Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-27T22:30:25.206Z Has data issue: false hasContentIssue false
  • English
  • Français

Decadal Changes of Radiocarbon in the Surface Bay of Bengal: Three Decades After Geosecs and One Decade After WOCE

Published online by Cambridge University Press:  18 July 2016

Koushik Dutta ,
G V Ravi Prasad ,
Dinesh K Ray  and
Sanjeev Raghav
Koushik Dutta*
Affiliation:
Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India
G V Ravi Prasad
Affiliation:
Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India Center for Applied Isotope Studies, University of Georgia, Athens, Georgia 30602, USA
Dinesh K Ray
Affiliation:
Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India
Sanjeev Raghav
Affiliation:
Marine Wing, Geological Survey of India, Kolkata 700 091, India
*
Corresponding author. Email: [email protected]
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.

Radiocarbon was measured in the surface seawater dissolved inorganic carbon (DIC) of the Bay of Bengal during November 2006. A meridional transect of the Δ14C in DIC was obtained from measurements in closely spaced samples collected roughly along 88°E. The Δ14C of these samples ranged from 44‰ to 57.7‰ (mean 51.8 ± 1.1‰, n = 12), and 38‰ at one station in the northern Bay of Bengal. The overall pattern of 14C distribution in DIC of surface Bay of Bengal during 2006 was roughly similar to that during the WOCE expedition of 1995. These results indicate a Δ14C decline rate of ∼4‰ per decade since WOCE in the surface Bay of Bengal, which is much smaller compared to a decline rate of ∼25‰ per decade observed in the 2 decades between the GEOSECS and WOCE expeditions, due to the smaller atmosphere-ocean Δ14C gradient.

Type
Marine
Information
Radiocarbon , Volume 52 , Issue 3: 20th Int. Radiocarbon Conference Proceedings , 2010 , pp. 1191 - 1196
Copyright
Copyright © 2010 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Bhushan, R, Somayajulu, BLK, Chakraborty, S, Krishnaswami, S. 2000. Radiocarbon in the Arabian Sea water column: temporal variations in bomb 14C inventory since the GEOSECS and CO2 air-sea exchange rates. Journal of Geophysical Research 105(C6):14,273–82.CrossRefGoogle Scholar
Bhushan, R, Dutta, K, Mulsow, S, Povinec, PP, Somayajulu, BLK. 2003. Distribution of natural and man-made radionuclides during the reoccupation of GEOSECS stations 413 and 416 in the Arabian Sea: temporal changes. Deep-Sea Research II 50(17–21):2777–84.Google Scholar
Druffel, ERM. 1987. Bomb radiocarbon in the Pacific: annual and seasonal timescale variations. Journal of Geophysical Research 45(3):667–98.Google Scholar
Druffel, ERM, Griffin, S. 2008. Daily variability of dissolved inorganic radiocarbon at three sites in the surface ocean. Marine Chemistry 110(3–4):185–9.CrossRefGoogle Scholar
Dutta, K. 2001. Study of marine processes in the northern Indian Ocean using radiocarbon [PhD dissertation]. M.S. University of Baroda, Vadodara, India. 142 p.Google Scholar
Dutta, K, Bhushan, R, Somayajulu, BLK. 2000. Anthropogenic radiocarbon in Bay of Bengal: two decades after GEOSECS [abstract]. 17th International Radiocarbon Conference, 18–23 June 2000, Judean Hills, Israel.Google Scholar
Dutta, K, Bhushan, R, Somayajulu, BLK, Rastogi, N. 2006. Inter-annual variation in atmospheric Δ14C over the northern Indian Ocean. Atmospheric Environment 40(24):4501–12.CrossRefGoogle Scholar
Dutta, K, Bhushan, R, Somayajulu, BLK. 2007. Rapid vertical mixing rates in the deep waters of the Andaman Basin. Science of the Total Environment 384(1–3):401–8.CrossRefGoogle ScholarPubMed
Guilderson, TP, Caldeira, K, Duffy, PB. 2000. Radiocarbon as a diagnostic tracer in ocean and carbon cycle modeling. Global Biogeochemical Cycles 14(3):887–902.CrossRefGoogle Scholar
Hua, Q, Barbetti, M. 2004. Review of tropospheric bomb 14C data for carbon cycle modeling and age calibration purposes. Radiocarbon 46(3):1273–98.CrossRefGoogle Scholar
Key, RM, Quay, PD. 2002. US WOCE Indian Ocean Survey: final report for radiocarbon. Ocean Tracer Laboratory, Technical Report 02-1.Google Scholar
Moore, WS. 1997. High fluxes of radium and barium from the mouth of the Ganges-Brahmaputra River during low river discharge suggest a large groundwater source. Earth and Planetary Science Letters 150(1–2):141–50.CrossRefGoogle Scholar
Ravi Prasad, GV, Dutta, K, Ray, DK. 2008. Radiocarbon AMS at IOP: system improvements and dating of groundwater from Bhadrak district, Orissa. Nuclear Instruments and Methods in Physics Research B 266(8):1833–6.Google Scholar
Sengupta, D, Bharat Raj, GN, Shenoi, SSC. 2006. Surface freshwater from Bay of Bengal runoff and Indonesian Throughflow in the tropical Indian Ocean. Geophysical Research Letters 33: L22609, doi:10.1029/2006GL027573.CrossRefGoogle Scholar
Schott, FA, McCreary, JP Jr. 2001. The monsoon circulation of the Indian Ocean. Progress in Oceanography 51(1):1–123.CrossRefGoogle Scholar
Shankar, D, Vinayachandran, PN, Unnikrishnan, AS. 2002. The monsoon currents in the north Indian Ocean. Progress in Oceanography 52(1):63–120.CrossRefGoogle Scholar
Stuiver, M, Östlund, HG. 1983. GEOSECS Indian Ocean and Mediterranean radiocarbon. Radiocarbon 25(1):1–29.CrossRefGoogle Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.CrossRefGoogle Scholar
Vogel, JS, Southon, JR, Nelson, DE, Brown, TA. 1984. Performance of catalytically condensed carbon for use in accelerator mass spectrometry. Nuclear Instruments and Methods in Physics Research B 5(2):289–93.CrossRefGoogle Scholar
Xu, X, Trumbore, S, Ajie, H, Tyler, S. 2007. Δ14C of atmospheric CO2 over the Subtropical and Equatorial Pacific and at Point Barrow, Alaska. EOS Transactions AGU 88(52), Fall Meeting Supplement, Abstract B43D-1581.Google Scholar