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[1] During 2006 and 2007 boreal fall, two consecutive positive Indian Ocean Dipole (pIOD) events occurred unprecedentedly regardless of the respective El Nino and La Nina condition in the Pacific. These two pIOD events had large climate impacts, particularly in the Eastern Hemisphere. Experimental forecasts using a coupled model show that the two pIOD events can be predicted 3 or 4 seasons ahead. The evolution of the 2006 pIOD is consistent with the large-scale IOD dynamics, and therefore, it has long-lead predictability owing to the oceanic subsurface memory in the South Indian Ocean. The 2007 pIOD event, however, is rather weak and peculiar without a long memory from the off-equatorial ocean. The model has less predictability for this weak event. The results show that seasonal climate anomalies in the Eastern Hemisphere associated with the two pIOD events can be predicted 1–2 seasons ahead. This indicates potential societal benefits of IOD prediction. |
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