You are here:
THE ROLE OF OXIDATION OF BVOCS IN SOA PRODUCTION IN THE SOUTHEASTERN U.S.
Impact/Purpose:
We are proposing to conduct a key set of measurements of ambient concentrations of a wide array of atmospheric volatile organic compounds and photoproducts as part of the Southern Oxidant & Aerosol Study (SOAS) during the summer of 2013. The overarching goal is to enable better understanding of interactions between the biosphere and the anthroposphere in the production of atmospheric organic nitrates and secondary organic aerosols. These interactions will be further investigated using 1-D and CMAQ models, as well as off-line aerosol chemistry measurements.
Description:
We plan to test three key hypotheses: 1) organic nitrates are important aerosol precursors in the southeastern U.S.; 2) NO3 - BVOC reactions are an important organic nitrate production route, even for daytime; and 3) the relative contributions of anthropogenic and biogenic SOA production in the southeastern U.S. can be determined, to a first order, using speciated VOC data, measured/calculated oxidant concentrations, and laboratory rate constants and aerosol yields. The relative importance of individual VOCs and oxidants will be tested using our 1-D modeling approach, and reaction of NO3 with isoprene will be added to CMAQ as a SOA production pathway to evaluate its significance in the southeastern U.S. This effort will also support a range of specific questions posed by SOAS, including uncertainties in the distribution and drivers of VOC and BVOC emissions, the roles of specific individual VOCs and BVOCs in SOA production, and the role of organic nitrates and nighttime chemistry in the production of SOA. Pursuit of these goals will yield a better understanding of the interactions between the atmosphere and the biosphere. This will allow more effective strategies for management of pollution sources and natural areas that ensure protection of environmental and human health. We also aim to provide undergraduate students with meaningful experiences conducting hypothesis-driven field research.