Impact of Environmental Conditions on Secondary Organic Aerosol Production from Photosensitized Humic Acid

• DOI: 10.1021/acs.est.9b07485
• Publication Date: 2020-04-03T20:59:36Z
• Authors: Alison M. Fankhauser; Mary Bourque; John Almazan; Daniela Marin; Lydia Fernandez; Remy Hutheesing; Nahin Ferdousi; William G. Tsui; V. Faye McNeill
• Keywords: Primary (astronomy)

Recent studies have shown the potential of photosensitizer chemistry humic acid, as a proxy for humic-like substances in atmospheric aerosols, to contribute secondary organic aerosol mass. The mechanism requires particle-phase acid absorb solar radiation and become photoexcited, then directly or indirectly oxidize volatile compound (VOC), resulting lower volatility product particle phase. We performed experiments photochemical chamber, with aerosol-phase limonene VOC. In presence 26 ppb under atmospherically relevant UV–visible irradiation levels, there is no significant change diameter. Calculations show that SOA production via this pathway highly sensitive VOC precursor concentrations. Under assumption HULIS equally less reactive than used these experiments, results suggest ambient aerosols unlikely be source