Understanding the effect of biogenic-anthropogenic interactions on the chemical composition and physical properties of organic aerosols (OA) is important for accurate modeling of the effect of OA on climate. We will examine the effect biogenic-anthropogenic interactions on the chemical composition and physical properties of particles collected during 'Green Ocean Amazon' (GoAmazon) field campaign sponsored by DOE-BER. To achieve this goal, we will use the unique HRMAC capability developed in EMSL to determine the chemical composition of both low molecular weight and heavier oligomeric compounds present in ambient particles. The samples will be collected by Dr. A. Laskin in collaboration with Prof. S. Martin, Dr. A. Guenther, and the Brazilian research group of Prof. P. Artaxo during both wet and dry seasons. The HRMAC analysis will be performed with help of tools developed by EMSL scientists Dr. A. Laskin and Dr. J. Laskin. To understand the mechanism of biogenic-anthropogenic transformations in isoprene SOA targeted experiments on laboratory model systems will be carried out by Prof. S. Nizkorodov. The HRMAC analysis of both GOAmazon and lab samples will be combined with characterization of particle physical properties using scanning transmission x-ray spectro-microscopy (STXM) by Dr. M. Gilles from LBNL, and ice nucleation (IN) activity using environmental scanning electron microscopy (ESEM) by Dr. B. Wang from EMSL and by Prof. D. Knopf. High resolution and accuracy of HRMAC will enable for the first time unambiguous identification of the elemental compositions of oligomeric products of isoprene oxidation and aging in the presence of multiple anthropogenic pollutants. Furthermore, the composition will be correlated to viscosity/surface tension and IN abilities of individual particles. This information will facilitate our understanding of the effect of biogenic-anthropogenic interactions on the climate-related physical properties of SOA.
The Effect of Biogenic-Anthropogenic Interactions on the Physical and Chemical Properties of Atmospheric Organic Aerosols
Tuesday, December 23, 2014
University of California, Irvine
Friday, September 30, 2016