Advertisement

Characteristics of a breaking wind-wave field in the light of the individual wind-wave concept

  • Momoki Koga
Article

Abstract

The relation between the intensity of breaking of individual wind-wave crests and parameters of wave size and wave form (e. g., height, period, steepness and skewness) is examined, and the process of change of these parameters is studied in a wind-wave tank (reference wind speed 15 m sec−1, fetch 16 m). Distributions of the wave form parameters are different for breaking and nonbreaking waves. Fully breaking waves seem to hold the relationHT2, whereH is the individual wave height andT is the period. The condition of breaking is not simply determined by the simple criterion of Stokes' limit. Wave height and steepness of a breaking wave are not always larger than those of a nonbreaking wave. This suggests the existence of an overshooting phenomenon in the breaking wave. The wave form parameters are found to change cyclically in a statistical sense during the wave propagation. The period of the cycle in the present case is estimated to be longer than four wave periods. An intermittency of wave breaking is associated with this cyclic process. Roughly speaking, two or three succeeding breaking-waves sporadically exist among a series of nonbreaking waves along the fetch.

Keywords

Wind Speed Wave Propagation Crest Wave Height Wave Period 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Benjamin, T.B. and J. E. Feir (1967): The disintegration of wave trains on deep water. J. Fluid Mech.,27, 417–430.Google Scholar
  2. Donelan, M., M. S. Longuet-Higgins and J. S. Turner (1972): Periodicity in whitecaps. Nature,239, 449–451.CrossRefGoogle Scholar
  3. Koga, M. (1981): Direct production of droplets from breaking wind waves: its observation by a multi-colored overlapping exposure photographing technique. Tellus,33, 552–563.Google Scholar
  4. Koga, M. (1982): Bubble entrainment in breaking wind waves. Tellus,34, 481–489.Google Scholar
  5. Kondo, J., Y. Fujinawa and G. Naito (1973): High-frequency components of ocean waves and their relation to the aerodynamic roughness. J. Phys. Oceanogr.,3, 197–202.CrossRefGoogle Scholar
  6. Monahan, E. C. (1969): Fresh water whitecaps. J. Atmos. Sci.,26, 1026–1029.CrossRefGoogle Scholar
  7. Monahan, E. C. (1971): Oceanic whitecaps. J. Phys. Oceanogr.,1, 139–144.CrossRefGoogle Scholar
  8. Okuda, K. (1982a): Internal flow structure of short wind waves. Part I. On the internal vorticity structure. J. Oceanogr. Soc. Japan,38, 28–42.Google Scholar
  9. Okuda, K. (1982b): Internal flow structure of short wind waves. Part II. On the streamline pattern. J. Oceanogr. Soc. Japan,38, 313–322.Google Scholar
  10. Okuda, K. (1983): Internal flow structure of short wind waves. Part III On the pressure distributions. J. Oceanogr. Soc. Japan,38, 331–338.CrossRefGoogle Scholar
  11. Thorpe, S. A. and P. N. Humphries (1980): bubbles and breaking waves. Nature,283, 463–465.CrossRefGoogle Scholar
  12. Toba, Y. (1961): Drop production by bursting of air bubbles on the sea surface (III). Study by use of a wind flume. Memoirs Coll. Sci. Univ. Kyoto, Ser. A,29, 313–344.Google Scholar
  13. Toba, Y. (1978): Stochastic form of the growth of wind waves in a single-parameter representation with physical implications. J. Phys. Oceanogr.,8, 494–507.CrossRefGoogle Scholar
  14. Toba, Y. and H. Kunishi (1970): Breaking of wind waves and the sea surface wind stress. J. Oceanogr. Soc. Japan,26, 71–80.Google Scholar
  15. Toba, Y., M. Tokuda, K. Okuda and S. Kawai (1975): Forced convection accompanying wind waves. J. Oceanogr. Soc. Japan,31, 192–198.CrossRefGoogle Scholar
  16. Tokuda, M. and Y. Toba (1981): Statistical characteristics of individual waves in laboratory wind waves. I. Individual wave spectra and similarity structure. J. Oceanogr. Soc. Japan,37, 243–258.CrossRefGoogle Scholar

Copyright information

© the Oceanographical Society of Japan 1984

Authors and Affiliations

  • Momoki Koga
    • 1
  1. 1.Geophysical Institute, Faculty of ScienceTohoku UniversitySendaiJapan

Personalised recommendations