• Ashok, K., and T. Yamagata, 2009: Climate change: The El Niño with a difference. Nature, 461, 481484, doi:10.1038/461481a.

  • Ashok, K., S. K. Behera, S. A. Rao, H. Weng, and T. Yamagata, 2007: El Niño Modoki and its possible teleconnection. J. Geophys. Res., 112, C11007, doi:10.1029/2006JC003798.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Behringer, D. W., and Y. Xue, 2004: Evaluation of the global ocean data assimilation system at NCEP: The Pacific Ocean. Proc. Eighth Symp. on Integrated Observing and Assimilation Systems for Atmosphere, Oceans, and Land Surface, Seattle, WA, Amer. Meteor. Soc., 2.3. [Available online at https://ams.confex.com/ams/pdfpapers/70720.pdf.]

  • Carton, J. A., B. S. Giese, and S. A. Grodsky, 2005: Sea level rise and the warming of the oceans in the Simple Ocean Data Assimilation (SODA) ocean reanalysis. J. Geophys. Res., 110, C09006, doi:10.1029/2004JC002817.

    • Search Google Scholar
    • Export Citation
  • Chen, L., T. Li, S. K. Behera, and T. Doi, 2016: Distinctive precursory air–sea signals between regular and super El Niños. Adv. Atmos. Sci., 33, 9961004, doi:10.1007/s00376-016-5250-8.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chung, P., and T. Li, 2013: Interdecadal relationship between the mean state and El Niño types. J. Climate, 26, 361379, doi:10.1175/JCLI-D-12-00106.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Compo, G. P., and Coauthors, 2011: The Twentieth Century Reanalysis Project. Quart. J. Roy. Meteor. Soc., 137, 128, doi:10.1002/qj.776.

  • Gu, D., and S. G. H. Philander, 1997: Interdecadal climate fluctuations that depend on exchanges between the tropics and extratropics. Science, 275, 805807, doi:10.1126/science.275.5301.805.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jin, F.-F., 1997: An equatorial ocean recharge paradigm for ENSO. Part I: Conceptual model. J. Atmos. Sci., 54, 811829, doi:10.1175/1520-0469(1997)054<0811:AEORPF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kang, I.-S., and J.-S. Kug, 2002: El Niño and La Niña sea surface temperature anomalies: Asymmetry characteristics associated with their wind stress anomalies. J. Geophys. Res., 107, 4372, doi:10.1029/2001JD000393.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kao, H., and J. Yu, 2009: Contrasting eastern-Pacific and central-Pacific types of ENSO. J. Climate, 22, 615632, doi:10.1175/2008JCLI2309.1.

  • Kessler, W. S., 1990: Observations of long Rossby waves in the northern tropical Pacific. J. Geophys. Res., 95, 51835217, doi:10.1029/JC095iC04p05183.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kim, W., S. Yeh, J. Kim, J. Kug, and M. Kwon, 2011: The unique 2009–2010 El Niño event: A fast phase transition of warm pool El Niño to La Niña. Geophys. Res. Lett., 38, L15809, doi:10.1029/2011GL048521.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kosaka, Y., and S.-P. Xie, 2013: Recent global-warming hiatus tied to equatorial Pacific surface cooling. Nature, 501, 403407, doi:10.1038/nature12534.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kug, J.-S., F.-F. Jin, and S.-I. An, 2009: Two types of El Niño events: Cold tongue El Niño and warm pool El Niño. J. Climate, 22, 14991515, doi:10.1175/2008JCLI2624.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kug, J.-S., J. Choi, S. An, F. Jin, and A. T. Wittenberg, 2010: Warm pool and cold tongue El Niño events as simulated by the GFDL 2.1 coupled GCM. J. Climate, 23, 12261239, doi:10.1175/2009JCLI3293.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Larkin, N. K., and D. E. Harrison, 2005: On the definition of El Niño and associated seasonal average U.S. weather anomalies. Geophys. Res. Lett., 32, L13705, doi:10.1029/2005GL022738.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lee, T., and M. J. McPhaden, 2010: Increasing intensity of El Niño in the central-equatorial Pacific. Geophys. Res. Lett., 37, L14603, doi:10.1029/2010GL044007.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, G., and B. Ren, 2012: Evidence for strengthening of the tropical Pacific Ocean surface wind speed during 1979–2001. Theor. Appl. Climatol., 107, 5972, doi:10.1007/s00704-011-0463-3.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, T., T. F. Hogan, and C. Chang, 2000: Dynamic and thermodynamic regulation of ocean warming. J. Atmos. Sci., 57, 33533365, doi:10.1175/1520-0469(2000)057<3353:DATROO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, T., Y. Zhang, E. Lu, and D. Wang, 2002: Relative role of dynamic and thermodynamic processes in the development of the Indian Ocean dipole: An OGCM diagnosis. Geophys. Res. Lett., 29, 2110, doi:10.1029/2002GL015789.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Li, X., C. Li, J. Ling, and Y. Tan, 2015: The relationship between contiguous El Niño and La Niña revealed by self-organizing maps. J. Climate, 28, 81188134, doi:10.1175/JCLI-D-15-0123.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McPhaden, M. J., S. E. Zebiak, and M. H. Glantz, 2006: ENSO as an integrating concept in Earth science. Science, 314, 17401745, doi:10.1126/science.1132588.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Meinen, C. S., and M. J. McPhaden, 2000: Observations of warm water volume changes in the equatorial Pacific and their relationship to El Niño and La Niña. J. Climate, 13, 35513559, doi:10.1175/1520-0442(2000)013<3551:OOWWVC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • North, G. R., T. L. Bell, R. F. Cahalan, and F. J. Moeng, 1982: Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Rev., 110, 699706, doi:10.1175/1520-0493(1982)110<0699:SEITEO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pedlosky, J., 1987: An inertial theory of the equatorial undercurrent. J. Phys. Oceanogr., 17, 19781985, doi:10.1175/1520-0485(1987)017<1978:AITOTE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rayner, N. A., D. E. Parker, E. B. Horton, C. K. Folland, L. V. Alexander, D. P. Rowell, E. C. Kent, and A. Kaplan, 2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res., 108, 4407, doi:10.1029/2002JD002670.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ren, H., and F. Jin, 2011: Niño indices for two types of ENSO. Geophys. Res. Lett., 38, L04704, doi:10.1029/2010GL046031.

  • Ren, H., and F. Jin, 2013: Recharge oscillator mechanisms in two types of ENSO. J. Climate, 26, 65066523, doi:10.1175/JCLI-D-12-00601.1.

  • Su, J., T. Li, and R. Zhang, 2014: The initiation and developing mechanisms of central Pacific El Niños. J. Climate, 27, 44734485, doi:10.1175/JCLI-D-13-00640.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and D. P. Stepaniak, 2001: Indices of El Niño evolution. J. Climate, 14, 16971701, doi:10.1175/1520-0442(2001)014<1697:LIOENO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, C., and X. Wang, 2013: Classifying El Niño Modoki I and II by different impacts on rainfall in southern China and typhoon tracks. J. Climate, 26, 13221338, doi:10.1175/JCLI-D-12-00107.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, L., T. Li, and T. Zhou, 2012: Intraseasonal SST variability and air–sea interaction over the Kuroshio Extension region during boreal summer. J. Climate, 25, 16191634, doi:10.1175/JCLI-D-11-00109.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wang, X., and C. Wang, 2014: Different impacts of various El Niño events on the Indian Ocean dipole. Climate Dyn., 42, 9911005, doi:10.1007/s00382-013-1711-2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wen, C., A. Kumar, Y. Xue, and M. J. McPhaden, 2014: Changes in tropical Pacific thermocline depth and their relationship to ENSO after 1999. J. Climate, 27, 72307249, doi:10.1175/JCLI-D-13-00518.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weng, H., K. Ashok, S. K. Behera, S. A. Rao, and T. Yamagata, 2007: Impacts of recent El Niño Modoki on dry/wet conditions in the Pacific rim during boreal summer. Climate Dyn., 29, 113129, doi:10.1007/s00382-007-0234-0.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wyrtki, K., 1989: Some thoughts about the west Pacific warm pool. Proc. West Pacific Int. Meeting and Workshop on TOGA COARE, Nouméa, New Caledonia, Office de la recherche scientifique et technique outre-mer (ORSTOM), 99–109.

  • Xiang, B., B. Wang, and T. Li, 2013: A new paradigm for the predominance of standing central Pacific warming after the late 1990s. Climate Dyn., 41, 327340, doi:10.1007/s00382-012-1427-8.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xie, S.-P., and S. G. H. Philander, 1994: A coupled ocean–atmosphere model of relevance to the ITCZ in the eastern Pacific. Tellus, 46A, 340350, doi:10.3402/tellusa.v46i4.15484.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xu, K., C. Zhu, and J. He, 2012: Linkage between the dominant modes in Pacific subsurface ocean temperature and the two type ENSO events. Chin. Sci. Bull., 57, 34913496, doi:10.1007/s11434-012-5173-4.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xu, K., C. Zhu, and J. He, 2013: Two types of El Niño-related Southern Oscillation and their different impacts on global land precipitation. Adv. Atmos. Sci., 30, 17431757.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xu, K., J. Su, and C. Zhu, 2014: The natural oscillation of two types of ENSO events based on analyses of CMIP5 model control runs. Adv. Atmos. Sci., 31, 801813, doi:10.1007/s00376-013-3153-5.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xu, K., C.-Y. Tam, C. Zhu, B. Liu, and W. Wang, 2017: CMIP5 projections of two types of El Niño and their related tropical precipitation in the twenty-first century. J. Climate, 30, 849864, doi:10.1175/JCLI-D-16-0413.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yeh, S., J. Kug, B. Dewitte, M. Kwon, B. P. Kirtman, and F. Jin, 2009: El Niño in a changing climate. Nature, 461, 511514, doi:10.1038/nature08316.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yu, J.-Y., and H.-Y. Kao, 2007: Decadal changes of ENSO persistence barrier in SST and ocean heat content indices: 1958–2001. J. Geophys. Res., 112, D13106, doi:10.1029/2006JD007654.

    • Search Google Scholar
    • Export Citation
  • Yu, J.-Y., and S. T. Kim, 2011: Relationships between extratropical sea level pressure variations and the central Pacific and eastern Pacific types of ENSO. J. Climate, 24, 708720, doi:10.1175/2010JCLI3688.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yu, J.-Y., H.-Y. Kao, and T. Lee, 2010: Subtropics-related interannual sea surface temperature variability in the central equatorial Pacific. J. Climate, 23, 28692884, doi:10.1175/2010JCLI3171.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yu, J.-Y., H.-Y. Kao, T. Lee, and S. T. Kim, 2011: Subsurface ocean temperature indices for central-Pacific and eastern-Pacific types of El Niño and La Niña events. Theor. Appl. Climatol., 103, 337344, doi:10.1007/s00704-010-0307-6.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Yu, J.-Y., Y. Zou, S. T. Kim, and T. Lee, 2012: The changing impact of El Niño on US winter temperatures. Geophys. Res. Lett., 39, L15702, doi:10.1029/2012GL052483.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, W., F. Jin, and A. Turner, 2014: Increasing autumn drought over southern China associated with ENSO regime shift. Geophys. Res. Lett., 41, 40204026, doi:10.1002/2014GL060130.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zhang, W., Y. Wang, F. Jin, M. F. Stuecker, and A. G. Turner, 2015: Impact of different El Niño types on the El Niño/IOD relationship. Geophys. Res. Lett., 42, 85708576, doi:10.1002/2015GL065703.

    • Crossref
    • Search Google Scholar
    • Export Citation
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Thermocline Fluctuations in the Equatorial Pacific Related to the Two Types of El Niño Events

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  • 1 State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, and State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
  • 2 Woods Hole Oceanographic Institute, Woods Hole, Massachusetts, and State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
  • 3 State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, and Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
  • 4 Institute of Climate System, Chinese Academy of Meteorological Sciences, Beijing, China
  • 5 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
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Abstract

The interannual fluctuations of the equatorial thermocline are usually associated with El Niño activity, but the linkage between the thermocline modes and El Niño is still under debate. In the present study, a mode function decomposition method is applied to the equatorial Pacific thermocline, and the results show that the first two dominant modes (M1 and M2) identify two distinct characteristics of the equatorial Pacific thermocline. The M1 reflects a basinwide zonally tilted thermocline related to the eastern Pacific (EP) El Niño, with shoaling (deepening) in the western (eastern) equatorial Pacific. The M2 represents the central Pacific (CP) El Niño, characterized by a V-shaped equatorial Pacific thermocline (i.e., deep in the central equatorial Pacific and shallow on both the western and eastern boundaries). Furthermore, both modes are stable and significant on the interannual time scale, and manifest as the major feature of the thermocline fluctuations associated with the two types of El Niño events. As good proxies of EP and CP El Niño events, thermocline-based indices clearly reveal the inherent characteristics of subsurface ocean responses during the evolution of El Niño events, which are characterized by the remarkable zonal eastward propagation of equatorial subsurface ocean temperature anomalies, particularly during the CP El Niño. Further analysis of the mixed layer heat budget suggests that the air–sea interactions determine the establishment and development stages of the CP El Niño, while the thermocline feedback is vital for its further development. These results highlight the key influence of equatorial Pacific thermocline fluctuations in conjunction with the air–sea interactions, on the CP El Niño.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Weiqiang Wang, weiqiang.wang@scsio.ac.cn.

Abstract

The interannual fluctuations of the equatorial thermocline are usually associated with El Niño activity, but the linkage between the thermocline modes and El Niño is still under debate. In the present study, a mode function decomposition method is applied to the equatorial Pacific thermocline, and the results show that the first two dominant modes (M1 and M2) identify two distinct characteristics of the equatorial Pacific thermocline. The M1 reflects a basinwide zonally tilted thermocline related to the eastern Pacific (EP) El Niño, with shoaling (deepening) in the western (eastern) equatorial Pacific. The M2 represents the central Pacific (CP) El Niño, characterized by a V-shaped equatorial Pacific thermocline (i.e., deep in the central equatorial Pacific and shallow on both the western and eastern boundaries). Furthermore, both modes are stable and significant on the interannual time scale, and manifest as the major feature of the thermocline fluctuations associated with the two types of El Niño events. As good proxies of EP and CP El Niño events, thermocline-based indices clearly reveal the inherent characteristics of subsurface ocean responses during the evolution of El Niño events, which are characterized by the remarkable zonal eastward propagation of equatorial subsurface ocean temperature anomalies, particularly during the CP El Niño. Further analysis of the mixed layer heat budget suggests that the air–sea interactions determine the establishment and development stages of the CP El Niño, while the thermocline feedback is vital for its further development. These results highlight the key influence of equatorial Pacific thermocline fluctuations in conjunction with the air–sea interactions, on the CP El Niño.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Weiqiang Wang, weiqiang.wang@scsio.ac.cn.
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