Measurement and Interpretation of OH, HO2, and OH Reactivity during BEARPEX 09

The Biosphere Effects on Aerosol and Photochemistry Experiment (BEARPEX-09) field study will be held in summer 2009 at Blodgett Forest in the Sierra Nevada Mountains in California to investigate the impact of gases emitted by forests on atmospheric chemistry and aerosol formation. This award will support measurements of hydroxyl radical (OH), OH reactivity, hydroperoxyl radical (HO2), naphthalene, nitric oxide (NO), ozone, UV flux, temperature, and wind at different heights below, in, and above the canopy on a movable lift. Research questions include: How do OH and HO2 vary with season and can models capture the observed differences? Are there temperature-dependent disagreements between measured and calculated OH reactivity and, if so, do they indicate biogenic emissions that are not being measured? How do models with and without isoprene chemistry compare? Are height profiles of OH, HO2, and OH reactivity similar to those measured during BEARPEX-07 and what is the nature of nighttime profiles? Which models best simulate OH and HO2 in this forested environment?

Information from this study will be used to test and improve the chemical mechanisms in air quality models. Laboratory demonstrations of atmospheric chemistry in forests will be developed for an exhibition at Penn State. Broader impacts also include education of undergraduates, graduate students, and post-doctoral associates through this project. Three to four high school students from under-represented groups will be sponsored each year in Penn State's six-week Summer Experience in Earth and Mineral Sciences (SEEMS). They will test different hypotheses using data from BEARPEX. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).