差分吸收激光雷达监测广州市臭氧垂直分布特征

Monitoring of Vertical Distribution of Ozone Using Differential Absorption Lidar in Guangzhou

利用差分吸收臭氧激光雷达对广州市对流层臭氧垂直结构进行长期连续观测,给出了广州市臭氧垂直结构的日变化特征,针对局地污染和区域传输两种不同的臭氧污染模式特征进行分析,提出臭氧污染模式的判定方法。结果表明:广州市臭氧全年日变化规律明显,午后单峰特征突出;臭氧浓度季节变化规律为夏季臭氧浓度最高,冬季浓度最低,春季和秋季差异较小;在局地污染过程中,高浓度的臭氧主要集中在近地面,并且随着高度的增大而逐渐减小,0.7 km以下臭氧浓度的递减速率随高度增大而增大,1.5~2 km的臭氧浓度趋于均匀;针对三个高度区间,给出了臭氧外部输送的特征值,分析了在同一高度上颗粒物消光系数和臭氧浓度的相关性,并结合气象场分析了各个季节臭氧输送的主导方向。

Herein,the long-term continuous observation of the vertical structure of tropospheric ozone in Guangzhou is conducted by using differential absorption lidar.The diurnal variation characteristics of ozone vertical structure in Guangzhou are provided.The characteristics of two different ozone pollution modes of local pollution and regional transmission are analyzed,and the determination method of the ozone pollution pattern is proposed.Results show that the daily variation of ozone in Guangzhou is obvious,and that the single peak characteristic is prominent.The seasonal variation law of ozone concentration is the following:ozone concentration is highest in summer and lowest in winter;there is little difference between spring and autumn.Local pollution analysis shows that the ozone with high concentration is mainly concentrated near the ground,and gradually decreases with an increase of the height.The decreasing rate of ozone concentration below 0.7 km increases rapidly with the increasing height,and for 1.5-2 km tends to be evenly distributed.The study provides the characteristic values of ozone transport for the three height intervals.The correlation between the extinction of particles and ozoneconcentration at the same height is analyzed.Combined with the meteorological field,the dominant direction of ozone transportation in each season is analyzed.