Two‐sided impacts of warm pool SSTs on Australian precipitation changes

ABSTRACT Optimal tropical ocean regions for forcing precipitation changes over Australia are identified from maps of sensitivity of Australian precipitation to tropical sea surface temperature (SST) anomalies. These sensitivity maps are derived by a series of atmospheric general circulation model simulations with prescription of an array of SST anomaly patches over the tropics. The results show that the Australian precipitation changes are most sensitive to SST anomalies over the Indo‐Pacific Warm Pool. There are competing opposing sensitivities such that warming over the Indian side of the Warm Pool increases precipitation, whereas that over the Pacific side decreases it. These sensitivity maps are validated by use in reconstruction of historical series of Australian precipitation with realistic interannual variability. The present results imply that monitoring and predicting the signs and magnitudes of SST anomalies over the critical Indo‐Pacific Warm Pool may improve the prediction skills of Australian precipitation changes.