Improvement of the anthropogenic emission rate estimate in Ulaanbaatar, Mongolia, for 2020-21 winter

Hyung-Min Lee; Eunlak Choi; Yong Pyo Kim; Tseren-Ochir Soyol-Erdene; Amgalan Natsagdorj; Zhijun Wu; Mijung Song; Changhyuk Kim; Kyoung-Soon Jang; Junyoung Ahn; Atsushi Matsuki; Esmatullah Torabi; Jung-Hun Woo; Chang Hoon Jung; Ji Yi Lee

doi:10.1016/j.envpol.2024.123870

Improvement of the anthropogenic emission rate estimate in Ulaanbaatar, Mongolia, for 2020-21 winter

Environ Pollut. 2024 Mar 26:349:123870. doi: 10.1016/j.envpol.2024.123870. Online ahead of print.

Authors

Affiliations

¹ Department of Environmental Science and Engineering, Ewha Womans University, Seoul, South Korea.
² Department of Chemical Engineering and Materials Science, Ewha Womans University, Seoul, South Korea.
³ Department of Environmental and Forest Engineering, National University of Mongolia, Ulaanbaatar, Mongolia.
⁴ Department of Chemistry, National University of Mongolia, Ulaanbaatar, Mongolia.
⁵ College of Environmental Sciences and Engineering, Peking University, Beijing, China.
⁶ Department of Environment and Energy, Jeonbuk National University, Jeonju, Republic of Korea; Department of Earth and Environmental Sciences, Jeonbuk National University, Jeonju, Republic of Korea.
⁷ School of Civil and Environmental Engineering, Pusan National University, Busan, Republic of Korea.
⁸ Biomedical Omics Group, Korea Basic Science Institute, Cheongju, Republic of Korea.
⁹ Air Quality Research Division, National Institute of Environmental Research, Incheon, South Korea.
¹⁰ Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa, Japan.
¹¹ Department of Advanced Technology Fusion, Konkuk University, Seoul, South Korea.
¹² Department of Health Management, Kyungin Women's University, Incheon, South Korea.
¹³ Department of Environmental Science and Engineering, Ewha Womans University, Seoul, South Korea. Electronic address: yijiyi@ewha.ac.kr.

PMID: 38548153
DOI: 10.1016/j.envpol.2024.123870

Abstract

Ulaanbaatar (UB), the fast-growing capital of Mongolia, is known for its world's worst level of particulate matter (PM) concentrations in winter. However, current anthropogenic emission inventories over the UB are based on data from more than fifteen years ago, and satellite observations are scarce because UB is in high latitudes. During the winter of 2020-21, the first period of the Fine Particle Research Initiative in East Asia considering the National Differences (FRIEND), several times higher concentrations of PM in UB compared to other urban sites in East Asia were observed but not reproduced with a chemical transport model mainly due to the underestimated anthropogenic emissions. Therefore, we devised a method for sequentially adjusting emissions based on the reactivity of PM precursors using ground observations. We scaled emission rates for the inert species (CO, elemental carbon (EC), and organic carbon (OC)) to reproduce their observed ambient concentrations, followed by SO₂ to reproduce the concentration of SO₄^2-, which was examined to have the least uncertainty based on the abundance of observed NH₃, and finally NO and NH₃ for NO₃^-, and NH₄⁺. This improved estimation is compared to regional inventories for Asia and suggests more than an order of magnitude increase in anthropogenic emissions in UB. Using the improved emission inventory, we were able to successfully reproduce independent observation data on PM_2.5 concentrations in UB in December 2021 from the U.S. Embassy. During the campaign period, we found more than 50% of the SO₄^2-, NO₃^-, and NH₄⁺ increased in UB due to the improvement could travel to Beijing, China (BJ), and about 20% of the SO₄^2- could travel to Noto, Japan (NT), more than 3000 km away. Also, the anthropogenic emissions in UB can effectively increase OC, NO₃^-, and NH₄⁺ concentrations in BJ when Gobi dust storms occur.

Keywords: CEDS; FRIEND project; GEOS-Chem; KORUS; REAS; Ulaanbaatar.