Distinctions in source regions and formation mechanisms of secondary aerosol in Beijing from summer to winter

Jing Duan, Ru Jin Huang, Chunshui Lin, Wenting Dai, Meng Wang, Yifang Gu, Ying Wang, Haobin Zhong, Yan Zheng, Haiyan Ni, Uli Dusek, Yang Chen, Yongjie Li, Qi Chen, Douglas R. Worsnop, Colin D. O'Dowd, Junji Cao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

44 Citations (Scopus)

Abstract

To investigate the sources and evolution of haze pollution in different seasons, long-term (from 15 August to 4 December 2015) variations in chemical composition of PM<span classCombining double low line"inline-formula were characterized in Beijing, China. Positive matrix factorization (PMF) analysis with a multi-linear engine (ME-2) resolved three primary and two secondary organic aerosol (OA) sources, including hydrocarbon-like OA (HOA), cooking OA (COA), coal combustion OA (CCOA), local secondary OA (LSOA) and regional SOA (RSOA). The sulfate source region analysis implies that sulfate was mainly transported at a large regional scale in late summer, while local and/or nearby sulfate formation may be more important in winter. Meanwhile, distinctly different correlations between sulfate and RSOA or LSOA (i.e., better correlation with RSOA in late summer, similar correlations with RSOA and LSOA in autumn, and close correlation with LSOA in early winter) confirmed the regional characteristic of RSOA and local property of LSOA. Secondary aerosol species including secondary inorganic aerosol (SIA - sulfate, nitrate, and ammonium) and SOA (LSOA and RSOA) dominated PM<span classCombining double low line"inline-formula during all three seasons. In particular, SOA contributed 46% to total PM<span classCombining double low line inline-formula (with 31% as RSOA) in late summer, whereas SIA contributed 41% and 45% to total PM<span classCombining double low line inline-formula in autumn and early winter, respectively. Enhanced contributions of secondary species (66%-76% of PM<span classCombining double low line inline-formula) were also observed in pollution episodes during all three seasons, further emphasizing the importance of secondary formation processes in haze pollution in Beijing. Combining chemical composition and meteorological data, our analyses suggest that both photochemical oxidation and aqueous-phase processing played important roles in SOA formation during all three seasons, while for sulfate formation, gas-phase photochemical oxidation was the major pathway in late summer, aqueous-phase reactions were more responsible during early winter and both processes had contributions during autumn.

Original languageEnglish
Pages (from-to)10319-10334
Number of pages16
JournalAtmospheric Chemistry and Physics
Volume19
Issue number15
DOIs
Publication statusPublished - 14 Aug 2019
Externally publishedYes

ASJC Scopus subject areas

  • Atmospheric Science

Fingerprint

Dive into the research topics of 'Distinctions in source regions and formation mechanisms of secondary aerosol in Beijing from summer to winter'. Together they form a unique fingerprint.

Cite this