Comparison of Summertime Aerosol- and Gas-Phase Measurements at Two Urban Atlanta Sites

ALISON FANKHAUSER, Ruizhe Liu, Asher Mouat, Aryiana Moore, Ann Dillner, Roya Bahreini, Armistead G. Russell, Jennifer Kaiser, Nga Lee Ng, Georgia Institute of Technology

     Abstract Number: 756
     Working Group: Aerosols Spanning Spatial Scales: Measurement Networks to Models and Satellites

Abstract
The southeastern United States has historically been a popular location to study atmospheric composition and air quality, in part due to complex interactions from strong biogenic and anthropogenic emissions. In particular, Atlanta is well-known for its heavy traffic, resulting in vehicular emissions, and also has a strong biogenic influence due to the dense tree canopy. Atlanta experiences exceedances of the National Ambient Air Quality Standards (NAAQS) due to high concentrations of fine particulate matter and ozone, especially during the summertime. To investigate the current state of air quality in Atlanta, Aerosol Chemical Speciation Monitors (ACSMs) were deployed to measure the composition of submicron, nonrefractory aerosols. Additionally, formaldehyde and NO_x analyzers collected concentrations of gaseous formaldehyde and nitrogen oxides, respectively. All measurements were simultaneously collected at two sites in the greater Atlanta area for several months during the summer of 2023. One site is on the Georgia Institute of Technology (GT) campus in midtown Atlanta. The other site, South DeKalb (SDK), is in a mixed commercial-residential area approximately 15 km east of downtown Atlanta. SDK is one of twelve sites comprising the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT). Preliminary analysis shows comparable time series for aerosol composition at both sites, with organic aerosol comprising >80% of non-refractory aerosol mass on average. We report trends and concentrations of aerosol species, formaldehyde, and nitrogen oxide between the two urban Atlanta sites, GT and SDK.