Accurate knowledge of the climatic state of the Indian Ocean could help predict El Nino and La Nina events that wreak havoc with weather and precipitation patterns worldwide, concludes an article published online in Nature Geoscience this week. Using this information, forecasts with significant skill 14 months in advance come into reach ― several months earlier than the current limit for reliable predictions.
Takeshi Izumo and colleagues used a simple forecasting model to show that a negative phase in the Indian Ocean Dipole, a climate oscillation specific to the Indian Ocean, usually precedes an El Nino event by just over a year. Similarly, a positive Indian Ocean Dipole phase tends to be followed by a La Nina event. The researchers suggest that the Indian and Pacific oceans are closely linked through an atmospheric circulation pattern that responds to the Indian Ocean Dipole and in turn affects winds over the Pacific Ocean.
In an accompanying News & Views article, Peter Webster writes "If the prediction horizon of El Nino and La Nina is to be extended, then both the Indian and Pacific Ocean basins must be included in empirical and dynamical forecasting schemes."