Ascending phase of solar cycle 25 tilts the current El Niño–Southern oscillation transition

A La Niña condition in the equatorial Pacific began in the early summer of 2020 and has lasted more than two and a half years (referred to as the 2020 La Niña hereafter). Predicting its temporal evolution had attracted a lot of attention. Considering the possible phase-locked impact of the 11-year solar cycle on the tropical Pacific variability, in this study the authors present the possible modulations by the solar cycle 25 (SC25) started from December 2019, on the future temporal evolution of the 2020 La Niña. Based on statistical features of historical solar cycles, the authors propose three possible scenarios of the timing of the SC25 maximum year and discuss its possible impacts on the temporal evolution of the 2020 La Niña in the next two years. The ongoing ascending phase of SC25 dampens the development of a super El Niño condition to some extent in 2023.

摘要

自2020年初夏, 赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜), 对其未来演变的预测引起了很多关注, 考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响, 本研究分析了当前太阳活动周(即第25太阳周(SC25))对目前热带太平洋ENSO现象未来演变的调节作用, 基于历史太阳周的统计特征, 作者对第25太阳周达到其最大值的时间提出三种可能的情景, 并讨论了不同情景下的太阳活动对未来两年ENSO演变的可能影响, 第25太阳周的持续上升阶段在一定程度上抑制了当前2023厄尔尼诺现象发展为超级事件.