[PAOCQ] Kelvin Bates (CU Boulder)

“Changing sources of atmospheric organics: impacts from local to global scales”

Volatile organic compounds (VOCs) emitted to the atmosphere from both natural and anthropogenic sources contribute to the formation of both ozone and particulate matter, the two leading causes of air-pollution-related morbidity and mortality. Shifting emission patterns have reduced the magnitude of anthropogenic fuel-related VOCs, increasing the relative importance of “novel” (i.e., previously underappreciated) sources. These novel VOC emissions include oxygenated organics from personal care products and cooking activities, as well as terpenoids from both anthropogenic and biogenic sources. Such compounds are often poorly represented in air quality and climate models, making it difficult to diagnose their individual effects on atmospheric outcomes of interest. Our research combines field observations, targeted laboratory experiments, and atmospheric modeling to determine the chemistry and the impacts of these compounds. In airborne mass spectrometric deployments, we identify gas-phase tracers of individual emission sources in major US cities. After quantifying their emissions, we replicate the chemistry of VOCs from individual sources in environmental chamber experiments, which enables us to diagnose the atmospheric fates of compounds from each source. Finally, we incorporate the chemistry elucidated by our experiments into GEOS-Chem, a global atmospheric chemistry model, and show that organic emissions from cooking, personal care products, and urban vegetation are all major contributors to modern US urban air pollution. Moreover, these sources are sufficiently strong and widespread to change atmospheric composition at regional to global scales, with important implications for climate-chemistry feedbacks.

PAOC Colloquium —

Interdisciplinary seminar series that brings together the whole PAOC (Program in Atmospheres, Oceans, and Climate) community. Seminar topics include all research concerning the physics, chemistry, and biology of the atmospheres, oceans and climate, as well as talks about societal impacts of climatic processes.

Contact: paoc-colloquium-comm@mit.edu