夏季欧亚阻塞活动的年代际变化及其与我国降水的可能联系

Decadal Characteristics of Summer Eurasian Blockings and Its Possible Relation to Precipitation over China

利用1952—2004年6—8月NCEP/NCAR逐日500 hPa高度资料及中国160站降水资料,对夏季欧亚地区阻塞活动的年代际变化特征及其与我国降水年代际变化的可能联系进行了分析。结果表明:夏季欧亚地区的阻塞活动存在明显的年代际变化特征,在年代际尺度上,夏季鄂霍茨克海地区阻塞活动偏多(少)与我国汉水和渭水流域夏季的旱(涝)密切相关,夏季贝加尔湖地区阻塞活动偏多(少)与我国黄淮、江淮地区夏季的涝(旱)密切相关,夏季乌拉尔山地区阻塞活动偏多(少)则与我国江南、华南大部分地区夏季的旱(涝)密切相关。

Using daily NCEP/NCAR height data at 500 hPa and Pecipitation of 160 station in China from June to August in 1952-2004,investigation is conducted on the decadal characteristics of summer Eurasian blockings and its possible relation to precipitation over China. Evidences suggest that the summer Eurasian blockings exist pronounced decadal variation. On the decadal timescale, the more （less） summer blockings over the Okhotsk, Ural, and Baikal regions are in close relation to the summer droughts （ floodings ） over the Hanshui River basin, and the Weishui River basin ;the summer droughts （ floodings ） over the south of the Yangtze River,and most of South China;and the summer floodings （droughts） over the Huanghe-Huaihe River basin,and the Changjiang-Huaihe River basin,respectively.