Abstract View
Aqueous-phase Secondary Organic Aerosol Formation: Laboratory Simulations and Field Observations in China
XINLEI GE, Zhaolian Ye, Nanjing University of Information Science & Technology
Abstract Number: 5
Working Group: Aerosol Chemistry
Abstract
Secondary organic aerosol formation in atmospheric aqueous phases (cloud/fog droplets or wet aerosols) (aqSOA) has been recognized as a possible and significant pathway that can help reconcile the discrepancies between observed and modelled PM properties. However, the efficient precursors, formation mechanisms, mass yields and properties of aqSOA are still less clear. In this presentation, we will present both laboratory experimental results and field observations regarding aqSOA. First, we studied the aqSOA formation originated from a series of biomass burning emitted organic compounds mimicking the atmospheric cloudy/foggy conditions. Reaction rates, formation yields, light absorption properties as well as the chemical compositions of the aqSOA formed from oxidation by various oxidants were investigated. Secondly, we investigated aqueous oxidation of a few species that belong to the intermediate volatility organic compounds (IVOCs), and demonstrate aqueous processing of IVOC can be a significant source of SOA as well as light-absorbing organics (Brown Carbon, BrC). At last, we analyzed the measurement data obtained by Aerodyne high resolution aerosol mass spectrometers in Chinese megacities including Beijing and Nanjing, and explored the relationships of different organic aerosol factors resolved by positive matrix factorization with the relative humidity and photochemical activities, etc. Field evidence of aqSOA, its chemical characteristics, controlling factors, etc., will be discussed.