On discriminating swell and wind-driven seas in Voluntary Observing Ship data

Authors

  • S. I. Badulin,

    Corresponding author
    1. P. P. Shirshov Institute of Oceanology, Russian Academy of Science, Moscow, Russia
    2. Also at Laboratory of Nonlinear Wave Processes, Novosibirsk State University, Novosibirsk, Russia
    3. Also at Satellite Oceanography Laboratory, Russian State Hydrometeorological University, Saint Petersburg, Russia
    • Corresponding author: S. I. Badulin, P. P. Shirshov Institute of Oceanology of the Russian Academy of Science, 36 Nakhimovsky Pr., 117997 Moscow, Russia. (badulin@ioran.ru)

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  • V. G. Grigorieva

    1. P. P. Shirshov Institute of Oceanology, Russian Academy of Science, Moscow, Russia
    2. Also at Natural Risk Assessment Laboratory, Moscow State University, Moscow, Russia
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Abstract

[1] The global visual wave observations are reanalyzed within the theoretical concept of self-similar wind-driven seas. The core of the analysis is one-parametric dependencies of wave height on wave period. Theoretically, wind-driven seas are governed by power-like laws with exponents close to Toba's one 3/2 while the corresponding swell exponent (−1/2) has an opposite signature. This simple criterion was used and appeared to be adequate to the problem of swell and wind-driven waves discrimination. This theoretically based discrimination does not follow exactly the Voluntary Observing Ship (VOS) data. This important issue is considered both in the context of methodology of obtaining VOS data and within the physics of wind waves. The results are detailed for global estimates and for analysis of particular areas of the Pacific Ocean. Prospects of further studies are discussed. In particular, satellite data are seen to be promising for tracking ocean swell and for studies of physical mechanisms of its evolution.

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