7A.3 Simulation of semi-explicit mechanisms of SOA formation from glyoxal in a 3D model

Knote, Christoph, Alma Hodzic, National Center for Atmospheric Research, Jose L. Jimenez, Rainer Volkamer, Sunil Baidar, University of Colorado (CU), Jerome Brioude, CU and National Oceanic and Atmospheric Administration (NOAA), Jerome Fast, Pacific Northwest National Laboratory (PNNL), Allen Goldstein, University of California, Joost de Gouw, CU and NOAA, Patrick Hayes, CU, B. Tom Jobson, Washington State University, W. Berk Knighton, Montana State University, John Orlando, National Center for Atmospheric Research (NCAR), Song Chen, PNNL, Harald Start, CU and Aerodyne Research, Inc., Philip S. Stevens, Indiana University, Ryan Thalman, CU, Geoff Tyndall, NCAR, Cartsten Warneke, Rebecca Washenfelder, CU and NOAA, and Qi Zhang, University of California

Several novel pathways to form secondary organic aerosols (SOA) have been proposed that include multiphase chemistry in deliquesce particles. One of them involves glyoxal, a very soluble organic molecule, which creates oxidation products with low enough volatility to remain permanently in the particle phase. So far no studies on the regional scale were done that included a detailed description of these mechanisms. We have added a module to WRFchem to describe SOA formation from glyoxal and investigated the results of both a simple approach as well as a more detailed, semiexplicit method. With simulations over California during June 2010 (CARES/CalNex campaigns) we could constrain our model results to a wealth of measurements. We show how we extended WRFchem and what steps were necessary to get good agreement with measurements, including how we had to modify existing emission inventories using inversionbased estimates of CO/NOy emissions and CO/VOC relations. We will present results of different parameterizations that show that a simple parameterization gives higher levels of SOA from glyoxal compared to a more detailed approach. Sensitivity studies indicate this is due to a kinetic limitation in the partitioning of glyoxal to the particle phase.