The cause of enhanced summertime aerosol optical thickness (AOT) values over the southeast US is an open question debated in the literature. Proposed explanations include seasonal patterns in aerosol liquid water (ALW), height of the planetary boundary layer and formation of biogenic secondary organic aerosol (SOA) during summer. Each explanation provides evidence that can explain the seasonal AOT anomaly, in part. Although geospatial patterns and seasonality in total particle organic mass at the surface are inconsistent with reported satellite AOT, aloft formation of biogenic SOA and differences in particle chemical speciation remain plausible factors. In this work, we explore differences in organic mass speciation, specifically classification as organic carbon (OC) fractions 1, 2, 3 and 4 as reported at Interagency Monitoring of PROtected Visual Environments (IMPROVE) monitoring locations across the continental United States in the context of spatial and temporal differences in Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)-measured AOT. IMPROVE sites located in areas of strong summertime enhancement in CALIPSO AOT demonstrate statistically significant (p&lt;0.05) differences in summer/winter “OC2” and “OC3” fractional contribution to total organic mass. Locations outside the strongest summertime enhancement, show smaller differences in organic fractionation. The exact chemical composition of individual species or functional group responsible for contribution to mass in these OC categories is a topic for future study. <br/>

Exploring spatial differences in satellite aerosol optical thickness as a function speciated organic particle mass

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.