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ENSO and greenhouse warming

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Abstract

The El Niño/Southern Oscillation (ENSO) is the dominant climate phenomenon affecting extreme weather conditions worldwide. Its response to greenhouse warming has challenged scientists for decades, despite model agreement on projected changes in mean state. Recent studies have provided new insights into the elusive links between changes in ENSO and in the mean state of the Pacific climate. The projected slow-down in Walker circulation is expected to weaken equatorial Pacific Ocean currents, boosting the occurrences of eastward-propagating warm surface anomalies that characterize observed extreme El Niño events. Accelerated equatorial Pacific warming, particularly in the east, is expected to induce extreme rainfall in the eastern equatorial Pacific and extreme equatorward swings of the Pacific convergence zones, both of which are features of extreme El Niño. The frequency of extreme La Niña is also expected to increase in response to more extreme El Niños, an accelerated maritime continent warming and surface-intensified ocean warming. ENSO-related catastrophic weather events are thus likely to occur more frequently with unabated greenhouse-gas emissions. But model biases and recent observed strengthening of the Walker circulation highlight the need for further testing as new models, observations and insights become available.

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Acknowledgements

W.C. and G.W. are supported by the Australian Climate Change Science Program and a CSIRO Office of Chief Executive Science Leader award. A.S. is supported by the Australian Research Council. M.C. was supported by NERC NE/I022841/1. S.W.Y. is supported by the National Research Fund of Korea grant funded by the Korean Government (MEST) (NRF-2009-C1AAA001-2009-0093042). S.I.A. was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (No. 2014R1A2A1A11049497). This is PMEL contribution number 4038.

Author information

Affiliations

  1. CSIRO Oceans and Atmosphere Flagship, Aspendale, Victoria 3195, Australia

    • Wenju Cai
    •  & Guojian Wang
  2. Physical Oceanography Laboratory, Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266003, China

    • Wenju Cai
    •  & Lixin Wu
  3. Australian Research Council (ARC) Centre of Excellence for Climate System Science and Climate Change Research Centre, Level 4 Mathews Building, The University of New South Wales, Sydney 2052, Australia

    • Agus Santoso
  4. Department of Environmental Marine Science, Hanyang University, Ansan 426-791, South Korea

    • Sang-Wook Yeh
  5. Department of Atmospheric Sciences, Yonsei University, Seoul 120-749, South Korea

    • Soon-Il An
  6. School of Earth & Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta 30332-0340, USA

    • Kim M. Cobb
  7. College of Engineering Mathematics and Physical Sciences, Harrison Building, Streatham Campus, University of Exeter, Exeter EX1 3PB, UK

    • Mat Collins
  8. Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN), IRD/UPMC/CNRS/MNHN, Paris Cedex 05, France

    • Eric Guilyardi
    •  & Matthieu Lengaigne
  9. NCAS-Climate, University of Reading, Reading RG6 6BB, UK

    • Eric Guilyardi
  10. Department of Meteorology, SOEST, University of Hawaii, Honolulu, Hawaii 96822, USA

    • Fei-Fei Jin
  11. School of Environmental Science & Engineering, Pohang University of Science and technology, Pohang 790-784, South Korea

    • Jong-Seong Kug
  12. NOAA/Pacific Marine Environmental Laboratory, Seattle, Washington 98115, USA

    • Michael J. McPhaden
  13. Instituto Geofísico del Perú, Lima 169, Perú

    • Ken Takahashi
  14. IPRC, Department of Oceanography, SOEST, University of Hawaii, Honolulu, Hawaii 96822, USA

    • Axel Timmermann
  15. Geophysical Fluid Dynamics Laboratory/NOAA, Princeton, New Jersey 08540-6649, USA

    • Gabriel Vecchi
  16. Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa 277-8564, Japan

    • Masahiro Watanabe

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Contributions

W.C., A.S., G.W. and S.W.Y wrote the initial version of the paper. G.W. performed the model output analysis and generated all figures. All authors contributed to interpreting results, discussion of the associated dynamics and improvement of this paper.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Wenju Cai.