Qi Chen

Peking University

10am, 3 June　　报告时间：2015年6月3日上午10:00 

LAPC meeting room, 2nd floor

Abstract:

Organic aerosol (OA) is an important contributor to aerosol radiation and aerosol-cloud interactions. The budget and the properties of OA are poorly understood, causing large uncertainties in the estimates of aerosol radiative effects. The average elemental composition is one approach to simply describe OA chemistry. We synthesized a large data set including surface, aircraft, and laboratory observations of the atomic oxygen-to-carbon (O:C) and hydrogen-to-carbon (H:C) ratios of OA. We show that laboratory OA including both source and aged types explains some of the key differences in OA observed across different environments. Significant gaps however exist. Some pathways may bridge the gaps, but experiments under realistic ambient conditions are needed to constrain the relative importance of these pathways. A global model simulation for the elemental composition of OA is greatly improved by the addition of a laboratory-based oxidative-aging scheme. The revised simulations are best able to capture the observed variability of O:C in remote regions when the heterogeneous aging of secondary organic aerosol is introduced.