Contents Development of Tropical Circulation in Response to an Equatorial Warm SST Anomaly Revealed by an switch-on Ensemble Aqua-planet GCM Background: Response of tropical circulation to SST anomaly Structure of Steady-state response Hosaka, Ishiwatari, Takehiro, Nakajima and Hayashi (1998) Effectiveness of Ensemble experiment Toyoda, Nakajima, Ishiwatari and Hayashi (1999) Development of East-West Asymmetry: 128 runs Toyoda, Nakajima, Ishiwatari, Takehiro and Hayashi (2002)