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Journal of Oceanography

, Volume 63, Issue 3, pp 483–490 | Cite as

Frequency-wavenumber spectra of equatorial waves detected from satellite altimeter data

  • Yoshinobu Wakata
Short Contribution

Abstract

The sea surface height anomaly in the Pacific equatorial area was separated into equatorial modes using satellite altimeter data. The power-spectral density (PSD) was obtained for the east-west wavenumber and frequency for each separated mode. The PSD distribution was compared with the theoretical dispersion curve for the equatorial modes derived by Matsuno (1966). The first Rossby modes have a high-density distribution that is slightly lower than the theoretical dispersion curve, but the Kelvin mode and the higher Rossby modes have high-density distribution that almost matches each dispersion curve. Results of analyses of satellite observational data show that wave motion near the equator mainly shows characteristics of equatorial waves, especially for a intraseasonal time scale.

Keywords

Equatorial wave mode separation TOPEX/POSEIDON sea surface height Pacific Ocean 

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References

  1. AVISO (2006): SSALTO/DUACS User Handbook: (M)SLA and (M)ADT near-teal time and delayed time products. Publ., CLS-DOS-NT-06.034, France.Google Scholar
  2. Boulanger, J.-P. and L.-L. Fu (1996): Evidence of boundary reflection of Kelvin and first-mode Rossby waves from TOPEX/POSEIDON sea level data. J. Geophys. Res., 101, 16361–16371.Google Scholar
  3. Boulanger, J.-P. and C. Menkes (1995): Propagation and reflection of long equatorial wave in the Pacific ocean during the 1992–1993 El Niño. J. Geophys. Res., 100, 25041–25095.Google Scholar
  4. Chelton, D. B., R. A. d. Szoeke, M. G. Schlax, K. E. Naggar and N. Siwertz (1998): Geographical variability of the first baroclinic Rossby radius of deformation. J. Phys. Oceanogr., 28, 433–460.CrossRefGoogle Scholar
  5. Chelton, D. B., M. G. Schlax, J. M. Lyman and G. C. Johnson (2003): Equatorially trapped Rossby waves in the presence of meridionally sheared baroclinic flow in the Pacific Ocean. Prog. Oceanogr., 56, 323–380.CrossRefGoogle Scholar
  6. Cravatte, S., J. Picaut and G. Eldin (2003): Second and first baroclinic Kelvin modes in the equatorial Pacific at intraseasonal timescales. J. Geophys. Res., 108, 3266, doi:10.1029/2002JC001511.CrossRefGoogle Scholar
  7. Delcroix, T., J. Picaut and G. Eldin (1991): Equatorial Kelvin and Rossby wave evidenced in the Pacific ocean through Geosat Sea level and surface current anomalies. J. Geophys. Res., 96, 3249–3262.CrossRefGoogle Scholar
  8. Delcroix, T., J.-P. Boulanger, F. Masia and C. Menkes (1994): Geosat-derived sea level and surface current anomalies in the equatorial Pacific during the 1986–1989 El Niño and La Niña. J. Geophys. Res., 99, 25093–25107.Google Scholar
  9. Eriksen, C. C., M. B. Blumenthal, S. P. Hayes and P. Ripa (1983): Wind-generated equatorial Kelvin wave observed across the Pacific Ocean. J. Phys. Oceanogr., 13, 1622–1640.CrossRefGoogle Scholar
  10. Legeckis, R. (1977): Long waves in the eastern equatorial Pacific; a view from a geostationary satellite. Science, 197, 1177–1181.CrossRefGoogle Scholar
  11. Matsuno, T. (1966): Quasi-geostrophic motions in equatorial areas. J. Meteor. Soc. Japan, 44, 25–43.Google Scholar
  12. Meyers, G. (1979): Annual variation in the slope of the 14°C isotherm along the equator in the Pacific ocean. J. Phys. Oceanogr., 9, 885–891.CrossRefGoogle Scholar
  13. Miller, L., R. Cheney and B. Douglas (1988): GEOSAT altimeter observations of Kelvin waves and the 1986–1987 El Niño. Science, 239, 52–54.CrossRefGoogle Scholar
  14. Moore, D. W. and S. G. H. Philander (1977): Modeling of tropical oceanic circulation. p. 319–361. Vol. 6, The Sea, Wiley (Interscience).Google Scholar
  15. Philander, S. G. H. (1979): Equatorial waves in the presence of the equatorial undercurrent. J. Phys. Oceanogr., 9, 254–262.CrossRefGoogle Scholar
  16. Tapley, B. D., D. P. Chamber, C. K. Shum, R. J. Eanes, J. C. Ries and R. H. Stewart (1994): Accuracy assessment of the large-scale dynamic ocean topography from TOPEX/ POSEIDON altimetry. J. Geophys. Res., 99, 24605–24617.Google Scholar
  17. Wakata, Y. and S. Kitaya (2002): Annual variability of sea surface height and upper layer thickness in the Pacific Ocean. J. Oceanogr., 58, 439–450.CrossRefGoogle Scholar
  18. Wakata, Y. and E. S. Sarachik (1991): On the role of equatorial ocean models in the ENSO cycle. J. Phys. Oceanogr., 21, 434–443.CrossRefGoogle Scholar
  19. Yu, X. and M. J. McPhaden (1999): Seasonal variability in the equatorial Pacific. J. Phys. Oceanogr., 29, 925–948.CrossRefGoogle Scholar
  20. Zang, X., L.-L. Fu and C. Wunsch (2002): Observed reflectivity of the western boundary of the equatorial Pacific Ocean. J. Geophys. Res., 107, C10, 3150, doi:10.1029/2000JC000719.CrossRefGoogle Scholar

Copyright information

© The Oceanographic Society of Japan/TERRAPUB/Springer 2007

Authors and Affiliations

  1. 1.Research Institute for Applied MechanicsKyushu UniversityKasuga-kohen, Kasuga-shi, FukuokaJapan

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