10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Insights into Aqueous-Phase Related Secondary Organic Aerosols via Mass Spectrometers in Winter in Urban Beijing

JIAN ZHAO, Conghui Xie, Weiqi Xu, Wei Du, Qingqing Wang, Wei Zhou, Pingqing Fu, Douglas Worsnop, Zifa Wang, Yele Sun, Institute of Atmospheric Physics, CAS

     Abstract Number: 1055
     Working Group: Aerosol Chemistry

Abstract
Haze pollution, characterized by high levels of fine particles (PM2.5, i.e. particulate matters with aerodynamic diameter less than 2.5 micrometers), had become a major concerning in megacities in China. Here, we deployed an HR-ToF-AMS with other collaborated on-line aerosol instruments including a SMPS, a CAPS extinction and an AE33 from 17 December to 30 December 2016 during the Air Pollution and Human Health (APHH)-Beijing winter campaign in an urban site. Overall, submicron aerosol species varied drastically with an average value of 126.65 (+96.22) μg m-3, which is much higher than the historic PM1 mass concentrations obtained in recent years, while the contribution of each species to NR-PM1 did not show large differences since 2010, indicating relatively stable sources of NR-PM1 during winter time in urban Beijing among these years. In addition, six OA components including three POA factors (CCOA, BBOA and COA) and three SOA factors (LO-OOA, aq-OOA and MO-OOA) were identified by PMF analysis. On average, CCOA contributed the most among POA to OA with 18.4% and LO-OOA dominated SOA with 31.3% (of OA). The aqueous phase related OOA (i.e. aq-OOA) was clearly identified during high RH period and correlated well with aerosol liquid water content and sulfate mass concentrations. Furthermore, aq-OOA together with a fog related factor (F-OA) and interstitial OA observed in Fresno, California fell into the same square region in triangle plot (f44 vs. f43), which might could define a specific region for aq-OOA in this plot. Finally, filter samples were off-line analyzed by FIGAERO-I-CIMS for aqueous phase related tracers to investigate its properties and the potential processes.