Huang Xin, Zhou Tianjun, Dai Aiguo, Li Hongmei, Li Chao, Chen Xiaolong, Lu Jingwen, Von Storch Jin-Song, Wu Bo
LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Adv. 2020 Mar 13;6(11):eaay6546. doi: 10.1126/sciadv.aay6546. eCollection 2020 Mar.
A reliable projection of future South Asian summer monsoon (SASM) benefits a large population in Asia. Using a 100-member ensemble of simulations by the Max Planck Institute Earth System Model (MPI-ESM) and a 50-member ensemble of simulations by the Canadian Earth System Model (CanESM2), we find that internal variability can overshadow the forced SASM rainfall trend, leading to large projection uncertainties for the next 15 to 30 years. We further identify that the Interdecadal Pacific Oscillation (IPO) is, in part, responsible for the uncertainties. Removing the IPO-related rainfall variations reduces the uncertainties in the near-term projection of the SASM rainfall by 13 to 15% and 26 to 30% in the MPI-ESM and CanESM2 ensembles, respectively. Our results demonstrate that the uncertainties in near-term projections of the SASM rainfall can be reduced by improving prediction of near-future IPO and other internal modes of climate variability.
对未来南亚夏季风（SASM）进行可靠预测，将惠及亚洲众多人口。通过马克斯·普朗克研究所地球系统模型（MPI - ESM）的100个成员模拟集合以及加拿大地球系统模型（CanESM2）的50个成员模拟集合，我们发现内部变率可能会掩盖强迫性SASM降雨趋势，导致未来15至30年的预测存在很大不确定性。我们进一步确定，年代际太平洋涛动（IPO）在一定程度上造成了这些不确定性。去除与IPO相关的降雨变化后，MPI - ESM和CanESM2集合中SASM降雨近期预测的不确定性分别降低了13%至15%和26%至30%。我们的结果表明，通过改进对近期IPO及其他气候变率内部模式的预测，可以降低SASM降雨近期预测的不确定性。
