AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Investigating Spatial Variation in Organic Aerosol Concentrations and Source Impact in a Metropolitan Area by Mobile Sampling with Aerodyne Aerosol Mass Spectrometer
PEISHI GU, Zhongju Li, Qing Ye, Ellis Shipley Robinson, Jiqiao Shi, Rishabh Shah, Naomi Zimmerman, Joshua Apte, Allen Robinson, Albert A. Presto, Carnegie Mellon University
Abstract Number: 300 Working Group: Urban Aerosols
Abstract Sharp spatial gradients of particulate matter (PM) and organic aerosol (OA) concentrations exist in intra-city scales (100 m) due to intense emission from sources like traffic and cooking activities. Typical stationary deployment of samplers is not capable of resolving these spatial gradients. By performing in motion sampling using Aerodyne Aerosol Mass Spectrometer (AMS) deployed on a mobile sampling platform, we are able to investigate the spatial variation of PM concentration and composition within a city. From August 2016 to June 2017, mobile measurement has been conducted with this platform in the Pittsburgh metro area. The sampling domain covers various types of land-use, including urban/suburban, high/low traffic area and high/low restaurant density area. Measurement took place during morning rush hour, daytime, afternoon rush hour and evening/dinner time. The data are corrected for day-by-day shift of regional background PM concentration, and an average concentration values were calculated on a 100 m x 100 m grid systems. Positive Matrix Factorization (PMF) results from our mobile data yield factors that are consistent with previous literature. Geospatial analysis shows that OA concentrations from traffic and cooking activities have very different spatial patterns over different communities in Pittsburgh, and in general, cooking creates higher localized OA concentrations than traffic. In some communities with high restaurant density, there is a factor of four difference on average in OA concentration over spatial scale of 200 meter. Cooking activities are often spatially correlated with population, and some restaurant-dense area are directly located inside populous residential area so nearby residents can be exposed to above average OA concentration. Thus findings from this study could lead to meaningful discussion in policy making and regulation for air quality related sectors.