Impacts of local versus long-range transported aerosols on PM10 concentrations in Seoul, Korea: An estimate based on 11-year PM10 and lidar observations

Do-Hyeon Park; Sang-Woo Kim; Man-Hae Kim; Huidong Yeo; Sang Seo Park; Tomoaki Nishizawa; Atsushi Shimizu; Cheol-Hee Kim

doi:10.1016/j.scitotenv.2020.141739

Impacts of local versus long-range transported aerosols on PM₁₀ concentrations in Seoul, Korea: An estimate based on 11-year PM₁₀ and lidar observations

Sci Total Environ. 2021 Jan 1:750:141739. doi: 10.1016/j.scitotenv.2020.141739. Epub 2020 Aug 17.

Authors

Do-Hyeon Park¹, Sang-Woo Kim², Man-Hae Kim¹, Huidong Yeo¹, Sang Seo Park³, Tomoaki Nishizawa⁴, Atsushi Shimizu⁴, Cheol-Hee Kim⁵

Affiliations

¹ School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
² School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea. Electronic address: sangwookim@snu.ac.kr.
³ School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
⁴ National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan.
⁵ Department of Atmospheric Sciences, Pusan National University, Busan 46241, Republic of Korea.

PMID: 32877787
DOI: 10.1016/j.scitotenv.2020.141739

Abstract

Extreme haze episodes have frequently occurred in Seoul since mid-2010s by the combined contributions of transboundary transported aerosols as well as locally emitted pollutants. In this study, we developed a novel method to estimate the contribution of long-range transport (LRT, aerosols are transported from any regions except local area near Seoul) and local pollution (LP, aerosols are originated from local area near Seoul) cases to the PM₁₀ concentration in Seoul, Korea, using the PM₁₀ concentration ratio between surface (PM₁₀^S) and mountaintop (PM₁₀^M) sites and the lidar-derived mixing layer height. The overall contributions of LRT and LP events to nighttime high-PM₁₀ episodes (PM₁₀ > 50 μg m^-3) during the period of May 2008-April 2019 were estimated to be approximately 32% and 47%, respectively. The monthly contribution of LRT events to the PM₁₀ concentration varied from approximately 18% (July) to 43% (January), whereas the contribution of LP events was estimated between 39% (March) and 69% (July); this pattern was associated with seasonal synoptic circulations. The similar PM₁₀^S values between the LRT (71 ± 22 μg m^-3) and LP (73 ± 26 μg m^-3) cases during the nighttime suggest that a reduction in local PM₁₀ emissions is crucial to decrease the PM₁₀ concentration during high-PM₁₀ events. The high PM₁₀^S for daytime LRT cases can be explained by the combined effects of increased local emissions and LRT aerosols.

Keywords: High-PM(10) event; Long-range transport; Mixing layer height; PM(10) concentration; Particulate air pollution.