Detailed Analysis of Brown Carbon Constituents in Biomass Burning Emissions

Nevada System Of Higher Education, Desert Research Institute, Reno NV

Investigators

Abstract

This proposal focuses on the study of brown carbon and its contribution to light absorption in the atmosphere. A significant portion of brown carbon emissions in the atmosphere has been associated with biomass burning during wildfires, such as forest and peat fires. In this project, fuels from a representative set of five wild land fuels will be burned under laboratory conditions. The researchers will use advanced techniques to determine the chemical composition and optical properties of the brown carbon produced. This research will greatly advance our knowledge of atmospheric aerosols and their impact on air quality and climate. Biomass burning experiments will be carried out using fuels from five different locations around the world: boreal forest and peat land, Siberia, Russia; extra tropical forest, Oregon, USA; tropical forest and peat, Brazil; coastal swamp peat, Florida, USA; and mixed conifer forest, Sierra Nevada mountains, USA. Highly resolved, quantitative chemical speciation of both gas and particle phases will contribute to the understanding of the volatility and reactivity of brown carbon compounds in biomass-burning emissions. Both the water-soluble and water-insoluble fractions of the organic aerosol will be analyzed with a variety of techniques to determine their speciation and absorption spectrum. The researchers will attempt to obtain closure on the light absorption by comparing model calculations of the optical properties based on knowledge of the chemical constituents and the measured optical properties of biomass burning smoke.