Australian rainfall and dipole-like sea surface temperature patterns in the Indian Ocean
In the first year of Pete's Chief Editorship I published, in the Journal of Climate, a paper describing the relationship between interannual Australian rainfall variability and a dipole-like pattern of sea surface temperature variations in the Indian Ocean (Nicholls, 1989). Previous work over many decades had documented the influence of the El Niño – Southern Oscillation on Australian rainfall variability, including the spatial pattern of the influence of ENSO. One intriguing aspect of the ENSO-rainfall relationship was that the phenomenon was less influential along the southern edge of the Australian continent, compared to its impact in inland eastern Australia (eg., McBride and Nicholls, 1983). Variations in the dipole-like SST pattern in the Indian Ocean, as the 1989 paper demonstrated, were closely linked to rainfall variations along the southern part of the continent, as well as through the centre and northwest. Patterns of sea surface temperature variability subsequently joined patterns related to the ENSO as predictors in the Bureau of Meteorology's operational seasonal rainfall forecast system (Drosdowsky and Chambers, 2001). Further work by many scientists has documented more clearly the presence of Indian Ocean dipole-like patterns, proposed mechanisms for their development, and related variations in these patterns to changes and variations in rainfall in various parts of the world, including Australia. I will review the research of the past 25 years regarding relationships between Indian Ocean sea surface temperature “dipoles” and Australian rainfall.
Drosdowsky, W and Chambers, LE, 2001. Near-global sea surface temperature anomalies as predictors of Australian seasonal rainfall. J. Climate, 14, 1677-1687.
McBride, JL and Nicholls, N. 1983. Seasonal relationships between Australian rainfall and the Southern Oscillation. Mon. Weath. Rev., 111, 1998-2004.
Nicholls, N. 1989. Sea surface temperature and Australian winter rainfall. J. Climate, 2, 965-973.