Abstract View
Temporal Trends in the Emissions and Impacts of Monoterpenes in the Southeastern U.S. Demonstrate the Dominant Influence of Low-Concentration, Highly Reactive Compounds
DEBORAH MCGLYNN, Graham Frazier, Laura E. R. Barry, Koong Yi, Xi Yang, Manuel Lerdau, Sally Pusede, Gabriel Isaacman-VanWertz, Virginia Tech
Abstract Number: 70
Working Group: Remote and Regional Atmospheric Aerosol
Abstract
More than 10,000 hours of chemically speciated biogenic volatile organic compound (BVOC) data have been collected at the Virginia Forest Research Lab, in Fluvanna County, Virginia. Data were collected using gas chromatography – flame ionization detection that was automated to take hourly air samples from within the forest canopy. With these data, changes in the diurnal profiles of individually resolved monoterpene species are identified over the course of the year. While all monoterpene species exhibit peak concentrations in the nighttime and early morning hours in the fall, winter, and spring, a small number of low-concentration species shift to a daytime and early evening peak in the summer months. Some of the species that exhibit this shift are highly reactive, so, while this shift does not substantially impact the temporal trends in total monoterpenes, it has significant implications for atmospheric reactivity in the summer months. In this presentation, we use co-located ecological measurements of sap flow, leaf area index (LAI), and PhenoCam data alongside positive matrix factorization to understand the importance of daytime peaks in low-concentration monoterpenes on regional reactivity and aerosol formation.