An, S. I., and B. Wang, 2001: Mechanisms of locking of the El Ni#cod#241; and La Ni#cod#241; mature phases to boreal winter. J. Climate, 14, 2164-2176.
An, S. I., and F. F. Jin, 2004: Nonlinearity and asymmetry of ENSO. J. Climate, 17, 2399-2412.
Birgin, E. G., J. M. Martinez, and M. Raydan, 2000: Nonmonotone spectral projected gradient methods on convex sets. SIAM J. Optim., 10, 1196-1211.
Birgin, E. G., J. M. Martinez, and M. Raydan, 2001: Algorithm 813: SPG——Software for convex-constrained optimization. ACM Trans. Math. Software, 27, 340-349.
Bjerknes, J., 1969: Atmospheric teleconnections from the equatorial pacific. Mon. Wea. Rev., 97, 163-172.
Blumenthal, M. B., 1991: Predictability of a coupled ocean-atmosphere model. J. Climate, 4, 766-784.
Chen, D., S. E. Zebiak, A. J. Busalacchi, and M. A. Cane, 1995: An improved procedure for El Ni#cod#241; forecasting: Implications for predictability. Science, 269, 1699-1702.
Chen, D., M. A. Cane, A. Kaplan, S. E. Zebiak, and D. J. Huang, 2004: Predictability of El Ni#cod#241; over the past 148 years. Nature, 428, 733-736.
Duan, W. S., and M. Mu, 2009: Conditional nonlinear optimal perturbation: Applications to stability, sensitivity, and predictability. Science in China (D ), 52, 884-906.
Duan, W. S., and R. Zhang, 2010: Is model parameter error related to a significant spring predictability barrier for El Ni#cod#241; events? Results from a theoretical model. Adv. Atmos. Sci., 27, 1003-1013, doi: 10.1007/s00376-009-9166-4.
Duan, W. S., and C. Wei, 2012: The "spring predictability barrier" for ENSO predictions and its possible mechanism: Results from a fully coupled model. Int. J. Climatol., 33, 1280-1292, doi: 10.1002/joc.3513.
Duan, W. S., M. Mu, and B. Wang, 2004: Conditional nonlinear optimal perturbations as the optimal precursors for El Ni#cod#241;-Southern Oscillation events. J. Geophys. Res.(Atmos), 109, doi: 10.1029/2004jd004756.
Duan, W. S., F. Xue, and M. Mu, 2009a: Investigating a nonlinear characteristic of El Ni#cod#241; events by conditional nonlinear optimal perturbation. Atmospheric Research., 94, 10-18.
Duan, W. S., X. C. Liu, K. Y. Zhu, and M. Mu, 2009b: Exploring the initial errors that cause a significant "spring predictability barrier" for El Ni#cod#241; events. J. Geophys. Res., 114, C04022, doi: 10.1029/2008JC004925.
Duan, W. S., Y. S. Yu, H. Xu, and P. Zhao, 2013a: Behaviors of nonlinearities modulating the El Ni#cod#241; events induced by optimal precursory disturbances. Climate Dyn., 40, 1399-1413, doi: 10.1007/s00382-012-1557-z.
Duan, W. S., R. Zhang, Y. S. Yu, and B. Tian, 2013b: The role of nonlinearities associated with air-sea coupling processes in El Ni#cod#241;'s peak-phase locking. Science China: Earth Sciences, doi: 10.1007/s11430-013-4629-y.
Kaplan, A., M. A. Cane, Y. Kushnir, A. C. Clement, M. B. Blumenthal, and B. Rajagopalan, 1998: Analyses of global sea surface temperature 1856-1991. J. Geophys. Res.-Oceans, 103, 18567-18589.
Karspeck, A. R., A. Kaplan, and M. A. Cane, 2006: Predictability loss in an intermediate ENSO model due to initial error and atmospheric noise. J. Climate, 19, 3572-3588.
Kleeman, R., 1991: A simple model of the atmospheric response to ENSO sea surface temperature anomalies. J. Atmos. Sci., 48, 3-19.
Liu, Z. Y., 2002: A simple model study of ENSO suppression by external periodic forcing. J. Climate, 15, 1088-1098.
Luo, J. J., S. Masson, S. K. Behera, and T. Yamagata, 2008: Extended ENSO predictions using a fully coupled ocean-atmosphere model. J. Climate, 21, 84-93.
Macmynowski, D. G., and E. Tziperman, 2008: Factors affecting ENSO's period. J. Atmos. Sci., 65, 1570-1586.
McPhaden, M. J., S. E. Zebiak, and M. H. Glantz, 2006: ENSO as an integrating concept in Earth science. Science, 314, 1740-1745.
Moore, A. M., and R. Kleeman, 1996: The dynamics of error growth and predictability in a coupled model of ENSO. Quart. J. Roy. Meteor. Soc., 122, 1405-1446.
Mu, M., and W. S. Duan, 2003: A new approach to studying ENSO predictability: Conditional nonlinear optimal perturbation. Chinese Sci. Bull., 48, 1045-1047.
Mu, M., H. Xu, and W. S. Duan, 2007: A kind of initial errors related to "spring predictability barrier" for El Ni#cod#241; events in Zebiak-Cane model. Geophy. Res. Lett., 34, doi: 10.1029/ 2006gl027412.
Mu, M., W. Duan, Q. Wang, and R. Zhang, 2010: An extension of conditional nonlinear optimal perturbation approach and its applications. Nonlin. Proc. Geophys., 17, 211-220.
Neelin, J. D., 1990: A hybrid coupled general circulation model for El-Ni#cod#241; studies. J. Atmos. Sci., 47, 674-693.
Neelin, J. D., 1991: The slow sea-surface temperature mode and the fast-wave limit-analytic theory for tropical interannual oscillations and experiments in a hybrid coupled model. J. Atmos. Sci., 48, 584-606.
Peng, Y. H., W. S. Duan, and J. Xiang, 2012: Can the uncertainties of Madden-Jullian Oscillation cause a significant "Spring Predictability Barrier" for ENSO events? Acta Meteorologica Sinica, 26, 566-578.
Penland, C., and T. Magorian, 1993: Prediction of Ni#cod#241; 3 sea surface temperatures using linear inverse modeling. J. Climate, 6, 1067-1076.
Qin, X. H., W. S. Duan, and M. Mu, 2013: Conditions under which CNOP sensitivity is valid for tropical cyclone adaptive observations. Quart. J. Roy. Meteor. Soc., 139, doi: 10.1002/qj.2109.
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.
Suarez, M. J., and P. S. Schopf, 1988: A delayed action oscillator for ENSO. J. Atmos. Sci., 45, 3283-3287.
Wang, B., and Z. Fang, 1996: Chaotic oscillations of tropical climate: A dynamic system theory for ENSO. J. Atmos. Sci., 53, 2786-2802.
Wang, C. Z., and J. Picaut, 2004: Understanding ENSO physics——A review. Geophys. Monog. Series, 147, 21-48.
Wyrtki, K., 1975: El Ni#cod#241;——The dynamic response of the equatorial Pacific Ocean to atmospheric forcing. J. Phys. Oceanogr., 5, 572-584.
Xue, Y., M. A. Cane, S. E. Zebiak, and M. B. Blumenthal, 1994: On the prediction of ENSO: A study with a low-order Markov model. Tellus A, 46, 512-528.
Yan, L., and Y. Q. Yu, 2012: The spring prediction barrier in ENSO hindcast experiments of FGOALS-g model. Chinese Journal of Oceanology and limnology, doi: 10.1007/s00343-012-1271-z.
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. (Atmos), 112, doi: 10.1029/2006jd007654.
Yu, Y. S., W. S. Duan, H. Xu, and M. Mu, 2009: Dynamics of nonlinear error growth and season-dependent predictability of El Ni#cod#241; events in the Zebiak-Cane model. Quart. J. Roy. Meteor. Soc., 135, 2146-2160.
Yu, Y. S., M. Mu, and W. S. Duan, 2012: Does model parameter error cause a significant "Spring Predictability Barrier" for El Ni#cod#241; events in the Zebiak-Cane model? J. Climate, 25, 1263-1277.
Zebiak, S. E., and M. A. Cane, 1987: A model El-Ni#cod#241; southern Oscillation. Mon. Wea. Rev., 115, 2262-2278.