The authors thank Dr. Gurvan Madec and Dr. Pascale Delecluse for fruitful discussions, and Pr. Shukuro Manabe for useful comments, as well as anonymous reviewers whose comments helped to improve this manuscript. We are also very grateful to Dr. Adam Clayton for his great kindness and help in improving manuscript English readability. The authors thank JAMSTEC, especially FRCGC and the Earth Simulator Center, for their great hospitality and the highest-performance material and computer facilities they offer. Dr. Sophie Cravatte, Dr. Fabien Durand, Dr. Jerome Vialard, and all the LEGOS and LOCEAN teams are greatly thanked for their support of this research project. Most of the observations data were made available mainly by NOAA/NCEP/CPC through Climate Diagnostics Center (CDC) and IRI/LDEO Climate Data Library servers. QuikScat data are produced by Remote Sensing Systems and sponsored by the NASA Ocean Vector Winds Science Team. Those data were obtained from the IFREMER (CERSAT) ftp server. Some of the rainfall data used in this study were acquired as part of the Tropical Rainfall Measuring Mission (TRMM; sponsored by Japan NASDA and U.S. NASA Office of Earth Sciences, and distributed by the Goddard Distributed Active Archive Center). The authors also wish to acknowledge the use of NOAA/PMEL Ferret program for analysis and graphics in this paper, as well as to thank Dr. Pascal Terray for the use of Statpacks, the statistical analysis package he developed. This work was mostly funded by the Japan Society for the Promotion of Science (JSPS), and partly by the Institut Pierre-Simon Laplace (IPSL).
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