AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Aqueous Sources of Secondary Organic Aerosol in the Southeast Atmosphere Study (SAS)
V. FAYE MCNEILL, Jason Surratt, Annmarie Carlton, Havala Pye, Columbia University
Abstract Number: 465 Working Group: Air Quality and Climate in the Southeast US: Insights from Recent Measurement Campaigns
Abstract The reactive uptake of water-soluble volatile organic compounds (VOCs) by wet aerosols or cloud droplets, also known as aqueous SOA (aqSOA) formation, is likely an important source of aerosol organic material. Aqueous SOA formation is believed to be particularly important in the Southeastern United States, where aerosol sulfate concentrations, humidity, and volatile organic compound (VOC) concentrations tend to be high during photochemically active periods. Quantifying the relative contribution of aqSOA in the SE USA is one of the goals of the Southeast Atmosphere Study (SAS).
We will present the results of modeling studies examining cloudwater and aerosol water SOA formation pathways simultaneously in the context of SAS. The simulation outputs are compared to aqSOA tracer data which was collected at three ground sites, along with other observations of aerosol composition and abundance. aqSOA formation at ground sites is modeled using the detailed photochemical box model for aqueous aerosol formation, GAMMA (McNeill et al., ES&T 2012), taking data from SAS observations and CMAQ as inputs. The regional contribution of aqSOA to particle loadings will be evaluated using CMAQ with cloudwater glyoxal chemistry (Carlton et al. , ES&T 2008) coupled with simpleGAMMA (a reduced version of GAMMA), and CMAQ with the recent isoprene epoxide chemistry module of Pye et al. (ES&T 2013).