AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Internal or External? The Mixing State of Biomass Burning Aerosol, Its Photochemical Evolution, and Climate Impacts
MICHAEL GIORDANO, Lelia Hawkins, Akua Asa-Awuku, University of California, Riverside
Abstract Number: 134 Working Group: Aerosols, Clouds, and Climate
Abstract Biomass burning is a global, yet poorly constrained, emitter of both primary and secondary organic and inorganic aerosols. The emission and downwind photochemical oxidation of these aerosols can both directly and indirectly modify climate. As these aerosols transform (age) in the atmosphere, their composition, cloud condensation nuclei (CCN) activity, soluble organic content, surface tension, and optical properties are all subject to change. To explore this process, controlled burns of common Southwestern shrubs, Manzanita and Chamise, were conducted at UC-Riverside’s CE-CERT facility. The biomass was burned in a wood stove, diluted, and injected into a 12m3 Teflon chamber. UV lights were turned on to promote photochemistry and a suite of instruments measured the gas and aerosol phases. This presentation continues the series of biomass burning studies at UCR and will focus on new information that highlights the significant changes in the organic and inorganic makeup of the aerosol as it ages as well as its CCN ability and optical properties. The organic content of the aerosol is analyzed with an Aerosol Mass Spectrometer and the inorganic content deduced from an online water soluble organic carbon analyzer and an SMPS. Additionally, changes in CCN ability with the use of different oxidizing agents (NO, NO2,O3), which can depress kappa below .1 and promote chemistry that raises kappa by 300% under photooxidative conditions, will be discussed.