Impacts of North Atlantic tripole SSTAs mode and its three individual components on ENSO

作者：Wei Yu, Dongxiao Wang, Kaiqiang Deng, Yimin Liu, Dake Chen, Shuheng Lin, Yuzhuo Peng · 发表于：npj Climate and Atmospheric Science · 年份：2025 · DOI：10.1038/s41612-025-01249-9 · 被引用次数：3 · 研究领域：Climate variability and models、Oceanographic and Atmospheric Processes、Tropical and Extratropical Cyclones Research

Previous studies have primarily examined the impacts of tropical North Atlantic or uniform extratropical North Atlantic sea surface temperature anomalies (SSTAs) on El Niño–Southern Oscillation (ENSO). However, how the dominant tripole SSTAs mode in the North Atlantic and its three individual components influence interannual ENSO evolution remains poorly understood. In this study, observational analyses reveal a significant connection between the winter–spring North Atlantic tripole SSTAs mode and ENSO development in the following autumn–winter. Model simulations demonstrate that a positive winter–spring North Atlantic tripole SSTAs mode (negative-positive-negative) results in spring westerly wind anomalies over the equatorial western Pacific through both tropical and mid-latitude pathways, ultimately contributing to an autumn–winter El Niño event. The tropical pathway triggers a westward Gill-type Rossby wave to induce the westerly wind anomalies. The mid-latitude pathway generates an eastward Rossby wave train that induces the westerly wind anomalies by modulating both tropical Indo-Pacific zonal-vertical circulations and North Pacific air-sea interactions. Further model analysis reveals that the relative contributions of tropical, mid-latitude, and high-latitude SSTAs of the North Atlantic tripole SSTAs mode to El Niño formation are approximately 43%, 34%, and 23%, respectively. The tropical SSTAs contribute to an El Niño event through both tropical and mid-latitude pathwa...