Volatile organic compounds emitted from western U.S. wildfire smoke

Wildfire smoke is a significant source of atmospheric volatile organic compounds (VOCs). We present an overview of on-going analyses of VOC observations measured on-board the NSF/NCAR C-130 aircraft during the Western wildfire Experiment for Cloud chemistry, Aerosol absorption and Nitrogen (WE-CAN) field campaign in 2018 summer. We determine the emission factors and speciation profiles of VOCs from wildfire smoke in the western U.S. These include more than 200 different organic species, many of which are rarely measured and reported. Field determined emission factors are compared to laboratory results and commonly used values in models. We report the fast formation of formic acid and acetic acid in fresh smoke with a physical age of up to 6 hours since fire sources, which cannot be explained in current models. We also examine furans-compounds' emissions from wildfires and determine their role in ozone production. Lastly, we will discuss preliminary results of evaluating existing biomass burning emission inventories for VOCs in the western U.S. with the WE-CAN data set.