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Publication Date
2 September 2021

Diverse impacts of Indian Ocean Dipole on El Niño-Southern Oscillation



Understanding the impact of the Indian Ocean dipole (IOD) on El Niño–Southern Oscillation (ENSO) is important for climate prediction. By analyzing observational data and performing Indian and Pacific Ocean pacemaker experiments using a state-of-the-art climate model, we find that a positive IOD (pIOD) can favor both cold and warm sea surface temperature anomalies (SSTA) in the tropical Pacific, in contrast to the previously identified pIOD–El Niño connection. The diverse impacts of the pIOD on ENSO are related to SSTA in the Seychelles–Chagos thermocline ridge (SCTR; 608–858E, 78–158S) as part of the warm pole of the pIOD. Specifically, a pIOD with SCTR warming can cause warm SSTA in the southeastern Indian Ocean, which induces La Niña–like conditions in the tropical Pacific through inter-basin interaction processes associated with a recently identified climate phenomenon dubbed the ‘‘warm pool dipole.’’ This study identifies a new pIOD–ENSO relationship and examines the associated mechanisms.

Zhang, Lei, Weiqing Han, Gerald A. Meehl, Aixue Hu, Nan A Rosenbloom, Toshiaki Shinoda, and Michael J. McPhaden. 2021. “Diverse Impacts Of Indian Ocean Dipole On El Niño-Southern Oscillation”. Journal Of Climate. American Meteorological Society, 1-46. doi:10.1175/jcli-d-21-0085.1.
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