Investigation of Reactive Nitrogen Chemistry in Smoke Plumes Emitted from Western Wildfires

Rising global temperatures are fueling an increase in the frequency and severity of wildfires in the Western United States. Warming, in conjunction with decades of fire suppression practices, has led to fuel buildups and the breakdown of natural ecosystems in our forested areas. As a result of abundant fuels, primed to burn, wildfires are impacting larger areas and releasing increasing amounts of smoke. This smoke has significant impacts on local and regional air quality, which impacts human health and plant tissues. Reactive Nitrogen species are of particular interest as they play crucial roles in photolysis driven chemistry and are precursors to several reservoir species involved in long distance transport. WE-CAN is investigating emissions and evolution of trace gases and particles in smoke plumes from wildfires in the western US using aircraft and ground platforms in July- September 2018. A dual Mist Chamber/ Ion chromatography system in a ground based mobile lab will be used to identify and quantify nitrous and nitric acid in smoke plumes as part of the WECAN campaign. Corresponding filters will be collected to investigate the ionic composition of smoke particulate matter. Diurnal cycles will be targeted along with aging plumes. This information will help illuminate the formation mechanisms for nitric and nitrous acids as well as particulate nitrate in smoke during both day and night. This information in turn will be used to better understand the effects of smoke plumes on the environment.