Abstract
State-of-the-art climate models have long-standing intrinsic biases that limit their simulation and projection capabilities. Significantly weak ENSO asymmetry and weakly nonlinear air–sea interaction over the tropical Pacific was found in CMIP5 (Coupled Model Intercomparison Project, Phase 5) climate models compared with observation. The results suggest that a weak nonlinear air–sea interaction may play a role in the weak ENSO asymmetry. Moreover, a weak nonlinearity in air–sea interaction in the models may be associated with the biases in the mean climate—the cold biases in the equatorial central Pacific. The excessive cold tongue bias pushes the deep convection far west to the western Pacific warm pool region and suppresses its development in the central equatorial Pacific. The deep convection has difficulties in further moving to the eastern equatorial Pacific, especially during extreme El Ni˜no events, which confines the westerly wind anomaly to the western Pacific. This weakens the eastern Pacific El Ni˜no events, especially the extreme El Ni˜no events, and thus leads to the weakened ENSO asymmetry in climate models. An accurate mean state structure (especially a realistic cold tongue and deep convection) is critical to reproducing ENSO events in climate models. Our evaluation also revealed that ENSO statistics in CMIP5 climate models are slightly improved compared with those of CMIP3. The weak ENSO asymmetry in CMIP5 is closer to the observation. It is more evident in CMIP5 that strong ENSO activities are usually accompanied by strong ENSO asymmetry, and the diversity of ENSO amplitude is reduced.
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An, S.-I., Y.-G. Ham, J.-S. Kug, F.-F. Jin, and I.-S. Kang, 2005: El Ni˜no–La Ni˜na asymmetry in the Coupled Model Intercomparison Project simulations. J. Climate, 18, 2617–2627.
Adler, R. F., and Coauthors, 2003: The version-2 Global Precipitation Climatology Project (GPCP) monthly precipitation analysis (1979–present). Journal of Hydrometeorology, 4(6), 1147–1167.
An, S.-I., 2009: A review of interdecadal changes in the nonlinearity of the El Ni˜no-Southern Oscillation. Theor. Appl. Climatol., 97, 29–40.
An, S.-I., and F. F. Jin, 2004: Nonlinearity and asymmetry of ENSO. J. Climate, 17, 2399–2412.
An, S.-I., Y.-G. Ham, J.-S. Kug, F. F. Jin, and I.-S. Kang, 2009: El Ni˜no–La Ni˜na asymmetry in the coupled model intercomparison project simulations. J. Climate, 18, 2617–2627.
Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial Pacific. Mon. Wea. Rev., 97, 163–172.
Burgers, G., and D. B. Stephenson, 1999: The “Normality” of El Ni˜no. Geophys. Res. Lett., 26, 1027–1030.
Cai, W. J., and Coauthors, 2014: Increasing frequency of extreme El Ni˜no events due to greenhouse warming. Nature Clim. Change, 4, 111–116.
Cane, M. A., 1983: Oceanographic events during El Ni˜no. Science, 222, 1189–1195.
Carton, J. A., and B. S. Giese, 2008: A reanalysis of ocean climate using Simple Ocean Data Assimilation (SODA). Mon. Wea. Rev., 136, 2999–3017, doi: 10.1175/2007MWR1978.1.
Graham, N. E., and T. P. Barnett, 1987: Sea surface temperature, surface wind divergence, and convection over tropical oceans. Science, 238, 657–659.
Guilyardi, E., 2006: El Ni˜no-mean state-seasonal cycle interactions in a multi-model ensemble. Climate Dyn., 26, 329–348.
Ham, Y. G., and J. S. Kug, 2012: How well do current climate models simulate two types of El Ni˜no? Climate Dyn., 39, 383–398.
Ham, Y. G., and J. S. Kug, 2014: Improvement of ENSO simulation based on intermodel diversity? J. Climate., 28, 998–1015.
Harrison, D. E., and G. A. Vecchi, 1999: On the termination of El Ni˜no. Geophys. Res. Lett., 26, 1593–1596.
Jin, F. F., D. Neelin, and M. Ghil, 1994: El Ni˜no on the devil’s staircase: Annual subharmonic steps to chaos. Science, 264, 70–72.
Jin, F. F., S.-I. An, A. Timmermann, and J. X. Zhao, 2003: Strong El Ni˜no events and nonlinear dynamical heating. Geophys. Res. Lett., 30, 1120, doi: 10.1029/2002GL016356.
Kim, S. T., and J. Y. Yu, 2012: The two types of ENSO in CMIP5 models. Geophys. Res. Lett., 39, L11704, doi: 10.1029/2012 GL052006.
Kim, S. T., W. J. Cai, F. F. Jin, J. Y. Yu. 2014: ENSO stability in coupled climate models and its association with mean state. Climate Dyn., 42, 3313–3321.
Kug, J.-S., I.-S. Kang, and S.-I. An, 2003: Symmetric and antisymmetric mass exchanges between the equatorial and offequatorial Pacific associated with ENSO. J. Geophys. Res., 108, 3284.
Kug, J.-S., F.-F. Jin, and S.-I. An, 2009: Two-types of El Ni˜no events: Cold tongue El Ni˜no and warm pool El Ni˜no. J. Climate, 22, 1499–1515.
Latif, M., and Coauthors, 2001: ENSIP: The El Ni˜no simulation intercomparison project. Climate Dyn., 18, 255–276.
Leloup, J., M. Lengaigne, and J.-P. Boulanger, 2008: Twentieth century ENSO characteristics in the IPCC database. Climate Dyn., 30, 277–291.
Li, G., and S. P. Xie, 2012: Origins of tropical-wide SST biases in CMIP multi-model ensembles. Geophys. Res. Lett., 39, L22703, doi: 10.1029/2012GL053777.
Li, G., and S. P. Xie, 2014: Tropical biases in CMIP5 multimodel ensemble: The excessive equatorial pacific cold tongue and double ITCZ problems. J. Climate, 27, 1765–1780, doi: 10.1175/JCLI-D-13-00337.1
McGregor, S., A. Timmermann, N. Schneider, M. Stuecker, and M. England, 2012: The Effect of the South Pacific convergence zone on the termination of El Ni˜no events and the meridional asymmetry of ENSO. J. Climate, 25, 5566–5586, doi: 10.1175/JCLI-D-11-00332.1.
McGregor, S., N. Ramesh, P. Spence, M. H. England, M. J. McPhaden, and A. Santoso, 2013: Meridional movement of wind anomalies during ENSO events and their role in event termination. Geophys. Res. Lett., 40, 749–754.
Mechoso, C. R., and Coauthors, 1995: The seasonal cycle over the tropical Pacific in coupled ocean-atmosphere general circulation models. Mon. Wea. Rev., 123, 2825–2838.
Philander, S. G. H., 1983: El Ni˜no Southern Oscillation phenomena. Nature, 302, 295–301.
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.
Rodgers, K. B., P. Friederichs, and M. Latif, 2004: Tropical Pacific decadal variability and its relation to decadal modulations of ENSO. J. Climate, 17, 3761–3774.
Sun, D. Z., and T. Zhang, 2006: A regulatory effect of ENSO on the time-mean thermal stratification of the equatorial upper ocean. Geophys. Res. Lett., 33, L07710, doi: 10.1029/2005 GL025296.
Sun, D.-Z., Y. Yu, and T. Zhang 2009: Tropical water vapor and cloud feedbacks in climate models: A further assessment using coupled simulations. J. Climate, 22(5), 1287–1304.
Sun, Y., D. Z. Sun, L. X. Wu, and F. Wang, 2013: Western Pacific warm pool and ENSO asymmetry in CMIP3 models. Adv. Atmos. Sci., 30, 940–953, doi: 10.1007/s00376-012-2161-1.
Wang, B., S.-I. An, 2002: A mechanism for decadal changes of ENSO behavior: Roles of background wind changes. Climate Dyn., 18, 475–486.
Wang, C. Z., L. P. Zhang, S. K. Lee, L. X.Wu, and C. R. Mechoso, 2014: A global perspective on CMIP5 climate model biases. Nature Clim. Change, 4, 201–205.
Zhang, W. J., and F. F. Jin, 2012: Improvements in the CMIP5 simulations of ENSO-SSTA meridional width. Geophys. Res. Lett., 39, L23704, doi: 10.1029/2012GL053588.
Zhang, T., and D. Z. Sun, 2014: ENSO asymmetry in CMIP5 models. J. Climate, 27, 4070–4093.
Zhang, T., D. Z. Sun, R. Neale, and P. Rasch, 2009: An evaluation of ENSO asymmetry in the Community Climate System Models: A view from the subsurface. J. Climate, 22, 5933–5961, doi: 10.1175/2009JCLI2933.1.
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Sun, Y., Wang, F. & Sun, DZ. Weak ENSO asymmetry due to weak nonlinear air–sea interaction in CMIP5 climate models. Adv. Atmos. Sci. 33, 352–364 (2016). https://doi.org/10.1007/s00376-015-5018-6
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DOI: https://doi.org/10.1007/s00376-015-5018-6