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Science in China Series D: Earth Sciences

, Volume 48, Issue 12, pp 2267–2275 | Cite as

Energy distributions of the large-scale horizontal currents caused by wind in the baroclinic ocean

  • Lei Zhou
  • Jiwei Tian
  • Dongxiao Wang
Article

Abstract

Ocean current data for nearly 3 months in the South China Sea (SCS), combined with the NCEP/NCAR reanalysis wind data, are analyzed. The results indicate that the wind energy enters the upper mixed layer in a wide continuous frequency band. In addition, the interaction between the low-frequency wind anomaly and the low-frequency current anomaly is the most ‘effective’ way for the energy input from the wind to the upper ocean. However, only the inertial and the near inertial energy propagate downwards through the upper mixed layer. The downward-propagating energy is distributed into the barotropic currents, the baroclinic currents and each mode of the baroclinic currents following the normal distributions. The energy change ratios between the barotropic motion to the baroclinic motion induced by the wind present a normal distribution of N (0.0242, 0.3947). The energy change ratios of the first 4 baroclinic modes to the whole baroclinic currents also follow the normal distributions. The first baroclinic mode follows N (0.2628, 0.1872), the second N (0.1979, 0.1504), the third N (0.1331, 0.1633), and the fourth N (0.0650, 0.1540), respectively.

Keywords

wind anomaly ocean current anomaly energy transportation wide frequency band near-inertial frequency energy distribution 

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References

  1. 1.
    Wunsch, C., The work done by the wind on the oceanic general circulation, J. Phys. Oceanogr., 1998, 28, 2332–2340.CrossRefGoogle Scholar
  2. 2.
    Watanabe, M., Hibiya, T., Global estimates of the wind-induced energy flux to inertial motions in the surface mixed layer, Geophys. Res. Lett., 2002, 29, 80, 1–4.Google Scholar
  3. 3.
    Graham, N. E., Diaz, H. F., Evidence for Intensification of North Pacific Winter Cyclones since 1948, Bulletin of the American Meteorological Society, 2001, 82, 1869–1893.CrossRefGoogle Scholar
  4. 4.
    Alford M. H., Internal Swell: Distribution and redistribution of internal-wave energy, near-boundary processes and their parame-terization, Proc. ‘Aha Huliko’a Hawaiian Winter Workshop (eds. P. Müller et al.), Hawaii Institute of Geophysics, 2003, 29–39.Google Scholar
  5. 5.
    Pollard, R. T., On the generation by winds of inertial waves in the ocean, Deep Sea Res., 1970, 17, 795–812.Google Scholar
  6. 6.
    Pollard, R. T., Millard, R. C. Jr., Comparison between observed and simulated wind-generated inertial oscillations, Deep Sea Res., 1970, 17, 813–821.Google Scholar
  7. 7.
    D’Asaro, E. A., Wind forced internal waves in the North Pacific and Sargasso Sea, J. Phys. Oceanogr., 1984, 14, 781–794.CrossRefGoogle Scholar
  8. 8.
    Gardner, W. D., Optics, particles, stratification, and storms on the New England continental shelf, J. Geophys. Res., 2001, 106: 9473–9498.CrossRefGoogle Scholar
  9. 9.
    Hristov, T. S., Miller, S. D., Friehe, C. A., Dynamical coupling of wind and ocean waves through wave-induced air flow, Nature, 2003, 422, 55–58.CrossRefGoogle Scholar
  10. 10.
    D’Asaro, E. A., Eriksen, C. C., Levin, M. D. et al., Upper-ocean inertial currents forced by a strong storm Part I: Data and comparisons with linear theory, J. Phys. Oceanogr., 1995. 25, 2909–2936.CrossRefGoogle Scholar
  11. 11.
    Alford, M., Gregg, M., Near-inertial mixing: Modulation of shear, strain and microstructure at low latitude, J. Geophys. Res., 2001, 106(C8): 16,947–16,968.CrossRefGoogle Scholar
  12. 12.
    D’Asaro, E. A., Upper-ocean inertial currents forced by a strong storm. Part III: Interaction of inertial currents and mesoscale ed-dies, J. Phys. Oceanogr., 1995, 25, 2953–2958.CrossRefGoogle Scholar
  13. 13.
    Zervakis, V., Levine, M. D., Near-inertial energy propagation from the mixed layer: Theoretical considerations, J. Phys. Oceanogr., 1995, 25, 2872–2889.CrossRefGoogle Scholar
  14. 14.
    Hibiya, T., Nagasawa, M., Niwa, Y., Model predicted distribution of internal wave energy for diapycnal mixing processes in the deep waters of the North Pacific, Dynamics of oceanic internal gravity waves, Proc. ‘Aha Huliko’a Hawaiian Winter Workshop (eds. P. Müller, D. Henderson), Hawaii Institute of Geophysics, 1999, 205–215.Google Scholar
  15. 15.
    D’Asaro, E. A., The energy flux from the wind to near-inertial motions in the surface mixed layer, J. Phys. Oceanogr., 1985, 15, 1043–1059.CrossRefGoogle Scholar
  16. 16.
    Conkright, M. E., Levitus, S., O’Brien, T. et al., World Ocean Database 1998, Documentation and Quality Control Version 2.0, NOAA National Oceanographic Data Center Internal Report 14, NOAA NODC/Ocean Climate Laboratory, Silver Spring, MD, 1999.Google Scholar
  17. 17.
    Gonella, J., A rotary-component method for analyzing meteoro-logical and oceanographic vector time series, Deep Sea Res., 1972, 19, 833–846Google Scholar
  18. 18.
    Kevin, D., Sanford, T. B., Vertical energy propagation of inertial waves: A vector spectral analysis of velocity profiles, J. Phys. Oceanogr., 1975, 80, 1975–1978Google Scholar
  19. 19.
    Price, J. F., Internal wave wake of a moving storm, Part I: Scales, energy budget and observations, J. Phys. Oceanogr., 1983, 13, 949–965.CrossRefGoogle Scholar
  20. 20.
    Gill, A. E., Atmosphere-Ocean Dynamics, New York: Academic Press, INC., 1982.CrossRefGoogle Scholar
  21. 21.
    MacKinnon, J. A., Gregg, M. C., Shear and baroclinic energy flux on the summer New England Shelf, J. Phys. Oceanogr., 2003, 33, 1462–1475.CrossRefGoogle Scholar

Copyright information

© Science in China Press 2005

Authors and Affiliations

  1. 1.Physical Oceanography LaboratoryOcean University of ChinaQingdaoChina
  2. 2.Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of OceanologyChinese Academy of SciencesGuangdongChina

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