Relative Importance of Primary Organic Aerosol Source Types across Spatiotemporal Scales in New York City
LIJIN ZHANG, Mitchell Rogers, Taekyu Joo, Tori Hass-Mitchell, Catelynn Soong, Havala Pye, Benjamin Murphy, Drew Gentner, Yale University
Abstract Number: 397
Working Group: Urban Aerosols
Abstract
Advanced aerosol measurements have been collected since summer 2022 as part of the ASCENT (Atmospheric Science and Chemistry mEasurement NeTwork) at the NYSDEC (New York State Department of Environmental Conservation) site in Queens, NYC, where the average PM2.5 concentrations are around 8 µg m-3 in recent years. The instruments employed include an Xact that measures trace metals, an Aethalometer measuring black and brown carbon, a Scanning Mobility Particle Sizer (SMPS) measuring aerosol size distribution, as well as an Aerosol Chemical Speciation Monitor (ACSM) that measures non-refractory aerosols, whose source types are examined using positive matrix factorization (PMF). Observations show the predominance of organic aerosols (OA) during summer months and increases in inorganic aerosol fractions during winter months. While OA is comprised of primary and secondary organic aerosol (POA, SOA), we examine the magnitude and dynamics of major POA source types, including cooking-related OA (COA), and hydrocarbon-like OA (HOA), across daily, weekly, and seasonal time scales, while considering variations in meteorology and transport. We compare the findings to model results, such as those from the Community Multiscale Air Quality (CMAQ). We also examine the relative influences of local, regional, and long-distance sources using meteorological data, modelling, and the network of NYSDEC sites measuring PM2.5 mass concentrations in the region. The source contributions of POA factors are interpreted along with gas-phase criteria pollutants, such as carbon monoxide (CO) and nitrogen oxides (NOx), then compared to emissions inventories, while considering spatiotemporal variations in emissions, which serves to advance the understanding of their roles in ambient PM2.5 in the New York Metropolitan Area.