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Radiocarbon in the Water Column of the Southwestern North Pacific Ocean—24 Years After Geosecs

Published online by Cambridge University Press:  18 July 2016

Pavel P Povinec ,
Takafumi Aramaki ,
George S Burr ,
A J Timothy Jull ,
Laval Liong Wee Kwong  and
Orihiko Togawa
Pavel P Povinec*
Affiliation:
International Atomic Energy Agency, Marine Environment Laboratory, Monte-Carlo, MC 98012 Monaco
Takafumi Aramaki
Affiliation:
Japan Atomic Energy Research Institute, Marine Research Laboratory, Mutsu, Aomori-ken, Japan
George S Burr
Affiliation:
University of Arizona, NSF Arizona AMS Facility, Tucson, Arizona, USA.
A J Timothy Jull
Affiliation:
University of Arizona, NSF Arizona AMS Facility, Tucson, Arizona, USA.
Laval Liong Wee Kwong
Affiliation:
International Atomic Energy Agency, Marine Environment Laboratory, Monte-Carlo, MC 98012 Monaco
Orihiko Togawa
Affiliation:
International Atomic Energy Agency, Marine Environment Laboratory, Monte-Carlo, MC 98012 Monaco Japan Atomic Energy Research Institute, Marine Research Laboratory, Mutsu, Aomori-ken, Japan
*
Corresponding author. Email: p.povinec@iaea.org.
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Abstract

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In the framework of the Worldwide Marine Radioactivity Studies (WOMARS) project, water profile samples for radiocarbon measurements were taken during the IAEA'97 cruise at 10 stations in the southwestern North Pacific Ocean. While 14C concentrations were rapidly decreasing from the surface (Δ14C about 100‰) down to about 800 m at all visited stations (Δ14C about −200‰), the concentrations below 1000 m were almost constant. Some stations were in proximity to the GEOSECS stations sampled in 1973; thus, 14C profiles could be compared after a 24-yr interval. Generally, 14C concentrations had decreased in surface waters (by 50–80‰) and increased (by about the same amount) in intermediate waters when compared with GEOSECS data. In deep waters (below 1000 m), the observed 14C concentrations were similar to GEOSECS values. The bomb-produced 14C inventory had increased by more than 20% over the 24 yr from 1973 to 1997 and was estimated to be about (32 ± 5) 1012 atom m-2, with an annual 14C flux of (1.3 ± 0.3) 1012 atom m-2 yr-1. The results suggest that bomb-produced 14C has been advected northwards by the Kuroshio Current and the Kuroshio Extension and stored in the intermediate layer as North Pacific Intermediate Water.

Type
Part II
Information
Radiocarbon , Volume 46 , Issue 2: Proceedings of the 18th International Radiocarbon Conference (Part 2 of 2), Conference Editors: Nancy Beavan Athfield, Rodger J Sparks , 2004 , pp. 583 - 594
Copyright
Copyright © The Arizona Board of Regents on behalf of the University of Arizona 

References

Aramaki, T. 2002. Study on seawater circulation in the western North Pacific and its marginal seas in the viewpoint of distribution of radiocarbon in seawater [PhD dissertation]. Sapporo, Japan: Hokkaido University.Google Scholar
Aramaki, T, Mizushima, T, Mizutani, Y, Yamamoto, T, Togawa, O, Kabuto, S, Kuji, T, Gottdang, A, Klein, M, Mous, DJW. 2000. The AMS facility at the Japan Atomic Energy Research Institute (JAERI). Nuclear Instruments and Methods in Physics Research B 172: 18–23.Google Scholar
Aramaki, T, Mizushima, T, Kuji, T, Povinec, PP, Togawa, O. 2001. Distribution of radiocarbon in the southwestern North Pacific. Radiocarbon 43(2B):857–68.Google Scholar
Broecker, WS, Peng, T-H, Ostland, G, Stuiver, M. 1985. The distribution of bomb radiocarbon in the ocean. Journal of Geophysical Research 90:6953–70.Google Scholar
Broecker, WS, Sutherland, S, Smethie, W, Peng, T-H. 1995. Oceanic radiocarbon: separation of the natural and bomb components. Global Biogeochemical Cycles 9: 263–88.Google Scholar
Donahue, DJ, Linick, TW, Jull, AJT. 1990a. Isotope-ratio and background corrections for accelerator mass spectrometry radiocarbon measurements. Radiocarbon 32(1):135–42.Google Scholar
Donahue, DJ, Jull, AJT, Toolin, LJ. 1990b. Radiocarbon measurements at the University of Arizona AMS facility. Nuclear Instruments and Methods in Physics Research B 52:224–8.Google Scholar
Gamo, T, Horibe, Y, Kobayashi, H. 1987. Comparison of oceanic Δ14C data with those of GEOSECS: vertical profiles in 1973 and 1980 at 30$dGN 170$dGE in the northwestern Pacific Ocean. Radiocarbon 29(1):53–6.Google Scholar
Kawabe, M, Taira, K. 1998. Water masses and properties at 165$dGE in the western Pacific. Journal of Geophysical Research 103:12,941–58.CrossRefGoogle Scholar
Key, RM, Quay, PD, Schlosser, P, McNichol, AP, von Reden, KF, Schneider, RJ, Elder, KL, Stuiver, M, Ostlund, HG. 2002. WOCE radiocarbon IV: Pacific Ocean results; P10, P13N, P14C, P18, P19 & S4P. Radiocarbon 44(1):239–392.Google Scholar
Kitagawa, H, Masuzawa, T, Nakamura, T, Matsumoto, E. 1993. A batch preparation method of graphite targets with low background for AMS 14C measurements. Radiocarbon 35(2):295–300.Google Scholar
Leboucher, V, Orr, J, Jean-Baptiste, P, Arnold, M, Monfray, P, Tisnerat-Laborde, N, Poisson, A, Duplessy, J-C. 1999. Oceanic radiocarbon between Antarctica and South Africa along WOCE section 16 at 30$dGE. Radiocarbon 41(1):51–73.Google Scholar
Levin, I, Kromer, B, Schoch-Fischer, H, Bruns, M, Munnich, M, Berdau, D, Vogel, JC, Munnich, KO. 1985. 25 years of tropospheric 14C observations in Central Europe. Radiocarbon 27(1):1–19.CrossRefGoogle Scholar
Levin, I, Kromer, B, Schoch-Fischer, H, Bruns, M, Munnich, M, Berdau, D, Vogel, JC, Munnich, KO. 1994. Δ14CO2 records from sites in Central Europe, Trends '93. In: Boden, TA, Kaiser, DP, Sepanski, RJ, Stoss, FW, editors. A Compendium of Data on Global Change. Oak Ridge: ORNL/CDIA-65. p 203–22.Google Scholar
Liong Wee Kwong, L, Povinec, PP, Jull, AJT. 2004. Preparation of graphite targets from small marine samples for AMS radiocarbon measurements. Radiocarbon, these proceedings.CrossRefGoogle Scholar
Mahadeva, A. 2001. An analysis of bomb radiocarbon trends in the Pacific. Marine Chemistry 73:273–90.Google Scholar
Ostlund, HG, Stuiver, M. 1980. GEOSECS Pacific radiocarbon. Radiocarbon 22(1):25–53.CrossRefGoogle Scholar
Peng, T-H, Key, RM, Ostlund, HG. 1998. Temporal variations of bomb radiocarbon inventory in the Pacific Ocean. Marine Chemistry 60:3–13.CrossRefGoogle Scholar
Povinec, PP, Togawa, O. 1999. Marine radioactivity studies in the world oceans (MARS). Marine Pollution: Proceedings of the International Symposium, Monaco, 5–9 October 1998. International Atomic Energy Agency TECDOC-1094:262–7.Google Scholar
Povinec, PP, Livingston, HD, Shima, S, Aoyama, M, Gastaud, J, Goroncy, I, Hirose, K, Huynh-Ngoc, L, Ikeuchi, Y, Ito, T, La Rosa, J, Liong Wee Kwong, L, Lee, SH, Moriya, H, Mulsow, S, Oregioni, B, Pettersson, H, Togawa, O. 2003. IAEA'97 expedition to the NW Pacific Ocean—results of oceanographic and radionuclide investigations of the water column. Deep-Sea Research II 50:2607–37.Google Scholar
Reid, JL. 1965. Intermediate waters of the Pacific Ocean. Johns Hopkins Oceanographic Studies 2. 85 p.Google Scholar
Stuiver, M. 1980. Workshop on 14C data reporting. In: Stuiver, M, Kra, R, editors. Proceedings of the 10th International 14C Conference. Radiocarbon 22(3):964–6.CrossRefGoogle Scholar
Suga, T, Hanawa, K, Toba, Y. 1989. Thermostad distribution in the North Pacific subtropical gyre: the central mode water and the subtropical mode water. Journal of Physical Oceanography 27:140–52.Google Scholar
Talley, LD. 1993. Distribution and formation of North Pacific Intermediate Water. Journal of Physical Oceanography 23:517–37.Google Scholar
Tsunogai, S. 1981. A method for chronology of the Pacific and Atlantic deep water and its application. Chikyukagaku 15:70–6. In Japanese with English abstract.Google Scholar
Watanabe, YW, Ono, T, Harada, K, Fukasawa, M. 1999. A preliminary study of oceanic bomb radiocarbon inventory in the North Pacific during the last two decades. Journal of Oceanography 55:705–16.Google Scholar