Seminar

Abstract

Due to global warming, many regions in the world experience drier and warmer climate that increases the frequency and intensity of wildfires. In addition, biomass burning is often used for heating and cooking in developed and developing countries. From the climate point of view, smoke from wild fires and biomass burring may have both cooling or heating effects, depending partially on the fire’s stage (flaming versus smoldering) and on chemical composition. Smoke particles can also affect cloud formation and properties. Finally, biomass burning can be a major source for black and brown carbon to the atmosphere, which can affect smoke particles’ optical and hygroscopic properties.

Despite extensive research, the optical properties of smoke particles in the UV and visible range are not well constrained. We will describe an approach to retrieve the optical broadband optical properties of aerosols using a combination of instruments. We will then describe the application of this method to ambient smoke particles. Detailed chemical analysis of collected ambient smoke particles, and of products from oxidation of phenols, enables to identify some of the important chromophores that contribute to brown carbon in smoke particles.