An atmospheric 'pendulum' swinging between the Pacific and Indian Ocean links El Niņo with its less-famous counterpart to the west.
Onsets of the El Niño ocean-warming phenomenon can be predicted up to 14 months ahead of time, according to a team of French and Japanese researchers.
Writing in the journal Nature Geoscience, lead researcher Takeshi Izumo said the development could help prevent agricultural losses and allow other industries to prepare for the effects of El Niño’s weather disruptions.
Izumo and his colleagues uncovered clues that a phenomenon equivalent to an El Niño in the Indian Ocean, discovered in 1999, has a role in causing its more famous Pacific counterpart.
The researchers say that by monitoring the Indian Ocean Dipole, it is now possible to provide El Niño outlooks several months earlier than through current forecasting methods.