Particle emissions from laboratory combustion of wildland fuels: In situ optical and mass measurements

Abstract

[1] Time-resolved optical properties of smoke particles from the controlled laboratory combustion of mid-latitude wildland fuels were determined for the first time using advanced techniques, including cavity ring-down/cavity enhanced detection (CRD/CED) for light extinction and two-wavelength photoacoustic detection for light absorption. This experiment clearly resolves the dependence of smoke properties on fuel and combustion phase. Intensive flaming combustion during ponderosa pine wood (PPW) burning produces particles with a low single scattering albedo of 0.32 and a specific mass extinction efficiency of 8.9 m 2 g À1. Burning white pine needles (WPN) features a prolonged smoldering phase emitting particles that are not light-absorbing and appear much larger in size with an extinction efficiency %5 m 2 g À1 . A Mie scattering model was formulated, which estimates the black carbon fraction in the PPW and WPN smoke particles at 66% and 12%, respectively. These observations may refine the current radiative forcing estimates for biomass burning emissions. Citation:

Spectral absorption of biomass burning aerosol determined from retrieved single scattering albedo during ARCTAS

“…The differences in SSA among biomass burning aerosols is likely explained by observed differences in combustion conditions generated by different fuel types, humidities, etc. as well as plume age (Reid and Hobbs, 1998;Eck et al, 2003;Kirchstetter et al, 2004;Chen et al, 2006;Lewis et al, 2008;Mack et al, 2010). For instance, in recent laboratory studies, the combustion of 14 different types of biomass fuel yielded a range in SSA 0.37-0.95 (Lewis et al, 2008;Mack et al, 2010).…”

Moisture effects on carbon and nitrogen emission from burning of wildland biomass

“…Flaming combustion involves a more complete oxidation, converting C and N to CO 2 and NO x , respectively, than smoldering combustion (Koppmann et al, 2005;6618 L.-W. A. Chen et al: Moisture effects on carbon and nitrogen emission from burning of biomass and smoldering phases, but they differ in size, morphology, and optical properties (Reid et al, 2005a, b;Chen et al, 2006;Chakrabarty et al, 2006;McMeeking et al, 2009). Light-absorbing black carbon with a structure similar to soot agglomerates dominates in high temperature flames, while smoldering particles are whiter and more spherical in shape.…”

Measured and modeled humidification factors of fresh smoke particles from biomass burning: role of inorganic constituents

“…These experiments were conducted at the US Forest Service's Fire Science Laboratory in Missoula MT in 2006 and 2007. Results from several subsets of these experiments include particle and gas emissions (McMeeking et al, 2009;Chakrabarty et al, 2006;Chen et al, 2006Chen et al, , 2007Engling et al, 2006;Smith et al, 2009;Laskin et al, 2009), smoke marker properties (Sullivan et al, 2008), particle physical and optical properties (Hopkins et al, 2007;Lewis et al, 2009;Levin et al, 2010), aerosol hygroscopicity, cloud condensation and ice nucleation ability Carrico et al, 2008Carrico et al, , 2010Petters et al, 2009;Demott et al, 2009). Burns were performed on fuels that represented biomass found in locations often involved in wild and prescribed fires, such as in the western and southeastern United States (McMeeking et al, 2009).…”