HR: 0800h
AN: A11A-0861    [Abstracts]
TI: Organic Carbon: Correlating UV-Vis Absorption Spectral Patterns to Hygroscopicity
AU: * Kanu, A M
EM: akanu2@uiuc.edu
AF: Department of Civil and Environmental Engineering, University of Illinois, Urbana-Champaign, 205 N. Mathews Avenue, Urbana, Il 61801 United States
AU: Bond, T C
EM: yark@uiuc.edu
AF: Department of Civil and Environmental Engineering, University of Illinois, Urbana-Champaign, 205 N. Mathews Avenue, Urbana, Il 61801 United States
AB: The complex composition of organic aerosols (OC) in the atmosphere results from an array of sources. Thousands of individual organic compounds within these aerosols are difficult to identify: however, studies suggest these mixtures affect the radiative balance of Earth's atmosphere. Therefore, it is at least as vital to study the absorption and scattering of incoming solar radiation by aerosols as it is to distinguish and quantify the myriad compounds. OC can represent significant fractions of atmospheric aerosol and can play a prominent role in atmospheric radiative forcing. My research focuses on identifying organic carbon with different hygroscopic and optical properties--both of which are affected by composition. We use gradient chromatographic elution with reverse-phase and ion-exchange chromatography columns. We examine aerosols from wood combustion generated within strict temperature regimes. Results demonstrate distinct clusters according to different water affinities. Furthermore, each cluster absorbs in staggered regimes of ultraviolet and visible light, depending on the combustion temperature at which the OC fraction is generated. The association between various absorbing features and hygroscopic properties may imply distinct climate forcing potentials for different fractions of the organic carbon.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005