Journal of Oceanography

, Volume 59, Issue 5, pp 651–661

Air-Sea Gas Transfer Velocity in Stormy Winter Estimated from Radon Deficiency

  • Hitoshi Kawabata
  • Hisashi Narita
  • Koh Harada
  • Shizuo Tsunogai
  • Masashi Kusakabe
Article

DOI: 10.1023/B:JOCE.0000009594.49463.1c

Cite this article as:
Kawabata, H., Narita, H., Harada, K. et al. Journal of Oceanography (2003) 59: 651. doi:10.1023/B:JOCE.0000009594.49463.1c

Abstract

Thirteen vertical profiles of 226Ra and 222Rn in the near-surface water were obtained in the western North Pacific in winter, and the gas transfer velocities across the air-sea interface were estimated. The transfer velocities found by applying a steady state model varied widely from 2.1 to 30.2 m day−1 with a mean of 9.4 m day−1. The mean value is almost 5 times higher than that in summer in other oceans, and the maximum value is a record high for world oceans. This is partly due to the inadequacy of the steady state model, which overestimates when stronger winds blow in more recent days than the 222Rn half-life of about 4 days. In fact, a strong low pressure zone passed through the station about 2 days earlier, which was one of the low pressure zones that with a period of develop once a week or so in the northwestern North Pacific in winter. Instead of steady-state removal, if half of the radon removal occurred sporadically every 7 days, and the last removal took place two days before the observation, the transfer velocity would be 26 m day−1. Our mean transfer velocity, which is less than 20% different from the steady state value including both overestimated and underestimated values, 9.4 ± 4.8 m day−1, seems to represent the mean state of this region in winter. This suggests that the gas exchange fluxes under extremely rough conditions in the open ocean are larger than those estimated by using a transfer velocity equation with a linear or quadratic relationship with wind speed.

Gas transfer velocity radon deficiency method western North Pacific winter stormy condition 

Copyright information

© The Oceanographic Society of Japan 2003

Authors and Affiliations

  • Hitoshi Kawabata
    • 1
  • Hisashi Narita
    • 1
  • Koh Harada
    • 2
  • Shizuo Tsunogai
    • 1
  • Masashi Kusakabe
    • 3
  1. 1.Graduate School of Environmental Earth ScienceHokkaido UniversitySapporoJapan
  2. 2.National Institute of Advanced Industrial and TechnologyTsukubaJapan
  3. 3.Japan Marine Science and Technology CenterYokosukaJapan

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