Abstract: Molecular characterization of Atmospheric Organic Aerosol (OA) using advanced methods of high-resolution mass spectrometry provides essential insights into the composition, properties, and behavior of chemical constituents, contributing to a more comprehensive understanding of its environmental impacts. These studies have enabled the identification and quantification of specific components of OA, including light-absorbing chromophores, such as phenolic, quinone and nitroaromatic compounds, N-heteroatom compounds, polycyclic aromatic hydrocarbons, etc. Through comprehensive understanding the chemical composition of OA, we can now assess its sources and atmospheric transformations. Recent investigations have also broadened their scope to explore the partitioning of OA species between the particle and gas phases. These measurements yield valuable data on particle-to-gas transition enthalpies and apparent volatilities of individual OA species, crucial for constructing volatility basis sets (VBS). The resulting VBS distributions enable an assessment of equilibrium gas-particle partitioning across various atmospheric conditions of organic mass loadings, temperatures, and pressures relevant to Earth’s atmosphere. Furthermore, novel parameterization models leverage chemical characterization and volatility datasets to evaluate the viscoelastic properties of OA. This comprehensive molecular understanding of OA chemistry is essential for predicting their ability to undergo chemical reactions, partition between gas and particle phases, and impact atmospheric environment and related processes, such as radiative forcing of climate and cloud formation. This presentation will provide an overview of recent advancements in this field and outline future directions for continued research.
Bio: Professor Alexander Laskin is a Professor in the Department of Chemistry with a courtesy appointment in the Department of Earth Atmospheric and Planetary Sciences at Purdue University in West Lafayette, Indiana. He received his M.Sc. in Mechanical Engineering from St. Petersburg Polytechnical Institute, Russia, and his Ph.D. in Physical Chemistry from The Hebrew University of Jerusalem, Israel. Dr. Laskin’s group advances aerosol and multiphase environmental chemistry with discoveries that reframe sources, composition, and climate/health impacts.
He is actively involved in the scientific community, serving as a Co-editor of the Atmospheric Chemistry and Physics journal since 2013, and as a member of the Editorial Board for Aerosol Science and Technology and Scientific Reports. His honors include the NASA Honor Award (FIREX-AQ Group Achievement) in 2019 and being named a W.R. Willey Research Fellow of the Environmental Molecular Sciences Laboratory at PNNL in 2018.