Environmental, Water Resources, and Coastal Engineering Seminar Series

In-person: Fitts-Woolard Hall 2331

Virtual seminar link: https://ncsu.zoom.us/j/92010077484?pwd=aFlOQmp5dHVKMmNnK0w0Qi9hREJWdz09

Abstract: Reactive organic carbon is emitted to the atmosphere as a relatively small number of molecules and compound classes, which undergo sunlight-drive oxidation processes to form a dynamic and complex mixture of thousands of compounds. The physical and chemical transformations of each organic compound is dictated by physicochemical properties that depend critically on the molecular structure of the molecule. However, little work has examined the prevalence of compounds that differ only in their molecular structure (i.e., isomers), or the extent to which ignoring structure degrades understanding of the sources, transformations, and fates of organic compounds in the atmosphere. This presentation will examine the prevalence of isomers in the atmosphere, where they come from, and the extent to which knowing their structures matters in understanding the atmosphere. Observations of biogenic organic carbon in central Virginia will be presented, with a focus on the dominant and variable role of isomers that are low in abundance by high in reactivity. The prevalence of isomers formed in the oxidation of these compounds will then be examined using a combination of novel instrumentation and chemical modeling. Finally, the physicochemical properties of isomers in these oxidation product mixtures will be compared to quantitatively understand differences in their atmospheric transformations. Together these approaches will provide insight into the role of structure in the competition between different atmospheric processes, and the consequent fate of a molecule.

Biography: Gabriel Isaacman-VanWertz is an Assistant Professor in the Department of Civil and Environmental Engineering at Virginia Tech. He completed
his PhD at the University of California, Berkeley, after which he spent two years as an NSF Postdoctoral Fellow at MIT. He is originally from the East Coast, growing up in Maryland and completing his undergraduate at Wesleyan University in Connecticut. He currently lives in Blacksburg, VA with his wife and two young kids, where he spends his free time trying to keep the deer and groundhogs from eating everything in their garden.