AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Polluted vs Clean: Chronic Nitrogen Deposition Affects on Emissions from Burning of Forest Litter
Michael Giordano, David R. Weise, AKUA ASA-AWUKU, University of California, Riverside
Abstract Number: 220 Working Group: Biomass Burning Aerosol: From Emissions to Impacts
Abstract Biomass burning is a large contributor of aerosols to the atmosphere. Aerosols from wildland fires can have a wide range of climatic impacts that are affected by combustion characteristics, fuel properties, and photochemical exposure. While the literature on biomass burning is continually expanding and exploring the impacts of these variables, one variable is heretofore understudied: the effects of chronic air pollution on biomass burning emissions. Here we explore the aerosol properties of forest litter collected from two sites along a nitrogen deposition gradient in the San Bernardino mountain range of southern California. Forest litter was burned at UC-Riverside’s College of Engineering-Center for Environmental Research and Technology facility to determine aerosol characteristics such as hygroscopicity, volatility, composition, and particle number and volume concentrations. Cast conifer needles collected from the top-most layer of the forest floor comprised the fuel burned in a wood stove. The emissions were diluted and injected into a 12 m^3 Teflon environmental chamber. Emissions were aged with ultraviolet light over 6-8 hours to simulate day time conditions. A characterization of the aerosols and trace gases emitted was conducted over the span of the experiment. Results showed that while weighted emission factors for particle number were similar between the two fuels, there were significant differences between the aerosol volatilities (as measured by particle Volume Fraction Remaining, VFR) upon injection into the chamber (VFR > 0.2 at 100 C). This study demonstrates how chronic air pollution can affect emissions from wildland fires occurring in the wildland-urban interface.