【作者】 李珍； 严中伟； 涂锴； 刘伟东； 王迎春；

【Author】 LI Zhen~(1,2) YAN Zhongwei~(*1) TU Kai~1 LIU Weidong~3 WANG Yingchun~4 (1.Key Laboratory of Regional Climate-Environment in Temperate East Asia,Institute of Atmospheric Physics, Chinese Academy of Sciences,Beijing 100029;2.Graduate University of Chinese Academy of Sciences,Beijing 100049;3.Institute of Urban Meteorology,China Meteorological Administration,Beijing 100089;4.Beijing Meteorological Bureau,Beijing 100089)

【机构】 中国科学院东亚区域气候—环境重点实验室； 中国科学院研究生院； 中国气象局城市气象研究所； 北京市气象局；

【摘要】 利用序列均一性的多元分析方法对北京地区12个气象台站1960-2008年逐日风速资料进行了均一化订正。均一化后北京地区年和季节（冬季、春季、夏季和秋季）平均风速线性趋势分别为-0.26、-0.39、-0.30、-0.12和-0.22ms^-110yr^-1。冬季风速降低幅度最大,依次分别为春季、秋季和夏季。年和季节极端风速事件（日数）也存在减少趋势,相对于其他季节冬季减少更为明显。风速和极端风速事件的减少趋势主要由20世纪70年代-80年代风速的突然减弱引起。风速减弱趋势最大的站点出现在朝阳（CY）——位于城市化水平最高的北京市中心商务区（CBD）。除冬季风速最大减弱趋势朝东北方向密云（MY）偏移外,年和其他季节风速减弱趋势的幅度由市中心向周边地区逐渐减小。1960-2008年北京地区城市化对年平均风速的影响大约为-0.05ms^-110yr^-1,占整个区域平均减小趋势的20%。基于EAR-40再分析逐日平均海平面气压（MSLP）资料分析表明:北京地区年和季节地转风风速也呈减弱趋势,与站点观测结果相一致。对比分析1966-1975年和1992-2001年平均海平面气压场发现:相对于早期近十年北京地区冬季和夏季季风均有所减弱。这表明北京地区的风速受城市化影响明显,而强风或极端风速则易于受到区域大尺度气候变化的影响。更多还原

【Abstract】 Daily observations of wind speed at 12 stations in Greater Beijing Area during 1961-2008 were homogenized by using the Multiple Analysis of Series for Homogenization method.The linear trends in the regional mean annual and seasonal（winter,spring,summer and autumn） wind speed series are -0.26,-0.39, -0.30,-0.12 and -0.22 m s^-1 10yr^-1,respectively.Winter is of the greatest magnitude of declining wind speed, followed by spring,autumn and summer in order.The annual and seasonal frequencies of the wind speed extremes （days） also decrease,more prominent for winter than for other seasons.The declining trends in wind speed and extremes are mainly formed with some rapid declining changes during the 1970s-1980s.The maximum declining trend in wind speed occurs at Chaoyang（CY ）,a station within the Central Business District（CBD ） of Beijing with the highest level of urbanization.The declining trends are in general smaller in magnitude away from the city center except for the winter case,in which the maximum declining trend shifts northeastward to rural Miyun （MY）.The influence of urbanization on the annual wind speed is estimated about -0.05 m s^-1 10yr^-1 during 1960-2008,accounting for about one fifth of the regional mean declining trend.The annual and seasonal geostrophic wind speeds around Beijing,based on daily mean sea level pressure（MSLP） from the ERA-40 reanalysis dataset,exhibit decreasing trends as well,coincident with the results of the site observations.A comparative analysis of the MSLP fields between 1966-1975 and 1992-2001 suggests that the influences of both the winter and summer monsoons on Beijing were weaker in the recent decade than in the early.It is suggested that the bulk of wind in Beijing is considerably influenced by urbanization,while changes in strong winds or wind speed extremes are prone to large-scale climate change in the region.更多还原