【摘要】 利用北京325 m气象塔不同阶段(第一阶段:1991—1995年;第二阶段:2004—2008年)风温梯度观测,北京地区气候站长期观测(1971—2008年,20站)和城市社会经济发展指标(1978—2008年),从城市化进程不同阶段对比的角度,分析研究北京近地层大气风温结构变化特征。结果表明,北京城市化进程已经导致该地区近地层大气特征发生明显变化。主要表现为:地面和近地层温度增加,热岛强度增强;地面风速和近地层低层风速明显减小;近地层低层(63 m以下)风向变得更为紊乱;近地层温度垂直递减率增加;近地层大气风温结构特征的变化表明:2004—2008年325 m气象塔,在63 m以下基本反映的是城市冠层流场特征,即气象塔周边地区城市冠层厚度约为63 m。更多还原

【Abstract】 This study analyzed Beijing surface atmospheric variations in wind and temperature structures,especially on the long-term changes and comparison of different urbanization stage(the first stage:1991—1995;the second stage:2004—2008),by using wind and temperature observations from Beijing 325 m meteorology tower(two period:1991—1995,2004—2008) and Beijing climate stations(from 1971—2008,20 stations),and the economics and social development index form yearbook in Beijing region(from 1978—2008).The study reveals obvious changes in the surface atmosphere associated with the fast urbanization in Beijing: the surface air temperature and urban heat island intensity increased;the wind strength decreased;the wind direction becomes disordered at lower levels which are below 63 m;the vertical decreasing rate of temperature increased;the variation of wind and temperature structure of surface layer reveals that the observations below 63 m reflect the characteristics of urban canopy layer,and the height of the urban canopy layer may reach 63 m in 2004—2008.更多还原