Measurement report: Variability in the composition of biogenic volatile organic compounds in a Southeastern US forest and their role in atmospheric reactivity

Abstract. Despite the significant contribution of biogenic volatile organic compounds (BVOCs) to aerosol formation and ozone production loss, there are few long-term, year-round, ongoing measurements their volume mixing ratios quantification impacts on atmospheric reactivity. To address this gap, we present 1 year hourly chemically resolved BVOCs between 15 September 2019 2020, collected at a research tower in Central Virginia mixed forest representative ecosystems Southeastern US. Mixing isoprene, isoprene oxidation products, monoterpenes, sesquiterpenes described examined for impact hydroxy radical (OH), ozone, nitrate range from negligible winter typical summertime 24 h averages 4–6 ppb, while monoterpenes have more stable tenths part per billion up ?2 ppb year-round. Sesquiterpenes typically observed <10 ppt, but represents lower bound abundance. In growing season, dominates OH reactivity is less important Monoterpenes most throughout outside season. better understand compound class OH, reactivity, role individual examined. dominant ?-pinene total monoterpene mass, average reaction rate mixture with oxidants 25 % 30 faster than due reactive abundant compounds. A majority comes limonene (the low-mixing-ratio, high-reactivity isomer), highlighting importance both ratio structure assessing emissions.