10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
The Impact of Aerosol Uptake of Organic Nitrates on Simulated Surface Ozone in CAM-Chem
REBECCA SCHWANTES, Louisa Emmons, Simone Tilmes, John Orlando, Geoffrey Tyndall, National Center for Atmospheric Research
Abstract Number: 832 Working Group: Aerosol Chemistry
Abstract Many regions in the United States have poor air quality because of high levels of ozone. Ozone is intrinsically hard to simulate in global and regional models because the amount of ozone present is controlled by large non-linear sources and sinks. Recently, the chemical mechanism for isoprene and monoterpene oxidation has been updated in CAM-Chem (Community Atmosphere Model with chemistry), which is a component of the Community Earth System Model (CESM). Assumptions made in the model about the aerosol uptake of organic nitrates derived from isoprene and monoterpene oxidation significantly impact ozone formation. This study will comprehensively examine assumptions made in the aerosol uptake of various organic nitrates in the model including those derived from isoprene and monoterpene oxidation. Additionally, if necessary, the aerosol uptake of other relevant chemical compounds will also be updated. The updated model results will be evaluated against data collected during the Studies of Emissions Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field campaign. The impact of uncertainties in the organic nitrate aerosol uptake on simulated surface ozone will be presented to motivate and direct future research in understanding this complex process. Results suggest that a more explicit treatment of secondary organic aerosol formation in models used to understand air quality is not only necessary for describing aerosol correctly, but also necessary for accurately simulating ozone.