American Association for Aerosol Research - Abstract Submission

AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA

Abstract View

Seasonal Characterization of Atmospheric Organic Aerosol at the Look Rock Site, Great Smoky Mountains National Park during 2013 Using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM)

SRI HAPSARI BUDISULISTIORINI, Xinxin Li, Philip Croteau, Manjula Canagaratna, Solomon Bairai, Roger Tanner, Stephanie Shaw, Eladio Knipping, John Jayne, Zhenfa Zhang, Avram Gold, Jason Surratt, University of North Carolina at Chapel Hill

Abstract Number: 292
Working Group: Air Quality and Climate in the Southeast US: Insights from Recent Measurement Campaigns

Abstract
Ambient PM$_1 at the Look Rock site, Great Smoky Mountains National Park was continuously measured using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during 2013. In addition, filter samples were collected using a Tisch PM$_(2.5) High-Volume Sampler for 1.5 months during the 2013 Southern Oxidant and Aerosol Study (SOAS). The organic mass spectra measured by the ACSM were analyzed with the Multi-linear Engine (ME-2) program using a-value equation for source apportionment. Two factors were identified during winter, spring, and fall: biomass burning organic aerosol (BBOA) and low-volatility oxygenated organic aerosol (LV-OOA). In summer, two factors were identified: isoprene epoxydiol-derived organic aerosol (IEPOX-OA) and LV-OOA. Identification of the IEPOX-OA factor in summer was confirmed by comparison with molecular tracers of IEPOX-derived secondary organic aerosol quantified by gas chromatography-electron ionization mass spectrometry (GC/EI-MS) and ultra-performance liquid chromatography-negative electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS). Contributions of each factor vary by season, with BBOA making the largest contribution in winter (~20%) and IEPOX-OA in summer (~50%). The LV-OOA remained constant (~80%) throughout, except in summer when the number decreases due to large IEPOX-OA contribution.