江淮地区梅雨的新定义及其气候特征  

A Study of Updated Definition and Climatological Characters of Meiyu Season in the Yangtze-Huaihe Region

作　　者：胡娅敏[1] 丁一汇[2] 廖菲[3] 

机构地区：[1]南京信息工程大学大气科学系 [2]中国气象局国家气候中心,北京100081 [3]中国气象局广州热带海洋气象研究所,广州510080

出　　处：《大气科学》2008年第1期101-112,共12页Chinese Journal of Atmospheric Sciences

基　　金：“九五”国家攀登A项目SCSMEX

摘　　要：用Cressman客观分析方法得到我国1954~2005年0.5°×0.5°的逐日降水格点资料,并定义了一个新的江淮地区的"广义梅雨评定标准",研究了包括长江中下游地区和淮河流域地区的整个江淮地区(28°N^34°N,110°E^122°E)梅雨期降水的气候特征。结果表明:江淮梅雨有显著的年际和年代际变化特征,主要存在2~3年、6~8年、12~15年和18~20年的周期变化,2~3年的显著周期主要集中在20世纪70年代末以后。江淮地区梅雨在1965年前后、70年代末~80年代初和90年代初发生了三次显著的气候跃变。最后,从季风气流的水汽输送和副热带高压及阻塞高压的稳定维持三个方面讨论了江淮梅雨丰梅年和弱梅年时大气环流的异常特征。In the previous researches, the onset date and ending date of Meiyu are always defined by 5 representative stations （Shanghai, Nanjing, Wuhu, Jiujiang and Hankou） in the middle and lower reaches of the Yangtze River valley. However, the precipitation of 5 representative stations during Meiyu duration cannot well depict the precipitation pattern happening in the Huaihe River basin and other regions. By means of Cressman＇s objective analysis method, a 0. 5°× 0. 5° grid point daily precipitation dataset of China for 1954 - 2005 has been obtained. Then, a generalized Meiyu criterion has been defined for investigating the Meiyu precipitation features over the whole Yangtze- Huaihe region （28°N- 34°N, 110°E- 122°E）, including the Yangtze River and the Huaihe River valleys. The updated criterion is used to analyze the precipitation characteristics during the Meiyu period in the Yangtze-Huaihe region. The results show that there is a prominent interannual and interdecadal variation of Meiyu rainfall in this region since 1954. According to the power spectrum, the maximum entropy spectrum and the Morlet wavelet analysis method, the 52-year Meiyu precipitation period features are analyzed. The Meiyu parameters have 2 - 3-year, 6 - 8- year, 12- 15-year and 18 - 20-year dominating periods, while the 2 - 3-year significant period almost concentrates after the late 1970s. The approximate 2 - 3-year significant period of Meiyu parameters （including the onset date, the ending date, the Meiyu duration, the Meiyu precipitation and the intensity index） may reflect the effects of Tropospheric Quasi-Biennial Oscillation （TBO）. The climatic jumps of Meiyu parameters over the Yangtze-Huaihe region are detected in terms of the moving t test technique, Yamamoto signal noise ratio method and Mann-Kendall （M-K） test method. Three obvious abrupt climatic changes have happened in the middle 1960s, the late 1970s through the early 1980s and the early 1990s. Furthermore, the atmospheric circulation characters, inclu

关 键 词：江淮地区梅雨 广义梅雨评定标准 气候特征 

分 类 号：P426.6[天文地球—大气科学及气象学]