Predicting Indian monsoon rainfall from sea-surface temperature in the Indonesia-north Australia area

Several recent studies^1-6 have described associations between inter-annual variations of the Indian south-west monsoon and the El Niño-Southern Oscillation (ENSO) phenomena, and methods for predicting monsoon rainfall based on these associations have been proposed. Rasmusson and Carpenter⁵ suggested that sea-surface temperature (SST) anomalies appearing along the equatorial Pacific South American coast early in the year can provide useful predictions of Indian monsoon rainfall, while Shukla ⁶ suggested that the change in atmospheric pressure anomalies at Darwin from winter to spring (Northern Hemisphere seasons) was useful. It has also been demonstrated^8-11 that SST anomalies in the Indonesia-north Australia region are closely related to the ENSO phenomena. I examine here the relationship between Indian south-west monsoon rainfall and Indonesian-north Australian SST and provide evidence suggesting that SST anomalies in this region can be used to predict Indian monsoon rainfall as accurately as the techniques proposed previously, but using data available several months earlier.