• Chelliah, M., 1990: The global climate for June–August 1989: A season of near-normal conditions in the tropical Pacific. J. Climate, 3 , 138160.

    • Search Google Scholar
    • Export Citation
  • Davis, R. E., 1976: Predictability of sea surface temperature and sea level pressure anomalies over the North Pacific Ocean. J. Phys. Oceanogr, 6 , 249266.

    • Search Google Scholar
    • Export Citation
  • Donguy, J-R., , and A. Dessier, 1983: El Niño-like events observed in the tropical Pacific. Mon. Wea. Rev, 111 , 21362139.

  • Duchon, C. E., 1979: Lanczos filtering in one and two dimensions. J. Appl. Meteor, 18 , 10161022.

  • Fink, A., , and P. Speth, 1997: Some potential forcing mechanisms of the year-to-year variability of the tropical convection and its intraseasonal (25–70-day) variability. Int. J. Climatol, 17 , 15131534.

    • Search Google Scholar
    • Export Citation
  • Gutzler, D. S., 1991: Interannual fluctuations of intraseasonal variance of near-equatorial zonal winds. J. Geophys. Res, 96 , 31733185.

    • Search Google Scholar
    • Export Citation
  • Hendon, H. H., , C. Zhang, , and J. D. Glick, 1999: Interannual variability of the Madden–Julian oscillation during austral summer. J. Climate, 12 , 25382550.

    • Search Google Scholar
    • Export Citation
  • Horel, J. D., 1981: A rotated principal component analysis of the interannual variability of the Northern Hemisphere 500 mb height field. Mon. Wea. Rev, 109 , 20802092.

    • Search Google Scholar
    • Export Citation
  • Jones, C., 2000: Occurrence of extreme precipitation events in California and relationships with the Madden–Julian oscillation. J. Climate, 13 , 35763587.

    • Search Google Scholar
    • Export Citation
  • ——, Waliser, D. E., , and C. Gautier, 1998: The influence of the Madden–Julian oscillation on ocean surface heat fluxes and sea surface temperature. J. Climate, 11 , 10571072.

    • Search Google Scholar
    • Export Citation
  • Kessler, W. S., , and M. J. McPhaden, 1995: Oceanic equatorial waves and the 1991–93 El Niño. J. Climate, 8 , 17571774.

  • ——, and Kleeman, R., 2000: Rectification of the Madden–Julian oscillation into the ENSO cycle. J. Climate, 13 , 35603575.

  • ——, McPhaden, M. J., , and K. M. Weickmann, 1995: Forcing of intraseasonal Kelvin waves in the equatorial Pacific. J. Geophys. Res, 100 , 10 61310 631.

    • Search Google Scholar
    • Export Citation
  • ——, Spillane, M. C., , M. J. McPhaden, , and D. E. Harrison, 1996: Scales of variability in the equatorial Pacific inferred from the TAO buoy array. J. Climate, 9 , 29993024.

    • Search Google Scholar
    • Export Citation
  • Lau, K-M., , and P. H. Chan, 1988: Intraseasonal and interannual variations of tropical convection: A possible link between the 40–50 day oscillation and ENSO? J. Atmos. Sci, 45 , 506521.

    • Search Google Scholar
    • Export Citation
  • Luther, D. S., , D. E. Harrison, , and R. A. Knox, 1983: Zonal winds in the central equatorial Pacific and El Niño. Science, 222 , 327330.

    • Search Google Scholar
    • Export Citation
  • Madden, R. A., , and P. A. Julian, 1994: Observations of the 40–50-day tropical oscillation—a review. Mon. Wea. Rev, 122 , 814837.

  • Maloney, E. D., , and D. L. Hartmann, 1998: Frictional moisture convergence in a composite life cycle of the Madden–Julian oscillation. J. Climate, 11 , 23872403.

    • Search Google Scholar
    • Export Citation
  • McPhaden, M. J., 1999: Genesis and evolution of the 1997–98 El Niño. Science, 283 , 950954.

  • ——, and Yu, X., 1999: Equatorial waves and the 1997–98 El Niño. Geophys. Res. Lett, 26 , 29612964.

  • Moore, A. M., , and R. Kleeman, 1999: Stochastic forcing of ENSO by the intraseasonal oscillation. J. Climate, 12 , 11991220.

  • North, G. R., , T. L. Bell, , R. F. Cahalan, , and F. J. Moenig, 1982: Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Rev, 110 , 669706.

    • Search Google Scholar
    • Export Citation
  • Preisendorfer, R. W., , F. W. Zwiers, , and T. P. Barnett, 1981: Foundations of principal coordinate selection rules. SOI Reference Series 81-4, Scripps Institution of Oceanography, La Jolla, CA, 192 pp.

    • Search Google Scholar
    • Export Citation
  • Richman, M. B., 1986: Rotation of principal components. J. Climatol, 6 , 293335.

  • Rui, H., , and B. Wang, 1990: Development characteristics and dynamic structure of tropical intraseasonal convection anomalies. J. Atmos. Sci, 47 , 357379.

    • Search Google Scholar
    • Export Citation
  • Shinoda, T., , H. H. Hendon, , and J. Glick, 1998: Intraseasonal variability of surface fluxes and sea surface temperature in the tropical western Pacific and Indian Oceans. J. Climate, 11 , 16851702.

    • Search Google Scholar
    • Export Citation
  • Slingo, J. M., , D. P. Rowell, , K. R. Sperber, , and F. Nortley, 1999: On the predictability of the inter annual behavior of the Madden–Julian oscillation and its relationship with El Niño. Quart. J. Roy. Meteor. Soc, 125 , 583609.

    • Search Google Scholar
    • Export Citation
  • Verbickas, S., 1998: Westerly wind bursts in the tropical Pacific. Weather, 53 , 282284.

  • Waliser, D. E., , N. E. Graham, , and C. Gautier, 1993: Comparison of highly reflective cloud and outgoing longwave radiation datasets for use in estimating tropical convection. J. Climate, 6 , 331353.

    • Search Google Scholar
    • Export Citation
  • Weickmann, K. M., 1991: El Niño/Southern Oscillation and Madden–Julian (30–60 day) oscillations during 1981–82. J. Geophys. Res, 96 , 31873195.

    • Search Google Scholar
    • Export Citation
  • Zhang, C., , and H. H. Hendon, 1997: Propagating and standing components of the intraseasonal oscillation in tropical convection. J. Atmos. Sci, 54 , 741752.

    • Search Google Scholar
    • Export Citation
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EOF Representations of the Madden–Julian Oscillation and Its Connection with ENSO

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  • 1 NOAA/Pacific Marine Environmental Laboratory, Seattle, Washington
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Abstract

Although recent El Niño events have seen the occurrence of strong intraseasonal winds apparently associated with the Madden–Julian oscillation (MJO), the usual indices of interannual variability of the MJO are uncorrelated with measures of the ENSO cycle. An EOF decomposition of intraseasonal outgoing longwave radiation and zonal wind identifies two modes of interannual variability of the MJO: a zonally stationary variation of amplitude that is unrelated to ENSO and a roughly 20°-longitude eastward extension of the MJO envelope during El Niño events. The stationary mode is represented by the first two EOFs, which form the familiar lag-correlated quadrature pair, and the eastward-extending mode is represented by the third EOF, which is usually ignored although it is statistically significant. However, the third EOF also has a systematic phase relation with the first pair, and all three should be considered as a triplet; rotating the EOFs makes the phase relation clear. The zonal shift represents about 20% of total MJO variance (which itself is about 55% of intraseasonal variance over the tropical strip). Although the eastward shift is small when compared with the global scale of the MJO, it produces a large proportional shift of MJO activity over the open Pacific, where physical interactions with ENSO processes can occur.

Corresponding author address: William S. Kessler, NOAA/PMEL/OC, 7600 Sand Point Way NE, Seattle, WA 98115. Email: kessler@pmel.noaa.gov

Abstract

Although recent El Niño events have seen the occurrence of strong intraseasonal winds apparently associated with the Madden–Julian oscillation (MJO), the usual indices of interannual variability of the MJO are uncorrelated with measures of the ENSO cycle. An EOF decomposition of intraseasonal outgoing longwave radiation and zonal wind identifies two modes of interannual variability of the MJO: a zonally stationary variation of amplitude that is unrelated to ENSO and a roughly 20°-longitude eastward extension of the MJO envelope during El Niño events. The stationary mode is represented by the first two EOFs, which form the familiar lag-correlated quadrature pair, and the eastward-extending mode is represented by the third EOF, which is usually ignored although it is statistically significant. However, the third EOF also has a systematic phase relation with the first pair, and all three should be considered as a triplet; rotating the EOFs makes the phase relation clear. The zonal shift represents about 20% of total MJO variance (which itself is about 55% of intraseasonal variance over the tropical strip). Although the eastward shift is small when compared with the global scale of the MJO, it produces a large proportional shift of MJO activity over the open Pacific, where physical interactions with ENSO processes can occur.

Corresponding author address: William S. Kessler, NOAA/PMEL/OC, 7600 Sand Point Way NE, Seattle, WA 98115. Email: kessler@pmel.noaa.gov

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