Laboratory Studies of Core Lightning Chemistry Products and Modeling of Corona Discharge Initiation

Lightning produces highly reactive chemical compounds that influence the atmosphere’s ability to remove pollutants. This project uses laboratory experiments and model comparisons to improve understanding of lightning-driven atmospheric chemistry. The project will improve understanding of the atmosphere’s oxidative capacity and predictions of associated pollutant removal. Extreme heat, electrical currents, and radiation emitted by lightning initiates the direct production of large amounts of hydroxyl radical (OH) and larger amounts of nitric oxide (NO). A substantial amount of nitrous acid (HONO) may also be generated. This effort consists of 5 tasks: (1) measurement of the temporal evolution of the OH distribution in a generated spark core and corona sheath using a laboratory setup; (2) measurement of the dependence of spark-generated HONO on environmental conditions; (3) determining the composition of ultrafine particles generated by spark discharge; (4) modeling the potential for corona to form on aircraft inlets (such as in the NSF-supported DC3 campaign) and generate interferences; and (5) relate the measurements of corona UV radiation made during field studies to OH production. Undergraduate students will participate in the research and project findings will be shared through scientific presentations to middle and high school students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.