Financial support for this research was provided by the National Oceanic and Atmospheric Administration under Grants NA26-GP0149 and NA46-GP0217 and by the National Science Foundation under Grant ATM-93-21354. The authors are grateful to Professor S.G.H. Philander for useful discussion during the course of this study, Drs. J.L. Kinter III and Y. Xue for helpful comments on the manuscript, and the two anonymous reviewers for constructive recommendations. We thank Drs. J. Servain and C. Penland for providing SST/wind stress datasets and the FORTRAN code of the POP analysis, respectively. We would also like to thank Dr. R. Yang for discussions about the usage of the POP method.
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