Potential Impact of Winter–Spring North Atlantic Tripole SSTAs on the Following Autumn–Winter El Niño–Southern Oscillation: Bridging Role of the Tibetan Plateau

Abstract

Abstract Sea surface temperature anomalies (SSTAs) over the North Atlantic could stimulate the El Niño–Southern Oscillation (ENSO) events through regulating the tropical and mid‐latitude atmospheric circulations. Whether the Tibetan Plateau (TP) play an important bridging role in the mid‐latitude pathway has been rarely considered. Observational analysis and model simulations show that the spring TP surface wind speed dipole mode forced by the winter–spring North Atlantic tripole SSTAs can induce surface zonal wind anomalies over the equatorial western Pacific from April to June through the Indo‐Pacific gearing process, favoring the occurrence of subsequent autumn–winter ENSO events through the Bjerknes feedback. Moreover, a flattened TP will obviously weaken the atmospheric and oceanic responses associated with ENSO development to the North Atlantic tripole SSTAs forcing. Quantitatively, the TP's bridging effect accounts for about 38% proportion in the above process. Our finding provides a new insight in understanding the mid‐latitude pathway.

Keywords

• North Atlantic tripole SSTAs
• El Niño‐Southern Oscillation
• bridging role of Tibetan Plateau
• interannual variability