Chemical Characterization of Ambient Aerosol during the 2022 ACROSS Campaign at the Urban Paris Site
Sydney Riley, DREW PRONOVOST, Lelia Hawkins, Ludovico Di Antonio, Astrid Beauville, Antonin Bergé, Mathieu Cazaunau, Pascale Chelin, Servanne Chevaillier, Anaïs Féron, Frank Maisonneuve, Christopher Cantrell, Vincent Michoud, Claudia Di Biago, Aline Gratien,
Harvey Mudd College Abstract Number: 610
Working Group: Urban Aerosols
AbstractThe Atmospheric Chemistry of the Suburban Forest (ACROSS) campaign focused on atmospheric composition and transformation of interacting biogenic and anthropogenic emissions. The campaign spanned 13 June to 26 July 2022 at three sites: the urban University of Paris Rive Gauche (PRG), the remote forest Rambouillet, and an aircraft that sampled throughout the region. A large suite of instrumentation at each site provided a comprehensive perspective of 2022 summertime chemistry. This poster will focus on aerosol composition and key gas phase components measured at the PRG site. The ACROSS campaign included periods of excessive heat and cooler periods, with weather more typical of European summer. During hot periods, winds were more likely to transport urban air masses toward the forest. An Aerodyne time-of-flight aerosol chemical speciation monitor (ToF-ACSM) was used to study non-refractory PM
1 chemical composition. Gases were measured with a chemiluminescence NO
x analyzer, an UV photometric ozone analyzer, a UV fluorescence SO
2 analyzer, and an laser infrared spectrometry ammonia analyzer.
The majority of non-refractory PM
1 was organic (0.60 ± 0.14) and sulfate (0.27 ± 0.10). The aerosol appeared to be highly acidic (57.0 ± 0.2% of predicted ammonium). Factor analysis indicates that organic mass was primarily oxygenated, which increased during heat waves. The expected diurnal NO
x and O
3 anticorrelation was observed throughout the campaign. The average daily maximum O
3 was 57.7 ± 2.5 ppb, with peaks above 90 ppb during the early heat wave. NO levels were largely below NO
2 levels. The SO
2 concentration approached the detection limit, averaging of 1.5 ± 1 ppb. SO
2 was sometimes correlated with aerosol sulfate, but other times showed little correspondence.
Further analysis will seek to identify distinct sources of organic aerosol through factor analysis and connections to the OA factors and indicators of photochemistry.