[세미나] 김 준 교수님

코로나사태로 본 대기질 문제 - 미세먼지 장거리 수송의 영향

Particulate matter (PM) concentrations at a given location are determined by local emission and long-range transport(LRT) from neighboring areas, where local emission consists of direct emission as particles (solid) and indirect emission as precursors (gas) to form particles through chemical reactions in the atmosphere. COVID-19 has changed our life style drastically affecting social behavior, economy, industry, traffic etc., which in turn affected air quality as well. Aerosol optical depth (AOD) from GOCI and NO2 from OMI and TROPOMI showed noticeable changes in the air quality in East Asia. With the longer lifetime of aerosols as compared to NO2, the reduction of these two pollutants appeared differently. While aerosols are affected by LRT, i.e. meteorology, and NO2 reflects the changes in social behavior. Furthermore, to assess the effects of transboundary transport of aerosols on air quality in Korea over long term, geostationary satellite measurements are used with back-trajectories using the NOAA HYSPLIT model. For LRT events, satellite observations showed high AOD plumes over the Yellow Sea, a pathway between Eastern China and South Korea, and the movements of aerosol plumes transported to South Korea were also detected. PM2.5 and PM10 concentrations, and AOD during LRT increased by 52%, 49%, and 81%, respectively, relative to their average values for 2015–2018. To quantitatively characterize the LRT of aerosols, the effects of LRT on PM2.5 concentration categories were estimated. When high concentrations of PM2.5 were observed in Seoul, they were likely to be associated with LRT events.