Abstract: Ozone lidar is an effective tool for detecting the spatial and temporal distribution of tropospheric ozone. An ozone lidar based on the differential absorption was developed in this work. The lidar emits Raman excited 289 nm and 316 nm wavelength pairs, uses a 300 mm aperture telescope to receive backscattered echo signals, and can perform ozone concentration profile detection within a height range of 300 – 3000 m. On the basis of comparing and calibrating the horizontal and vertical detection data with those of ozone analyzer at national control points and those of sounding balloons respectively, the ozone lidar was placed in the Beijing-Tianjin-Hebei region, China, for all-weather real-time monitoring. The observation results of two typical ozone pollution processes occurred in the region in 2022 were selected to analyze the causes of local ozone pollution and the deposition process of polluted air masses in the air. It was shown that in one of the ozone transport process, polluted air masses appeared in the atmosphere at an altitude of 900 – 1400 m above the ground and continued to settle, resulting in an increase in the mass concentration of ozone pollutants. And airborne polluted air masses and locally generated ozone interacted with each other, resulting in heavily polluted weather. Another long-term ozone pollution process analysis showed that, during the pollution period, the concentration of ozone near the ground varied greatly between day and night. An ozone residue layer appeared above 500 m, and high concentration of ozone in the residue layer continued to exist until the next day, then continued to overlap with locally generated pollutants, resulting in prolonged and persistent ozone pollution weather.

Key words: ozone lidar, differential absorption, data validation, pollution process analysis