AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Sources of Organic Aerosol during Severe Haze Episodes in Beijing
CAIQING YAN, Mei Zheng, Orjan Gustafsson, Carme Bosch, August Andersson, Xiaoying Li, Huaiyu Fu, Peking University
Abstract Number: 389 Working Group: Haze in China: Sources, Formation Mechanisms, and Current Challenges
Abstract Organic aerosol (OA), a substantial fraction of fine particles, plays an important role on human health and climate. Due to its abundance in atmospheric aerosol and its optical properties, significantly high concentration OA in China could contribute to air quality deterioration, health impact, and visibility reduction. Severe haze episodes occurred frequently in the past few years in Beijing, China. The objective of this study is to better understand sources of OA and its evolution during haze episodes. Dual carbon isotope (radiocarbon isotope $^(14)C and stable carbon isotope $^(13)C) measurements were performed on total organic carbon (OC) and water-soluble organic carbon (WSOC) in fine particles collected in summer and winter haze episodes of 2013 in Beijing. Thus, contributions from biomass/biogenic and fossil sources to different sub-fractions of OA (WSOC and water-insoluble organic carbon, WIOC) can be determined. Our results showed that fossil source contributed more than biomass/biogenic source to WIOC (~75%) as well as WSOC (~56%) during winter, while biomass/biogenic source contributed more to WSOC (~65%) and WIOC (~68%) in summer. With the dual carbon isotope signatures (△$^(14)C and δ$^(13)C), fuel types of biomass/biogenic and fossil sources as well as atmospheric processing of organic aerosol during haze episodes were investigated. To further explore the evolution of OA during haze episodes, high-time resolution single particle aerosol mass spectrometry (SPAMS) was also applied to examine variation of its sources as well as its size distributions. Results from the offline and online measurements will be also compared and integrated to characterize OA during summer and winter haze episodes.
*Corresponding author: Mei Zheng, mzheng@pku.edu.cn