广东海洋大学学报2025，Vol.45Issue(5)：26-33,8.DOI:10.3969/j.issn.1673-9159.2025.05.004
海气耦合对热带夏季风降水季节内尺度可预报性的潜在影响
Potential Impacts of Air-Sea Coupling on Intraseasonal-Scale Predictability of Tropical Summer Monsoon Precipitation
摘要
Abstract
[Objective]This study aims to improve the simulation space of seasonal scale predictable signals,and explore the upper limit of summer monsoon precipitation predictability at the seasonal scale.[Method]Based on satellite rainfall data and CMIP6 climate models outputs,including both Coupled General Circulation Models(CGCMs)and Atmospheric General Circulation Models(AGCMs),the predictability limit of intraseasonal rainfall was determined by the method of the Nonlinear Local Lyapunov Exponent(NLLE)during the South Asian summer monsoon(SASM),the South China Sea summer monsoon(SCSSM),and the west North Pacific summer monsoon(WNPSM).[Result and Conclusion]These monsoon systems have an actual predictability limit(PL)of about 31‒32 days at the intraseasonal timescale,and the nonlinear error evolution of the WNPSM is longer due to significant air sea coupling.However,current climate models in CMIP6 fall short of this predictability limit,and the PL of intraseasonal precipitation in CGCMs is about 16.0,17.7 and 19.7 days during SCSM,SCSSM and WNPSM,while it is just 14.0,15.4 and 17.0 days in AGCMs.It reveals that current models leave substantial room for improvement in intraseasonal predictability.Further signal-to-noise ratio analysis shows that the simulation ability in the intensity of intraseasonal precipitation from the CMIP6 models is positive correlated with its predictability.The air-sea coupling process significantly improves intraseasonal-scale predictability by enhancing the intensity of precipitation variability.These findings offer fresh clues about monsoon forecasting at the intraseasonal timescale,which implies that unlocking the secrets of air-sea interactions could be the next breakthrough for better predictions.关键词
亚洲夏季风/季节内降水/可预报期限/海气耦合/非线性局部Lyapunov指数Key words
Asian summer monsoon/intraseasonal rainfall/predictability limit/air-sea coupling/nonlinear local Lyapunov exponent分类
海洋科学引用本文复制引用
蒙泽,李保生..海气耦合对热带夏季风降水季节内尺度可预报性的潜在影响[J].广东海洋大学学报,2025,45(5):26-33,8.基金项目
广东省基础与应用基础研究基金(2025A1515011394) （2025A1515011394）
