北京上空大气臭氧垂直分布的特征

CHARACTERISTICS OF OZONE VERTICAL DISTRIBUTION IN THE ATMOSPHERE OVER BEIJING

利用我国自行研制的探空仪和地面接收设备首次较系统地获得了北京地区连续一年(2001年3月至2002年2月)的大气臭氧垂直分布资料。结果分析表明:①北京地区上空臭氧浓度极大值的季节均值的变化范围为15.1～16.7mPa,其高度位于20.7～25.1km之间,极小值的季节均值的变化范围为2.0～2.8mPa,其高度在对流层顶附近。②边界层和平流层下部是臭氧浓度变化的活跃区域,并具有明显的季节变化,在边界层内夏季臭氧积分浓度高于冬季相应值的1.7倍之多,而在平流层下部,冬季臭氧积分浓度则高于夏季的相应值。夏季边界层中臭氧浓度偏高,表明臭氧是北京地区夏季重要的污染气体之一。③北京上空臭氧垂直廓线的形态呈多样性,夏秋季节以单峰为主,冬春季节经常出现双峰和多峰结构;次峰出现的区域一般在10～18km高度范围内。

Ozonesonde measurements were carried out from March 2001 to February 2002 at Nanyuan Station, Beijing. Both ozonesonde and ground receiving system used in the measurements were designed and made in China. The consecutive one year data on ozone vertical distribution over Beijing were obtained. Analysis of the results indicates: ①The seasonal average maximum of ozone partial pressure ranges from 15.1 to 16.7mPa with altitude range of 20.7～25.1 km over Beijing; the range of seasonal average minimum of ozone partial pressure is 2.0～(2.8) mPa, and the altitude of the minimum occurs near the tropopause. ②The boundary layer and the lower stratosphere are susceptible regions of ozone concentration with a prominent seasonal variations. In the boundary layer, the ozone concentration in summer is 1.7 times higher than that in winter, while in the lower stratosphere the ozone concentration in winter is higher than it in summer. The higher ozone concentration in summer in the boundary layer indicates that ozone is one of the major pollutants in summer in Beijing. ③The ozone vertical profile structure over Beijing can be classified as profile with a single ozone peak appeared mainly in summer and autumn, with double and multiple ozone peaks observed always in spring and winter, in the last two cases, the secondary ozone peak normally appears at 10～18 km.