Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-17T16:58:08.810Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  28 May 2018

Ellen R M Druffel*
Affiliation:
Department of Earth System Science, University of California, Irvine, CA 92697-3100USA
Sheila Griffin
Affiliation:
Department of Earth System Science, University of California, Irvine, CA 92697-3100USA
Ning Wang
Affiliation:
Department of Earth System Science, University of California, Irvine, CA 92697-3100USA State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
Brett D Walker
Affiliation:
Department of Earth System Science, University of California, Irvine, CA 92697-3100USA
*
*Corresponding author. Email: [email protected].

Abstract

We report marine dissolved organic carbon (DOC) ∆14C from seawater collected from the North central Pacific Ocean (NCP) in 2015. These measurements show DOC ∆14C 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 ∆14C profiles from the NCP in 1985 and 1987 reveals that deep DOC ∆14C values have decreased. We discuss several possible mechanisms that could cause such a shift in DOC ∆14C values, including spatial inhomogeneity and temporal variability due to changes in the dissolution and ∆14C value of surface derived particles in the deep sea. We find that forthcoming profiles of DOC ∆14C results from the NCP will determine the primary mechanisms controlling deep DOC ∆14C distributions, and changes over the past three decades.

Type
Marine & Other Methods
Copyright
© 2018 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Andrews, A, Siciliano, D, Potts, D, DeMartini, E, Covarrubias, S. 2016. Bomb radiocarbon and the Hawaiian Archipelago: Coral, otoliths and seawater. Radiocarbon 58(3):531548.Google Scholar
Bauer, JE, Williams, PM, Druffel, ERM. 1992. 14C activity of dissolved organic carbon fractions in the north central Pacific and Sargasso Sea. Nature 357:667670.Google Scholar
Bauer, JE, Druffel, ERM, Williams, PM, Wolgast, DM, Griffin, S. 1998. Inter- and intra-annual variability in isotopic (14C and 13C) signatures of dissolved organic carbon in the eastern North Pacific Ocean. Journal of Geophysical Research 103:28672882.Google Scholar
Beaupré, SR, Druffel, ERM, Griffin, S. 2007. A low-blank photochemical extraction system for concentration and isotopic analyses of marine dissolved organic carbon. Limnology and Oceanography Methods 5:174184.Google Scholar
Beaupré, SR, Druffel, ERM. 2009. Constraining the propagation of bomb-radiocarbon through the dissolved organic carbon (DOC) pool in the northeast Pacific Ocean. Deep-Sea Research I 56:17171726.Google Scholar
Bien, GS, Rakestraw, NW, Suess, HE. 1965. Radiocarbon in the Pacific and Indian Oceans and its relation to deep water movements. Limnology and Oceanography 10:R25R37.Google Scholar
Broecker, WS, Gerard, R, Ewing, M, Heezin, B. 1960. Natural radiocarbon in the Atlantic Ocean. Journal of Geophysical Research 65:29032931.Google Scholar
Druffel, E, Williams, P, Bauer, J, Ertel, J. 1992. Cycling of dissolved and particulate organic matter in the open ocean. Journal of Geophysical Research 97:1563915659.Google Scholar
Druffel, ERM, Bauer, JE. 2000. Radiocarbon distributions in Southern Ocean dissolved and particulate organic carbon. Geophysical Research Letters 27:14951498.Google Scholar
Druffel, ERM, Griffin, S. 2008. Daily variability of dissolved inorganic radiocarbon at three sites in the surface ocean. Marine Chemistry 110:185189.Google Scholar
Druffel, ERM, Griffin, S, Walker, BD, Coppola, AI, Glynn, DS. 2013. Total uncertainty of radiocarbon measurements of marine dissolved organic carbon and methodological recommendations. Radiocarbon 55(2–3):11351141.Google Scholar
Druffel, ERM, Griffin, S, Walker, BD, Coppola, AI. 2016. Radiocarbon in dissolved organic carbon of the Atlantic Ocean. Geophysical Research Letters 43. doi: 10.1002/2016GL068746.Google Scholar
Druffel, ERM, Griffin, S. 2015. Radiocarbon in dissolved organic carbon of the South Pacific Ocean. Geophysical Research Letters 42:40964101.Google Scholar
Falkowski, PG. 2014. The biogeochemistry of primary production in the sea. Treatise on Geochemistry (Second Edition) 10. Biogeochemistry. 163187.Google Scholar
Griffin, S, Beaupré, SR, Druffel, ERM. 2010. An alternate method of diluting dissolved organic carbon seawater samples for 14C analysis. Radiocarbon 52(2):12241229.Google Scholar
Griffith, DR, McNichol, AP, Xu, L, McLaughlin, FA, MacDonald, RW, Brown, KA, Eglinton, TI. 2012. Carbon dynamics in the western Arctic Ocean: insights from full-depth carbon isotope profiles of DIC, DOC, and POC. Biogeosciences 9:12171224.Google Scholar
Hansell, DA, Carlson, CA, Repeta, DJ, Schlitzer, R. 2009. Dissolved organic matter in the ocean: A controversy stimulates new insights. Oceanography 22:202211.Google Scholar
Hansman, RS, Griffin, S, Watson, J, Druffel, ERM, Ingalls, A, Pearson, A, Aluwihare, A. 2009. The radiocarbon signature of microorganisms in the mesopelagic ocean. Proceedings of the National Academy of Sciences 106:65136518.Google Scholar
Hawkes, JA, Rossel, PE, Stubbins, A, Butterfield, D, Connelly, DP, Achterberg, EP, Koschinsky, A, Chavagnac, V, Hansen, CT, Bach, W, Dittmar, T. 2015. E fficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation. Nature Geoscience 8:856861.Google Scholar
Komada, T, Burdige, D, Cripso, S, Druffel, E, Griffin, S, Johnson, L, Le, D. 2013. Dissolved organic carbon dynamics in anaerobic sediments of the Santa Monica Basin. Geochimica et Cosmochimica Acta 110:253273.Google Scholar
Lang, SQ, Butterfield, DA, Lilley, MD, Johnson, HP, Hedges, JI. 2006. Dissolved organic carbon in ridge-axis and ridge-flank hydrothermal systems. Geochimica et Cosmochimica Acta 70:38303842.Google Scholar
McCarthy, MD, Beaupré, SR, Walker, BD, Voparil, I, Guilderson, TP, Druffel, ERM. 2011. Chemosynthetic origin of 14C-depleted dissolved organic matter in a ridge-flank hydrothermal system. Nature Geoscience 4:3236.Google Scholar
McNichol, AP, Druffel, ERM. 1992. Variability of the d13C of dissolved inorganic carbon at a site in the North Pacific Ocean. Geochimica et Cosmochimica Acta 56:35893592.Google Scholar
Pohlman, J, Bauer, J, Waite, W, Osburn, C, Chapman, N. 2011. Methane hydrate-bearing seeps as a source of aged dissolved organic carbon to the oceans. Nature Geoscience 4:3741.Google Scholar
Smith, KL. 1989. Short time-series measurements of particulate organic carbon flux and sediment community oxygen consumption in the North Pacific. Deep Sea Res 36:11111119.Google Scholar
Sonnerup, R, Quay, P, McNichol, A. 2000. The Indian Ocean 13C Suess effect. Global Biogeochemical Cycles. doi: 10.1029/1999GB001244.Google Scholar
Southon, JR, Santos, M, Druffel-Rodriguez, KC, Druffel, ERM, Trumbore, SE, Xu, X, Griffin, S, Ali, S, Mazon, M. 2004. The Keck Carbon Cycle AMS Laboratory, U.C.I.: Initial operation and a background surprise. Radiocarbon 46(1):4150.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: Reporting of 14C data. Radiocarbon 19(3):355363.Google Scholar
Tanaka, N, Otosaka, S, Wakita, M, Amano, H, Togawa, O. 2010. Preliminary result of dissolved organic radiocarbon in the western North Pacific Ocean. Nuclear Instruments and Methods Physics Research 268:12191221.Google Scholar
Walker, BD, Griffin, S, Druffel, ERM. 2016. Linked changes in marine dissolved organic carbon molecular size and radiocarbon age. Radiocarbon 58. DOI: 10.1017/RDC.2016.48.Google Scholar
Williams, PM, Druffel, ERM. 1987. Radiocarbon in dissolved organic carbon in the central North Pacific Ocean. Nature 330:246248.Google Scholar
Williams, PM, Oeschger, H, Kinney, P. 1969. Natural radiocarbon activity of dissolved organic carbon in northeast Pacific Ocean. Nature 224(5216):256–248.Google Scholar
Xu, X, Trumbore, SE, Zheng, S, Southon, JR, McDuffee, KE, Luttgen, M, Liu, JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: Reducing background and attaining high precision. Nuclear Instruments and Methods in Physics Research B 259:320329.Google Scholar