Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T05:50:48.268Z Has data issue: false hasContentIssue false

Bomb 14C in the Indian Ocean Measured by Accelerator Mass Spectrometry: Oceanographic Implications

Published online by Cambridge University Press:  18 July 2016

Edouard Bard
Affiliation:
Centre des Faibles Radioactivités (CFR), Laboratoire Mixte CNRS-CEA Pare du CNRS BP 1, F-91190, Gif-sur-Yvette, France Lamont-Doherty Geological Observatory (L-DGO), Columbia University, Palisades, New York 10964
Maurice Arnold
Affiliation:
Centre des Faibles Radioactivités (CFR), Laboratoire Mixte CNRS-CEA Pare du CNRS BP 1, F-91190, Gif-sur-Yvette, France
J R Toggweiler
Affiliation:
Geophysical Fluid Dynamics Laboratory (GFDL), Princeton University, Princeton, New Jersey 08540
Pierre Maurice
Affiliation:
Centre des Faibles Radioactivités (CFR), Laboratoire Mixte CNRS-CEA Pare du CNRS BP 1, F-91190, Gif-sur-Yvette, France
Jean-Claude Duplessy
Affiliation:
Centre des Faibles Radioactivités (CFR), Laboratoire Mixte CNRS-CEA Pare du CNRS BP 1, F-91190, Gif-sur-Yvette, France
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

AMS 14C measurements on samples collected in the tropical-equatorial Indian Ocean during the INDIGO program (leg II, 1986) are presented and compared with β-counting results obtained under both INDIGO program and GEOSECS expedition in the Indian Ocean (1978). The most significant observation is a doubling of the bomb-14C inventory and mean penetration depth in the equatorial zone. Based on hydrologic considerations, two hypotheses can be proposed: 1) direct influx of Pacific mid-latitude waters through the Indonesian archipelago and 2) advection and/or mixing with Mode Water from the southern gyre of the Indian Ocean. Results obtained with a general circulation model of the ocean suggest that the influx from the Pacific is important in the upper 300m and that below 500m the bomb-14C budget is dominated by Mode Water advection.

Type
II. Carbon Cycle in the Environment
Copyright
Copyright © The American Journal of Science 

References

Arnold, M, Bard, E, Maurice, P and Duplessy, JC, 1987, C-14 dating with Gif-sur-Yvette tandetron accelerator: Status report: Nuclear Instruments & Methods, v B29, p 120123.Google Scholar
Bard, E, Arnold, M, Maurice, P and Duplessy, JC, 1987, Measurements of bomb radiocarbon in the ocean by means of accelerator mass spectrometry: technical aspects: Nuclear Instruments & Methods, v B29, p 297301.Google Scholar
Bard, E, Arnold, M, Ostlund, G H, Maurice, P, Monfray, P and Duplessy, JC, 1988, Penetration of bomb radiocarbon in the tropical Indian ocean measured by means of accelerator mass spectrometry: Earth Planetary Sci Letters, v 87, p 379389.Google Scholar
Broecker, WS, Peng, T H, Östlund, H G and Stuiver, M, 1985, The distribution of bomb radiocarbon in the ocean: Jour Geophys Research, v 90, no. C4, p 69536970.Google Scholar
Bryan, K and Lewis, LJ 1979, A water mass model of the world ocean circulation: Jour Geophys Research, v 84, p 25032517.Google Scholar
Gordon, A L, 1986, Interocean exchange of thermocline water: Jour Geophys Research v 91, no. C4, p 50375046.CrossRefGoogle Scholar
McCartney, M S, 1982, The subtropical recirculation of Mode Waters: Jour Marine Research v 40, Supp, p 427464.Google Scholar
Nydal, R and Lövseth, K, 1983, Tracing bomb 14C in the atmosphere 1962–1980: Jour Geophys Research, v 88, no. C6, p 36213642.Google Scholar
Östlund, H G and Grall, C (ms), 1988, INDIGO 1985–1987 Indian Ocean radiocarbon: Tritium Lab data rept 17, Univ Miami.Google Scholar
Sharma, GS, 1972, Water characteristics at 200 cl/t in the intertropical Indian Ocean during the southwest monsoon: Jour Marine Research, v 30, p 102111.Google Scholar
Stuiver, M and Östlund, HG, 1983, GEOSECS Indian Ocean and Mediterranean radiocarbon: Radiocarbon, v 25, no. 1, p 129.CrossRefGoogle Scholar
Toggweiler, J R, Dixon, K and Bryan, K, 1988a, Simulations of radiocarbon in a coarse resolution world ocean model I: steady state, pre-bomb distributions: Jour Geophys Research, in press.Google Scholar
Toggweiler, J R, Dixon, K and Bryan, K, 1988b, Simulations of radiocarbon in a coarse resolution world ocean model II: distributions of bomb-produced 14C: Jour Geophys Research, in press CrossRefGoogle Scholar
Toggweiler, J R and Trumbore, S, 1985, Bomb-test 90Sr in Pacific and Indian Ocean surface water as recorded by banded corals: Earth Planetary Sci Letters, v 74, p 306314.Google Scholar
Vogel, J S, Southon, J R, Nelson, D E and Brown, T A, 1984, Performance of catalytically condensed carbon for use in accelerator mass spectrometry: Nuclear Instruments & Methods, v B5, p 289293.Google Scholar
Warren, B A, 1981, Transindian hydrographic section at Lat 18°S: property distributions and circulation in the south Indian ocean: Deep Sea Research, v 28A, no. 8, p 759788.CrossRefGoogle Scholar
Wyrtki, K, 1973, Physical oceanography of the Indian Ocean, in Zeitzschel, B, ed, Ecological studies. Analysis and synthesis, vol 3: Berlin, Springer-Verlag, p 1836.Google Scholar