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Mode of Precipitation Variability Generated by Coupling of ENSO With Seasonal Cycle in the Tropical Pacific
Author(s) -
Fukuda Yoshihiro,
Watanabe Masahiro,
Jin FeiFei
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2021gl095204
Subject(s) - climatology , sea surface temperature , precipitation , zonal and meridional , pacific decadal oscillation , mode (computer interface) , indian ocean dipole , el niño southern oscillation , oscillation (cell signaling) , anomaly (physics) , environmental science , atmospheric sciences , walker circulation , geology , physics , meteorology , chemistry , condensed matter physics , computer science , operating system , biochemistry
Tropical precipitation anomalies show very different patterns over the central‐eastern equatorial Pacific between the developing and decay phases of extreme El Niño despite similar patterns of sea surface temperature (SST) anomalies. Using observational data and atmospheric simulations for 1979–2018, we identified a meridional dipole mode of tropical precipitation variability, called the Pacific precipitation dipole mode (PPDM), which is critical for seasonally varying rainfall patterns related to extreme El Niño. We examined the mechanism of PPDM using a numerical model and found that the seasonal shift of the warm SST band in the eastern equatorial Pacific, when coupled with extreme SST anomalies, causes phase reversal of the PPDM. The PPDM can be regarded as a different manifestation of the El Niño/Southern Oscillation combination mode, as revealed by the surface wind anomalies, which also explains the distinct impact of extreme El Niño events over East Asia.