Analysis of Pollution Characteristics and Influencing Factors of Main Pollutants in the Atmosphere of Shenyang City

Abstract

Air pollution is one of the most concerning environmental problems in cities. Hourly data on pollutant concentrations from 11 automatic atmospheric monitoring stations and meteorological data in Shenyang from 2017 to 2019 were used to analyze the spatio-temporal variation rules of CO (carbon monoxide), SO₂ (sulfur dioxide), NO₂ (nitrogen dioxide), O₃ (ozone), PM_2.5 and PM₁₀ (PM particles with an aerodynamic diameters of not more than 2.5 µm and 10 µm) and their relationships with meteorological parameters. Meanwhile, the regional transmission route of pollutants was analyzed by the hybrid single particle Lagrangian integrated trajectory (HYSPLIT) model. The results showed that the concentration of O₃ in the northern area of the city was higher than that in the south; CO, SO₂ and NO₂ were relatively high in the urban center; and PM_2.5 and PM₁₀ were relatively high in the southwest. The average concentration of pollutants was lowest in 2019. The concentration of O₃ was the highest in spring, while CO showed no significant variations between different seasons. The remaining pollutant concentrations appeared to be high in winter and low in summer. The cumulative concentrations of the six pollutants were the highest in March, and relatively low in July–September. The diurnal concentration variations of O₃, CO and SO₂ exhibited a “single peak,” while others showed a “double peak and double valley.” Temperature was positively correlated with O₃ concentration and negatively correlated with others. Wind speed was negatively correlated with the concentration of PM_2.5, NO₂, and O₃. The air quality of the main urban area in spring and summer was mainly affected by the coastal air flow, while it was mostly affected by the northwest air flow in autumn and winter.