여름철 도심 공원의 O3과 NO2 농도의 일변화 : 기온과 풍속의 영향

초록

The diurnal variations of O3 and NO2 in an urban park and the effects of air temperature and wind speed on the diurnal variations are investigated. O3 and NO2 concentrations were observed at a site in an urban park of Seoul from 27 July 2015 to 9 August 2015. The O3 and NO2 concentrations observed in the urban park are compared to those observed at the Gangnam air quality monitoring station (AQMS). The O3 concentration is higher in the urban park than at the Gangnam AQMS in the daytime because the amount of O3 dissociated by NO is smaller as well as partly because the amount of O3 produced in the oxidation process of biogenic volatile organic compounds (VOCs) is larger in the urban park than at the Gangnam AQMS. The NO2 concentration is lower in the urban park than at the Gangnam AQMS during day and night because the observation site in the urban park is relatively far from roads where NOx is freshly emitted from vehicles. The difference in NO2 concentration is larger in the daytime than in the nighttime. To examine the effects of air temperature and wind speed on the diurnal variations of O3 and NO2, the observed O3 and NO2 concentrations are classified into high or low air temperature and high or low wind speed days. The high O3 and NO2 concentrations in the daytime appear for the high air temperature and low wind speed days. This is because the daytime photochemical processes are favorable when the air temperature is high and the wind speed is low. The scatter plots of the daytime maximum O3 and minimum NO2 concentrations versus the daytime averages of air temperature and wind speed show that the daytime maximum O3 and minimum NO2 concentrations tend to increase as the air temperature increases or the wind speed decreases. The daytime maximum O3 concentration is more sensitive to the changes in air temperature and wind speed in the urban park than at the Gangnam AQMS.

키워드