LABORATORY OBSERVATIONS OF DISSOLVED CARBON DIOXIDE TRANSPORT UNDER REGULAR BREAKING WAVES

  • Junichi Otsuka
  • Yasunori Watanabe

Abstract

Air bubbles and strong turbulence that form in water from breaking waves play important roles in gas transfer across the air-sea interface (Melville, 1996). The entrained bubbles increase the total area of air-water interface per unit volume and enhance local gas dissolution into water. The dissolved gases mix in the water mass diffuse by the strong turbulence. These gas transfer-enhancing factors have been parameterized by only wind speed in models of gas transfer velocity in the deep ocean. Bulk parameters based on wind speed cannot be used for a surf zone, where waves break due to shoaling. In a surf zone, the cross-shore distributions of entrained bubbles and the turbulent intensity vary as waves propagate. The physical process of gas transfer under the complex air-water turbulent flows in breaking waves has not been clarified. Thus, breaking-wave factors that enhance gas transfer in a surf zone cannot be parameterized. In this study, we observed the transport process of dissolved carbon dioxide (DCO2) under air-water turbulent flows in a laboratory surf zone using image measurement systems.

References

Melville (1996): The role of surface-wave breaking in air-sea interaction, Ann Rev of Fluid Mech, 28, pp. 279-321.

Published
2018-12-30
How to Cite
Otsuka, J., & Watanabe, Y. (2018). LABORATORY OBSERVATIONS OF DISSOLVED CARBON DIOXIDE TRANSPORT UNDER REGULAR BREAKING WAVES. Coastal Engineering Proceedings, 1(36), waves.77. https://doi.org/10.9753/icce.v36.waves.77