A novel approach to characterize the complex refractive index spectrum of organic aerosols

摘要: Organic aerosols play a significant role in the adsorption and radiative budget of the atmosphere. Still, current modeling approaches do not adequately capture the photo-chemical and oxidative bleaching during their atmospheric lifetime. In this work, we present a method to parameterize better the optical properties of atmospheric aerosols, including brown carbon (BrC). We used thin-film spectrometry to measure the full spectrum (190 nm to 1100 nm) of reflectivity and emissivity. We used this measurement to calculate the complex refractive index for multiple species of organic aerosols. This approach contrasts with previous techniques, which only probe single wavelengths (or narrow bands). Initially, we used organic dyes to measure the absorption of several different molecular constituents of BrC and to verify our methods by comparing these results to those found using aerosolized dye films. Since BrC is a …