15:30 〜 15:50
[ACG35-07] Extreme El Niño: A Product of Three-Ocean Interactions
★Invited Papers
キーワード：Ocean-atmosphere interaction, El Nino, Climate variability
El Niño is the largest climate phenomenon on Earth and affects global climate, weather, ecosystems and human societies. In particular, extreme El Niño has a profound impact on Asia’s climate and extreme weather events, but its formed mechanism is unknown. This paper uses observations and climate models to show that interactions of the tropical Pacific, Indian and Atlantic Oceans produce extreme El Niño. An early onset type-El Niño endows El Niño with adequate strength in the summer and fall to excite the Atlantic Niño and Indian Ocean dipole. In return, the Atlantic Niño and Indian Ocean dipole alternately produce additional zonal winds over the equatorial western-central Pacific, augmenting El Niño via the Bjerknes feedback to grow into extreme El Niño. This new mechanism is called the Indo-Atlantic booster. The results highlight extreme El Niño as a product of three-interactions, so including both the Indian and Atlantic Oceans and their teleconnections with the Pacific will greatly improve extreme El Niño and climate predictions.