[PAST EVENT] Physics Colloquium
Nathan Kidwell, William & Mary, Title of Talk: Lights, Camera, Action! Taking a Molecular-Level Snapshot of Atmospheric Photochemistry
Abstract: The Earth's atmosphere has experienced an unprecedented transformation in its chemical composition due to anthropogenic and biogenic emissions. This presents a challenge to the scientific community seeking to provide a molecular-scale understanding of the impact on the atmosphere. The development of accurate models to predict atmospheric reactions relies on experimental data encompassing the spectroscopy, dynamics, and kinetics of photoinitiated and bimolecular chemical events. I will discuss recent results from our laboratory on the photodissociation dynamics of atmospherically-relevant molecules that serve as temporary reservoirs of reactive species, which may further react with ambient compounds or participate in new particle formation. In particular, we utilize laser spectroscopy and advance particle imaging methods accompanied by high-level theory and reaction modeling to address atmospheric chemistry problems. Our experimental measurements provide important benchmarks for theoretical studies in order to determine detailed mechanisms for the first few nucleation events towards aerosol formation, which are necessary for predictive atmospheric chemistry modeling.