Optical Properties of Biomass Burning Aerosols from Simulated Wildfires and Prescribed Fires with Representative Fuel Beds from the Southeast United States

We report measurements of the absorption Ångström exponent (AAE) and single scattering albedo (SSA) of biomass burning aerosol from the combustion of fuel beds representing three eco-regions of the Southeast U.S. (Piedmont, Coastal Plain, and Blue Ridge Mountains) with moisture content representative of wildfires and prescribed fires. We find a strong correlation between the AAE and SSA for both simulated wildfires (low fuel moisture) and prescribed fires (higher fuel moisture). For wildfires, the AAE and SSA are strongly dependent on the eco-region of the fuel bed and span a much wider range (AAE = 1.3-4.2, SSA = 0.75-0.97) than they do for prescribed fires (AAE = 2.4-3.1, SSA = 0.88-0.96). The AAE and SSA are also found to be correlated with the fraction of total carbon that is elemental carbon (