Based on the NCEP/NCAR reanalysis dataset of sea level pressure and winds for the period 1948-2013,temporal and spatial distribution and period and lifespan characteristics of wintertime extra-tropical anticyclone activity in the Northern Hemisphere were presented in this study using objective identification method and tracking algorithm.The results show that the wintertime extra-tropical anticyclones in the Northern Hemisphere are active mainly in the Northeast Pacific,the North Atlantic,the eastern Rocky Mountains and eastern United States,Europe,and Central and East Asia.The genesis regions of anticyclones in the Pacific and the Atlantic are dispersed.Most anticyclones originally form in the western part of the ocean,become mature in the middle and eastern parts of the ocean,and decay in the eastern part of the ocean and western coasts of the continents.The difference in the region of lysis of anticyclone between the Pacific and the Atlantic Ocean is that,the large value area of lysis is a belt extending from the middle of the Atlantic to the western coast of Europe in the Atlantic along the southwest-northeast direction,while in the Pacific Ocean the two large value areas of lysis are distributed separately.Over the continent,anticyclones mostly occur in the high latitudes and polar regions,and move eastward or southeastward.It is found that the frequency and intensity,and the mean latitude and latitudinal range of the moving trajectories of anticyclones have different interannual and interdecadal variabilities in different regions.The occurrence frequency of anticyclones shows a significant period of 2-3 years in most part of the Northern Hemisphere,and a significant period of 16-18 years in Eurasia.As the anticyclone intensity increases,its trajectory becomes further northward in all regions except Eurasia.In North America,the stronger the anticyclone is,the greater the mean latitudinal range will be.On the contrary,the anticyclone intensification is often accompanied with a smaller latitudinal range in Eurasia.The occurrence frequency of anticyclones decreases rapidly with longer lifespan,and less than 10％ of the total anticyclones can last for more than one week.%利用NCEP/NCAR再分析资料,通过客观判定和追踪反气旋的方法统计分析了1948～2013年北半球冬季温带反气旋的时空分布、周期和生命史等气候特征.结果表明,北半球冬季温带反气旋主要活动在东北太平洋、北大西洋、北美落基山脉东部和加拿大、美国东部、欧洲、亚洲中部和东亚地区.太平洋和大西洋上反气旋的生成区分布较分散,于大洋西部生成,在中、东部达到成熟期,最后主要在大洋东部和大陆西岸消亡.大西洋上反气旋消亡区域的大值区从大西洋中部到欧洲西海岸呈西南—东北带状分布,而太平洋上的反气旋消亡区域的两个大值区独立分布.大陆上反气旋多生成于较高纬度和极地地区,主要向东、向东南方移动.北半球各区域反气旋数均具有显著的2～3年周期变化特征,欧亚地区则具有显著的16～18年周期的年代际变化特征.除了欧亚大陆,其他三个区域的反气旋偏强时,其运动轨迹偏北.北美地区反气旋越强,其运动的纬度范围越大;而欧亚大陆反气旋越强,其运动的纬度范围越小.生命史越长的反气旋数比例越少,只有不到10％的反气旋生命史超过一周.
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