AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Light-absorbing Properties of Brown Carbon Emitted from Chinese Residential Sources
CAIQING YAN, Mei Zheng, Xiaoying Li, Xiaoshuang Guo, Peking University
Abstract Number: 717 Working Group: Haze in China: Sources, Formation Mechanisms, and Current Challenges
Abstract Atmospheric brown carbon (BrC) has been widely observed in emissions of biomass/biofuel burning and fossil fuel combustion sources. Inclusion of light absorption contributions of BrC emitted from different sources in climate and chemical transport models could improve simulations of aerosol light absorption and modeling their climate effects. Knowledge of optical properties of source specific BrC are still limited and essential. Previous studies indicated that light-absorbing properties of organic carbon might be dependent on factors such as fuel types and combustion conditions. However, BrC studies are quite limited in China, where sources of fine particulate matter and organic matter are extremely complicated. To investigate light absorption properties of BrC from different sources, identify the potential key sources of brown carbon in China, and determine influencing factors of light absorptivity, source testing in laboratory for simulating residential source emission of fine particulate matter were conducted. Source samples were collected using offline dilution chamber connected with filter samplers and online Aethalometer (AE31). Light absorptivity of brown carbon emitted from residential biomass (crop straw and wood) burning and coal combustion were investigated and compared. Influencing factors of source specific light-absorbing properties of brown carbon will be further discussed from the aspects of fuel types, combustion conditions (smoldering or flaming), as well as co-emitted chemical components. Our results indicated that coal combustion source emission could be an important contributor to atmospheric BrC in China besides biomass burning emission, especially in winter. Light-absorbing properties of biomass burning and coal combustion source emitted BrC exhibited strong dependence on fuel types, respectively, as well as burning state.
*Corresponding author: Mei Zheng, mzheng@pku.edu.cn