A1 - McNichol, A. P. A1 - Schneider, R. J. A1 - von Reden, K. F. A1 - Zheng, Y. VL - 40 IS - 1 N1 - id: 1621 ER - TY - JOUR T1 - Microscale AMS 14C measurements at NOSAMS: (Proceedings of the 16th International Radiocarbon Conference, 1997) JF - Radiocarbon Y1 - 1998 A1 - Pearson, A. A1 - McNichol, A. P. A1 - Schneider, R. J. A1 - von Reden, K. F. A1 - Zheng, Y. VL - 40 IS - 1 N1 - id: 1814 ER - TY - CONF T1 - 14C AMS measurement of C AMS measurement of C AMS measurement of T2 - 16th International Radiocarbon Conference, Groningen Y1 - 1997 A1 - von Reden, K. A1 - McNichol, A. A1 - Pearson, A. A1 - Schneider, R. JF - 16th International Radiocarbon Conference, Groningen VL - Book of Abstracts N1 - id: 952 ER - TY - CONF T1 - Determination of the radiocarbon ages of individual PAH extracted from urban aerosol and marine sediment T2 - 16th International Radiocarbon Conference Y1 - 1997 A1 - Pearson, A. A1 - Eglinton, T. I. A1 - McNichol, A. P. A1 - Currie, L. A. A1 - Schneider, R. J. A1 - von Reden, K. F. A1 - Benner, B. A. A1 - Wise, S. A. JF - 16th International Radiocarbon Conference CY - Groningen VL - Book of Abstracts N1 - id: 951 ER - TY - JOUR T1 - Variability in radiocarbon ages of individual organic compounds from marine sediments JF - Science Y1 - 1997 A1 - Eglinton, T. I. A1 - BenitezNelson, B. C. A1 - Pearson, A. A1 - McNichol, A. P. A1 - Bauer, J. E. A1 - Druffel, E. R. M. AB - 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. VL - 277 IS - 5327 N1 - Xq247Times Cited:175Cited References Count:37 JO - Variability in radiocarbon ages of individual organic compounds from marine sediments ER - TY - JOUR T1 - Compound specific radiocarbon analysis as a tool to quantitatively apportion modern and fossil sources of polycyclic aromatic hydrocarbons in environmental matrices. JF - Abstracts of Papers of the American Chemical Society Y1 - 1996 A1 - Eglinton, T. I. A1 - Pearson, A. A1 - McNichol, A. P. A1 - Currie, L. A. A1 - Benner, B. A. A1 - Wise, S. A. VL - 212 SN - 0065-7727 IS - 2 N1 - 1Va915 Times Cited:0 Cited References Count:0 JO - Abstr Pap Am Chem S ER - TY - CONF T1 - Expanded Small Sample Capabilities at NOSAMS: Preparation and Analysis of Conventional Graphite Targets Containing 0.15 mg Carbon T2 - 7th International Conference on Accelerator Mass Spectrometry Y1 - 1996 A1 - Pearson, A. A1 - McNichol, A. P. A1 - Schneider, R. J. A1 - von Reden, K. F. JF - 7th International Conference on Accelerator Mass Spectrometry PB - Radiocarbon CY - Tucson, AZ VL - 38 N1 - id: 946; 1 ER - TY - JOUR T1 - Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis--A Novel Approach JF - Radiocarbon Y1 - 1996 A1 - Eglinton, T. I. A1 - McNichol, A. P. A1 - Benitez-Nelson, B. C. A1 - Pearson, A. A1 - von Reden, K. F. A1 - Schneider, R. J. A1 - Bauer, J. E. A1 - Druffel, E. R. M. VL - 38 IS - 1 N1 - id: 1650 ER - TY - CONF T1 - Isolation of Individual Organic Compounds for AMS Radiocarbon Analysis -- A Novel Approach T2 - 7th International Conference on Accelerator Mass Spectrometry Y1 - 1996 A1 - Eglinton, T. I. A1 - McNichol, A. P. A1 - Benitez-Nelson, B. C. A1 - Pearson, A. A1 - von Reden, K. F. A1 - Schneider, R. J. A1 - Bauer, J. E. A1 - Druffel, E. R. M. JF - 7th International Conference on Accelerator Mass Spectrometry PB - Radiocarbon CY - Tucson, AZ VL - 38 N1 - id: 1800; 1 ER -