Wildfire Impacts on Air Quality and Nighttime Brown Carbon Formation

University Of Montana, Missoula MT

Investigators

Abstract

This project is part of a larger field campaign, the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption and Nitrogen (WE-CAN), designed to characterize the emissions and evolution of western U.S. wildfire plumes. The larger field campaign consists of an aircraft study based out of Boise ID focused on scientific questions related to fixed nitrogen, absorbing aerosols, cloud activation and chemistry in wildfire plumes. This project is focused on ground-based measurements, in conjunction with the aircraft flights, to assess wildfire emissions of non-methane organic gases and to evaluate the optical properties of aerosols emitted by wildfires. Results from this effort will provide data and information for more accurately modeling biomass burning emissions to the atmosphere and for potentially reducing exposures to harmful pollutants that result from wildfires. This ground-based effort will be focused mainly on the nearby impacts of smoke chemistry in rural valleys near Boise both night and day. The project includes a 6-week ground-based field deployment during the summertime in 2018. Comprehensive air quality and atmospheric chemistry data will be collected for CO2, CO, NOx, NH3, VOCs, oxidants, PM, tracers, O3, NO3, IVOC, SVOC, black carbon (BC), and brown carbon (BrC). In addition to supplementing the aircraft data, this data will be used to calculate smoldering/flaming ratios and emission factors for nighttime open burning. There are also plans to explore, and quantify to the degree possible, the secondary source of BrC in nighttime aging of smoke. The data collected in this research will be used to improve the representation of nighttime smoke emissions, and especially that of BrC, for fire modeling. The NSF-funded WE-CAN field campaign is part of a more comprehensive team effort that is co-funded by NOAA (the NOAA project is named FIREX) and NASA (the NASA project is named FIREChem). The NSF campaign will take place in the summer of 2018 and the NOAA and NASA campaigns are planned for the summer of 2019.