Decadal Change in the Influence of the Western North Pacific Subtropical High on Summer Rainfall over the Yangtze River Basin in the Late 1970s

作     者：Xinyu LI Riyu LU Xinyu LI;Riyu LU

作者机构：Key Laboratory of Marine Hazards ForecastingMinistry of Natural ResourcesHohai UniversityNanjing 210098China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid DynamicsInstitute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary SciencesUniversity of the Chinese Academy of SciencesBeijing 100049China College of OceanographyHohai UniversityNanjing 210098China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2021年第38卷第11期

页      面：1823-1834页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.41905055 and 41721004) the Natural Science Foundation of Jiangsu Province(Grant No.BK20190500) the Fundamental Research Funds for the Central Universities(Grant No.B200202145) 

主　　题：Yangtze River basin western North Pacific subtropical high rainfall interannual relationship decadal change 

摘      要：It is well known that on the interannual timescale,the westward extension of the western North Pacific subtropical high(WNPSH)results in enhanced rainfall over the Yangtze River basin(YRB)in summer,and vice *** study identifies that this correspondence experiences a decadal change in the late *** is,the WNPSH significantly affects YRB precipitation(YRBP)after the late 1970s(P2)but not before the late 1970s(P1).It is found that enhanced interannual variability of the WNPSH favors its effect on YRB rainfall in *** the other hand,after removing the strong WNPSH cases in P2 and making the WNPSH variability equivalent to that in P1,the WNPSH can still significantly affect YRB rainfall,suggesting that the WNPSH variability is not the only factor that affects the WNPSH-YRBP *** results indicate that the change in basic state of thermal conditions in the tropical WNP provides a favorable background for the enhanced WNPSH-YRBP *** P2,the lower-tropospheric atmosphere in the tropical WNP gets warmer and wetter,and thus the meridional gradient of climatological equivalent potential temperature over the YRB is *** a result,the WNPSH-related circulation anomalies can more effectively induce YRB rainfall anomalies through affecting the meridional gradient of equivalent potential temperature over the YRB.