Characterization of Liquid Smoke by Size Distribution and Kappa Values

Biomass burning is an important part of our global carbon cycle. Biomass burning is important to study because it can affect our atmosphere, health, and living conditions. The aerosols and greenhouse gases emitted in burning can alter processes in the atmosphere, such as the warming of the Earth, by scattering sunlight and changing the microphysics of clouds. There have been studies conducted by burning different types of biomass, then measuring certain properties of emissions to study interactions between biomass burning and the atmosphere. One difficulty is that there is no standard for the emissions. In each experiment that includes biomass burning, different biomass substances are used, leading to different results across experiments. One of those problems is pinpointing a hygroscopic parameter to the biomass emissions. Kappa values are hygroscopicity parameters that show the relationship between the dry diameter of a particle and the cloud condensation nuclei (CCN) activity. Fresh biomass has a complex hygroscopic behavior and data shows that the smaller the particle size, the less hygroscopic and the larger the particle the more hygroscopic. This also contributes to inaccurate CCN measurements. Liquid smoke has potential to eliminate issues and become a standard for biomass burning in atmospheric aerosol research. We have measured a few lab properties including the Kappa values and size distribution of liquid smoke. The size distribution is measured using a TSI Scanning Mobility Particle Sizer (SMPS). The Kappa values were found using a Cambustion Centrifugal Particle Mass Analyzer (CPMA), TSI Condensation particle counter (CPC), and DMT Cloud Condensation Nuclei Counter (CCNC). Obtaining these lab properties will help determine if liquid smoke could be a proxy for biomass burning in atmospheric research.