Liquid Smoke as an Optical Surrogate for Biomass-burning Aerosols
Shreya Joshi, Susan Mathai, Swarup China, Nurun Nahar Lata, Timothy Onasch, Arthur J. Sedlacek, Lynn Mazzoleni, Thusitha Divisekara, Simeon Schum, Kyle Gorkowski, CLAUDIO MAZZOLENI,
Michigan Technological University Abstract Number: 725
Working Group: Aerosol Physics
AbstractBiomass-burning aerosols play a significant role in determining Earth's radiative budget, influencing climate through interactions with radiation and clouds. These aerosols mainly consist of Black Carbon (BC) and Organic Carbon (OC), with BC primarily absorbing and OC predominantly scattering sunlight. The interplay between these two aerosol types, solar radiation, and the atmosphere necessitates a comprehensive study to understand the full impact of biomass-burning aerosols.
Several previous studies on this type of aerosols involved collecting organic carbon directly from the atmosphere or generating them in controlled laboratory conditions by burning selected wood fuels. In this study, we characterized the properties of commercially available liquid smoke as a potential surrogate for biomass burning OC for laboratory investigations. Liquid smoke is a water-soluble flavoring substitute produced by condensing smoke from smoldering wood chips. It is readily available on the market in large batches and it is low cost. Mass spectrometry analysis suggested that the chemical composition of liquid smoke resembles that of biomass-burning aerosol to a high degree (Divisekara et al., 2023). To further determine if liquid smoke can be used as an optical surrogate for biomass-burning aerosols, we compared the optical properties of aerosolized liquid smoke with those reported in the literature and with aerosols generated in the laboratory through the smoldering combustion of wood chips. We used a differential mobility analyzer to select particles of different sizes and utilized several optical instruments including nephelometer and photoacoustic spectrometers, a two-wavelength aethalometer, and cavity phase shift single scattering albedo monitors. We measured high single scattering albedo values and absorption Ångström exponents consistent with weakly absorbing brown carbon. Using electron microscopy on samples collected during the experiments, we determined that the particles are typically spherical in shape as expected for organic particles.
From these preliminary results, we conclude that liquid smoke is a good candidate as an optical surrogate for the study of biomass-burning aerosols to gain insights into the behavior of organic carbon aerosols, how they evolve, and their effects on the atmosphere in controlled laboratory settings.