Nonlinear features of the atmospheric evolution of the absorption properties of biomass burning aerosol
Nikolai A. Golovushkin, I. B. Konovalov
Abstract
Numerical experiments using a microphysical box model were performed to study the changes in the mass absorption efficiency (MAE) of biomass burning (BB) aerosol during its atmospheric aging in an isolated smoke plume. The model describes the oxidation and gas-particle partitioning processes within the volatility basis set (VBS) framework and involves a schematic representation of plume dispersion. The computations of MAE which is determined by the composition, size distribution, and mixing state of the particles were based on the Mie theory by assuming that the aerosol particles consist of an absorbing black carbon core and a non-absorbing organic shell. The results indicate that the atmospheric evolution of BB aerosol can be associated with considerable changes in MAE. The changes are found to depend in a nonlinear manner on both the initial parameters of the BB plume and the duration of the aerosol evolution. They are also found to be sensitive to how the oxidation processes are represented in the model.