Paper No. 3
Presentation Time: 2:05 PM
SOURCE APPORTIONMENT OF URBAN AND RURAL REACTIVE NITROGEN EMISSIONS
Reactive nitrogen emissions, including NOx and NH3, are significant contributors to global water and air quality degradation. The atmospheric lifetimes of NOx and NH3 (and their oxidation products) allow transport of reactive N across large urban to rural regions. Thus, it is important to improve our understanding of the sources, transport, and fate of reactive N in the environment. This research lays the foundation for using isotopic data to apportion sources of reactive nitrogen deposition. Here, we present a comprehensive inventory of the isotopic composition of reactive N sources. To accomplish this reactive N source sampling locations included a concentrated animal feeding operation (CAFO), livestock barns, a conventionally managed cornfield, coal-fired power plants, a tallgrass prairie, and a highly trafficked tunnel. In particular, we address the largest NOx emission source in the U.S., fossil fuel combustion. We characterize the isotopic composition of NOx derived from both mobile and stationary source NOx. Further, we use transects radiating out from agricultural emission sources to demonstrate how reactive N sources can be traced across landscapes using isotopes.