Variation Characteristics of NO_X Concentrations and its Impact on O₃ concentration at Night in Bayanhot, Inner Mongolia

The characteristics and correlations of ozone and nitrogen oxide pollution were explored using the air quality concentration and meteorological data of Bayanhot from 2018 to 2021.The results showed that the ozone quality concentration at the new building site of the environmental protection bureau was the highest,while the West garden and the Mongolian second kindergarten station were relatively low,and the NO_Xquality concentration showed the opposite trend from 2018 to 2021.The difference in ozone quality concentration between daytime and nighttime at the new building site of the environmental protection bureau was smaller than other sites.The daily variation of NO quality concentration was a single peak distribution,with the peak appearing from west to east,and the daily variation of NO₂ quality concentration was a double peak distribution,with the first peak appearing at 9:00 am,and the second peak appearing from east to west,the peak quality concentrations of NO and NO₂ in the new building of the Environmental Protection Bureau was significantly smaller than that in the Mongolian second kindergarten and the West Garden Station.The O₃ of the three stations has a significant positive correlation with wind speed and temperature,and a significant negative correlation with humidity,and the change of temperature had the greatest impact on the change of ozone quality concentration.The negative correlation between NO₂,NO and O₃ was stronger at the Mongolian second kindergarten station,which had the greatest impact on ozone,while the new building station of the environmental protection bureau were relatively weak,which had the least impact on ozone.There is a positive correlation between the NO_X quality concentration and the decrease of ozone at night in the three national control stations.Low quality concentration of NO_X is one of the important reasons for the high quality concentration of ozone at night in Bayanhot area.