Case Analysis of Near-Surface Ozone Pollution Events Based on the WRF-CAMx Model
Using the hourly meteorological data from the Putian meteorological station and hourly O3 data from the environmental monitoring station in November 8-9,2020,as well as the wind profiler radar data and emission source data,this article analyzes the meteorological characteristics of the nighttime O3 pollution process.Additionally,the WRF-CAMx model is employed for vertical distribution simulation and source analysis of O3.The results indicate that the nighttime peak concentration of O3 in Putian City was 212 µg·m-3,significantly higher than that in Fuzhou and Quanzhou.Prior to the O3 pollution epi-sode,the air temperature was on the rise,which was likely caused by the warming effect ahead of the southward-moving cold front.During the O3 pollution at night,the wind profiler radar data showed a 27.2%decline in wind speed from the near-surface to the 750 m height in Putian City,exacerbating the O3 pollution.The Hysplit 4 model results reveal that during the nighttime O3 pollution period,the airflow passed through the region with significant NOX and VOCS emissions,while during non-pollution periods,the airflow mainly originated from the East China Sea.WRF-CAMx model results demonstrate that during the heavy nighttime O3 pollution period(23:00),the atmospheric O3 concentration could reach the 1500 m height at 850 hPa.Ningde City contributed 94%to the nighttime O3 pollution in Futian City among va-rious cities in Fujian Province.