10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Aqueous Formation of Low Volatile Organic Compounds using Coupled CMAQ-MCM-CAPRAM
QI YING, Jingyi Li, Jianlin Hu, Texas A&M University
Abstract Number: 1622 Working Group: Aerosol Modeling
Abstract Many of the secondary organic aerosol modules in current air quality models assume equilibrium partitioning of semi-volatile organic compounds with an absorbing organic phase. However, water soluble organics have been identified to account for a significant fraction of ambient organic aerosol mass, suggesting that the aqueous phase on aerosols and fog/cloud droplets may have significant contributions to secondary organic aerosol (SOA). In a previous study, the semi-explicit Master Chemical Mechanism (MCM) was incorporated into the Community Multiscale Air Quality (CMAQ) model (i.e. the CMAQ-MCM-SOA model) to study regional SOA formation by gas-to-organic phase partitioning of thousands of semi-volatile organic compounds (VOCs). In this study, a detailed chemical aqueous phase radical mechanism based on CAPRAM 3.0i was coupled with the CMAQ-MCM to predict the regional formation of low volatile oxygenated VOCs (OVOCs) in aerosol and cloud water. The CAPRAM mechanism treats detailed oxidation pathways of 34 oxygenated organic species of two to six carbons (including 5 alcohols, 10 carbonyl compounds, 13 mono- and dicarboxylic acids, 1 ester, 4 polyfunctional compounds and 1 heterocyclic compound) with ~400 model species and ~ 830 reactions. 3D regional simulations will be carried out for the TexAQS 2006 to evaluate the importance of these low volatile OVOCs in SOA predictions in southeast Texas.