Аннотация:Impact of Siberian biomass burning phase on optical properties of smoke aerosols is investigated in smallscalefires performed in a Large Aerosol Chamber (LAC). The analyses have revealed the influence ofcombustion temperature on scattering and light absorption of pine and debris smoke. Scattering in smolderingphase is significantly exceeding the flaming one. Spectral absorption obtained throughout the near-ultravioletto near-infrared spectral region emphasizes the high absorption Angstrom exponent (AAE), up to 4.4 forfresh debris smoke, and a large fraction of light-absorbing brown carbon (BrC) in the smoldering phase. Inopposite, open flaming smoke shows low AAE around 1, typical for high-temperature fossil fuel combustionwhile mixed fires emit particles absorbing with the intermediate AAE characteristics.