AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Black Carbon Emissions from Prescribed Forest Fires in the Southeast United States
AMARA HOLDER, Gayle Hagler, Gavin McMeeking, William Mitchell, Robert Black, Johanna Aurell, Michael Hays, Amy P. Sullivan, Taehyoung Lee, Shawn P. Urbanski, Robert J. Yokelson, Sonia Kreidenweis, Brian Gullett, U.S. EPA
Abstract Number: 258 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Open biomass burning is one of the largest contributors to atmospheric black carbon (BC), which is an important climate forcer. However, there have only been a few measurements of BC emission factors in the field. The emission factor data previously generated focused on a limited number of fuel types, and did not include temperate forests. To address this knowledge gap, BC emissions were measured from several prescribed forest fires in the Southeastern United States. Black carbon was measured with a Single Particle Soot Photometer (SP2) and a Microaethalometer (AE-51); additionally, aerosol optical properties were measured with a Photoacoustic Soot Spectrometer (PASS-3) and an integrating nephelometer (Aurora 3000). Measurements were made at ground level immediately downwind from the burn zone. For a subset of the prescribed fires, a second SP2 was available for airborne measurements of the plume. Biomass fuel samples from the field study sites were also collected and burned in the laboratory to assess the representativeness of laboratory fire simulations. In general, the emission factors measured in the field corresponded to those from the laboratory. However, our field studies produced considerably larger emission factors than those reported for tropical and Savanna fires. We also found that BC concentrations from the different instruments varied substantially, showing nearly a three-fold difference between the lowest and the highest measurements. These preliminary results suggest laboratory simulations provide reasonable estimates of prescribed fire BC emissions, but different measurement methods continue to contribute to BC measurement uncertainty.