Near-term projection of precipitation over the southern Tibetan Plateau constrained by the Interdecadal Pacific Oscillation

The Tibetan Plateau (TP) precipitation is crucial for the ecosystem, yet its near-term changes, which demand urgent climate adaptation, remain underexplored. The near-term (2026–2055) projection of TP precipitation using 100 MPI-ESM ensemble members is investigated in this study. Results show that although the TP exhibits an overall wetting trend, significant inter-member uncertainty persists in the trends of the southern TP (STP) precipitation, dominated by an east–west dipole mode modulated by the Interdecadal Pacific Oscillation (IPO) phase transition. Specifically, a positive IPO phase transition enhances eastern STP precipitation but suppresses western rainfall, whereas a negative transition reverses this pattern. Original near-term projections of the precipitation mode in the STP show limited support for policymaking, with equal likelihood (50% each) of opposing trends across simulation ensembles. Therefore, an adjustment method of the IPO phase transition is applied to constrain the uncertainty and improve the consistency of the near-term projection of the STP precipitation. By leveraging the influence of the IPO phase transition on the STP precipitation change, the consistency of the near-term projection of the STP precipitation increases from 50% to 70% and 55%, when the 100 members share the same IPO phase transition of +2 (30 yr) −1 and −2 (30 yr) −1 , respectively. Accurate simulation of IPO phase transitions is critical for refining near-term regional precipitation projections. The findings advance the understanding of near-term precipitation changes by reconciling model uncertainties with large-scale oceanic drivers, offering reference for adaptive water resource management. 青藏高原降水变化对当地生态系统至关重要, 但对其近期预估 (2026–2055) 的研究尚不充分.利用MPI-ESM超级集合的100个模式成员, 发现高原南部 (STP) 降水的近期预估存在较大的不一致性, 受太平洋年代际振荡 (IPO) 位相转换的调控, IPO转为正位相将增加 (减弱) STP东 (西) 部降水, 反之亦然.为此, 基于IPO位相转换调整方法约束STP降水的近期预估, 当约束所有100个成员具有相同的IPO正 (负) 位相转换时, STP降水预测的一致性从原始的50%提升至70% (55%) .准确模拟IPO的位相转换对改进青藏高原区域降水的近期预估至关重要.