我国夏季东部区域降水异常年代际、年际变化分析  

Analysis on the Interdecadal and Interannual Variations of Regional Summer Rainfall Anomalies over Eastern China

作　　者：段明铿[1] 王盘兴[1] 林开平[1] 

机构地区：[1]南京信息工程大学大气科学系,江苏南京210044

出　　处：《南京气象学院学报》2005年第1期93-100,共8页Journal of Nanjing Institute of Meteorology

基　　金：科技部社会公益研究专项资金"珠江流域广西境内流域面雨量预报与汛期洪涝监测业务体系研究"(37020)

摘　　要：用华南、江淮、华北代表站 6—8月降水量标准化距平的区域平均值定义了降水异常指数I,论证了它与常用指数Z、R的一致性。不同区域I的同期相关不显著,表明 3区降水年际异常具有独立性。用周期分析将I分解为年代际、年际变化指数Is、If,方差分析表明,只有华南区域Is在其I的构成中显著,表明区域夏季降水异常是复杂的。对Is、If曲线的分析表明, 3个区域Is均表现出与太平洋年代际振荡(PDO)20世纪 70年代的转折有关的相关关系,华北区域If的显著偏少与强ElNino事件的同时性关系密切。The index of regional rainfall anomaly(I index) is defined as the regional average of representative station′s JJA standardized rainfall anomaly in South China,Changjiang-Huaihe valley,and North China.And it is proved that I index is consistent with commonly used Z and R index.The correlation of I between different regions is insignificant,indicating that the interannual changes of summer rainfall are independent in the above three regions.The I index is decomposed into the interdecadal variation index (I_s) and interannual variation index (I_f) by means of periodical analysis.And the variance analysis indicates that I_s is significant among the components of I only in South China,suggesting that the regional rainfall anomaly in summer is complicated.The analysis of the curves of I_s and I_f indicates that I_s in the three regions is related to the 1970s′ transition of Pacific Decadal Oscillation (PDO),and the significant negative anomaly of I_f in North China is contemporaneously close related to strong El Nino events.

关 键 词：夏季(6—8月) 区域降水异常指数 年代际和年际变化 PD0 ENSO事件 

分 类 号：P467[天文地球—大气科学及气象学]