Concurrent increases of PM2.5 and Ozone observed in Seoul, May 2019
- 1Dept. of Earth and Environmental Sciences, Korea University, Seoul, South Korea (jeewon1107@gmail.com)
- 2Graduate School of Energy and Environment (Green School), Korea University, Seoul, South Korea (ksg946@korea.ac.kr)
- 3Dept. of Environmental Sciences, Hankuk University of Foreign Studies, Yongin, South Korea (thlee@hufs.ac.kr)
- 4Research Center for Atmospheric Environment, Hankuk University of Foreign Studies, Yongin, South Korea (moonsoo@paran.com)
- 5Air Quality Forecasting Center, National Institute of Environmental Research, Incheon, South Korea (gookyoung@korea.kr)
In Seoul, PM2.5 concentrations were frequently elevated with O3 in May 2019. The most abundant constituent of PM2.5 was nitrate, which was the best correlated with OC (organic carbon) as well as NH4+. An intensive experiment was conducted in the eastern part of Seoul from March 29 to June 19, 2019. Measurement was made for PM2.5 and its chemical composition including NO3-, SO42-, NH4+ , OC, EC (elemental carbon), and reactive gases including O3, NO, NO2, CO, HONO, HNO3, NH3, and SO2, and meteorological variables including vertical winds and mixed layer height (MLH). The particle number concentration was measured using SMPS (Scanning Mobility Particle Sizer). All measurements were averaged for 1 hour according to the resolution of PM2.5 chemical composition. For the entire experiment, the mean mass concentrations of PM2.5, NO3-, SO42-, NH4+, OC, and EC were 20.40 μg/m3, 4.07 μg/m3, 2.62 μg/m3, 2.01 μg/m3, 4.01 μg/m3, and 1.04 μg/m3, respectively. For reactive gases, the mean concentration was 1.03 ppbv for HONO, 0.70 ppbv for HNO3, 14.87 ppbv for NH3, 2.77 ppbv for SO2, and 48.79 ppbv for O3.
The maximum PM2.5 concentration of 72.81 μg/m3 was observed under the influence of weak Asian dust event in the end of April. In May, there were three distinct episodes with highly enhanced PM2.5. In the early May, the maximum nitrate concentration (36.11 μg/m3) was observed with high HONO (2.41 ppbv) on 4 May. In the middle of May, PM2.5 was raised with SO42- under stagnant condition. On 25 May, PM2.5 was raised up to 92 μg/m3 with high nitrate concentration (18.56 μg/m3) , when O3 reached 205 ppbv. In this episode, O3 concentration remained around 90 ppbv at night and OC and EC were well correlated with highly enhanced K+. Thus, the concurrent enhancement of PM2.5 and O3 was likely due to the influence of aged biomass combustion plume laden air transported from southeast China. At the same time, HNO3 and HONO concentration was highly elevated, indicating that heterogeneous reactions played a role.
How to cite: Son, J., Kang, S., Kim, J., Gil, J., Lee, M., Lee, T., Park, M., and Heo, G.: Concurrent increases of PM2.5 and Ozone observed in Seoul, May 2019, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7020, https://doi.org/10.5194/egusphere-egu2020-7020, 2020.
