Increasing Isoprene Epoxydiol-to-Inorganic Sulfate Aerosol Ratio Results in Extensive Conversion of Inorganic Sulfate to Organosulfur Forms: Implications for Aerosol Physicochemical Properties
Acid-driven multiphase chemistry of isoprene epoxydiols (IEPOX), key isoprene oxidation products, with
inorganic sulfate aerosol yields substantial amounts of secondary organic aerosol (SOA) through the formation oforganosulfur compounds. The extent and implications of inorganic-to-organic sulfate conversion, however, are un- known. In this article, we demonstrate that extensive consumption of inorganic sulfate occurs, which increases with the IEPOX-to-inorganic sulfate concentration ratio
(IEPOX/Sulfinorg), as determined by laboratory measurements. Characterization of the total sulfur aerosol observed at Look Rock, Tennessee, from 2007 to 2016 shows that organosulfur mass fractions will likely continue to increase with ongoing declines in anthropogenic Sulfinorg, consistent with our laboratory findings. We further demonstrate that organosulfur compounds greatly modify critical aerosol properties, such as acidity, morphology, viscosity, and phase state. These new mechanistic insights demonstrate that changes in SO2 emissions, especially in isoprene-dominated environments, will significantly alter biogenic SOA physicochemical properties. Consequently, IEPOX/Sulfinorg will play an important role in understanding the historical climate and determining future impacts of biogenic SOA on the global climate and air quality.
Matthieu Riva, Yuzhi Chen,a, Yue Zhang,a,b Ziying Lei, Nicole E. Olson, Hallie C. Boyer, Shweta Narayan, Lindsay D. Yee, Hilary S. Green, Tianqu Cui,a Zhenfa Zhang, Karsten Baumann, Mike Fort,g Eric Edgerton, Sri H. Budisulistiorini, Caitlin A. Rose, Igor O. Ribeiro, Rafael L. e Oliveira, Erickson O. dos Santos, Cristine M. D. Machado, Sophie Szopa,j Yue Zhao, Eliane G. Alves, Suzane S. de Sa, Weiwei Hu, Eladio M. Knipping, Stephanie L. Shaw, Sergio Duvoisin Junior, Rodrigo A. F. de Souza, Brett B. Palm, Jose-Luis Jimenez,
Marianne Glasius, Allen H. Goldstein, Havala O. T. Pye, Avram Gold,a Barbara J. Turpin, William Vizuete, Scot T. Martin, Joel A. Thornton, Cari S. Dutcher, Andrew P. Ault, and Jason D. Surratt