中文摘要：

利用1948-2009年美国环境预报中心（NCEP）500 hPa高度场逐日再分析资料,按照通用的阻塞高压天气学定义,采用机器自动识别方法,检索和分析近62 a亚洲夏季阻高活动时空变化特征,结果表明：共统计到1 337个阻塞高压个例,以生命期3-7 d的过程居多,占80.1%,阻高活动累计个数和累计天数集中区可分为偏东类（鄂霍次克海）、偏西类（乌拉尔山）、中间类（贝加尔湖）和其他类4类,其中中间类阻塞高压活动累计个数最多,占总个数的30.4%,偏东类次之,占27.5%,其他类占23.8%,偏西类最弱,占18.3%;20世纪90年代以来,乌拉尔山地区阻高处于明显偏弱期,鄂霍次克海阻高处于偏强期;但是,21世纪初叶,乌拉尔山地区阻高活动开始呈上升趋势,而鄂霍次克海阻高却呈明显下降趋势,值得关注;夏季阻塞高压与东北冷涡活动天数呈显著同期正相关,与长春、哈尔滨同期平均气温呈显著负相关;亚洲夏季阻塞高压是影响东北夏季低温重要的环流系统;鄂霍次克海阻高6月活动异常年,850hPa风距平场在120°E-140°E,40°N-55°N存在很强的偏东气流,有利于来自鄂霍次克海偏东北路径的冷空气入侵东北亚及中国东北地区。

英文摘要：

Based on the daily NECP /NCAR reanalysis data of 500 hPa height field from 1948 to 2009,an objective classification and widely-agreed method was applied to analyze the temporal and spatial distributions of atmospheric blockings high in Asia during summer,In addition,the location and numbers of blockings high was automatically determined.The results show that there are 1 337 blocking events during the last 62 summers.According to the active period of blocking events,a period of 3-7 days are dominant during all the events which account for 80.1%.Based on the accumulative numbers and days,the blockings are divided into eastward type（blocking high over the Okhotsk Sea）,westward type（blocking high over Ural Mountain）,central type（blocking high over Baikal Lake） and the others,totally four types,occupying at 27.5%,30.4%,18.3%,and 23.8 %,respectively.Since 1990s,blocking events in Ural region are in a weak period,otherwise in Okhotsk region are in a strong period,but blocking events in Ural region begin taking upward trend at the beginning of 21st century.Bblockings in Okhotsk region take a clear downward trend.There is a significant positive relationship between blocking events and cold vortex in Northeast China,but a negative correlation between blocking events and temperature of Changchun and Harbin in summer.Blocking high is one of important circulation system which causes the low temperature in Northeast of China in summer.During westward type blocking events strongly active years in June,a strong easterlies air flow in 850 hPa is found over the region of 20°E-140°E,40°N-55°N,It is advantageous for cold air come from the northeast path in Okhotsk region to invade Northeast Asia and the northeast area in China.