北京城区奥运期间与其他时段激光雷达观测实例分析

Case Study by Lidar at Downtown of Beijing During the Olympic Games and Other Times

为了研究北京城区在北京奥运会期间大气边界层变化特征及大气边界层内气溶胶的消光特性,2008年8月利用MPL激光雷达对北京城区的大气边界层进行了系统观测。反演出了测站地域上空大气气溶胶的消光特性垂直分布以及大气边界层的高度。同往年北京城区的雷达监测数据进行了系统的对比,并与设在北京南郊梨花村的清洁对照点数据进行了比较。观测数据表明:北京城区奥运期间大气边界层日变化趋势明显,呈早晚低、午间高的特点。大气边界层高度相对稳定,多分布在2.0 km下,平均值为0.79km。奥运期间气溶胶粒子浓度水平较往年有明显下降。观测点处气溶胶浓度水平每天呈周期性变化。

In order to study the structural feature of the atmosbhere boundary layer （ABL） over downtown of Beijing and the aerosol extinction characteristics in it during the Beijing Olympic Games, ABL over Beijing was observed with a MPL lidar in August, 2008. The vertical distribution of extinction properties and the height of ABL over the observation site were inverted. The observation data was compared with the results of observations in previous years at downtown of Beijing and Lihua Village in souther suburb of Beijing which was viewed as a standard of clean control site. The data indicate that the diurnal variation of ABL over Beijing during the Olympic Games is obvious, which is low in morning and evening, and high at noon time. The ABL height is relatively stable, it is always less than 2.0 km, its average height is 0.79 km. Compared with the data of previous years, the aerosol particle concentration level at downtown of Beijing during the Olympic Games is descended apparently. The aerosol concentration at observation site changes periodically every day .