222Rn and 226Ra: indicators of sea-ice effects on air-sea gas exchange

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Fanning, Kent A. ; Torres, Linda M. (1991)

222 Rn and 226Ra distributions beneath the sea ice of the Barents Sea revealed that ice cover has varied effects on air-sea gas exchange. Twice, once in late summer and once in late winter, seawater samples from the top meter below drill holes had 222Rn activities that were not lower than their 226,Ra activities, indicating the existence of secular equilibrium and a negligible net exchange of 222Rn and other gases with the atmosphere. However, seawater in the upper 20-85 m usually exhibited at least some 222Rn depletion; 222Rn-to-226Ra activity ratios tended to have ‘ice-free’ values (0.3-0.9) in the summer and values between 0.9 and 1.0 in the winter. Integrated 222Rn depletions and piston velocities in both seasons typically fell in the lower 25% of the ranges for ice-free seawater, suggesting that a moderate but far from total reduction in gas exchange is normally caused by ice cover and/or meltwater. The results demonstrate that sea-ice interference with the oceanic uptake of atmospheric gases such as CO, is not well understood and needs further investigation.
  • References (14)
    14 references, page 1 of 2

    Broecker. W. S . & Peng. Ts.-H. 1Y71: The vertical distribution of radon in the BOMEX area. Earth Planer. Sci. Len. 11, 99-108.

    Broecker, W. S . & Pcng. Ts.-H. 1974: Gas exchange rates between air and sea. Tellur 26. 21-35.

    Broecker, W. S. & Peng. Ts.-H. 1982: Tracers in the Sea. Eldigio Press, Palisades. N.Y

    Fanning, K . A,, Brcland. J . A , . 11. & Byrne, R. H. 1Y82: Radium-226 and radon-222 in the coastal waters of west Florida: concentration and atmospheric degassing. Science 215. 667-670.

    Glover. D. M. & Reeburgh. W . S . 1987:Radon-222 and radium226 in southeastern Bering Sea shelf waters and bediment. Conr. Sherf Res. 7. 433-456.

    Krysell. M. & Wallace. D. W . R 1988:Arcticocean ventilation studies with a suite of anthropogcnic halocarhon tracers. Science, 242. 746749.

    Mathieu. G. G.. Biscaye. P. E . . Lupton. R. A. & Hammond. D. E. IY8X: Measurement of radon-222 in natural watcr systems. Healrli Pltys 55. 989-Y92.

    Moore. W. S . IYXI: Radium isotopes in the Chesapeake Bay. Esruar. Cousr. Shelf Scr. 12. 713-723.

    Peng, T5.-H., Broecker. W . S . . Mathicu. G. G. & Li. Y.-€1. 1979: Radon evasion rates In the Atlantic and Pacific ocean5 as determined during the Gcosecs program. J . Geophvs. Res. 84. 2471-2486

    Poisson. A . & Chcn. C:T. 1987. Why is there littlc anthropogcnic CO: in the Antarctic Bottom Watcr? Deep-Sea Res 34. 1255-1275.

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