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Recent multidecadal strengthening of the Walker circulation across the tropical Pacific

Nature Climate Change volume 3, pages 571–576 (2013)Cite this article

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Abstract

The Pacific Walker circulation is a large overturning cell that spans the tropical Pacific Ocean, characterized by rising motion (lower sea-level pressure) over Indonesia and sinking motion (higher sea level-pressure) over the eastern Pacific1,2. Fluctuations in the Walker circulation reflect changes in the location and strength of tropical heating, so related circulation anomalies have global impacts3,4. On interannual timescales, the El Niño/Southern Oscillation accounts for much of the variability in the Walker circulation, but there is considerable interest in longer-term trends and their drivers, including anthropogenic climate change5,6,7,8,9,10,11,12. Here, we examine sea-level pressure trends in ten different data sets drawn from reanalysis, reconstructions and in situ measurements for 1900–2011. We show that periods with fewer in situ measurements result in lower signal-to-noise ratios, making assessments of sea-level pressure trends largely unsuitable before about the 1950s. Multidecadal trends evaluated since 1950 reveal statistically significant, negative values over the Indonesian region, with weaker, positive trends over the eastern Pacific. The overall trend towards a stronger, La Niña-like Walker circulation is nearly concurrent with the observed increase in global average temperatures, thereby justifying closer scrutiny of how the Pacific climate system has changed in the historical record.

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Figure 1: SLP linear trends for 10-, 20-, 30-, 40-year moving windows from January 1900 to December 2011.
Figure 2: SLP linear trends over the eastern Pacific Ocean and over Indonesia for 10-, 20-, 30- and 40-year moving windows for January 1900–December 2011.
Figure 3: Residual SLP trends, with Niño-3.4 SST linearly removed, over the eastern Pacific Ocean and over Indonesia for 10-, 20-, 30- and 40-year moving windows for January 1900–December 2011.
Figure 4: Hovmoller diagrams of 30-year moving SLP linear trends, averaged between 10° S and 10° N, across the tropical Indo-Pacific Ocean.

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References

  1. Bjerknes, J. Atmospheric teleconnections from the equatorial Pacific. Mon. Weath. Rev. 97, 163–172 (1969).

    Article  Google Scholar 

  2. Gill, A. E. Some simple solutions for heat-induced tropical circulation. Q. J. R. Meteorol. Soc. 106, 447–462 (1980).

    Article  Google Scholar 

  3. Horel, J. D. & Wallace, J. M. Planetary-scale atmospheric phenomena associated with the Southern Oscillation. Mon. Weath. Rev. 109, 813–829 (1981).

    Article  Google Scholar 

  4. Kousky, V. E., Kagano, M. T. & Cavalcanti, I. F. A review of the Southern Oscillation: Oceanic–atmospheric circulation changes and related rainfall anomalies. Tellus A 36, 490–504 (1984).

    Article  Google Scholar 

  5. Vecchi, G. A. et al. Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing. Nature 441, 73–76 (2006).

    Article  CAS  Google Scholar 

  6. Meng, Q. et al. Twentieth century walker circulation change: Data analysis and model experiments. Clim. Dynam. 38, 1757–1773 (2012).

    Article  Google Scholar 

  7. Knutson, T. R. & Manabe, S. Time-mean response over the tropical Pacific to increased CO2 in a coupled ocean–atmosphere model. J. Clim. 8, 2181–2199 (1995).

    Article  Google Scholar 

  8. Vecchi, G. A. & Soden, B. J. Global warming and the weakening of the tropical circulation. J. Clim. 20, 4316–4340 (2007).

    Article  Google Scholar 

  9. Held, I. M. & Soden, B. J. Robust responses of the hydrological cycle to global warming. J. Clim. 19, 5686–5699 (2006).

    Article  Google Scholar 

  10. Sohn, B. J. & Park, S-C. Strengthened tropical circulations in past three decades inferred from water vapor transport. J. Geophys. Res. 115, D15112 (2010).

    Article  Google Scholar 

  11. DiNezio, P. N., Vecchi, G. A. & Clement, A. C. Detectability of changes in the walker circulation in response to global warming. J. Clim. http://dx.doi.org/10.1175/JCLI-D-12-00531.1 (2013).

  12. Tokinaga, H., Xie, S-P., Deser, C., Kosaka, Y. & Okumura, Y. Slowdown of the Walker circulation by tropical Indo–Pacific warming. Nature 491, 439–443 (2012).

    Article  CAS  Google Scholar 

  13. Ropelewiski, C. F. & Halpert, M. S. Precipitation patterns associated with the high index phase of the Southern Oscillation. J. Clim. 2, 268–284 (1989).

    Article  Google Scholar 

  14. Lyon, B. & DeWitt, D. G. A recent and abrupt decline in the East African long rains. Geophys. Res. Lett. 39, L02702 (2012).

    Article  Google Scholar 

  15. Gastineau, G. & Soden, B. J. Evidence for a weakening of tropical surface wind extremes in response to atmospheric warming. Geophys. Res. Lett. 38, L09706 (2011).

    Article  Google Scholar 

  16. Merrifield, M. A. & Maltrud, M. E. Regional sea level trends due to Pacific trade wind intensification. Geophys. Res. Lett. 38, L21605 (2011).

    Article  Google Scholar 

  17. Walker, G. T. Correlation in seasonal variations of weather, IX. A further study of world weather. Mem. India Meteor. Dept. 24, 275–333 (1924).

    Google Scholar 

  18. Betts, A. K. & Ridgway, W. L. Climatic equilibrium of the atmospheric convective boundary layer over a tropical ocean. J. Atmos. Sci. 45, 2621–2641 (1989).

    Article  Google Scholar 

  19. Wentz, F. J., Ricciardulli, L., Hilburn, K. A. & Mears, C. A. How much more rain will global warming bring? Science 317, 233–235 (2007).

    Article  CAS  Google Scholar 

  20. Allen, M. R. & Ingram, W. J. Constraints on future changes in the hydrological cycle. Nature 419, 224–228 (2002).

    CAS  Google Scholar 

  21. Allan, R. P. & Soden, B. J. Atmospheric warming and the amplification of precipitation extremes. Science 321, 1481–1484 (2008).

    Article  CAS  Google Scholar 

  22. John, V. O., Allan, R. P. & Soden, B. J. How robust are observed and simulated precipitation responses to tropical ocean warming? Geophys. Res. Lett. 36, L14702 (2009).

    Article  Google Scholar 

  23. Liepert, B. G. & Previdi, M. Do models and observations disagree on the rainfall response to global warming? J. Clim. 22, 3156–3166 (2009).

    Article  Google Scholar 

  24. Durack, P. J., Wijffels, S. E. & Matear, R. J. Ocean salinities reveal strong global water cycle intensification during 1950 to 2000. Science 336, 455–458 (2012).

    Article  CAS  Google Scholar 

  25. Santer, B. D. et al. Separating signal and noise in atmospheric temperature changes: The importance of timescale. J. Geophys. Res. 116, D22105 (2011).

    Article  Google Scholar 

  26. Barnston, A. G., Chelliah, M. & Goldenberg, S. B. Documentation of a highly ENSO-related SST region in the equatorial Pacific. Atmos.-Ocean. 35, 367–383 (1997).

    Article  Google Scholar 

  27. Solomon, A. & Newman, M. Reconciling disparate 20th century Indo–Pacific ocean temperature trends in the instrumental record. Nature Clim. Change 2, 691–699 (2012).

    Article  Google Scholar 

  28. Cane, M. A. et al. Twentieth century sea surface temperature trends. Science 275, 957–960 (1997).

    Article  CAS  Google Scholar 

  29. Fu, Q., Manabe, S. & Johanson, C. M. On the warming in the tropical upper troposphere: Models versus observations. Geophys. Res. Lett. 38, L15704 (2011).

    Google Scholar 

  30. Clement, A. C., Seager, R., Cane, M. A. & Zebiak, S. E. An ocean dynamical thermostat. J. Clim. 9, 2190–2196 (1996).

    Article  Google Scholar 

  31. Bretherton, C. S., Widmann, M., Dymnikov, V. P., Wallace, J. M. & Bladé, I. The effective number of spatial degrees of freedom of a time-varying field. J. Clim. 12, 1990–2009 (1999).

    Article  Google Scholar 

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Acknowledgements

We thank Z-Z. Hu and W. Ebisuzaki for their comments and suggestions, and L. Zhang for directing us to some of the data. We also thank NOAA ESRL/PSD and the National Energy Research Scientific Computing Center for providing several data sets on their websites.

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Authors and Affiliations

  1. NOAA Climate Prediction Center, 5830 University Research Court, Room 3115, College Park, Maryland 20740, USA

    Michelle L. L’Heureux

  2. Meteorology and Atmospheric Science, Pennsylvania State University, 524 Walker Building, University Park, Pennsylvania 16802, USA

    Sukyoung Lee

  3. International Research Institute for Climate and Society, 110 Monell Building, Palisades, New York 10964, PO Box 1000, USA

    Bradfield Lyon

Authors
  1. Michelle L. L’Heureux
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  2. Sukyoung Lee
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  3. Bradfield Lyon
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All authors contributed to the ideas in this paper. M.L.L. carried out the analysis and wrote the paper. S.L. and B.L. offered their help with interpreting the analysis and also edited the paper.

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Correspondence to Michelle L. L’Heureux.

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The authors declare no competing financial interests.

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L’Heureux, M., Lee, S. & Lyon, B. Recent multidecadal strengthening of the Walker circulation across the tropical Pacific. Nature Clim Change 3, 571–576 (2013). https://doi.org/10.1038/nclimate1840

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