Abstract:
Urban volatile organic compounds (VOCs) have many emission sources, and the composition of VOCs in urban air has changed as emissions from tailpipes have decreased and the use of volatile chemical products has risen. VOCs are precursors to ozone and secondary organic aerosols (SOA), and understanding the complexity of urban VOC emissions and fates requires field measurements and collaborative campaigns.
In this presentation, I will show recent work measuring urban VOCs using two mass spectrometry techniques. To find significant urban emission sources, we conducted mobile measurements with a Vocus PTR-ToF-MS around Austin, Texas. The VOC mobile data was overlaid with building type information using geospatial databases from OpenStreetMap and Austin’s Land Use Map to “fingerprint” VOC enhancements around different emission sources. We confirmed the presence of aldehydes and acids probably related to cooking emissions all over the study domain. To investigate the reactivity of VOC concentrations in an urban environment, we conducted rooftop measurements in Manhattan, New York City as part of the AEROMMA research campaign. VOCs were measured by gas chromatography and were compared to another NYC site and a suburban/rural site downwind which showed differences in relative OH reactivity and SOA formation potential.