Dr. H. Spencer and an anonymous reviewer provided constructive comments that helped in improving the content of the manuscript. Discussions and correspondences with Drs. G. Meyers, B. N. Goswami, J. Slingo, S. A. Rao, N. H. Saji, Y. Masumoto, H. Annamalai, H. Hendon, S. Zebiak, S. Hastenrath, and R. H. Kripalani were very helpful.
Allan, R., and Coauthors, 2001: Is there an Indian Ocean dipole, and is it independent of the El Niño–Southern Oscillation? CLIVAR Exchanges, Vol. 6, 18–22.
Ashok, K., Z. Guan, and T. Yamagata, 2001: Impact of the Indian Ocean dipole on the decadal relationship between the Indian monsoon rainfall and ENSO. Geophys. Res. Lett., 28 , 4499–4502.
Ashok, K., W. Chan, T. Motoi, and T. Yamagata, 2004: Decadal variability of the Indian Ocean dipole. Geophys. Res. Lett., 31 .L24207, doi:10.1029/2004GL021345.
Baquero-Bernal, A., M. Latif, and S. Legutke, 2002: On dipole-like variability in the tropical Indian Ocean. J. Climate, 15 , 1358–1368.
Behera, S. K., and T. Yamagata, 2003: Influence of the Indian Ocean dipole on the Southern Oscillation. J. Meteor. Soc. Japan, 81 , l69–177.
Behera, S. K., R. Krishnan, and T. Yamagata, 1999: Unusual ocean–atmosphere conditions in the tropical Indian Ocean during 1994. Geophys. Res. Lett., 26 , 3001–3004.
Behera, S. K., J-J. Luo, S. Masson, T. Yamagata, P. Delecluse, S. Gualdi, and A. Navarra, 2003a: Impact of the Indian Ocean dipole on the East African short rains: A CGCM study. CLIVAR Exchanges, Vol. 27, 43–45.
Behera, S. K., S. A. Rao, H. N. Saji, and T. Yamagata, 2003b: Comments on “A cautionary note on the interpretation of EOFs.”. J. Climate, 16 , 1087–1093.
Black, E., J. Slingo, and K. R. Sperber, 2003: An observational study of the relationship between excessively strong short rains in coastal East Africa and Indian Ocean SST. Mon. Wea. Rev., 131 , 74–94.
Carton, J. A., G. Chepurin, X. Cao, and B. S. Giese, 2000: A simple ocean data assimilation analysis of the global upper ocean 1950–1995. Part 1: Methodology. J. Phys. Oceanogr., 30 , 294–309.
Clark, C. O., P. J. Webster, and J. E. Cole, 2003: Interdecadal variability of the relationship between the Indian Ocean zonal mode and East African coastal rainfall anomalies. J. Climate, 16 , 548–554.
CLIVAR Africa Report, 1999: Climate research for Africa. WCRP Informal Rep. 16/1999, ICPO Publication Series 29, 79 pp.
Feng, M., G. Meyers, and S. Wijffels, 2001: Interannual upper ocean variability in the tropical Indian Ocean. Geophys. Res. Lett., 28 , 4151–4154.
Gualdi, S., E. Guilyardi, A. Navarra, S. Masina, and P. Delecluse, 2003: The interannual variability in the tropical Indian Ocean as simulated by a CGCM. Climate Dyn., 20 , 567–582.
Guan, Z., and T. Yamagata, 2003: The unusual summer of 1994 in East Asia: IOD teleconnections. Geophys. Res. Lett., 30 .1544, doi:10.1029/2002GL016831.
Guilyardi, E., G. Madec, and L. Terray, 2001: The role of lateral ocean physics in the upper ocean thermal balance of a coupled ocean–atmosphere GCM. Climate Dyn., 17 , 589–599.
Hastenrath, S., and D. Polzin, 2003: Circulation mechanisms of climate anomalies in the equatorial Indian Ocean. Meteor. Z., 12 , 81–93.
Hastenrath, S., A. Nicklis, and L. Greischar, 1993: Atmospheric–hydrospheric mechanisms of climate anomalies in the western equatorial Indian Ocean. J. Geophys. Res., 98 , 20219–20235.
Iizuka, S., T. Matsuura, and T. Yamagata, 2000: The Indian Ocean SST dipole simulated in a coupled general circulation model. Geophys. Res. Lett., 27 , 3369–3372.
Jury, R. M., 2002: Economic impacts of climate variability in South Africa and development of resource prediction models. J. Appl. Meteor., 41 , 46–55.
Lau, N-C., and M. J. Nath, 2004: Coupled GCM simulation of atmosphere–ocean variability associated with zonally asymmetric SST changes in the tropical Indian Ocean. J. Climate, 17 , 245–265.
Legates, D. R., and C. J. Willmott, 1990: Mean seasonal and spatial variability in gauge-corrected, global precipitation. Int. J. Climatol., 10 , 111–127.
Luo, J-J., S. Masson, S. Behera, P. Delecluse, S. Gualdi, A. Navarra, and T. Yamagata, 2003: South Pacific origin of the decadal ENSO-like variation as simulated by a coupled GCM. Geophys. Res. Lett., 30 .2250, doi:10.1029/2003GL018649.
Madec, G., P. Delecluse, M. Imbard, and C. Levy, 1998: OPA version 8.1 ocean general circulation model reference manual. Tech. Rep./Note 11, LODYC/IPSL, 91 pp.
Masson, S., and Coauthors, 2005: Impact of barrier layer on winter–spring variability of the southeastern Arabian Sea. Geophys. Res. Lett., 32 .L07703, doi:10.1029/2004GL021980.
Morse, A. P., M. B. Hoshen, F. D. Reyes, and M. C. Thomson, 2003: Towards forecasting epidemics in Africa—The use of seasonal forecasting. CLIVAR Exchanges, Vol. 27, 50–52.
Murtugudde, R. G., J. P. McCreary, and A. J. Busalacchi, 2000: Oceanic processes associated with anomalous events in the Indian Ocean with relevance to 1997–1998. J. Geophys. Res., 105 , 3295–3306.
Mutai, C. C., and M. N. Ward, 2000: East African rainfall and the tropical circulation/convection on intraseasonal to interannual time scales. J. Climate, 13 , 3915–3939.
Ogallo, L. J., 1988: Relationship between seasonal rainfall in East Africa and the Southern Oscillation. J. Climatol., 8 , 31–43.
Ogallo, L. J., J. E. Janowiak, and M. S. Halpert, 1988: Teleconnection between seasonal rainfall over East Africa and global surface temperature anomalies. J. Meteor. Soc. Japan, 66 , 807–821.
Philippon, N., P. Camberlin, and N. Fauchereau, 2002: Empirical predictability study of October–December East African rainfall. Quart. J. Roy. Meteor. Soc., 128 , 2239–2256.
Rao, S. A., and T. Yamagata, 2004: Abrupt termination of Indian Ocean dipole events in response to intraseasonal disturbances. Geophys. Res. Lett., 31 .L19306, doi:10.1029/2004GL020842.
Rao, S. A., and S. K. Behera, 2005: Subsurface influence on SST in the tropical Indian Ocean structure and interactions. Dyn. Atmos. Ocean, 39 , 103–135.
Rao, S. A., S. K. Behera, Y. Masumoto, and T. Yamagata, 2002: Interannual variability in the subsurface tropical Indian Ocean with a special emphasis on the Indian Ocean dipole. Deep-Sea Res., 49B , 1549–1572.
Rayner, N. A., E. B. Horton, D. E. Parker, C. K. Folland, and R. B. Hackett, 1996: Version 2.2 of the Global Sea-Ice and Sea Surface Temperature data set, 1903–1994. Climate Research Tech. Note 74, U.K. Met Office, 21 pp.
Reverdin, G., D. L. Cadet, and D. Gutzler, 1986: Interannual displacements of convection and surface circulation over the equatorial Indian Ocean. Quart. J. Roy. Meteor. Soc., 112 , 43–67.
Roeckner, E., and Coauthors, 1996: The atmospheric general circulation model ECHAM4: Model description and simulation of present day climate. Max-Plank-Institut für Meteorologie Rep. 218, Hamburg, Germany, 90 pp.
Ropelewski, F., and M. S. Halpert, 1987: Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation. Mon. Wea. Rev., 115 , 1602–1626.
Saji, H. N., and T. Yamagata, 2003a: Structure of SST and surface wind variability in COADS observations during IOD years. J. Climate, 16 , 2735–2751.
Saji, N. H., and T. Yamagata, 2003b: Interference of teleconnection patterns generated from the tropical Indian and Pacific Oceans. Climate Res., 25 , 151–169.
Saji, N. H., B. N. Goswami, P. N. Vinayachandran, and T. Yamagata, 1999: A dipole mode in the tropical Indian Ocean. Nature, 401 , 360–363.
Shinoda, T., M. A. Alexander, and H. H. Hendon, 2004: Remote response of the Indian Ocean to interannual SST variations in the tropical Pacific. J. Climate, 17 , 362–372.
Valcke, S., L. Terray, and A. Piacentini, 2000: The OASIS coupler user guide version 2.4. Tech. Rep. TR/CMGC/00-10, CERFACS, Toulouse, France, 85 pp.
Vinayachandran, P. N., N. H. Saji, and T. Yamagata, 1999: Response of the equatorial Indian Ocean to an anomalous wind event during 1994. Geophys. Res. Lett., 26 , 1613–1616.
Webster, P. J., A. Moore, J. Loschnigg, and M. Leban, 1999: Coupled ocean–atmosphere dynamics in the Indian Ocean during 1997–98. Nature, 401 , 356–360.
Willmott, C. J., and K. Matsuura, 1995: Smart interpolation of annually averaged air temperature in the United States. J. Appl. Meteor., 34 , 2557–2586.
Xie, S-P., H. Annamalai, F. Schott, and J. P. McCreary, 2002: Structure and mechanisms of south Indian Ocean climate variability. J. Climate, 15 , 864–878.
Yamagata, T., S. K. Behera, S. A. Rao, Z. Guan, K. Ashok, and H. N. Saji, 2002: The Indian Ocean dipole: A physical entity. CLIVAR Exchanges, Vol. 24, 15–18.
Yamagata, T., S. K. Behera, S. A. Rao, Z. Guan, K. Ashok, and H. N. Saji, 2003: Comments on “Dipoles, temperature gradient, and tropical climate anomalies.”. Bull. Amer. Meteor. Soc., 84 , 1418–1422.
Yamagata, T., S. K. Behera, J-J. Luo, S. Masson, M. Jury, and S. A. Rao, 2004: Coupled ocean–atmosphere variability in the tropical Indian Ocean. Earth Climate: The Ocean–Atmosphere Interaction, Geophys. Monogr., No. 147, Amer. Geophys. Union, 189–212.
Yu, J-Y., and K. M. Lau, 2004: Contrasting Indian Ocean SST variability with and without ENSO influence: A coupled atmosphere–ocean GCM study. Meteor. Atmos. Phys., doi:10.1007/s00703-00400094-7.
Yule, G. U., 1907: On the theory of correlation for any number of variables treated by a new system of notation. Proc. Roy. Soc., 79A , 182–193.
Zubair, L., S. A. Rao, and T. Yamagata, 2003: Modulation of Sri Lankan Maha rainfall by the Indian Ocean dipole. Geophys. Res. Lett., 30 .1063, doi:10.1029/2002GL015639.