Vertical distribution of ozone in summer and autumn in Guangdong Province, Southern China

<p>A differential absorption lidar was used to study the vertical structure of ozone in Jiangmen city and Yangjiang city, Guangdong Province, Southern China in summer and autumn of 2019, and analyze the two typical pollution characteristics and spatial-temporal distribution characteristics of atmospheric ozone local pollution and regional transport. The results show that the vertical concentration of ozone in Jiangmen city in the summer and autumn seasons is characterized by a single peak of ozone in the afternoon. It is mainly distributed below 600 m in summer and mainly distributed within 1.0 km in autumn. There is ozone residual in Yangjiang city in summer at night. In summer, the differences between the average ozone values in Jiangmen city and Yangjiang city are small, being 92.22 μg/m<sup>3</sup> and 82 μg/m<sup>3</sup>, respectively. In autumn, the average ozone concentration in Jiangmen city is 1.58 times the ozone concentration in Yangjiang city, which is 122.27 μg/m<sup>3</sup> and 77.36 μg/m<sup>3</sup>. In the process of local pollution, high-concentration ozone is mainly concentrated near the ground, and the ozone concentration of 1.5-2km tends to be uniformly distributed. In regional transport, the transport heights of the two stations are mainly in two height intervals, ranging from 0.7 to 1.1 km and above 1.1 km. And use TrajStat to perform trajectory clustering analysis on the main airflows that affect Jiangmen city and Yangjiang city in summer and autumn, the dominant directions of ozone transport at the two cities in summer and autumn are analyzed. In addition, we studied two typical pollution processes, on August 24, the lidar of both cities detected the presence of ozone input and sedimentation at a height of about 1.5 km, and found that the ozone transport came from the northeast through the backward trajectory. During September 28-30, the two cities were locally polluted by ozone and there were obvious ozone residues at night.</p><p>Keywords: Differential absorption lidar；Ozone；Local pollution；Regional transport</p><p><strong> </strong></p>