Subsurface ocean turbulent mixing enhances central Pacific ENSO

作者：Chuanyu Liu, Fan Wang, Armin Koehl, Xiaowei Wang, Chunzai Wang, Kelvin J Richards · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-57058-4 · 被引用次数：8 · 研究领域：Oceanographic and Atmospheric Processes、Climate variability and models、Tropical and Extratropical Cyclones Research

Since the 21st century, the El Niño and Southern Oscillation (ENSO) exhibits more pronounced signals in the central Pacific (CP) rather than the eastern Pacific (EP), but the prediction skill has waned, suggesting limited understanding of crucial dynamics within the prediction framework. The ocean mixing around the mixed layer base, which transfers heat downward in a diabatic manner, was considered a potential influencing factor; yet, its effect has not been adequately examined in either CP or EP regions due to insufficient data. Here, we propose an Argo profile data-based mixing estimation model, which yields abundant estimates of subsurface ocean mixing and turbulent heat flux. Consequently, we find significant positive feedback of the ocean mixing-induced diabatic warming/cooling on the CP ENSO, but not on the EP ENSO. Particularly, the diabatic effect dominates sea surface temperature change in the CP region, highlighting the necessity for diabatic CP ENSO positive feedback dynamics in prediction models. Using Argo profile data with a mixing estimation method, this work reveals ocean subsurface mixing acting as pivotal positive feedback on the central Pacific ENSO and suggests ENSO diabatic positive feedback mechanism.