Correlation Analysis of PM_(2.5) and NO_2 Concentrations in City Ambient Air of Changsha

摘要

The Changsha city of Hunan province was selected as study area to monitor the concentrations of PM_(2.5) and NO_2 in ambient air automatically. The correlation relationship between PM_(2.5) and NO_2 was also analyzed. Results showed that the concentrations of PM_(2.5) and NO_2 changed significantly with seasons, and they manifested the same change trend, as winter > autumn > spring > concentration in summer, In a day, the lowest concentration of NO_2 generally appeared in the afternoon. However, the present time of lowest and the peak values of PM_(2.5) concentration were uncertain. The highest concentration of NO_2 was in the business district, and the distribution of PM_(2.5) concentration did not have an obviously regional. Furthermore, the PM_(2.5) and NO_2 concentration changed in positive correlation, and these two were easy to produce pollution overlay. On the whole, the main seasons to control PM_(2.5) and NO_2 were winter and autumn.