Abstract:

Rising demands for energy and food production are altering the global nitrogen cycle at a record pace with unintended consequences for human health, ecosystem health, and climate. Reduced nitrogen compounds such as ammonia and amines constitute a major component of reactive nitrogen and, as the major alkaline species in the atmosphere, play an important role in the formation and growth of aerosol. Despite the importance of these gases to atmospheric and biogeochemistry, our understanding of their sources, sinks, and transformations remain poorly constrained. My group has advanced the use of chemical ionization mass spectrometry to characterize and constrain the chemistry of reduced nitrogen species. In this seminar, I will present both ambient measurements and laboratory results that expand our understanding of reduced nitrogen chemistry. The ambient results provide insight into the sources and oxidation products of amines in an agricultural setting. The laboratory measurements explore how aging of biogenic secondary organic aerosol by ammonia and ammonium alters aerosol composition and volatility. Together, these results provide insights into the gas- and condensed-phase atmospheric chemistry of reduced nitrogen compounds with implications for our understanding of air quality, climate, and the nitrogen cycle.