Transport and Chemistry of Forest Emissions

Jose D. Fuentes is Professor of Atmospheric Science at Penn State University, where he studies and teaches the processes governing exchanges of energy and gases between Earth’s surface and the lower atmosphere. His research examines how changes in atmospheric composition influence climate, air quality, and biosphere–atmosphere interactions. To address these questions, he combines field observations with numerical modeling. His field programs involve the deployment of instruments on towers, tethered balloons, drones, and research aircraft in environments ranging from the high Arctic to the Amazon rainforest, West Africa, Panama, the Republic of the Marshall Islands, and locations across Canada and the United States. Fuentes earned a B.Sc. in Meteorology from Millersville University and both his M.Sc. in Agricultural Meteorology and Ph.D. in Micrometeorology from University of Guelph. Before joining Penn State, he served as a research scientist at Environment Canada and later held faculty positions at the University of Virginia. Throughout his career, he has actively promoted the participation of underrepresented groups in science and engineering, including serving as chair of the congressionally mandated Committee on Equal Opportunities in Science and Engineering, which advises the National Science Foundation.

Abstract: Plants emit a wide range of reactive hydrocarbons that serve as precursors of atmospheric oxidants and secondary organic aerosols. This seminar will examine the processes governing the temporal and spatial variability of isoprene and monoterpene emissions from forests. Results from several field campaigns will be presented to illustrate the seasonal behavior of these compounds across contrasting environmental conditions. Large-eddy simulation (LES) results are used to quantify vertically resolved budgets of isoprene and monoterpenes within forest canopies, including the effects of emissions, turbulent transport, surface deposition, and chemical transformations. Simulations indicate that emissions and turbulent dispersion dominate the isoprene budget as these compounds are transported upward and out of the canopy. In contrast, under nitrogen oxide-limited conditions, in-canopy chemical reactions remove substantial fractions of locally emitted monoterpenes. In forests with co-located emissions of isoprene and monoterpenes, hydroxyl radical production from monoterpene ozonolysis can be comparable in magnitude to photochemically driven hydroxyl radical formation. The seminar will also highlight how regional atmospheric warming substantially alters the emissions, transport, and atmospheric chemistry of plant-emitted hydrocarbons.

Transport and Chemistry of Forest Emissions
Jose D Fuentes
Professor of Atmospheric Science
Penn State University