An international research team, led by the
To date, reliable records of the Indian Ocean Dipole a climate phenomenon similar to El Nino go back about 50 years. Palaeoclimatologist Mike Gagan, of the ANU's Research School of Earth Sciences, said the researchers' techniques allowed them to analyse sea-surface temperature and salinity stretching back hundreds, even thousands, of years.
Indian Ocean Dipole events occur when the ocean temperature and winds along the equatorial
Dr Gagan said the frequency of dipole events was increasing. ''In the last 160 years, there's been about 21 dipole events that we can see, and there's only been about five very strong events,'' he said. ''But it turns out, four out of the five very strong events have occurred since 1960, and three of the very strong events have occurred since 1994.''
Dr Gagan said this meant farmers across southern