Analysis of NOx Pollution Characteristics in the Atmospheric Environment in Changchun City

Nitrogen oxide (NOx) pollution has become one of the most challenging problems in China in the past 20 years. In this study, on the basis of the Jilin Province Atmospheric Environmental Quality Bulletin and hourly NOx data from the Atmospheric Environment Automatic Monitoring Station in Changchun, temporal and spatial variations in NOx concentration in the province and Changchun and their relationships with various pollutants and meteorological factors were analyzed. The results show that Changchun had the highest NOx concentration of all cities in the province, with a high concentration in the center and a low concentration in the east and west. The areas with high NOx concentrations in Changchun were mainly distributed in urban centers, and the concentration in the northern part of the city was higher than that in the south. The seasonal variation and average daily variation in NOx concentration in Changchun had a bimodal distribution, and the NOx concentration in autumn and winter was higher than that in spring and summer. The maximum monthly average concentrations of NOx and nitric oxide (NO) were reached in October, and the maximum monthly average concentration of nitrogen dioxide (NO2) was reached in March. The average daily variation in NOx concentration first peaked at 07:00-08:00 in the morning, and the second peak occurred between 20:00 and 22:00 at night. The NOx concentration in Changchun was positively correlated with NO2, NO, PM2.5 (fine particulate matter), PM10 (particulate matters), CO (carbon monoxide), and pressure, and it showed a significant negative correlation with O-3, temperature, wind speed, and humidity.